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Northwest Natural Company

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FY2015 Annual Report · Northwest Natural Company
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BUILDING

WITH FORESIGHT

2015 ANNUAL REPORT

 
 
 
 
 
 
 
 
CORPORATE PROFILE

NW Natural (NYSE: NWN) 
is a 157-year-old natural 
gas distribution company 
headquartered in Portland, 
Oregon.

NW Natural serves more than 

714,000 utility customers in Oregon 

and Southwest Washington and 

provides natural gas storage to 

customers on the West Coast.  

In keeping with its steady  

growth strategy, the company  

has increased dividends  

paid to shareholders  

for 60 consecutive  

years.

WASHINGTON

ASTORIA

MIST STORAGE

VANCOUVER

GASCO LNG

PORTLAND

THE DALLES

TRAINING 
CENTER

LINCOLN CITY

NEWPORT LNG

SALEM

ALBANY

SERVICE TERRITORY
AND STORAGE FACILITIES

EUGENE

OREGON

COOS BAY

ASTORIA

MIST STORAGE

VANCOUVER

GASCO LNG

WASHINGTON

PORTLAND

THE DALLES

TRAINING 
CENTER

LINCOLN CITY

SALEM

ALBANY

NEWPORT LNG

EUGENE

OREGON

COOS BAY

SAN FRANCISCO

KEY

NEVADA

NW NATURAL SERVICE TERRITORY
TRAINING CENTER
REGIONAL RESOURCE CENTER
LNG PLANT
UNDERGROUND STORAGE

HEADQUARTERS

GILL RANCH
STORAGE

FRESNO

CALIFORNIA

2015 

2014 

increase
(decrease )

FINANCIAL OVERVIEW 

earnings
Financial facts ($000):

Operating revenues 
Utility margin 
Net income 
Adjusted net income* 

Financial ratios (%): 

Return on average common equity 
Adjusted return on average common equity* 
Capital structure** at year-end: 
  Long-term debt 
  Common stock equity 

**Excluding short-term debt and current long-term maturities. 

common stock 
Shareholder data (000): 

 723,791 
 371,392 
 53,703 
 62,778   

754,037 
  366,088 
58,692 
58,692 

6.9 
8.1 

42.5 
57.5 

7.7 
7.7 

44.8 
55.2 

Average shares outstanding – diluted 
Year-end shares outstanding 

 27,417 
 27,427 

 27,223    
 27,284 

Per share data ($): 

Diluted earnings 
Adjusted diluted earnings* 
Dividends paid 
Book value at year-end 
Market value at year-end 

utility operating highlights

 1.96 
 2.29 
1.86 
28.47 
50.61 

2.16 
2.16 
1.85 
28.12 
49.90 

Gas sales and transportation deliveries (000 therms)   1,028,612 
 3,458 
Degree days 
 714,428 
Customers at year-end 
1,061 
Employees at year-end 

 1,092,990 
3,792 
 704,644   
1,084 

dividends paid on common stock (per share)
PAYMENT DATE
February 15 
May 15    
August 15 
November 15 

Total dividends paid 

$ 0.4650  
0.4650  
0.4650  
0.4675 

$ 1.8625 

 $ 0.460  
 0.460 
 0.460  
0.465 

$ 1.845 

(4) %
1 
(9) 
7 

bps

(80) 
40

bps

(230)
230

 1%
1

(9)%
6 
1
1 
1 

(6)%
(9)
 1
(2) 

diluted earnings per share
(in dollars)

dividends paid per share
(in dollars)

$2.60

$2.10

$1.60

$1.10

$0.60

$0.10

$1.90

$1.85

$1.80

$1.75

$1.70

$1.65

$1.60

$1.55

2011

2012

2013

2014

2015

2011

2012

2013

2014

2015

Diluted earnings per share were $1.96 or 
$2.29 adjusted for the regulatory  
disallowance in 2015.*

Annual dividends paid per share in 2015 
increased for the 60th consecutive year. 
The current indicated annual dividend is 
$1.87 per share.

* Indicates non-GAAP measures based on the $15 million pre-tax or $9.1 million after-tax charge from the 2015 
environmental order. After-tax amounts calculated using statutory tax rate of 39.5% and EPS uses 27.4 million 
diluted shares.

LOS ANGELES

NEVADA

SAN FRANCISCO

GILL RANCH

STORAGE

FRESNO

CALIFORNIA

LOS ANGELES

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    
 
        
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Left: Gregg Kantor, CEO
Right: David Anderson, President and COO

LETTER TO SHAREHOLDERS

3

NW Natural has a long record of thinking ahead, 

of careful planning and disciplined execution. 

These attributes served us well in 2015. 

This past year we completed the removal of our bare steel pipe – 

making NW Natural’s distribution system one of the most modern 

in the nation. A milestone made possible due to pipe replace-

ment cost trackers established three decades ago.  

We successfully navigated the financial impacts of a record-warm 

winter as a result of effective cost management and our weather 

normalization mechanism (WARM) put in place in 2003. 

We advanced a proposal to expand our storage assets in 

Oregon, first identified in 1979, to serve gas-fired electric  

generation that will back up recently built wind resources.  

And we began collecting revenues in November through our 

new environmental cost recovery mechanism. The Site Reme-

2015 HIGHLIGHTS

•  Reported net income of $53.7 million or $1.96 per share. 

Excluding the environmental charge, net income was  

$62.8 million or $2.29 per share, an increase of  

13 cents per share compared to 2014 results.*  

•  Continued to add new customers at an annual growth rate 

of 1.4 percent, bringing our customer base to more than 

714,000. 

•  Reduced residential customer rates by approximately 7 percent 

in Oregon and 14 percent in Washington, as a result of the 

lowest natural gas commodity prices in 15 years. 

•  Earned the highest customer satisfaction score among large 
utilities in the West in the 2015 J.D. Power Gas Utility Resi-

dential Customer Satisfaction Study. 

diation and Recovery Mechanism (SRRM) allows us to recover 

•  Invested $129 million in capital expenditures for customer 

prudently incurred environmental cleanup costs allocated to 

growth and system improvements.

Oregon, associated with legacy manufactured gas plants that 

operated until 1957. While that docket required a $15 million 

write-down in 2015 due to over-earning in years past, the  

recovery mechanism aligns our company and customers 

around a responsible cleanup of these legacy assets.  

Acting with foresight is no accident. It is part of our culture and key 

to a successful business in the Pacific Northwest. At NW Natural, 

we are proud of our ability to anticipate the needs of our customers, 

find innovative solutions, and successfully respond to challenges. 

Evidence of this can be seen in our 2015 performance:

•  Received key regulatory decisions from the Public Utility  

Commission of Oregon that resulted in cost recovery for 

prudently incurred environmental expenses and Jonah Field 

investments.

•  Increased common dividends paid for the 60th consecutive 
year, one of the longest dividend increase records of any 

company on the NYSE. 

4

LETTER TO SHAREHOLDERS

System Safety and Preparedness

Removing the last few miles of all identified bare 

steel pipe in our system last year was a major  

accomplishment, but it was just one of many  

initiatives we’re working on to ensure our  

systems’ safety and reliability. 

In 2015, we moved forward on a five-year, $25 million 

infrastructure investment plan in Clark County, WA. 

The system upgrades planned for Clark County  

will include new high-pressure distribution lines and 

extensions to better serve customers in our service 

territory’s fastest-growing community.  

We also began to make additional improvements to 

our Newport LNG facility, built in 1977. Upgrades 

planned for this natural gas storage facility on the 

Oregon Coast include tank refurbishments, turbine 

modernization, and control room enhancements at 

an estimated cost of $25 million. 

Customer and system safety remains at the core of 

our operational priorities. In 2015, we once again 

reached our emergency response goals of answering 

90 percent of emergency calls within 10 seconds, 

and responding on-site to damage and odor calls 

within 30 minutes on average. 

We also continued to prepare for a large-scale 

emergency event, such as a severe earthquake. 

Should our Portland headquarters be rendered 

unsafe, we can now transfer gas control and 

emergency dispatch operations to our new Business Continuity Center in 

Sherwood, Oregon. The facility was built to the highest structural standards 

for earthquake preparedness and has been outfitted to host employees crucial 

to core business functions during the first phases of a natural disaster. 

But today system safety doesn’t stop at state-of-the art pipelines and  

facilities. Utilities must also anticipate and mitigate cybersecurity threats.  

In 2015, our Information Technology team made significant strides to increase 

our cyber resiliency, deploying new cybersecurity technology, employee 

education and training on new policies and emergency response protocols 

company-wide. 

Regulatory Progress

Last year, we continued to manage several  

important regulatory dockets at the Public 

Utility Commission of Oregon (OPUC).

Early in 2015, we received the commission’s 

decision on our environmental cost recovery 

proceeding. In its order, the OPUC found that 

$114 million of environmental remediation 

expenses and carrying costs incurred through 

March of 2014 were prudent, as were the 

insurance settlements we executed totaling 

approximately $150 million. However, the 

OPUC disallowed recovery of $15 million of 

environmental costs based on the application 

of an earnings test for past years when the 

company earned above its authorized rate  

of return. As a result, we took an after-tax 

charge of $9.1 million to net income in 2015. 

SYSTEM  
SAFETY

COMPLETED  
THE REMOVAL OF 
BARE STEEL AND 
CAST IRON PIPES 

CAPITAL EXPENDITURES  
WITH DEPRECIATION & AMORTIZATION
(in millions)

2011

2012

2013

2014

2015

CAPITAL EXPENDITURES

DEPRECIATION & AMORTIZATION

$150

$125

$100

$75

$50

$25

$0

Total investment in capital expenditures during 2015 was $129 million, of 
which nearly $100 million was related to system integrity, maintenance and 
customer growth. 

Andrea Kuehnel and Scott Burg were  part of the team 
that worked to remove the last known bare steel from 
NW Natural’s system.

LETTER TO SHAREHOLDERS

5

In January 2016, the commission 

reviewed our compliance filing under 

their 2015 order and confirmed the 

company’s recovery of environmental 

costs allocated to Oregon rate payers 

under the mechanism. However, they 

disallowed interest earned on the 

original $15 million disallowance, which 

resulted in the company recognizing 

a $2 million after-tax charge in 2016. 

Although the charges were disappoint-

ing, this was a complex docket, and 

we believe the mechanism provides a 

good path forward for all stakeholders.

In September of last year, the OPUC 

also adopted an all-party settlement 

that determined how we would recover 

costs associated with seven wells  

we drilled under our amended gas 

WE REDUCED
RESIDENTIAL  
CUSTOMER RATES
APPROXIMATELY
7 PERCENT
IN OREGON AND

14 PERCENT
IN WASHINGTON

reserves agreement. This $10 million additional investment provides long-term 

price protection for Oregon utility customers. We were pleased with this  

collaborative settlement and the positive conclusion to the docket. 

In 2016, we will be working with the commission and other utilities in Oregon  

on a policy docket to explore commodity hedging, including what role gas  

reserves could play in a balanced natural gas supply portfolio. It’s our view 

that today’s low prices, coupled with the expected increase in demand for 

natural gas to serve power generation, make long-term hedging opportunities 

like gas reserves an important option to help ensure future price stability for 

our customers. 

Utility and Storage Operations

In November, we reduced residential customer 

rates approximately 7 percent in Oregon and 14 

percent in Washington. With that reduction, our 

customers are paying less for their natural gas 

now than they did 15 years ago. This price decline 

helps our customers and improves the company’s 

competitive position, as consumers in our service 

area can save about 50 percent by switching from 

an electric or oil furnace to natural gas. 

UTILITY CUSTOMERS AT YEAR-END

720,000

700,000

680,000

660,000

640,000

620,000

600,000

580,000

560,000

2011

2012

2013

2014

2015

INDUSTRIAL

COMMERCIAL

RESIDENTIAL

We added 9,784 new customers in 2015, and now serve 714,428 customers.

6

LETTER TO SHAREHOLDERS

Our engineering team created a streamlined piping and metering design that reduces  
developer costs. As a result, this 10-story “Block 75” project in Portland will now include 
gas amenities in all 75 apartments, when it opens later in 2016.

We were pleased to pair these lower rates with  

flexible energy resources Gill Ranch can deliver. 

another year of outstanding service from our  

As the impacts of those RPS requirements unfold, 

employees. For the sixth time in nine years,  

our priority is to pursue higher value service con-

NW Natural ranked first in the annual J.D. Power 

tracts and tap into new market opportunities.

Residential Customer Satisfaction Study for natural 

gas utilities in the West. This also marked the eighth 

time in nine years of posting among the top two 

highest satisfaction scores in the nation. 

Also in 2015, operations at our underground 

storage facility near Mist, Oregon performed well, 

providing valuable services to our core utility cus-

tomers and profitably serving storage customers in 

the Northwest. However, our California Gill Ranch 

storage facility continued to operate in challenging 

market conditions. 

Excess natural gas storage capacity and limited 

gas price volatility have kept storage values low in 

California over the last several years. But new legis-

lation recently signed by the Governor is likely to 

change the state’s energy landscape in substantial 

ways. California’s new Renewable Portfolio Standard 

(RPS) requires 50 percent of its power generation 

be produced from renewables by 2030, which we 

believe provides a strategic opportunity for the 

NW NATURAL
RANKED FIRST
in the J.D. Power Residential 
Customer Satisfaction Study 
in the West

Competing for the Future

Our region is attracting young, college educated 

households considered vital for both economic 

development and longer-term growth. More 

people were employed in 2015, with the average 

monthly employment in the Portland and Van-

couver Metro area increasing by about 35,000 

new jobs for an annual employment growth rate 

of 3.2 percent. This is more than one percentage 

point above the national average. In that same 

time period, the unemployment rate fell 100 basis 

points to 5.3 percent. Oregon’s average wage 

today is the highest it has been in a generation. 

PORTLAND 
AREA  
RENTERS
prefer natural gas  
amenities

We are also seeing strong housing growth in the Portland area with a  

25 percent increase in single-family building permits in the last 12 months.  

NW Natural leveraged these economic improvements last year to sign up 

nearly 9,800 new customers, an annual growth rate of 1.4 percent.

Nationally, single-family new construction has yet to rebound to pre-recession 

levels – and the Northwest is no exception. But there has been an upturn in 

the housing sector locally, particularly in multifamily apartments. Seeing this 

trend emerge, we created a cross-functional team to evaluate every aspect  

of the apartment rental market – a market typically underserved with natural 

gas in the Northwest and across the U.S. 

One of the first steps we took to assess our opportunity was to conduct  

renter preference research. A recent study showed 80 percent of Portland  

area renters paying average rent prices or above prefer gas amenities such  

OREGON & WASHINGTON AVERAGE RESIDENTIAL RATES
(in dollars per therm)

LETTER TO SHAREHOLDERS

7

$1.60

$1.40

$1.20

$1.00

$0.80

$0.60

2001

2003

2005

2007

2009

2011

2013

2015

OREGON AND WASHINGTON AVERAGE RESIDENTIAL RATES

Today’s residential rates are lower than they were 15 years ago.

The portal team is now working on new enhancements 
to leverage web analytics and cost data to identify 
main extension opportunities.

as cooktops, water heating and fireplaces – demonstrating a clear gap between 

amendment to our existing Mist Site Certificate to 

what renters’ desire and what’s available. 

Armed with this data, we created a comprehensive marketing program to  

target apartment developers. While still early, we’ve been pleased with the level 

of interest from project owners. We view rental apartments as an untapped 

growth opportunity and a priority segment for us moving forward. 

Competing for growth today requires making it easier and faster to connect to 

gas. In 2015, the use of our industry-leading online portal grew, as consumers 

searched for gas availability in their area with the click of a mouse or a tap on 

the screen. In fact, almost 30 percent of our conversion sales used this web 

tool and more than 1,500 online orders were submitted by builders and con-

tractors last year. Strong adoption of the portal’s 

functionality helps us operate more efficiently. 

But, as important, portal analytics allow us to 

strategically target new areas for growth and  

create customized marketing programs in 2016 

and beyond.

Leading with Solutions

Policy makers in the Pacific Northwest are 

committed to shutting down coal-fired electric 

generation and substantially increasing the use 

of renewables to meet our region’s power needs. 

Natural gas and its supporting infrastructure  

are critical to helping achieve this goal. One 

way is by helping to back-up intermittent wind 

resources at a local electric utility’s gas-fired 

generating plants. 

In 2015, we submitted an application to the 

Oregon Energy Facility Siting Council for an 

30 

PERCENT
of conversions 
used the portal

allow us to provide on-demand storage services  

to these gas-fired generating plants. Last year, we 

also held an open house with the local community, 

obtained required permits and property rights, and 

worked with local agencies on the details of the 

project. In early 2016, the Department of Energy 

published a proposed order as part of the permit-

ting process. If there are no challenges to that 

order, we could receive approval from the Oregon 

Energy Facility Siting Council for our permit later 

this spring. Concurrently, we are in the process 

of rebidding the engineering, procurement, and 

construction portion of the project. Following the 

approval of the permit and the rebidding process, 

we expect to receive a notice to proceed from the 

project sponsor later this year. 

Another way NW Natural is striving to support 

our region’s environmental goals is through a new 

Combined Heat and Power (CHP) program. The 

CHP program is the first proposal submitted by  

the company under Senate Bill 844 – the Oregon  

legislation designed to incent natural gas utilities to 

invest in projects that reduce carbon emissions. As 

submitted, the CHP program would provide finan-

cial incentives to customers in our service territory 

that invest in and install CHP at their facilities. We 

submitted the program in June 2015, and expect 

a decision from the Commission in the spring of 

2016. That decision will also help determine how 

we proceed with other potential carbon reduction 

programs under this legislation.

8

LETTER TO SHAREHOLDERS

LIVING OUR MISSION & VALUES

Leadership for the Future

Over many years, NW Natural has demonstrated 

the careful planning essential to finding and retain-

ing the talent necessary to drive future success. 

Detailed succession plans are an integral part of 

the company’s business activities, and this past 

year, the benefits of that work were visible.    

In July of 2015, the board of directors elected  

David H. Anderson as President, adding to his  

responsibilities as Chief Operating Officer. Then  

in December, we announced my retirement at the 

end of 2016 and that David would begin serving  

as Chief Executive Officer effective Aug. 1 this year. 

To help with the transition, I will be staying on as an 

advisor to the board until the end of December.

A smooth transition at the top is critical, but as  

important is developing the talent for succession  

in key positions across the organization. That has 

been a long-held commitment at NW Natural, one 

that in my opinion is the true mark of a company 

with foresight.  

In today’s complex and rapidly changing energy 

landscape, foresight has never been more impor-

tant. In 2016, NW Natural will remain focused on 

meeting today’s expectations while keeping an eye 

on the horizon.  

We will continue to safely provide our product with 

great customer service; provide a solid financial 

value to our customers and to you, our shareholders; 

and look toward the future – ensuring we have the 

expertise to drive growth and provide innovative 

solutions that fuel our long-term success.    

As I complete my last year at the company, I would 

like you to know it has been a great privilege to 

work with the talented men and women who make 

up NW Natural and to lead this great company on 

your behalf. And finally, as we continue into our 

157th year, from all of us at NW Natural, we thank 

you for your investment and support.

Gregg S. Kantor

CEO

OUR MISSION
We provide safe, reliable and affordable 
energy in an environmentally responsible 
way to better the lives of the public  
we serve.

OUR CORE VALUES
Integrity
Safety
Service Ethic
Caring
Environmental Stewardship

Produced by NW Natural’s  
Corporate Communications
photo credits
Bruce Forster - Cover: Tilikum Crossing;  
Page 3: Gregg Kantor and David Anderson

Dale Headrick - Page 4: Andrea Kuehnel and Scott Burg;  
Page 5: Newport storage facility; Page 6: D.G. Graham,  
Block 75 project

Robbie McClaran - Page 9: Board of Directors

Corky Miller - Page 4: Bare steel removal, Page 6: Customer 
Service Rep; Page 7: Kristen Brown and Walter Cahall;  
Inside back cover: Nikki Sparley, Chu Lee and backpack event;  
Page 8: Corporate Officers

printing

RR Donnelley

 
Front to back – left to right

lea anne doolittle
Senior Vice President and 
Chief Administrative Officer

mardilyn saathoff
Senior Vice President 
and General Counsel

gregg s. kantor
Chief Executive Officer

david r. williams
Vice President
Utility Services

david h. anderson
President and  
Chief Operating Officer

kimberly heiting
Vice President  
Communications and 
Chief Marketing Officer

shawn m. filippi
Vice President and 
Corporate Secretary

c. alex miller
Vice President Regulation 
and Treasurer

tom imeson
Vice President  
Public Affairs

gregory c. hazelton
Senior Vice President and 
Chief Financial Officer

grant m. yoshihara
Vice President  
Utility Operations

brody j. wilson
Controller and Chief 
Accounting Officer

CORPORATE OFFICERS

9

BOARD OF DIRECTORS

timothy p. boyle
Chief Executive Officer
Columbia Sportswear 
Company

martha l.  
“stormy” byorum
Chief Executive Officer 
Cori Investment  
Advisors, LLC

john d. carter
Chairman  
of the Board 
Schnitzer Steel  
Industries, Inc.

mark s. dodson
Former Chief  
Executive Officer 
NW Natural

c. scott gibson
President 
Gibson Enterprises

tod r. hamachek
Chairman of the Board
NW Natural

gregg s. kantor
Chief Executive Officer 
NW Natural

jane l. peverett
Former President and 
Chief Executive Officer 
British Columbia Trans-
mission Corporation

kenneth thrasher
Chairman  
of the Board 
Compli Corporation

malia wasson
Former Executive 
Vice President of 
Commercial Banking, 
U.S. Bank

10 CORPORATE INFORMATION

Notice of Annual Meeting

The 2016 Annual Meeting will be held at 2 p.m., Thursday, May 26, at the company’s headquarters, One Pacific Square, 220 NW 2nd Ave., 

4th floor, Portland, Oregon 97209. A meeting notice and proxy statement will be sent to all shareholders in April. If you plan to attend the 

annual meeting, you will need to detach and retain the admission ticket attached to your proxy card mailed to you with the notice of the 

annual meeting and the proxy statement. As space is limited, you may bring only one guest to the meeting. If you hold your stock through 

a broker, bank or other nominee, please bring a legal proxy or other evidence to the meeting showing that you owned NW Natural 

Common Stock as of the record date, April 7, 2016, and we will provide you with an admission ticket. A form of government-issued 

photograph identification will be required for both you and your guest to enter the meeting.

to NW Natural Board of Directors,  

Request for publications

Dividend reinvestment and  
direct stock purchase plan 

Participants may make an initial invest-

ment in company stock and common 

shareholders of record may reinvest all  

or part of their dividends in additional 

shares under the company’s plan. Cash 

purchases may also be made. Participants 

in the plan bear the cost of brokerage fees 

and commissions for shares purchased  

on the open market to fulfill purchases 

under the plan. A prospectus will be  

sent upon request. 

c/o Corporate Secretary.  

Forward-looking statements

The statements made in this Annual  

Report that are not purely historical, 

including statements regarding strat-

egy, growth and marketing initiatives, 

dividends, earnings, financial value, future 

demand for gas, commodity costs and 

competitiveness, revenues, customer 

growth, gas supplies and reserves, hedge 

efficacy, capital expenditures, pipeline 

and storage infrastructure investments, 

Scheduled dividend payment dates 

system expansion, Mist storage expan-

Subject to Board approval, the following 

dates are scheduled for dividend payment:

February 12, 2016

May 13, 2016

August 15, 2016

November 15, 2016

Certifications 

The Chief Executive Officer certified  

to the NYSE on June 25, 2015, that,  

as of that date, he was not aware of  

any violation by the company of NYSE’s 

corporate governance listing standards, 

and the company had filed with the  

Securities and Exchange Commission 

(SEC), as exhibits 31.1 and 31.2 to its 

Annual Report on Form 10-K for the year 

ended December 31, 2014, the certificates 

of the Chief Executive Officer and the Chief 

Financial Officer of the company certifying the 

quality of the company’s public disclosure. 

For the year ended December 31, 2015, 

the certificates of the Chief Executive Officer 
and Chief Financial Officer are attached 

as exhibits 31.1 and 31.2 to the Form 10-K 

included in this Annual Report.

Contact the NW Natural Board

Concerns may be directed to the  

nonmanagement directors by writing  

sion project, including but not limited 

to cost and timelines, growth initiatives 

including SB844 projects, emergency 

preparedness, cyber resiliency and 

preparedness, system reliability, storage 

performance values, governmental policy 

and legislation and the effects thereof, 

regulatory cost recovery mechanisms, 

including, but not limited to, the SRRM, 

regulatory prudence reviews including, 

but not limited to, commodity hedging, 

regulatory proceedings and actions,  

economic recovery factors, customer 

savings, market trends and the com-

petitive environment, and coal-fired 

and renewable energy resources, are 

forward-looking statements within the 

“safe harbor” provisions of the Private 

Securities Litigation Reform Act of 1995. 

NW Natural’s actual results could differ 

materially from those anticipated in these 

forward-looking statements as a result of 

risks and uncertainties, including those 
described in the attached report on  

Form 10-K.

For a more complete description of  

these risks and uncertainties, please  

refer to our filings with the SEC on  

Forms 10-K and 10-Q.

The following publications may be 

obtained without charge by contacting 

the Corporate Secretary at NW Natural’s 

address: Annual Report; Form 10-K; Form 

10-Q; Corporate Governance Standards; 

Director Independence Standards; Code 

of Ethics; and Board Committee Charters. 

These publications, as well as other filings 

made with the SEC, are also available  

on our website at nwnatural.com. Our 

SEC filings are also available by request 

through the SEC by mail at U.S. Securi-

ties and Exchange Commission, Office  

of FOIA/PA Operations, 100 F Street, 

N.E., Washington, D.C. 20549, or online 

at sec.gov. You can obtain information 

about access to the Public Reference 

Room and how to access or request 

records by calling the SEC at  

1-800-SEC-0330.

comparison of five-year  
cumulative total return
(Based on $100 invested on 12/31/2010)

$250

$200

$150

$100

$50

$0

2010

2011

2012

2013

2014

2015

NWN

S&P UTILITIES INDEX

S&P 500 INDEX

Total shareholder return (annualized) over the five 
years ending December 31, 2015 for NW Natural 
was 5.9%, compared to Standard & Poor’s (S&P) 
Utilities Index return of 11%, and the S&P 500 
Index return of 12.5%.

Form 10-K
Annual Report

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 10-K

(Mark One)
[X]       ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2015
OR

[  ]       TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from ___________ to____________
Commission file number 1-15973

NORTHWEST NATURAL GAS COMPANY
(Exact name of registrant as specified in its charter) 

 Oregon 

(State or other jurisdiction of    

incorporation or organization)  

93-0256722

(I.R.S. Employer

Identification No.)

220 N.W. Second Avenue, Portland, Oregon 97209
(Address of principal executive offices)  (Zip Code)
Registrant’s telephone number, including area code:  (503) 226-4211

Securities registered pursuant to Section 12(b) of the Act:
Title of each class                                                                                   Name of each exchange on which registered
Common Stock                                                                                       New York Stock Exchange
Securities registered pursuant to Section 12(g) of the Act:  None.

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Yes  [ X ]    No  [    ]

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.

Yes  [   ]    No  [ X ]

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the 
Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to 
file such reports), and (2) has been subject to such filing requirements for the past 90 days. 
Yes  [ X ]    No  [    ]

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every 

Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) 
during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). 
Yes [ X ]     No  [   ]

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405) is not contained 
herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated 
by reference in Part III of this Form 10-K or any amendment to this Form 10-K. 

[ X ]
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a 
smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in 
Rule 12b-2 of the Exchange Act. (Check one):

Large Accelerated Filer [ X ]                                                                      Accelerated Filer [    ]
Non-accelerated Filer [    ]                                                                         Smaller Reporting Company [    ]
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes  [   ]    No  [ X ]

As of June 30, 2015, the registrant had 27,355,642 shares of its Common Stock outstanding, of which 26,973,861 shares 
were held by non-affiliates. The aggregate market value of the shares of Common Stock (based upon the closing price of these 
shares on the New York Stock Exchange on that date) held by non-affiliates was $1,137,757,457.

At February 19, 2016, 27,435,906 shares of the registrant’s Common Stock (the only class of Common Stock) were 

outstanding.

Portions of the Proxy Statement of the registrant, to be filed in connection with the 2016 Annual Meeting of Shareholders, are 
incorporated by reference in Part III.

DOCUMENTS INCORPORATED BY REFERENCE

NORTHWEST NATURAL GAS COMPANY
Annual Report to Securities and Exchange Commission on Form 10-K
For the Fiscal Year Ended December 31, 2015

TABLE OF CONTENTS

PART I

Glossary of Terms

Forward-Looking Statements

Item 1.

Business

Overview

Business Model

Local Gas Distribution

Gas Storage

Other

Environmental Issues

Employees

Additions to Infrastructure

Executive Officers of the Registrant

Available Information

Item 1A. Risk Factors

Item 1B. Unresolved Staff Comments

Properties

Legal Proceedings

Mine Safety Disclosures

Item 2.

Item 3.

Item 4.

PART II

Item 5.

Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer

Item 6.

Item 7.

Purchases of Equity Securities

Selected Financial Data

Management’s Discussion and Analysis of Financial Condition and Results of Operations

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Item 8.
Item 9.

Financial Statements and Supplementary Data

Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Item 9A. Controls and Procedures

Item 9B. Other Information

PART III

Item 10. Directors, Executive Officers and Corporate Governance

Item 11. Executive Compensation
Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13. Certain Relationships and Related Transactions, and Director Independence

Item 14. Principal Accountant Fees and Services

PART IV  

Item 15. Exhibits and Financial Statement Schedules

SIGNATURES

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1

4

5

5

5

5

10

12

12

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13

13

14

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21

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24

46

48

86

86

86

87

88

88

89

89

90

91

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
GLOSSARY OF TERMS AND ABBREVIATIONS

AFUDC

AOCI / AOCL

ASC

ASU

Average Weather

Bcf

Btu

CAP

CNG

CO2

Allowance for Funds Used During Construction

Accumulated Other Comprehensive Income (Loss)

Accounting Standards Codification

Accounting Standards Update as issued by the FASB

The 25-year average heating degree days based on temperatures established in our last
Oregon general rate case

Billion cubic feet, a volumetric measure of natural gas, where one Bcf is roughly equal to
10 million therms

British thermal unit, a basic unit of thermal energy measurement; one Btu equals the
energy required to raise one pound of water one degree Fahrenheit at an atmospheric
pressure of one and 60 degrees Fahrenheit. One hundred thousand Btu's equal one
therm
Compliance Assurance Process with the Internal Revenue Service

Compressed Natural Gas

Carbon Dioxide

Core Utility Customers

Residential, commercial and industrial customers receiving firm service from the utility

Cost of Gas

CPUC

Decoupling

Demand Cost

Dth

EBITDA

EE/CA

Encana

The delivered cost of natural gas sold to customers, including the cost of gas purchased
or withdrawn/produced from storage inventory or reserves, gains and losses from gas
commodity hedges, pipeline demand costs, seasonal demand cost balancing
adjustments, regulatory gas cost deferrals and Company gas use

California Public Utilities Commission, the entity that regulates our California gas storage
business at our Gill Ranch facility with respect to rates and terms of service, among other
matters

A billing rate mechanism, also referred to as our conservation tariff, which is designed to
break the link between utility earnings and the quantity of natural gas sold to customers;
the design is intended to allow the utility to encourage industrial and small commercial
customers to conserve energy while not adversely affecting its earnings due to
reductions in sales volumes

A component in core utility customer rates representing the cost of securing firm pipeline
capacity, whether the capacity is used or not
Dekatherm (also decatherm) is equal to 10 therms or one million British thermal units
(Btu)

Earnings before interest, taxes, depreciation and amortization, a non-GAAP financial
measure

Engineering Evaluation / Cost Analysis

Encana Oil & Gas (USA) Inc.

Energy Corp

Northwest Energy Corporation, a wholly-owned subsidiary of NW Natural

EPA

EPS

FASB

FERC

Firm Service

FMBs

GAAP

General Rate Case

GHG

Gill Ranch

Gill Ranch Facility

Environmental Protection Agency

Earnings per share

Financial Accounting Standards Board

Federal Energy Regulatory Commission; the entity regulating interstate storage services
offered by our Mist gas storage facility as part of our gas storage segment

Natural gas service offered to customers under contracts or rate schedules that will not
be disrupted to meet the needs of other customers

First Mortgage Bonds

Accounting principles generally accepted in the United States of America

A periodic filing with state or federal regulators to establish billing rates for utility
customers

Greenhouse gases

Gill Ranch Storage, LLC, a wholly-owned subsidiary of NWN Gas Storage

Underground natural gas storage facility near Fresno, California, with 75% owned by Gill
Ranch and 25% owned by PG&E

1

GTN

Heating Degree Days

Gas Transmission Northwest, which owns a transmission pipeline serving California and
the Pacific Northwest

Units of measure reflecting temperature-sensitive consumption of natural gas, calculated
by subtracting the average of a day’s high and low temperatures from 65 degrees
Fahrenheit

HATFA

Highway and Transportation Funding Act of 2014

Interruptible Service

Natural gas service offered to customers (usually large commercial or industrial users)
under contracts or rate schedules that allow for interruptions when necessary to meet the
needs of firm service customers

IRP

IRS

KB

LIBOR

LNG

LWG

MAP-21

Moody's

NAV

Integrated Resource Plan

United States Internal Revenue Service

Kelso-Beaver Pipeline, of which 10% is owned by K-B Pipeline Company, a subsidiary of
NNG Financial

London Interbank Offered Rate

Liquefied Natural Gas, the cryogenic liquid form of natural gas. To reach a liquid form at
atmospheric pressure, natural gas must be cooled to approximately negative 260
degrees Fahrenheit

Lower Willamette Group

A federal pension plan funding law called the Moving Ahead for Progress in the 21st
Century Act, July 2012

Moody's Investors Service, Inc. is a credit rating agency

Net Asset Value

NNG Financial

NNG Financial Corporation, a wholly-owned subsidiary of NW Natural

NOL

NRD

Net Operating Loss

Natural Resource Damages

NWN Energy

NW Natural Energy, LLC, a wholly-owned subsidiary of NW Natural

NWN Gas Reserves

NW Natural Gas Reserves, LLC, a wholly-owned subsidiary of Northwest Energy
Corporation

NWN Gas Storage

NW Natural Gas Storage, LLC, a wholly-owned subsidiary of NWN Energy

ODEQ

OPEIU

OPUC

PBGC

PG&E

PGA

PGE

PHMSA

PRP

RI/FS

ROD

ROE

ROR

S&P

Department of Environmental Quality

Office and Professional Employees International Union Local No. 11, AFL-CIO, which is
also referred to as the Union representing NW Natural's bargaining unit employees

Public Utility Commission of Oregon; the entity that regulates our Oregon utility business
with respect to rates and terms of service, among other matters; the OPUC also
regulates our Mist gas storage facility's intrastate storage services

Pension Benefit Guaranty Corporation

Pacific Gas & Electric Company; is a 25% owner of the Gill Ranch Facility

Purchased Gas Adjustment, a regulatory mechanism which adjusts customer rates to
reflect changes in the forecasted cost of gas and differences between forecasted and
actual gas costs from the prior year

Portland General Electric

U.S. Department of Transportation's Pipeline and Hazardous Materials Safety
Administration

Potentially Responsible Parties

Remedial Investigation / Feasibility Study

Record of Decision

Return on Equity, a measure of corporate profitability, calculated as net income divided
by average common stock equity. Authorized ROE refers to the equity rate approved by a
regulatory agency for use in determining utility revenue requirements

Rate of Return

Standard & Poor's, a division of The McGraw-Hill Companies, Inc., is a credit rating
agency

Sales Service

Service provided whereby a customer purchases both natural gas commodity supply and
transportation from the utility

SEC

U.S. Securities and Exchange Commission

2

SIP

SRRM

TAIL

Therm

TWH

TWP

System Integrity Program, an Oregon billing rate mechanism that provides cost recovery
of pipeline system integrity programs, which are required under various safety standards
prescribed by both state and federal regulators
Site Remediation and Recovery Mechanism, an Oregon billing rate mechanism for
recovering prudently incurred environmental site remediation costs through customer
billings, subject to an earnings test

TransCanada American Investments, Ltd., a 50% owner of TWH

The basic unit of natural gas measurement, equal to one hundred thousand Btu’s

Trail West Holdings, LLC is 50% owned by NWN Energy

Trail West Pipeline, LLC, a subsidiary of TWH

TransCanada

TransCanada Pipelines Limited, owner of TAIL and GTN

Transportation Service

Service provided whereby a customer purchases natural gas directly from a supplier but
pays the utility to transport the gas over its distribution system to the customer’s facility

Utility Margin

A financial measure consisting of utility operating revenues less the associated cost of
gas, franchise tax and environmental recoveries

VIE

Variable Interest Entity

Weather Normalization

WUTC

An Oregon billing rate mechanism applied to residential and commercial customers to
adjust for temperature variances from average weather; rates decrease when the
weather is colder than average, and rates increase when the weather is warmer than
average; the mechanism is applied to customer bills from December through mid-May of
each heating season

Washington Utilities and Transportation Commission, the entity that regulates our
Washington utility business with respect to rates and terms of service, among other
matters

3

FORWARD-LOOKING STATEMENTS

plans, projections and predictions;
objectives;
goals;
strategies;
assumptions and estimates;
future events or performance;
trends;
risks;
timing and cyclicality;
earnings and dividends;
capital expenditures and allocation; 
capital structure;
growth;
customer rates;

This report contains forward-looking statements within the 
meaning of the U.S. Private Securities Litigation Reform Act 
of 1995. Forward-looking statements can be identified by 
words such as anticipates, assumes, intends, plans, seeks, 
believes, estimates, expects, and similar references to 
future periods. Examples of forward-looking statements 
include, but are not limited to, statements regarding the 
following:
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
•  workforce succession; 
commodity costs;
• 
gas reserves;
• 
operational performance and costs;
• 
energy policy and preferences;
• 
efficacy of derivatives and hedges;
• 
liquidity and financial positions;
• 
• 
project and program development, expansion, or 
investment;
competition;
procurement and development of gas supplies;
estimated expenditures;
costs of compliance;
credit exposures;
potential efficiencies;
rate or regulatory outcomes, recovery or refunds;
impacts of laws, rules and regulations;
tax liabilities or refunds;
levels and pricing of gas storage contracts and gas 
storage markets;
outcomes and effects of potential claims, litigation, 
regulatory actions, and other administrative matters;
projected obligations under retirement plans;
availability, adequacy, and shift in mix, of gas supplies;
effects of new or anticipated changes in critical accounting 
policies; 
approval and adequacy of regulatory deferrals;
effects and efficacy of regulatory mechanisms; and
environmental, regulatory, litigation and insurance costs 
and recoveries, and timing thereof.

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 

• 
• 
• 

• 
• 
• 

• 

Forward-looking statements are based on our current 
expectations and assumptions regarding our business, the 
economy and other future conditions. Because forward-
looking statements relate to the future, they are subject to 
inherent uncertainties, risks and changes in circumstances 
that are difficult to predict. Our actual results may differ 
materially from those contemplated by the forward-looking 
statements. We therefore caution you against relying on any 
of these forward-looking statements. They are neither 
statements of historical fact nor guarantees or assurances 
of future performance. Important factors that could cause 
actual results to differ materially from those in the forward-
looking statements are discussed at Item 1A., "Risk 
Factors" of Part I and Item 7. and Item 7A., "Management’s 
Discussion and Analysis of Financial Condition and Results 
of Operations" and "Quantitative and Qualitative Disclosures 
About Market Risk", respectively, of Part II of this report.

Any forward-looking statement made by us in this report 
speaks only as of the date on which it is made. Factors or 
events that could cause our actual results to differ may 
emerge from time to time, and it is not possible for us to 
predict all of them. We undertake no obligation to publicly 
update any forward-looking statement, whether as a result 
of new information, future developments or otherwise, 
except as may be required by law.

4

 
NORTHWEST NATURAL GAS 
COMPANY
PART I

ITEM 1. BUSINESS

OVERVIEW

Northwest Natural Gas Company (NW Natural or the 
Company) was incorporated under the laws of Oregon in 
1910. Our Company and its predecessors have supplied 
gas service to the public since 1859, and we have been 
doing business as NW Natural since 1997. We maintain 
operations in Oregon, Washington, and California and 
conduct business through NW Natural and its subsidiaries. 
References in this discussion to "Notes" are to the Notes to 
the Consolidated Financial Statements in Item 8 of this 
report.

We have two core businesses: our regulated local gas 
distribution business, referred to as the utility segment, 
which serves residential, commercial, and industrial 
customers in Oregon and southwest Washington; and our 
gas storage businesses, referred to as the gas storage 
segment, which provides storage services for utilities, gas 
marketers, electric generators, and large industrial users 
from storage facilities located in Oregon and California. In 
addition, we have investments and other non-utility activities 
we aggregate and report as other. See Note 4 to the 
Consolidated Financial Statements for further information on 
total assets and results of operations for our segments for 
the years ended December 31, 2013, 2014 and 2015.

The utility business is our largest segment, while our gas 
storage businesses account for the majority of our 
remaining net income. The following table reflects the 
percentage allocation between segments and other as of 
December 31, 2015:

Non-Utility(1)

Utility

Gas 
Storage(2)

Other

Total

Assets

91.0%

8.5%

0.5%

100.0%

100.0%

0.3%

99.4%

Net Income
(1)  We refer to our gas storage segment and other as non-utility 
as they are not included in our regulated gas distribution 
business; however, certain aspects of the gas storage 
segment and other may be regulated by the OPUC, WUTC, 
CPUC, or FERC. 

0.3%

(2)   Gas Storage segment includes asset management services 
for both the utility and non-utility portion of our Mist gas 
storage facility. 

LOCAL GAS DISTRIBUTION "UTILITY"

The utility is principally engaged in the regulated distribution 
of natural gas in Oregon and southwest Washington to over 
714,000 customers with approximately 89% of our 
customers located in Oregon and 11% located in 
Washington. In total, we provide natural gas service to over 
100 cities in 18 counties with an estimated population of 3.5 
million in our service territory.

5

We have been allocated an exclusive service territory by the 
OPUC and WUTC, which includes a major portion of 
western Oregon, including the Portland metropolitan area, 
most of the Willamette Valley, the Coastal area from Astoria 
to Coos Bay, and portions of Washington along the 
Columbia River. Portland serves as one of the largest 
international ports on the West Coast and is a key 
distribution center due to its comprehensive transportation 
system of ocean and river shipping, transcontinental 
railways and highways, and an international airport. Major 
businesses located in our service territory include retail, 
manufacturing, and high-technology industries. 

Natural gas provides a clean, low-carbon, and affordable 
energy source, and supply in the United States is at an all-
time high. We are committed to environmental stewardship 
and furthering the usage of natural gas to fuel heat, electric 
generation, and transportation systems in our communities. 
To this end, we filed our first proposal in 2015 with state 
regulators under a Carbon Solutions Program incentivizing 
industrial users to install combined heat and power systems 
using natural gas. See Part II, Item 7, "Results of 
Operations—Regulatory Matters". We also have an 
approved CNG tariff in place to provide customers with high-
pressured gas service. Further, we have partnered with 
local agencies on environmental programs, and are able to 
allow residential and commercial customers to offset their 
carbon emissions by supporting carbon-reduction projects 
at dairies and other farms. Energy conservation is another 
key component of our environmental focus and competitive 
advantage, and we were among the first utilities in the 
nation to break the link between utility earnings and the 
quantity of natural gas sold to customers with our 
decoupling mechanism or conservation tariff. The 
decoupling mechanism is intended to allow the utility to 
encourage industrial and small commercial customers to 
conserve energy while not adversely affecting its earnings 
due to reductions in sales volumes. We will continue to 
further the role of natural gas in our region and country as it 
is an affordable, energy efficient fuel source.  

Customers
We serve residential, commercial and industrial customers 
with no individual customer or industry accounting for more 
than 10% of our utility revenues. On an annual basis, 
residential and commercial customers typically account for 
around 60% of our utility’s total volumes delivered and 90% 
of our utility’s margin. Industrial customers largely account 
for the remaining volumes and utility margin. The following 
table presents summary customer information as of 
December 31, 2015:

Residential

Commercial

Industrial
Other(1)

Total

Number of
Customers

% of
Volumes

% of Utility 
Margin (1)

646,841

66,584

1,003

N/A

34%

21%

45%

N/A

63%

27%

8%

2%

714,428

100%

100%

(1)   Utility margin is also affected by other items, including 

miscellaneous services, gains or losses from our incentive gas 
cost sharing mechanism, and other service fees. 

  
  
Generally residential and commercial customers purchase 
both their natural gas commodity (gas sales) and natural 
gas delivery services (transportation services) from the 
utility. Industrial customers also purchase transportation 
services from the utility, but may buy the gas commodity 
either from the utility or directly from a third-party gas 
marketer or supplier. Our gas commodity cost is primarily a 
pass-through cost to customers; therefore, our profit 
margins are not materially affected by an industrial 
customer's decision to purchase gas from us or from third 
parties. Industrial and large commercial customers may also 
select between firm and interruptible service levels, with firm 
services generally providing higher profit margins compared 
to interruptible services.

To help manage gas supplies, our industrial tariffs are 
designed to provide some certainty regarding industrial 
customers' volumes by requiring an annual service election, 
special charges for changes between elections, and in 
some cases, a minimum or maximum volume requirement 
before changing options. 

Customer growth rates for natural gas utilities in the Pacific 
Northwest historically have been among the highest in the 
nation due to lower market saturation as natural gas 
became widely available as a residential heating source 
after other fuel options. We estimate natural gas is currently 
in approximately 60% of residential single-family dwellings 
in our service territory. Customer growth in our region 
comes from the following main sources, in both new 
construction and conversions: single-family housing, both 
new construction and conversions; multifamily housing 
construction; and commercial buildings, both new 
construction and conversions. Single family new 
construction has consistently been our strongest performing 
source of growth. We have added increasing numbers of 
customers in our service territory for the last four years as 
the economy has recovered. Continued customer growth is 
closely tied to the comparative pricing of natural gas to 
electricity and fuel oil and the health of the Portland, Oregon 
and Vancouver, Washington economies. We believe there is 
potential for continued growth as natural gas is affordable, 
reliable, a clean fuel choice, and a preferred energy source 
in our service territory. See Note 4 for information on the 
utility's assets and results of operations.

Competitive Conditions
In our service areas, we have no direct competition from 
other natural gas distributors, but we compete with other 
forms of energy supply in each customer class. This 
competition among energy suppliers is based on price, 
efficiency, reliability, performance, market conditions, 
technology, federal and state energy policy, and 
environmental impacts. 

For residential and small to mid-size commercial customers, 
we compete primarily with electricity, fuel oil, propane, and 
renewable energy providers. 

In the industrial and large commercial markets, we compete 
with all forms of energy, including competition from 
wholesale natural gas marketers. In addition, large industrial 
customers could bypass our local gas distribution system by 
installing their own direct pipeline connection to the 
interstate pipeline system. We have designed custom 
transportation service agreements with several of our 
largest industrial customers to provide transportation service 
rates that are competitive with the customer’s costs of 
installing their own pipeline; these agreements generally 
prohibit bypass. Due to the cost pressures confronting a 
number of our largest customers competing in global 
markets, bypass continues to be a competitive 
threat. Although we do not expect a significant number of 
our large customers to bypass our system in the 
foreseeable future, we could experience deterioration of 
utility margin if customers bypass or switch over to custom 
contracts with lower profit margins.

Seasonality of Business
Our utility business is seasonal in nature due to higher gas 
usage by residential and commercial customers during the 
cold winter heating months.

Regulation and Rates
The utility is subject to regulation by the OPUC, WUTC, and 
FERC. These regulatory agencies authorize rates and allow 
recovery mechanisms to provide our utility the opportunity to 
recover prudently incurred capital and operating costs from 
customers, while also earning a reasonable return on 
investment for investors. In addition, the OPUC and WUTC 
also regulate the system of accounts and issuance of 
securities by our utility.

We file general rate cases and rate tariff requests 
periodically with the commissions to establish approved 
rates, an authorized ROE, an overall rate of return on rate 
base (ROR), an authorized utility capital structure, and other 
revenue/cost deferral and recovery mechanisms.

In addition, under our Mist interstate storage certificate with 
FERC, the utility is required to file either a petition for rate 
approval or a cost and revenue study every five years to 
change or justify maintaining the existing rates for the 
interstate storage service. We filed a rate petition in 2013 
and received approval in 2014 for new maximum cost-
based rates effective January 1, 2014. 

6

The utility's most recent general rate case in Oregon was 
effective November 1, 2012, and the latest Washington rate 
case was effective January 1, 2009. Our current approved 
rates and recovery mechanisms for each service area 
include:

Authorized Rate Structure:

ROE

ROR

Oregon

Washington

9.5%

7.8%

10.1%

8.4%

Debt/Equity Ratio

50%/50%

49%/51%

Key Regulatory Mechanisms:

PGA

Incentive Sharing

Weather Normalization Tariff

Decoupling
SIP(1)

Pension Balancing

Environmental Cost Deferral

SRRM

X

X

X

X

X

X

X

X

X

X

(1)       Regulatory authority for SIP expired October 31, 2014, 
although the bare steel replacement portion of the mechanism 
remained in place until the end of 2015. 

In general, these rates and regulatory mechanisms do not 
allow the utility to earn a profit or incur a loss on our gas 
commodity purchases. This means gas commodity 
purchase costs are primarily a pass-through cost in 
customer rates, with the exception of our gas reserves 
investments and incentive cost sharing mechanism in 
Oregon. Under this mechanism, we can either increase or 
decrease margin revenues based on higher or lower actual 
gas purchase costs compared to gas purchase costs 
embedded in the PGA.

For a complete discussion of regulatory matters, open 
dockets, current regulatory activities, and additional details 
on each rate mechanism, see Part II, Item 7, "Results of 
Operations—Regulatory Matters" and "Gas Storage".

Gas Supply
The utility strives to secure sufficient, reliable supplies of 
natural gas to meet the needs of customers at the lowest 
reasonable cost, while maintaining price stability and 
managing gas purchase costs prudently. This is 
accomplished through a comprehensive strategy focused on 
the following items:
•  Diverse Supply - providing diversity of supply sources;
•  Diverse Contracts - maintaining a variety of contract 

durations and types; 

•  Reliability - ensuring gas resource portfolios are 
sufficient to satisfy customer requirements under 
extreme cold weather conditions; and 

•  Cost Management and Recovery - employing prudent 

gas cost management strategies. 

Diversity of Supply Sources 
We purchase our gas supplies primarily from the Alberta 
and British Columbia areas of Canada and multiple receipt 
points in the U.S. Rocky Mountains to protect against 

regional supply disruptions and to take advantage of price 
differentials. For 2015, 62% of our gas supply came from 
Canada, with the balance primarily coming from the U.S. 
Rocky Mountain region. We believe gas supplies available 
in the western United States and Canada are adequate to 
serve our core utility requirements for the foreseeable 
future. We continue to evaluate the long-term supply mix 
based on projections of gas production and pricing in the 
U.S. Rocky Mountain region as well as other regions in 
North America; however, we believe the cost of natural gas 
coming from western Canada and the U.S. Rocky Mountain 
region will continue to track with broader U.S. market 
pricing. Additionally, the extraction of shale gas has 
increased the availability of gas supplies throughout North 
America for the foreseeable future.

We supplement our firm gas supply purchases with gas 
withdrawals from gas storage facilities, including 
underground reservoirs and LNG storage facilities. Storage 
facilities are generally injected with natural gas during the 
off-peak months in the spring and summer and the gas is 
withdrawn for use during peak demand months in the winter. 

The following table presents the storage facilities available 
for our utility supply:

Gas Storage Facilities:

Owned Facility:
Mist, Oregon(1)

Contracted Facilities:

Jackson Prairie, Washington(2)
Alberta, Canada(3)

LNG Facilities:

Owned Facilities:

Newport, Oregon

Portland, Oregon

Total

Maximum 
Daily 
Deliverability 
(therms in 
millions)

Capacity 
(Bcf)

3.1

0.5

0.7

0.6

1.2

6.1

10.6

1.1

4.4

0.9

0.6

17.6

(1)   The Mist gas storage facility has a total maximum daily 

deliverability of 5.2 million therms and a total working gas 
capacity of about 16 Bcf, of which 3.1 million therms of daily 
deliverability and 10.6 Bcf of storage capacity are reserved for 
core utility customers. 

(2)   The storage facility is located near Chehalis, Washington and 
is contracted from Northwest Pipeline, a subsidiary of The 
Williams Companies.

(3)   This resource does not add to our total peak day capacity, but 
mitigates price risks as it displaces equivalent volumes of 
heating season spot purchases. 

The Mist facility is used for both utility and non-utility 
purposes. Under our regulatory agreements with the OPUC 
and WUTC, non-utility gas storage at Mist can be developed 
in advance of core utility customer needs but is subject to 
recall by the utility when needed to serve utility customers 
as their demand increases. In May 2015, the utility recalled 
0.3 million therms per day of deliverability and 0.7 Bcf of 
associated storage capacity from the non-utility business to 
serve core utility customer needs.  

7

In addition, we have the ability to recall pipeline capacity 
and supply resources from certain customers if needed to 
meet high demand requirements.

Diverse Contract Durations and Types
We have a diverse portfolio of short-, medium-, and long-
term firm gas supply contracts and a variety of contract 
types including firm and interruptible supplies plus 
supplemental supplies from gas storage facilities. 

Our portfolio of firm gas supply contracts typically includes 
the following gas purchase contracts: year-round and 
winter-only baseload supplies; seasonal supply with an 
option to call on additional daily supplies during the winter 
heating season; and daily or monthly spot purchases.

During 2015, we purchased a total of 669 million therms 
under contracts with durations outlined in the chart below:

Contract Duration (primary term)

Long-term (one year or longer)

Short-term (more than one month, less than one
year)

Spot

Total

Percent of
Purchases

33%

30

37

100%

We renew or replace gas supply contracts as they expire. 
Aside from the gas supplies provided by an independent 
energy marketing company as part of asset management 
services, no individual supplier provided over 10% of our 
gas supply requirements in 2015. 

Reliability
The effectiveness of our gas distribution system ultimately 
rests on whether we provide reliable service to our core 
utility customers. To ensure our effectiveness, we develop a 
composite design year, including a seven day design peak 
event based on the most severe cold weather experienced 
during the last 30 years in our service territory. 

Our projected maximum design day firm utility customer 
sendout totals are approximately 9.5 million therms. Of this 
total, we are currently capable of meeting about 50% of our 
maximum design day requirements with gas from storage 
located within or adjacent to our service territory, while the 
remaining supply requirements would come from gas 
purchases under firm gas purchase contracts and recall 
agreements. 

To supplement near-term natural gas supplies, we planned 
to segment transportation capacity during the 2014-2015 
and 2015-2016 heating seasons for approximately 0.4 
million therms per day if needed. Pipeline segmentation is a 
natural gas transportation mechanism under which a 
shipper can leverage its firm pipeline transportation capacity 
by separating it into multiple segments with alternate 
delivery routes. The reliability of service on these alternate 
routes will vary depending on the constraints of the pipeline 
system. For those segments with acceptable reliability, 
segmentation provides a shipper with increased flexibility 
and potential cost savings compared to traditional pipeline 
service.

Specifically, we could segment pipeline capacity that flows 
from Stanfield, Oregon with additional gas expected from 
the Sumas, Washington trading hub. This segmented 
capacity is considered reliable as the pipeline has not 
experienced constraints from Sumas in recent years. 

We believe our gas supplies would be sufficient to meet 
existing firm customer demand if we were to experience 
maximum design day weather conditions. We will continue 
to evaluate and update our forecasted requirements and 
incorporate changes in our IRP process.  

The following table shows the sources of supply projected to 
be used to satisfy the design day sendout for the 2015-2016 
winter heating season:

 Therms in millions

Sources of utility supply:

Firm supply purchases

Mist underground storage (utility only)

Company-owned LNG storage

Off-system storage contract

Pipeline segmentation capacity

Recall agreements
Peak day citygate deliveries(1)

Therms

Percent

3.3

3.1

1.8

0.5

0.4

0.4

0.2

34%

32

19

5

4

4

2

Total

100%
(1)   These citygate deliveries are contracted from December 2015 
to February 2016 with this resource being evaluated for future 
heating seasons after the current winter. 

9.7

The OPUC and WUTC have IRP processes in which utilities 
define different growth scenarios and corresponding 
resource acquisition strategies in an effort to evaluate 
supply and demand resource requirements, consider 
uncertainties in the planning process and the need for 
flexibility to respond to changes, and establish a plan for 
providing reliable service at the least cost.

In general, the IRP is filed biannually with both the OPUC 
and the WUTC. An update is filed in Oregon in the off 
year. The OPUC acknowledges receipt of the IRP; whereas 
the WUTC provides notice our IRP met the requirements of 
the Washington Administrative Code. OPUC 
acknowledgment of the IRP does not constitute ratemaking 
approval of any specific resource acquisition strategy or 
expenditure. However, the Commissioners generally 
indicate they would give considerable weight in prudence 
reviews to utility actions consistent with acknowledged 
plans. The WUTC has indicated the IRP process is one 
factor it will consider in a prudence review. We filed our 
2014 IRP in both Oregon and Washington in August 2014 
and received acknowledgment from the OPUC in February 
2015, and notice from the WUTC in March 2015. We plan to 
file an IRP with both Commissions in 2016.

Gas Cost Management Strategy 
The cost of gas sold to utility customers primarily consists of 
the following items, which are included in annual PGA rates: 
purchase price paid to suppliers; charges paid to pipeline 
companies to transport gas to our distribution system; costs 
paid to store gas; our gas reserves contracts; and gains or 
losses related to gas commodity derivative contracts.

8

We employ a number of strategies to mitigate the cost of 
gas sold to utility customers. Our primary strategies for 
managing gas commodity price risk include:
• 
• 

negotiating fixed prices directly with gas suppliers;
negotiating financial derivative contracts that: (1) 
effectively convert floating index prices in physical gas 
supply contracts to fixed prices (referred to as 
commodity price swaps); or (2) effectively set a ceiling 
or floor price, or both, on floating index priced physical 
supply contracts (referred to as commodity price 
options such as calls, puts, and collars). See Part II, 
Item 7A, "Quantitative and Qualitative Disclosures 
About Market Risk—Credit Risk—Credit Exposure to 
Financial Derivative Counterparties";
buying physical gas supplies at a set price and injecting 
the gas into storage for price stability and to minimize 
pipeline capacity demand costs; and
investing in gas reserves for longer term price stability. 
See Note 11 for additional information about our gas 
reserves.

• 

• 

We also contract with an independent energy marketing 
company to capture opportunities regarding our storage and 
pipeline capacity when those assets are not serving the 
needs of our core utility customers. Our asset management 
activities provide cost savings that reduce our utility 
customer's cost of gas and opportunities to generate 
incremental revenues for our shareholders from a regulatory 
incentive-sharing mechanism, which are included in our gas 
storage segment.

Cost Recovery
Mechanisms for gas cost recovery are designed to be fair 
and reasonable, with an appropriate balance between the 
interests of our customers and shareholders. In general, 
utility rates are designed to recover the costs of, but not to 
earn a return on, the gas commodity sold. We minimize 
risks associated with gas cost recovery by resetting 
customer rates annually through the PGA and aligning 
customer and shareholder interests through the use of 
sharing, weather normalization, and conservation 
mechanisms in Oregon. See Part II, Item 7, "Results of 
Operations—Regulatory Matters—Rate Mechanisms" and 
"Results of Operations—Business Segments—Local Gas 
Distribution Utility Operations—Cost of Gas."

Transportation of Gas Supplies
Our local gas distribution system is reliant on a single, bi-
directional interstate transmission pipeline to bring gas 
supplies into our distribution system. Although we are 
dependent on a single pipeline, the pipeline’s gas flows into 
the Portland metropolitan market from two directions: (1) the 
north, which brings supplies from the British Columbia and 
Alberta supply basins; and (2) the east, which brings 
supplies from Alberta as well as the U.S. Rocky Mountain 
supply basins. 

We incur monthly demand charges related to our firm 
pipeline transportation contracts. Our largest pipeline 
agreements are with Northwest Pipeline. These contracts 
are multi-year contracts with expirations ranging from 2016 
to 2044. We actively work with Northwest Pipeline and 
others to renew contracts in advance of expiration to ensure 

9

gas transportation capacity is sufficient to meet our utility 
needs. 

Rates for interstate pipeline transportation services are 
established by FERC within the U.S. and by Canadian 
authorities for services on Canadian pipelines.

As mentioned above, our service territory is dependent on a 
single pipeline for its natural gas supply. Although supply 
has not been disrupted in the recent past, pipeline 
replacement projects and long-term projected natural gas 
demand in our region underscore the need for pipeline 
transportation diversity. In addition, there are several 
potential industrial projects in the region, which could 
increase the demand for natural gas and the need for 
additional pipeline capacity and pipeline diversity. 

Several interstate pipeline projects currently proposed could 
meet the region's and our projected demand. The pipeline 
location is dependent on the location of the committed 
industrial project. We will evaluate and closely monitor the 
currently prospected projects to determine the best option 
for ratepayers. The Company also has an equity investment 
in Trail West Holdings, LLC (TWH) that is developing plans 
to build the Trail West pipeline. This pipeline would connect 
TransCanada Pipelines Limited’s (TransCanada) Gas 
Transmission Northwest (GTN) interstate transmission line 
to our local gas distribution system. If constructed, this 
pipeline would provide another transportation path for gas 
purchases from Alberta and the U.S. Rocky Mountains in 
addition to the one that currently moves gas through the 
Northwest Pipeline system. See Part II, Item 7, "2016 
Outlook".

Gas Distribution
The primary goals of our gas distribution operations are 
safety and reliability of our system, which entails building 
and maintaining a safe pipeline distribution system. 

Safety and the protection of our employees, our customers, 
and the public at large are, and will remain, our top 
priorities. We construct, operate and maintain our pipeline 
distribution system and storage operations with the goal of 
ensuring natural gas is delivered and stored safely, reliably, 
and efficiently. 

NW Natural has one of the most modern distribution 
systems in the country with no identified cast iron pipe or 
bare steel main. We removed the final three miles of known 
bare steel from our system in 2015 and completed our cast 
iron pipe removal in 2000. Since the 1980s, we have taken 
a proactive approach to replacement programs and 
partnered with our Commissions on progressive regulation 
to further safety and reliability efforts for our distribution 
system. In the past, we had a cost recovery program in 
Oregon that encompassed the Company’s programs for 
bare steel replacement, transmission pipeline integrity 
management, and distribution pipeline integrity 
management. Currently, we are working with the OPUC and 
other Oregon natural gas utilities to evaluate guidelines for 
potential future safety cost-recovery tracking programs. See 
Part II, Item 7, "Results of Operations-Regulatory Matters-
System Integrity Program". 

Natural gas distribution businesses are likely to be subject 
to even greater federal and state regulation in the future due 
to pipeline incidents involving other companies. Additional 
regulations from the U.S. Department of Transportation’s 
Pipeline and Hazardous Materials Safety Administration 
(PHMSA) are currently under development with final 
regulations expected in 2016 and effective dates beginning 
in 2017. We will continue to work diligently with industry 
associations as well as federal and state regulators to 
ensure the safety of our system and compliance with new 
laws and regulations. We expect the costs associated with 
compliance of federal, state, and local rules would be 
recoverable in rates.

GAS STORAGE

Our gas storage segment includes the following:
• 

the non-utility portion of the Mist gas storage facility 
near Mist, Oregon;
our Gill Ranch gas storage facility near Fresno, 
California; and
asset management services provided by an 
independent energy marketing company. 

• 

• 

In general, the supply of natural gas remains relatively 
stable over the course of a year, while the demand for 
natural gas typically fluctuates seasonally. Storage facilities 
allow customers to purchase and inject natural gas supplies 
during periods of low demand and withdraw these supplies 
for use or resale during periods of higher demand. These 
facilities allow us to capitalize on the imbalance of supply 
and demand and price volatility for natural gas. 

See Note 4 for more information on gas storage assets and 
results of operations and "Financial Condition—Liquidity 
and Capital Resources".

Gas Storage Facilities
The following table provides information concerning the 
Company’s non-utility gas storage facilities:

Maximum

Designed 
Storage
Capacity 
(Bcf)

Deliverability
(Therms in 
millions/day(3)

Injection
(Therms in 
millions/day)(3)

Mist Storage(1)

5.4

2.1

Gill Ranch Storage(2)
15.0
(1)   Approximately 5.4 Bcf of a total 16 Bcf at Mist is currently 

4.9

0.8

2.4

available to our gas storage segment. The remaining 10.6 Bcf 
is used to provide gas storage for our local distribution 
business and its utility customers. All storage capacity and 
daily deliverability currently developed for the gas storage 
segment at Mist is available for recall by the utility. In May 
2015, the utility recalled approximately 0.3 million therms per 
day of deliverability and 0.7 Bcf of capacity for core utility 
customer use. 

(2)   Our share of the Gill Ranch facility is currently 15 Bcf out of a 

total capacity of 20 Bcf.

(3)   Our share of the expected daily maximum injection and 

deliverability rates.

Mist Storage Facility
The Mist storage facility began operations in 1989 and 
currently consists of seven depleted natural gas reservoirs, 
22 injection and withdrawal wells, a compressor station, 
dehydration and control equipment, gathering lines and 
other related facilities.

SERVICES. Mist provides multi-cycle gas storage services to 
customers in the interstate and intrastate markets from the 
facility located in Columbia County, Oregon, near the town 
of Mist. The Mist field was initially converted to storage 
operations for our utility customers. Since 2001, gas storage 
capacity at Mist has also been made available to interstate 
customers by developing new incremental capacity in 
advance of core utility customer requirements to meet the 
demands for interstate storage service. These interstate 
storage services are offered under a limited jurisdiction 
blanket certificate issued by FERC. In addition, since 2005 
we have offered intrastate firm storage services in Oregon 
under an OPUC-approved rate schedule as an optional 
service to eligible non-residential utility customers. 

CUSTOMERS. For Mist storage services, firm service 
agreements with customers are entered into with terms 
typically ranging from 2 to 10 years. Currently, our gas 
storage revenues from Mist are derived primarily from firm 
service customers who provide energy related services, 
including natural gas distribution, electric generation, and 
energy marketing. Three storage customers currently 
account for all of our existing contracted non-utility gas 
storage capacity at Mist, with the largest customer 
accounting for about half of the total capacity. These three 
customers have contracts expiring at various dates through 
2019.

COMPETITIVE CONDITIONS. Our Mist gas storage facility 
benefits from limited competition from other Pacific 
Northwest storage facilities primarily because of its 
geographic location. However, competition from other 
storage providers in Washington and Canada, as well as 
competition for interstate pipeline capacity, does exist. In the 
future, we could face increased competition from new or 
expanded gas storage facilities as well as from new natural 
gas pipelines, marketers, and alternative energy sources. 

SEASONALITY. Mist gas storage revenues generally do not 
follow seasonal patterns similar to those experienced by the 
utility because most of the storage capacity is contracted 
with customers for firm service, which are primarily in the 
form of fixed monthly reservation charges and are not 
affected by customer usage. However, there is seasonal 
variation with Mist storage capacity related to utility 
customers' lower demand during the spring and summer 
months. This surplus storage capacity and related 
transportation capacity can be optimized under regulatory 
sharing agreements with the OPUC and WUTC. See "Asset 
Management" below.

REGULATION. Our Mist facility is subject to regulation by the 
OPUC and WUTC. In addition, FERC has approved 
maximum cost-based rates under our Mist interstate storage 
certificate. We are required to file either a petition for rate 
approval or a cost and revenue study with FERC at least 
every five years to change or justify maintaining the existing 

10

 
 
rates for the interstate storage service. See Part II, Item 7, 
"Results of Operations—Regulatory Matters".

EXPANSION OPPORTUNITIES. The need for new, flexible 
gas-fired electricity generation has been identified in the 
Pacific Northwest region to integrate intermittent wind 
resources into the power system, thereby increasing the 
associated need for gas storage. To address this need, we 
are planning a potential expansion of our Mist storage 
facility. If completed, this expansion would be supported by 
a long-term contract with Portland General Electric (PGE) to 
serve gas-fired electric power generation facilities at Port 
Westward, Oregon, which is located approximately 15 miles 
from Mist. 

The project would include a new reservoir providing up to 
2.5 Bcf of available storage, an additional compressor 
station with design capacity of 1.2 million therms of gas 
per day, innovative no-notice service with uninterrupted 
turn capability, and a 13-mile pipeline to connect to PGE’s 
gas plants at Port Westward. The current estimated cost of 
the expansion is approximately $125 million with a 
targeted in-service date in winter of 2018-19, depending 
on the permitting process and construction schedule.

In early 2015, we received authorization from PGE to begin 
permitting and land acquisition work, and a new rate 
schedule was approved in October 2014 under which we 
will provide no-notice gas storage service associated with 
the expansion. This expansion project is subject to PGE's 
final approval of project costs and a notice to proceed, as 
well as the receipt of permits, certain land rights, and other 
conditions. 

Gill Ranch Storage Facility
Gill Ranch Storage, LLC (Gill Ranch), our subsidiary, has a 
joint project agreement with Pacific Gas and Electric 
Company (PG&E) to develop and own the Gill Ranch 
underground natural gas storage facility near Fresno, 
California. Currently, Gill Ranch is the sole operator of the 
facility. The facility began operations in 2010 and consists of 
three depleted natural gas reservoirs, 12 injection and 
withdrawal wells, a compressor station, dehydration and 
control equipment, gathering lines, an electric substation, a 
natural gas transmission pipeline extending 27 miles from 
the storage field to an interconnection with the PG&E 
transmission system, and other related facilities. Gill Ranch 
owns the rights to 75% of the available storage capacity at 
the facility. Gill Ranch’s share of the facility currently 
provides 15 Bcf of working gas capacity.

California has been impacted by challenging market 
conditions for gas storage, with contract prices in the region 
near historic lows and a greater number of competitors in 
the area compared to the Pacific Northwest region. Prices 
for the 2015-16 gas year showed improvement, however 
prices remained low relative to the pricing in our original 
long-term contracts which ended primarily in the 2013-14 
gas storage year. In the future, we may see an improvement 
in gas storage values and an increase in the demand for 
natural gas driven by a number of factors, including 
changes in electric generation triggered by California's 
renewable portfolio standards, an increase in use of 
alternative fuels to meet carbon reduction targets, 
improvement of the California economy, growth of domestic 

11

industrial manufacturing, potential exports of liquefied 
natural gas from the west coast, and other favorable storage 
market conditions in and around California. These factors, if 
they occur, may contribute to higher summer/winter natural 
gas price spreads, gas price volatility, and gas storage 
values. We are continuing to explore opportunities to 
increase revenues through enhanced services for storage 
customers and capitalizing on opportunities that fit our 
business-risk profile. 

SERVICES. Gill Ranch provides intrastate, multi-cycle 
storage services in California at market-based rates under a 
CPUC-approved tariff that includes firm storage service, 
interruptible storage service, and park and loan storage 
services. Our Gill Ranch facility is not currently authorized to 
provide interstate gas storage services.

CUSTOMERS. Customer contracts for firm storage capacity 
at Gill Ranch are as long as 27 years in duration; however, 
the majority of the contracted capacity is shorter term in 
nature due to market conditions. In the near-term, we 
expect Gill Ranch to contract for terms ranging from one to 
five years. For the 2015-16 gas storage year, Gill Ranch has 
several storage customers, with the largest single contract 
accounting for approximately 13% of our storage capacity. 
In the near term, we continue to expect shorter contract 
lengths reflecting current market prices and trends. 

The California market served by Gill Ranch is larger, and 
has a greater diversity of prospective customers, than the 
Pacific Northwest market served by Mist. Therefore, we 
expect less sensitivity to any single customer or group of 
customers at Gill Ranch. Current Gill Ranch customers 
provide energy related services, including natural gas 
production, marketing, and electric generation.

COMPETITIVE CONDITIONS. The Gill Ranch storage facility 
competes with a number of other storage providers, 
including local integrated gas companies and other 
independent storage operators in the northern California 
market. The Gill Ranch storage facility currently competes 
with a number of other storage providers, including local 
integrated gas companies and other independent storage 
providers (ISPs) in the northern California market. There are 
currently four ISPs authorized by the CPUC to provide 
storage services in California, with the Gill Ranch storage 
facility comprising approximately 12% of the storage 
capacity held by ISPs. A recent proposed acquisition, which 
is pending CPUC approval, will consolidate approximately 
80% of the storage capacity authorized by the CPUC to 
ISPs in California. The effect of this dominant market share 
on the Gill Ranch storage facility pricing and contracting 
levels remains unknown and cannot be predicted at this 
time. 

In addition, in October 2015 a significant natural gas leak 
occurred at a southern California gas storage facility that 
persisted in 2016. During this time-frame, short-term 
storage spreads for the region improved. At this time, we do 
not know the long-term effects of this incident on gas 
storage prices. Regulatory proceedings at both the national 
and California state level have been opened in response to 
the incident, and it is likely additional regulations will result 
and increase short-term costs for all storage providers. The 

implications of the regulatory proceeding are unknown and 
cannot be predicted at this time until the rules are finalized. 

summary information for these assets and results of 
operations.

SEASONALITY. While the majority of our Gill Ranch 
revenues are not subject to seasonality, and although we 
expect much of the storage revenue at Gill Ranch to be in 
the form of fixed monthly demand charges, cash flows can 
fluctuate due to timing of asset management and other 
revenues. In addition, a significant portion of operating costs 
at Gill Ranch are subject to fluctuations based on periods 
when storage customers elect to inject or withdraw.

REGULATION. Gill Ranch has a tariff on file with the CPUC 
authorizing it to charge market-based rates for the storage 
services offered. See Part II, Item 7, "Results of 
Operations–Regulatory Matters".

EXPANSION OPPORTUNITIES. Subject to market demand, 
project execution, available financing, receipt of future 
permits, and other rights, the Gill Ranch storage facility can 
be expanded beyond the current combined permitted 
capacity of 20 Bcf without further expansion of the takeaway 
pipeline system. Taking these considerations into account 
and with certain infrastructure modifications, we currently 
estimate the Gill Ranch storage facility could support an 
additional 25 Bcf of storage capacity, bringing the total 
storage capacity to approximately 45 Bcf, of which our 
current rights would give us up to an additional 7.5 Bcf or 
ownership of a total of approximately 22.5 Bcf.

Asset Management
We contract with an independent energy marketing 
company to provide asset management services, primarily 
through the use of commodity and pipeline capacity release 
transactions. The results are included in the gas storage 
segment, except for amounts allocated to our utility 
pursuant to regulatory sharing agreements involving the use 
of utility assets. Utility pre-tax income from third-party asset 
management services is subject to revenue sharing with 
core utility customers. See Part II, Item 7, "Results of 
Operations—Business Segments—Gas Storage".

OTHER 

We have non-utility investments and other business 
activities which are aggregated and reported as other. Other 
primarily consists of: 
• 

an equity method investment in a joint venture to build 
and operate a gas transmission pipeline in Oregon.  
TWH is owned 50% by NWN Energy, a wholly-owned 
subsidiary of NW Natural, and 50% by TransCanada 
American Investments Ltd., an indirect wholly-owned 
subsidiary of TransCanada Corporation. See Part II, 
Item 7, "2016 Outlook";
a minority interest in Kelso-Beaver Pipeline held by our 
wholly-owned subsidiary NNG Financial Corporation 
(NNG Financial); and 
other operating and non-operating income and 
expenses of the parent company that are not included 
in utility or gas storage operations. 

• 

• 

The pipelines referred to above are regulated by FERC. 
Less than 1% of our consolidated assets and consolidated 
net income are related to activities in other. See Note 4 for 

12

ENVIRONMENTAL ISSUES 

Properties and Facilities  
We own, or previously owned, properties and facilities that 
are currently being investigated that may require 
environmental remediation and are subject to federal, state 
and local laws and regulations related to environmental 
matters. These laws and regulations may require 
expenditures over a long timeframe to address certain 
environmental impacts. Estimates of liabilities for 
environmental costs are difficult to determine with precision 
because of the various factors that can affect their ultimate 
disposition. These factors include, but are not limited to, the 
following:
• 
• 

the complexity of the site;
changes in environmental laws and regulations at the 
federal, state and local levels;
the number of regulatory agencies or other parties 
involved;
new technology that renders previous technology 
obsolete, or experience with existing technology that 
proves ineffective;
the ultimate selection of a particular technology;
the level of remediation required;
variations between the estimated and actual period of 
time that must be dedicated to respond to an 
environmentally-contaminated site; and 
the application of environmental laws that impose joint 
and several liabilities on all potentially responsible 
parties. 

• 

• 

• 
• 
• 

• 

We seek recovery of environmental costs through received 
insurance proceeds and customer rates, and we believe 
recovery of these costs is probable. In Oregon, we have a 
mechanism to recover expenses, subject to an earnings test 
and allocation rules. See Part II, Item 7, "Results of 
Operations—Rate Matters—Rate Mechanisms—
Environmental Costs", Note 2, Note 15, and Note 16.

Greenhouse Gas Issues
We recognize our businesses are likely to be impacted by 
future requirements to address greenhouse gas emissions. 
Future federal and/or state requirements may seek to limit 
future emissions of greenhouse gases, including both 
carbon dioxide (CO2) and methane. These future laws and 
regulations may require certain activities to reduce 
emissions and/or increase the price paid for energy based 
on its carbon content. 

Current federal rules require the reporting of greenhouse 
gas emissions. In September 2009, the EPA issued a final 
rule requiring the annual reporting of greenhouse gas 
emissions from certain industries, specified large 
greenhouse gas emission sources, and facilities that emit 
25,000 metric tons or more of CO2 equivalents per year. We 
began reporting emission information in 2011. Under this 
reporting rule, local gas distribution companies like NW 
Natural are required to report system throughput to the EPA 
on an annual basis. The EPA also issued additional 
greenhouse gas reporting regulations requiring the annual 
reporting of fugitive emissions from our operations. 

 
The outcome of federal and state policy development in the 
area of climate change cannot be determined at this time, 
but these initiatives could produce a number of results 
including new regulations, legal actions, additional charges 
to fund energy efficiency activities, or other regulatory 
actions. The adoption and implementation of any 
regulations limiting emissions of greenhouse gas from our 
operations could require us to incur costs to reduce 
emissions of greenhouse gases associated with our 
operations, which could result in an increase in the prices 
we charge our customers or a decline in the demand for 
natural gas. On the other hand, because natural gas is a 
fossil fuel with relatively low carbon content, it is also 
possible future carbon constraints could create additional 
demand for natural gas for electric generation, direct use of 
natural gas in homes and businesses, and as a reliable and 
relatively low-emission back-up fuel source for alternative 
energy sources. Requirements to reduce greenhouse gas 
emissions from the transportation sector, such as those in 
Oregon’s clean fuel standard, could also result in additional 
demand for natural gas for use in vehicles.

We continue to take steps to address future greenhouse 
gas emission issues, including actively participating in policy 
development through participation on various Oregon 
taskforces and, at the federal level, within the American Gas 
Association. We engage in policy development and in 
identifying ways to reduce greenhouse gas emissions 
associated with our operations and our customers’ gas use, 
including offering the Smart Energy program, which allows 
customers to voluntarily contribute funds to projects such as 
biodigesters on dairy farms that offset the greenhouse 
gases produced from their natural gas use.

EMPLOYEES 

At December 31, 2015, the utility workforce consisted of 598 
members of the Office and Professional Employees 
International Union (OPEIU) Local No. 11, AFL-CIO, and 
463 non-union employees. Our labor agreement with 
members of OPEIU covers wages, benefits and working 
conditions. On May 22, 2014, our union employees ratified a 
new labor agreement (Joint Accord) that extends to 
November 30, 2019, and thereafter from year to year unless 
either party serves notice of its intent to negotiate 
modifications to the collective bargaining agreement. 

At December 31, 2015, our subsidiaries had a combined 
workforce of 15 non-union employees. Our subsidiaries 
receive certain services from centralized operations at the 
utility, and the utility is reimbursed for those services 
pursuant to a Shared Services Agreement.

ADDITIONS TO INFRASTRUCTURE

We make capital expenditures in order to maintain and 
enhance the safety and integrity of our pipelines, gate 
stations, storage facilities and related assets, to expand the 
reach or capacity of those assets, or improve the efficiency 
of our operations. We expect to make a significant level of 
capital expenditures for additions to utility and gas storage 
infrastructure over the next five years, reflecting continued 
investments in customer growth, technology, and 
distribution system improvements. For the five-year period 

13

ending in 2020, capital expenditures for the utility are 
estimated to be between $850 and $950 million, including 
the Company's proposed investment in an expansion of our 
Mist gas storage facility and excluding any potential future 
gas reserves investments. In addition, we are evaluating the 
impact of the five-year extension of bonus depreciation 
resulting from the enactment of the Federal Protecting 
Americans From Tax Hikes Act of 2016 on the mix and 
profile of our investments. We expect cash tax savings from 
bonus depreciation and are evaluating how to best take 
advantage of these savings during the period in which they 
are in effect. Our current capital expenditure range does not 
consider any additional capital that may be available as a 
result of this legislation. 

In 2016, utility capital expenditures are estimated to be 
between $155 and $175 million, and non-utility capital 
investments are estimated to be less than $5 million. 
Additional spend for gas storage and other investments 
during and after 2016 will depend largely on future decisions 
about potential expansion opportunities in gas storage 
projects. 

EXECUTIVE OFFICERS OF THE REGISTRANT

For information concerning our executive officers, see Part 
III, Item 10.

AVAILABLE INFORMATION

We file annual, quarterly and special reports and other 
information with the Securities and Exchange Commission 
(SEC). Reports, proxy statements and other information 
filed by us can be read and requested through the SEC by 
mail at U.S. Securities and Exchange Commission, Office of 
FOIA/PA Operations, 100 F Street, N.E., Washington, D.C. 
20549, by facsimile at (202) 772-9337, or online at its 
website (http://www.sec.gov). You can obtain information 
about access to the Public Reference Room and how to 
access or request records by calling the SEC at 1-800-
SEC-0330. The SEC website contains reports, proxy and 
information statements and other information we file 
electronically. In addition, we make available on our website 
(http://www.nwnatural.com), our annual report on Form 10-
K, quarterly reports on Form 10-Q, current reports on Form 
8-K, and amendments to those reports filed or furnished 
pursuant to Section 13(a) or 15(d) and proxy materials filed 
under Section 14 of the Securities Exchange Act of 1934, as 
amended (Exchange Act), as soon as reasonably 
practicable after we electronically file such material with, or 
furnish it to, the SEC. 

We have adopted a Code of Ethics for all employees and 
officers that is available on our website. We intend to 
disclose amendments to, and any waivers from the Code of 
Ethics on our website. Our Corporate Governance 
Standards, Director Independence Standards, charters of 
each of the committees of the Board of Directors and 
additional information about the Company are also available 
at the website. Copies of these documents may be 
requested, at no cost, by writing or calling Shareholder 
Services, NW Natural, One Pacific Square, 220 N.W. 
Second Avenue, Portland, Oregon 97209, telephone 
503-226-4211 ext. 2402.

ITEM 1A. RISK FACTORS 

Our business and financial results are subject to a number 
of risks and uncertainties, many of which are not within our 
control. When considering any investment in our securities, 
investors should carefully consider the following information, 
as well as information contained in the caption "Forward-
Looking Statements", Item 7A, and other documents we file 
with the SEC. This list is not exhaustive and the order of 
presentation does not reflect management’s determination 
of priority or likelihood. Additionally, our listing of risk factors 
that primarily affects one of our business segments does not 
mean that such risk factor is inapplicable to our other 
business segments.

Risks Related to our Business Generally
REGULATORY RISK. Regulation of our businesses, including 
changes in the regulatory environment, failure of regulatory 
authorities to approve rates which provide for timely 
recovery of our costs and an adequate return on invested 
capital, or an unfavorable outcome in regulatory 
proceedings may adversely impact our financial condition 
and results of operations.

The OPUC and WUTC have general regulatory authority 
over our utility business in Oregon and Washington, 
respectively, including the rates charged to customers, 
authorized rates of return on rate base, including ROE, the 
amounts and types of securities we may issue, services we 
provide and the manner in which we provide them, the 
nature of investments we make, actions investors may take 
with respect to our company, and deferral and recovery of 
various expenses, including, but not limited to, pipeline 
replacement, environmental remediation costs, commodity 
hedging expense, transactions with affiliated interests, 
weather adjustment mechanisms and other matters. 
Similarly, in our gas storage businesses FERC has 
regulatory authority over interstate storage services, the 
CPUC has regulatory authority over our Gill Ranch storage 
operations, and the WUTC and OPUC have regulatory 
authority over our Mist storage operations.

The prices the OPUC and WUTC allow us to charge for 
retail service, and the maximum FERC-approved rates 
FERC authorizes us to charge for interstate storage and 
related transportation services, are the most significant 
factors affecting our financial position, results of operations 
and liquidity. The OPUC and WUTC have the authority to 
disallow recovery of costs they find imprudently incurred or 
otherwise disallow. For example, in February 2015 the 
OPUC issued an Order to the Company regarding 
implementation of our SRRM that disallowed from rate 
recovery approximately $15 million of approximately $95 
million of our total environmental expenditures made from 
2003 to 2012, due to the OPUC's application of a recently 
formulated earnings test. The OPUC issued a subsequent 
Order in January 2016 that, among other things, disallowed 
interest on the $15 million disallowance after 2012 and 
found only 96.68% of prudently incurred environmental 
remediation costs to be allowable to Oregon. Additionally, 
the rates allowed by the FERC may be insufficient for 
recovery of costs incurred. We expect to continue to make 
expenditures to expand, improve and operate our utility 
distribution and gas storage systems. Regulators can find 
such expansions or improvements of expenditures were not 

14

prudently incurred, and deny recovery. Additionally, while 
the OPUC and WUTC have established an authorized rate 
of return for our utility through the ratemaking process, the 
regulatory process does not provide assurance that we will 
be able to achieve the earnings level authorized.

Moreover, in the normal course of business we may place 
assets in service or incur higher than expected levels of 
operating expense before rate cases can be filed to recover 
those costs—this is commonly referred to as regulatory lag. 
The failure of any regulatory commission to approve 
requested rate increases on a timely basis to recover 
increased costs or to allow an adequate return could 
adversely impact our financial condition and results of 
operations.

As a regulated utility, we frequently have dockets open with 
our regulators. The regulatory proceedings for these 
dockets typically involve multiple parties, including 
governmental agencies, consumer advocacy groups, and 
other third parties. Each party has differing concerns, but all 
generally have the common objective of limiting amounts 
included in rates. We cannot predict the timing or outcome 
of these deferred proceedings or the effects of those 
outcomes on our results of operations and financial 
condition.

ENVIRONMENTAL LIABILITY RISK. Certain of our properties 
and facilities may pose environmental risks requiring 
remediation, the costs of which are difficult to estimate and 
which could adversely affect our financial condition, results 
of operations, and cash flows.

We own, or previously owned, properties that require 
environmental remediation or other action. We accrue all 
material loss contingencies relating to these properties. A 
regulatory asset at the utility has already been recorded for 
estimated costs pursuant to a deferral Order from the OPUC 
and WUTC. In addition to maintaining regulatory deferrals, 
we settled with most of our historical liability insurers for 
only a portion of the costs we have incurred to date and 
expect to incur in the future. To the extent amounts we 
recovered from insurance are inadequate or we are unable 
to recover these deferred costs in utility customer rates, we 
would be required to reduce our regulatory assets which 
would result in a charge to current year earnings. In 
addition, in our most recent Oregon general rate case, the 
OPUC approved the SRRM, which limits recovery of our 
deferred amounts to those amounts which satisfy an annual 
prudence review and a recently adopted earnings test that 
requires the Company to contribute additional amounts 
toward environmental remediation costs above 
approximately $10 million in years in which the Company 
earns above its authorized Return on Equity (ROE). To the 
extent the Company earns more than its authorized ROE in 
a year, the Company would be required to cover 
environmental expenses greater than the $10 million with 
those earnings that exceed its authorized ROE. In addition, 
the OPUC ordered a review of the SRRM in 2018 or when 
we obtain greater certainty of environmental costs, 
whichever occurs first. These ongoing prudence reviews, 
the earnings test, or the three-year review could reduce the 
amounts we are allowed to recover, and could adversely 
affect our financial condition, results of operations and cash 
flows.

Moreover, we may have disputes with regulators and other 
parties as to the severity of particular environmental matters 
and what remediation efforts are appropriate. We cannot 
predict with certainty the amount or timing of future 
expenditures related to environmental investigation, 
remediation or other action, the portions of these costs 
allocable to us, or disputes or litigation arising in relation 
thereto. Our liability estimates are based on current 
remediation technology, industry experience gained at 
similar sites, an assessment of the probable level of 
involvement, and the financial condition of other potentially 
responsible parties. However, it is difficult to estimate such 
costs due to uncertainties surrounding the course of 
environmental remediation, the preliminary nature of certain 
of our site investigations, and the application of 
environmental laws that impose joint and several liabilities 
on all potentially responsible parties. These uncertainties 
and disputes arising therefrom could lead to further 
adversarial administrative proceedings or litigation, with 
associated costs and uncertain outcomes, all of which could 
adversely affect our financial condition, results of operations 
and cash flows. 

ENVIRONMENTAL REGULATION COMPLIANCE RISK. We are 
subject to environmental regulations for our ongoing 
operations, compliance with which could adversely affect 
our operations or financial results.

We are subject to laws, regulations and other legal 
requirements enacted or adopted by federal, state and local 
governmental authorities relating to protection of the 
environment, including those legal requirements that govern 
discharges of substances into the air and water, the 
management and disposal of hazardous substances and 
waste, groundwater quality and availability, plant and wildlife 
protection, and other aspects of environmental regulation. 
Current and additional environmental regulations could 
result in increased compliance costs or additional operating 
restrictions and could have an adverse effect on our 
financial condition and results of operations, particularly if 
those costs are not fully recoverable from insurance or 
through utility customer rates.

GLOBAL CLIMATE CHANGE RISK. Future legislation to 
address global climate change may expose us to regulatory 
and financial risk. Additionally, our business may be subject 
to physical risks associated with climate change, all of which 
could adversely affect our financial condition, results of 
operations and cash flows.

There are a number of international, federal and state 
legislative and regulatory initiatives being proposed and 
adopted in an attempt to measure, control or limit the effects 
of global warming and overall climate change, including 
greenhouse gas emissions such as carbon dioxide and 
methane. Such current or future legislation or regulation 
could impose on us operational requirements, additional 
charges to fund energy efficiency initiatives, or levy a tax 
based on carbon content. Such initiatives could result in us 
incurring additional costs to comply with the imposed 
restrictions, provide a cost advantage to energy sources 
other than natural gas, reduce demand for natural gas, 
impose costs or restrictions on end users of natural gas, 
impact the prices we charge our customers, impose 
increased costs on us associated with the adoption of new 

15

infrastructure and technology to respond to such 
requirements, and may impact cultural perception of our 
service or products negatively, diminishing the value of our 
brand, all of which could adversely affect our business 
practices, financial condition and results of operations.
Climate change may cause physical risks, including an 
increase in sea level, intensified storms, water scarcity and 
changes in weather conditions, such as changes in 
precipitation, average temperatures and extreme wind or 
other climate conditions. A significant portion of the nation’s 
gas infrastructure is located in areas susceptible to storm 
damage that could be aggravated by wetland and barrier 
island erosion, which could give rise to gas supply 
interruptions and price spikes.

These and other physical changes could result in 
disruptions to natural gas production and transportation 
systems potentially increasing the cost of gas beyond that 
assumed in our PGA and affecting our ability to procure gas 
to meet our customer demand. These changes could also 
affect our distribution systems resulting in increased 
maintenance and capital costs, disruption of service, 
regulatory actions and lower customer satisfaction. 
Additionally, to the extent that climate change adversely 
impacts the economic health or weather conditions of our 
service territory directly, it could adversely impact customer 
demand or our customers' ability to pay. Such physical risks 
could have an adverse effect on our financial condition, 
results of operations, and cash flows.

BUSINESS DEVELOPMENT RISK. Our business development 
projects may encounter unanticipated obstacles, costs, 
changes or delays that could result in a project becoming 
impaired, which could negatively impact our financial 
condition, results of operations and cash flows.

Business development projects involve many risks. We are 
currently engaged in several business development 
projects, including, but not limited to, the early planning and 
development stages for a regional pipeline in Oregon, and a 
potential expansion of our gas storage facility at Mist. We 
may also engage in other business development projects 
such as investment in additional long-term gas reserves or 
CNG refueling stations. These projects may not be 
successful.  Additionally, we may not be able to obtain 
required governmental permits and approvals to complete 
our projects in a cost-efficient or timely manner potentially 
resulting in delays or abandonment of the projects. We 
could also experience startup and construction delays, 
construction cost overruns, inability to negotiate acceptable 
agreements such as rights-of-way, easements, construction, 
gas supply or other material contracts, changes in customer 
demand or commitment, public opposition to projects, 
changes in market prices, and operating cost increases. 
Additionally, we may be unable to finance our business 
development projects at acceptable interest rates or within a 
scheduled time frame necessary for completing the project. 
One or more of these events could result in the project 
becoming impaired, and such impairment could have an 
adverse effect on our financial condition and results of 
operations.

JOINT PARTNER RISK. Investing in business development 
projects through partnerships, joint ventures or other 
business arrangements affects our ability to manage certain 

 
risks and could adversely impact our financial condition, 
results of operations and cash flows.

We use joint ventures and other business arrangements to 
manage and diversify the risks of certain utility and non-
utility development projects, including our Trail West 
pipeline, Gill Ranch storage and our gas reserves 
agreements. We may acquire or develop part-ownership 
interests in other similar projects in the future. Under these 
arrangements, we may not be able to fully direct the 
management and policies of the business relationships, and 
other participants in those relationships may take action 
contrary to our interests including making operational 
decisions that could affect our costs and liabilities. In 
addition, other participants may withdraw from the project, 
divest important assets, become financially distressed or 
bankrupt, or have economic or other business interests or 
goals that are inconsistent with ours. 

For example, our gas reserves arrangements, which 
operate as a hedge backed by physical gas supplies, 
involve a number of risks. These risks include gas 
production that is significantly less than the expected 
volumes, or no gas volumes; operating costs that are higher 
than expected; changes in our consolidated tax position or 
tax laws that could affect our ability to take, or timing of, 
certain tax benefits that impact the financial outcome of this 
transaction; inherent risks of gas production, including 
disruption to operations or complete shut-in of the field; and 
a participant in one of these business arrangements acting 
contrary to our interests. In addition, while the cost of the 
original gas reserves venture is currently included in 
customer rates, the occurrence of one or more of these 
risks, could affect our ability to recover this hedge in rates.  
Further, any new gas reserves arrangements have not been 
approved for inclusion in rates, and our regulators may 
ultimately determine to not include all or a portion of future 
transactions in rates.  The realization of any of these 
situations could adversely impact the project as well as our 
financial condition, results of operations and cash flows. 

OPERATING RISK. Transporting and storing natural gas 
involves numerous risks that may result in accidents and 
other operating risks and costs, some or all of which may 
not be fully covered by insurance, and which could 
adversely affect our financial condition, results of operations 
and cash flows.

Our operations are subject to all of the risks and hazards 
inherent in the businesses of local gas distribution and 
storage, including:
• 

earthquakes, floods, storms, landslides and other 
adverse weather conditions and hazards;
leaks or other losses of natural gas or other chemicals 
or compounds as a result of the malfunction of 
equipment or facilities;
damages from third parties, including construction, farm 
and utility equipment or other surface users;
operator errors;
negative performance by our storage reservoirs that 
could cause us to fail to meet expected or forecasted 
operational levels or contractual commitments to our 
customers;
problems maintaining, or the malfunction of, pipelines, 
wellbores and related equipment and facilities that form 

• 

• 

• 
• 

• 

a part of the infrastructure that is critical to the 
operation of our gas distribution and storage facilities;
collapse of underground storage caverns;
operating costs that are substantially higher than 
expected;

• 
• 

• 

•  migration of natural gas through faults in the rock or to 
some area of the reservoir where existing wells cannot 
drain the gas effectively resulting in loss of the gas;
blowouts (uncontrolled escapes of gas from a pipeline 
or well) or other accidents, fires and explosions; and
risks and hazards inherent in the drilling operations 
associated with the development of the gas storage 
facilities and/or wells.

• 

These risks could result in personal injury or loss of human 
life, damage to and destruction of property and equipment, 
pollution or other environmental damage, breaches of our 
contractual commitments, and may result in curtailment or 
suspension of our operations, which in turn could lead to 
significant costs and lost revenues. Further, because our 
pipeline, storage and distribution facilities are in or near 
populated areas, including residential areas, commercial 
business centers, and industrial sites, any loss of human life 
or adverse financial outcomes resulting from such events 
could be significant. Additionally, we may not be able to 
obtain the level or types of insurance we desire, and the 
insurance coverage we do obtain may contain large 
deductibles or fail to cover certain hazards or cover all 
potential losses. The occurrence of any operating risks not 
covered by insurance could adversely affect our financial 
condition, results of operations and cash flows.

BUSINESS CONTINUITY RISK. We may be adversely 
impacted by local or national disasters, pandemic illness, 
terrorist activities, including cyber-attacks, and other 
extreme events to which we may not able to promptly 
respond.

Local or national disasters, pandemic illness, terrorist 
activities, including cyber-attacks, and other extreme events 
are a threat to our assets and operations. Companies in our 
industry may face a heightened risk due to exposure to acts 
of terrorism, including physical and security breaches of our 
information technology infrastructure in the form of cyber-
attacks.  These attacks could target or impact our 
technology or mechanical systems that operate our natural 
gas distribution, transmission or storage facilities and result 
in a disruption in our operations, damage to our system and 
inability to meet customer requirements. In addition, the 
threat of terrorist activities could lead to increased economic 
instability and volatility in the price of natural gas that could 
affect our operations. Threatened or actual national 
disasters or terrorist activities may also disrupt capital 
markets and our ability to raise capital, or impact our 
suppliers or our customers directly. Local disaster or 
pandemic illness could result in part of our workforce being 
unable to operate or maintain our infrastructure or perform 
other tasks necessary to conduct our business. A slow or 
inadequate response to events may have an adverse 
impact on operations and earnings. We may not be able to 
obtain sufficient insurance to cover all risks associated with 
local and national disasters, pandemic illness, terrorist 
activities and other events.  Additionally, large scale natural 
disasters or terrorist attacks could destabilize the insurance 
industry making insurance we do have unavailable, which 

16

could increase the risk that an event could adversely affect 
our operations or financial results.

EMPLOYEE BENEFIT RISK. The cost of providing pension 
and postretirement healthcare benefits is subject to changes 
in pension assets and liabilities, changing employee 
demographics and changing actuarial assumptions, which 
may have an adverse effect on our financial condition, 
results of operations and cash flows.

Until we closed the plans to new hires, which for non-union 
employees was in 2006 and for union employees was in 
2009, we provided pension plans and postretirement 
healthcare benefits to eligible full-time utility employees and 
retirees. Most of our current utility employees were hired 
prior to these dates, and therefore remain eligible for these 
plans. Our cost of providing such benefits is subject to 
changes in the market value of our pension assets, changes 
in employee demographics including longer life 
expectancies, increases in healthcare costs, current and 
future legislative changes, and various actuarial calculations 
and assumptions. The actuarial assumptions used to 
calculate our future pension and postretirement healthcare 
expense may differ materially from actual results due to 
significant market fluctuations and changing withdrawal 
rates, wage rates, interest rates and other factors. These 
differences may result in an adverse impact on the amount 
of pension contributions, pension expense or other 
postretirement benefit costs recorded in future periods. 
Sustained declines in equity markets and reductions in bond 
rates may have a material adverse effect on the value of our 
pension fund assets and liabilities. In these circumstances, 
we may be required to recognize increased contributions 
and pension expense earlier than we had planned to the 
extent that the value of pension assets is less than the total 
anticipated liability under the plans, which could have a 
negative impact on financial condition, results of operations 
and cash flows.

WORKFORCE RISK. Our business is heavily dependent on 
being able to attract and retain qualified employees and 
maintain a competitive cost structure with market-based 
salaries and employee benefits, and workforce disruptions 
could adversely affect our operations and results.

Our ability to implement our business strategy and serve our 
customers is dependent upon our continuing ability to attract 
and retain talented professionals and a technically skilled 
workforce, and being able to transfer the knowledge and 
expertise of our workforce to new employees as our largely 
older workforce retires. We expect that a significant portion 
of our workforce will retire within the current decade, which 
will require that we attract, train and retain skilled workers to 
prevent loss of institutional knowledge or skills gap.  Without 
an appropriately skilled workforce, our ability to provide 
quality service and meet our regulatory requirements will be 
challenged and this could negatively impact our earnings. 
Additionally, within our utility segment a majority of our 
workers are represented by the OPEIU Local No.11 AFL-
CIO (the Union), and are covered by a collective bargaining 
agreement that extends to November 30, 2019. Disputes 
with the Union over terms and conditions of the agreement 
could result in instability in our labor relationship and work 
stoppages that could impact the timely delivery of gas and 
other services from our utility and Mist gas storage facility, 

17

which could strain relationships with customers and state 
regulators and cause a loss of revenues. Our collective 
bargaining agreement may also limit our flexibility in dealing 
with our workforce, and our ability to change work rules and 
practices and implement other efficiency-related 
improvements to successfully compete in today’s 
challenging marketplace, which may negatively affect our 
financial condition and results of operations.

LEGISLATIVE, COMPLIANCE AND TAXING AUTHORITY RISK. 
We are subject to governmental regulation, and compliance 
with local, state and federal requirements, including taxing 
requirements, and unforeseen changes in or interpretations 
of such requirements could affect our financial condition and 
results of operations.

We are subject to regulation by federal, state and local 
governmental authorities. We are required to comply with a 
variety of laws and regulations and to obtain authorizations, 
permits, approvals and certificates from governmental 
agencies in various aspects of our business. We cannot 
predict with certainty the impact of any future revisions or 
changes in interpretations of existing regulations or the 
adoption of new laws and regulations applicable to them. 
Additionally, any failure to comply with existing or new laws 
and regulations could result in fines, penalties or injunctive 
measures that could affect operating assets. For example, 
under the Energy Policy Act of 2005, the FERC has civil 
authority under the Natural Gas Act to impose penalties for 
current violations of up to $1 million per day for each 
violation. In addition, as the regulatory environment for our 
industry increases in complexity, the risk of inadvertent 
noncompliance may also increase. Changes in regulations, 
the imposition of additional regulations, and the failure to 
comply with laws and regulations could negatively influence 
our operating environment and results of operations. 

Additionally, changes in federal, state or local tax laws and 
their related regulations, or differing interpretations or 
enforcement of applicable law by a federal, state or local 
taxing authority, could result in substantial cost to us and 
negatively affect our results of operations. Tax law and its 
related regulations and case law are inherently complex and 
dynamic. Disputes over interpretations of tax laws may be 
settled with the taxing authority in examination, upon appeal 
or through litigation. Our judgments may include reserves 
for potential adverse outcomes regarding tax positions that 
have been taken that may be subject to challenge by taxing 
authorities. Changes in laws, regulations or adverse 
judgments may negatively affect our financial condition and 
results of operations.

SAFETY REGULATION RISK. We may experience increased 
federal, state and local regulation of the safety of our 
systems and operations, which could adversely affect our 
operating costs and financial results.

The safety and protection of the public, our customers and 
our employees is and will remain our top priority. We are 
committed to consistently monitoring and maintaining our 
distribution system and storage operations to ensure that 
natural gas is acquired, stored and delivered safely, reliably 
and efficiently. Given recent high-profile natural gas 
explosions, leaks and accidents in other parts of the country 
involving both distribution systems and storage facilities, we 

anticipate that the natural gas industry may be the subject of 
even greater federal, state and local regulatory oversight. 
We intend to work diligently with industry associations and 
federal and state regulators to ensure compliance with the 
new laws. We expect there to be increased costs 
associated with compliance, and those costs could be 
significant. If these costs are not recoverable in our 
customer rates, they could have a negative impact on our 
operating costs and financial results.

HEDGING RISK. Our risk management policies and hedging 
activities cannot eliminate the risk of commodity price 
movements and other financial market risks, and our 
hedging activities may expose us to additional liabilities for 
which rate recovery may be disallowed, which could result 
in an adverse impact on our operating revenues, costs, 
derivative assets and liabilities and operating cash flows.

Our gas purchasing requirements expose us to risks of 
commodity price movements, while our use of debt and 
equity financing exposes us to interest rate, liquidity and 
other financial market risks. In our Utility segment, we 
attempt to manage these exposures with both financial and 
physical hedging mechanisms, including our gas reserves 
transactions which are hedges backed by physical gas 
supplies. While we have risk management procedures for 
hedging in place, they may not always work as planned and 
cannot entirely eliminate the risks associated with hedging. 
Additionally, our hedging activities may cause us to incur 
additional expenses to obtain the hedge. We do not hedge 
our entire interest rate or commodity cost exposure, and the 
unhedged exposure will vary over time. Gains or losses 
experienced through hedging activities, including carrying 
costs, generally flow through the PGA mechanism or are 
recovered in future general rate cases. However, the hedge 
transactions we enter into for the utility are subject to a 
prudence review by the OPUC and WUTC, and, if found 
imprudent, those expenses may be, and have been 
previously, disallowed, which could have an adverse effect 
on our financial condition and results of operations. 

In addition, our actual business requirements and available 
resources may vary from forecasts, which are used as the 
basis for our hedging decisions, and could cause our 
exposure to be more or less than we anticipated. Moreover, 
if our derivative instruments and hedging transactions do 
not qualify for hedge accounting under generally accepted 
accounting standards, our hedges may not be effective and 
our results of operations and financial condition could be 
adversely affected.

We also have credit-related exposure to derivative 
counterparties. In general, we require our counterparties to 
have an investment-grade credit rating at the time the 
derivative instrument is entered into, and we specify limits 
on the contract amount and duration based on each 
counterparty’s credit rating. Nevertheless, counterparties 
owing us money or physical natural gas commodities could 
breach their obligations. Should the counterparties to these 
arrangements fail to perform, we may be forced to enter into 
alternative arrangements to meet our normal business 
requirements. In that event, our financial results could be 
adversely affected. Additionally, under most of our hedging 
arrangements, any downgrade of our senior unsecured 
long-term debt credit rating could allow our counterparties to 

18

require us to post cash, a letter of credit or other form of 
collateral, which would expose us to additional costs and 
may trigger significant increases in borrowing from our 
credit facilities if the credit rating downgrade is below 
investment grade.  Further, based on current interpretations, 
we are not considered a "swap dealer" or "major swap 
participant" in 2015, so we are exempt from certain 
requirements under the Dodd-Frank Act.  If we are unable to 
claim this exemption, we could be subject to higher costs for 
our derivatives activities. 

INABILITY TO ACCESS CAPITAL MARKET RISK. Our inability 
to access capital, or significant increases in the cost of 
capital, could adversely affect our financial condition and 
results of operations.

Our ability to obtain adequate and cost effective short-term 
and long-term financing depends on maintaining investment 
grade credit ratings as well as the existence of liquid and 
stable financial markets. Our businesses rely on access to 
capital markets, including commercial paper, bond and 
equity markets, to finance our operations, construction 
expenditures and other business requirements, and to 
refund maturing debt that cannot be funded entirely by 
internal cash flows. Disruptions in capital markets could 
adversely affect our ability to access short-term and long-
term financing. Our access to funds under committed short-
term credit facilities, which are currently provided by a 
number of banks, is dependent on the ability of the 
participating banks to meet their funding commitments. 
Those banks may not be able to meet their funding 
commitments if they experience shortages of capital and 
liquidity. Disruptions in the bank or capital financing markets 
as a result of economic uncertainty, changing or increased 
regulation of the financial sector, or failure of major financial 
institutions could adversely affect our access to capital and 
negatively impact our ability to run our business and make 
strategic investments.

A negative change in our current credit ratings, particularly 
below investment grade, could adversely affect our cost of 
borrowing and access to sources of liquidity and capital. 
Such a downgrade could further limit our access to 
borrowing under available credit lines. Additionally, 
downgrades in our current credit ratings below investment 
grade could cause additional delays in accessing the capital 
markets by the utility while we seek supplemental state 
regulatory approval, which could hamper our ability to 
access credit markets on a timely basis. A credit downgrade 
could also require additional support in the form of letters of 
credit, cash or other forms of collateral and otherwise 
adversely affect our financial condition and results of 
operations.

Risks Related Primarily to Our Local Utility Business
GAS PRICE RISK. Higher natural gas commodity prices and 
volatility in the price of gas may adversely affect our results 
of operations and cash flows.

The cost of natural gas is affected by a variety of factors, 
including weather, changes in demand, the level of 
production and availability of natural gas supplies, 
transportation constraints, availability and cost of pipeline 
capacity, federal and state energy and environmental 
regulation and legislation, natural disasters and other 

 
catastrophic events, national and worldwide economic and 
political conditions, and the price and availability of 
alternative fuels. In our utility segment, the cost we pay for 
natural gas is generally passed through to our customers 
through an annual PGA rate adjustment. If gas prices were 
to increase significantly, it would raise the cost of energy to 
our utility customers, potentially causing those customers to 
conserve or switch to alternate sources of energy. 
Significant price increases could also cause new home 
builders and commercial developers to select alternative 
fuel sources. Decreases in the volume of gas we sell could 
reduce our earnings, and a decline in customers could slow 
growth in our future earnings. Additionally, because a 
portion of any 10% or 20% difference between the 
estimated average PGA gas cost in rates and the actual 
average gas cost incurred is recognized as current income 
or expense, higher average gas costs than those assumed 
in setting rates can adversely affect our operating cash 
flows, liquidity and results of operations. Additionally, 
notwithstanding our current rate structure, higher gas costs 
could result in increased pressure on the OPUC or the 
WUTC to seek other means to reduce rates, which also 
could adversely affect our results of operations and cash 
flows.

Higher gas prices may also cause us to experience an 
increase in short-term debt and temporarily reduce liquidity 
because we pay suppliers for gas when it is purchased, 
which can be in advance of when these costs are recovered 
through rates. Significant increases in the price of gas can 
also slow our collection efforts as customers experience 
increased difficulty in paying their higher energy bills, 
leading to higher than normal delinquent accounts 
receivable resulting in greater expense associated with 
collection efforts and increased bad debt expense.

CUSTOMER GROWTH RISK. Our utility margin, earnings and 
cash flow may be negatively affected if we are unable to 
sustain customer growth rates in our local gas distribution 
segment.

Our utility margins and earnings growth have largely 
depended upon the sustained growth of our residential and 
commercial customer base due, in part, to the new 
construction housing market, conversions of customers to 
natural gas from other fuel sources and growing commercial 
use of natural gas. The recent recession slowed new 
construction. While construction has resumed, it has not 
returned to its original pace and has been heavily multi-
family, which is a segment that has historically used natural 
gas less frequently. Insufficient growth in these markets, for 
economic, political or other reasons could result in an 
adverse long-term impact on our utility margin, earnings and 
cash flows.

RISK OF COMPETITION. Our gas distribution business is 
subject to increased competition which could negatively 
affect our results of operations.

In the residential and commercial markets, our gas 
distribution business competes primarily with suppliers of 
electricity, fuel oil, propane, and renewable energy. In the 
industrial market, we compete with suppliers of all forms of 
energy. Competition among these forms of energy is based 
on price, efficiency, reliability, performance, market 

19

conditions, technology, environmental impacts and public 
perception.

Technological improvements in other energy sources such 
as heat pumps, batteries or other alternative technologies 
could erode our competitive advantage. If natural gas prices 
rise relative to other energy sources, or if the cost, 
environmental impact or public perception of such other 
energy sources improves relative to natural gas, it may 
negatively affect our ability to attract new customers or 
retain our existing residential, commercial and industrial 
customers, which could have a negative impact on our 
customer growth rate and results of operations.

RELIANCE ON THIRD PARTIES TO SUPPLY NATURAL GAS 
RISK. We rely on third parties to supply the natural gas in 
our distribution segment, and limitations on our ability to 
obtain supplies, or failure to receive expected supplies for 
which we have contracted, could have an adverse impact 
on our financial results.

Our ability to secure natural gas for current and future sales 
depends upon our ability to purchase and receive delivery of 
supplies of natural gas from third parties. We, and in some 
cases, our suppliers of natural gas do not have control over 
the availability of natural gas supplies, competition for those 
supplies, disruptions in those supplies, priority allocations 
on transmission pipelines, or pricing of those supplies. 
Additionally, third parties on whom we rely may fail to deliver 
gas for which we have contracted. If we are unable to 
obtain, or are limited in our ability to obtain, natural gas from 
our current suppliers or new sources, we may not be able to 
meet our customers' gas requirements and would likely 
incur costs associated with actions necessary to mitigate 
services disruptions, both of which could significantly and 
negatively impact our results of operations.

SINGLE TRANSPORTATION PIPELINE RISK. We rely on a 
single pipeline company for the transportation of gas to our 
service territory, a disruption of which could adversely 
impact our ability to meet our customers’ gas requirements.

Our distribution system is directly connected to a single 
interstate pipeline, which is owned and operated by 
Northwest Pipeline. The pipeline’s gas flows are bi-
directional, transporting gas into the Portland metropolitan 
market from two directions: (1) the north, which brings 
supplies from the British Columbia and Alberta supply 
basins; and (2) the east, which brings supplies from the 
Alberta and the U.S. Rocky Mountain supply basins. If there 
is a rupture or inadequate capacity in the pipeline, we may 
not be able to meet our customers’ gas requirements and 
we would likely incur costs associated with actions 
necessary to mitigate service disruptions, both of which 
could significantly and negatively impact our results of 
operations.

WEATHER RISK. Warmer than average weather may have a 
negative impact on our revenues and results of operations.

We are exposed to weather risk primarily in our utility 
segment. A majority of our volume is driven by gas sales to 
space heating residential and commercial customers during 
the winter heating season. Current utility rates are based on 
an assumption of average weather. Warmer than average 

weather typically results in lower gas sales. Colder weather 
typically results in higher gas sales. Although the effects of 
warmer or colder weather on utility margin in Oregon are 
expected to be mitigated through the operation of our 
weather normalization mechanism, weather variations from 
normal could adversely affect utility margin because we may 
be required to purchase more or less gas at spot rates, 
which may be higher or lower than the rates assumed in our 
PGA. Also, a portion of our Oregon residential and 
commercial customers (usually less than 10%) have opted 
out of the weather normalization mechanism, and 11% of 
our customers are located in Washington where we do not 
have a weather normalization mechanism. These effects 
could have an adverse effect on our financial condition, 
results of operations and cash flows.

CUSTOMER CONSERVATION RISK. Customers’ conservation 
efforts may have a negative impact on our revenues.

An increasing national focus on energy conservation, 
including improved building practices and appliance 
efficiencies may result in increased energy conservation by 
customers. This can decrease our sales of natural gas and 
adversely affect our results of operations because revenues 
are collected mostly through volumetric rates, based on the 
amount of gas sold. In Oregon, we have a conservation 
tariff which is designed to recover lost utility margin due to 
declines in residential and small commercial customers’ 
consumption. However, we do not have a conservation tariff 
in Washington that provides us this margin protection on 
sales to customers in that state.

RELIANCE ON TECHNOLOGY RISK. Our efforts to integrate, 
consolidate and streamline our operations have resulted in 
increased reliance on technology, the failure or security 
breach of which could adversely affect our financial 
condition and results of operations.

Over the last several years we have undertaken a variety of 
initiatives to integrate, standardize, centralize and 
streamline our operations. These efforts have resulted in 
greater reliance on technological tools such as: an 
enterprise resource planning system, an automated 
dispatch system, an automated meter reading system, a 
customer information system, a web-based ordering and 
tracking system, and other similar technological tools and 
initiatives. The failure of any of these or other similarly 
important technologies, or our inability to have these 
technologies supported, updated, expanded or integrated 
into other technologies, could adversely impact our 
operations. We take precautions to protect our systems, but 
there is no guarantee that the procedures we have 
implemented to protect against unauthorized access to 
secured data and systems are adequate to safeguard 
against all security breaches. Our utility could experience 
breaches of security pertaining to sensitive customer, 
employee and vendor information maintained by the utility in 
the normal course of business which could adversely affect 
the utility’s reputation, diminish customer confidence, disrupt 
operations, materially increase the costs we incur to protect 
against these risks, and subject us to possible financial 
liability or increased regulation or litigation, any of which 
could adversely affect our financial condition and results of 
operations.

20

Furthermore, we rely on information technology systems in 
our operations of our distribution and storage operations. 
There are various risks associated with these systems, 
including, hardware and software failure, communications 
failure, data distortion or destruction, unauthorized access 
to data, misuse of proprietary or confidential data, 
unauthorized control through electronic means, 
programming mistakes and other inadvertent errors or 
deliberate human acts. In particular, cyber security attacks, 
terrorism or other malicious acts could damage, destroy or 
disrupt all of our business systems. Any failure of 
information technology systems could result in a loss of 
operating revenues, an increase in operating expenses and 
costs to repair or replace damaged assets. As these 
potential cyber security attacks become more common and 
sophisticated, we could be required to incur costs to 
strengthen our systems or obtain specific insurance 
coverage against potential losses.

Risks Related Primarily to Our Gas Storage 
Businesses
LONG-TERM LOW OR STABILIZATION OF GAS PRICE RISK. 
Any significant stabilization of natural gas prices or long-
term low gas prices could have a negative impact on the 
demand for our natural gas storage services, which could 
adversely affect our financial results.

Storage businesses benefit from price volatility, which 
impacts the level of demand for services and the rates that 
can be charged for storage services. Largely due to the 
abundant supply of natural gas made available by hydraulic 
fracturing techniques, natural gas prices have dropped 
significantly to levels that are near historic lows. If prices 
and volatility remain low or decline further, then the demand 
for storage services, and the prices that we will be able to 
charge for those services, may decline or be depressed for 
a prolonged period of time. Prices below the costs to 
operate the storage facility could result in a decision to shut 
in all or a portion of the facility. A sustained decline in these 
prices or a shut-in of all or a portion of the facility could have 
an adverse impact on our financial condition, results of 
operations and cash flows.

NATURAL GAS STORAGE COMPETITION RISK. Increasing 
competition in the natural gas storage business could 
reduce the demand for our storage services and drive prices 
down for storage, which could adversely affect our financial 
condition, results of operation and cash flows.

Our natural gas storage segment competes primarily with 
other storage facilities and pipelines. Natural gas storage is 
an increasingly competitive business, with the ability to 
expand or build new storage capacity in California, the U.S. 
Rocky Mountains and elsewhere in the United States and 
Canada. Increased competition in the natural gas storage 
business could reduce the demand for our natural gas 
storage services, drive prices down for our storage 
business, and adversely affect our ability to renew or 
replace existing contracts at rates sufficient to maintain 
current revenues and cash flows, which could adversely 
affect our financial condition, results of operations and cash 
flows.

lands. We also hold permits for the crossing of numerous 
navigable waterways and smaller tributaries throughout our 
entire service territory.

We own service building facilities in Portland, as well as 
various satellite service centers, garages, warehouses, and 
other buildings necessary and useful in the conduct of our 
business. We also lease office space in Portland for our 
corporate headquarters, which expires on May 31, 2020. 
Resource centers are maintained on owned or leased 
premises at convenient points in the distribution system to 
provide service within our utility service territory. We also 
own LNG storage facilities in Portland and near Newport, 
Oregon.

In order to reduce risks associated with gas leakage in older 
parts of our system, we undertook accelerated pipe 
replacement programs under which we removed and 
replaced 100% of our cast iron mains by the end of 2000, 
and under which we eliminated all remaining known bare 
steel mains and services by the end of 2015.

Gas Storage Properties 
We hold leases and other property interests in 
approximately 12,000 net acres of underground natural gas 
storage in Oregon and approximately 5,000 net acres of 
underground natural gas storage in California, and 
easements and other property interests related to pipelines 
associated with those facilities. We own rights to depleted 
gas reservoirs near Mist, Oregon, that are continuing to be 
developed and operated as underground gas storage 
facilities. We also hold an option to purchase future storage 
rights in certain other areas of the Mist gas field in Oregon, 
as well as in California related to the Gill Ranch storage 
project.

We consider all of our properties currently used in our 
operations, both owned and leased, to be well maintained, 
in good operating condition, and, along with planned 
additions, adequate for our present and foreseeable future 
needs.

Our Mortgage and Deed of Trust (Mortgage) is a first 
mortgage lien on substantially all of the property constituting 
our utility plant.

ITEM 3. LEGAL PROCEEDINGS 

Other than the proceedings disclosed in Note 15, we have 
only nonmaterial litigation in the ordinary course of 
business.

ITEM 4. MINE SAFETY DISCLOSURES

Not applicable.

IMPAIRMENT OF LONG-LIVED ASSETS RISK. If storage 
pricing does not improve, or higher value customers are not 
obtained, our Gill Ranch storage asset may be impaired, 
which could have a material effect on our financial condition, 
or results of operations.

We review the carrying value of long-lived assets whenever 
events or changes in circumstances indicate the carrying 
amount of the assets might not be recoverable. The 
determination of recoverability is based on the undiscounted 
net cash flows expected to result from the operations of 
such assets. Projected cash flows depend on the future 
operating costs associated with the asset, storage pricing, 
the ability to contract with higher value customers, and the 
future market and price for gas storage over the remaining 
life of the asset. Sustained low gas storage prices, the 
failure to contract with higher value customers, or operating 
costs that are above revenues from the facility could result 
in an impairment of the carrying value of our Gill Ranch 
storage facility. Similarly, if we were to determine to sell the 
Gill Ranch storage facility, such determination may result in 
an impairment of the carrying value of the facility. Any 
impairment charge taken by the Company with respect to its 
long-lived assets, including Gill Ranch, could be material to 
the quarter that the charge is taken and could otherwise 
have a material effect on the Company’s financial condition, 
and results of operations.

THIRD-PARTY PIPELINE RISK. Our gas storage businesses 
depend on third-party pipelines that connect our storage 
facilities to interstate pipelines, the failure or unavailability of 
which could adversely affect our financial condition, results 
of operations and cash flows.

Our gas storage facilities are reliant on the continued 
operation of a third-party pipeline and other facilities that 
provide delivery options to and from our storage facilities. 
Because we do not own all of these pipelines, their 
operations are not within our control. If the third-party 
pipeline to which we are connected were to become 
unavailable for current or future withdrawals or injections of 
natural gas due to repairs, damage to the infrastructure, 
lack of capacity or other reasons, our ability to operate 
efficiently and satisfy our customers’ needs could be 
compromised, thereby potentially having an adverse impact 
on our financial condition, results of operations and cash 
flows.

ITEM 1B. UNRESOLVED STAFF COMMENTS

We have no unresolved comments.

ITEM 2. PROPERTIES

Utility Properties
Our natural gas pipeline system consists of approximately 
14,000 miles of distribution and transmission mains located 
in our service territory in Oregon and Washington. In 
addition, the pipeline system includes service pipelines, 
meters and regulators, and gas regulating and metering 
stations. Pipeline mains are located in municipal streets or 
alleys pursuant to franchise or occupation ordinances, in 
county roads or state highways pursuant to agreements or 
permits granted pursuant to statute, or on lands of others 
pursuant to easements obtained from the owners of such 

21

 
 
  
  
 
 
  
PART II

ITEM 5. MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND 
ISSUER PURCHASES OF EQUITY SECURITIES

Our common stock is listed and trades on the New York Stock Exchange under the symbol NWN. The high and low trades for 
our common stock during the past two years were as follows:

Quarter Ended

March 31

June 30

September 30

December 31

2015

2014

High

Low

High

Low

$

52.25

$

43.35

$

44.09

$

49.77

46.74

51.85

41.32

42.00

45.03

47.32

47.50

52.57

40.05

43.06

41.81

42.29

The closing price for our common stock on December 31, 2015 and 2014 was $50.61 and $49.90, respectively. 

As of February 19, 2016, there were 5,697 holders of record of our common stock.

We have paid quarterly dividends on our common stock in each year since the stock first was issued to the public in 1951. 
Annual common dividend payments per share, adjusted for stock splits, have increased each year since 1956. Dividends per 
share paid during the past two years were as follows:

Payment Date

February 15

May 15

August 15

November 15

Total per share

2015

2014

$

$

0.4650

$

0.4650

0.4650

0.4675

1.8625

$

0.460

0.460

0.460

0.465

1.845

The declaration and amount of future dividends depend upon our earnings, cash flows, financial condition, and other factors. 
The amount and timing of dividends payable on our common stock are within the sole discretion of our Board of Directors. 
Subject to Board approval, we expect to continue paying cash dividends on our common stock on a quarterly basis. 

The following table provides information about purchases of our equity securities that are registered pursuant to Section 12 of 
the Securities Exchange Act of 1934 during the quarter ended December 31, 2015:

Period

Balance forward

10/01/15-10/31/15

11/01/15-11/30/15

12/01/15-12/31/15

Total

Issuer Purchases of Equity Securities

Total Number
of Shares Purchased(1)

Average
Price Paid per Share

Total Number of Shares
Purchased as Part of
Publicly Announced 
Plans or Programs(2)

Maximum Dollar Value of
Shares that May Yet Be
Purchased Under the 
Plans or Programs(2)

2,124,528

$

16,732,648

3,279

$

26,594

1,204

31,077

47.12

46.37

48.27

46.52

—

—

—

—

—

—

2,124,528

$

16,732,648

(1)  During the quarter ended December 31, 2015, 26,529 shares of our common stock were purchased on the open market to meet the 
requirements of our Dividend Reinvestment and Direct Stock Purchase Plan. In addition, 4,548 shares of our common stock were 
purchased on the open market to meet the requirements of our share-based programs. During the quarter ended December 31, 2015, no 
shares of our common stock were accepted as payment for stock option exercises pursuant to our Restated Stock Option Plan.

(2)  We have a common stock share repurchase program under which we purchase shares on the open market or through privately negotiated 
transactions. We currently have Board authorization through May 31, 2016 to repurchase up to an aggregate of 2.8 million shares or up to 
an aggregate of $100 million. During the quarter ended December 31, 2015, no shares of our common stock were repurchased pursuant to 
this program. Since the program’s inception in 2000, we have repurchased approximately 2.1 million shares of common stock at a total cost 
of approximately $83.3 million.

22

 
 
 
 
ITEM 6. SELECTED FINANCIAL DATA

In thousands, except share data

2015

2014

2013

2012

2011

Operating revenues

Net income

$

723,791

$

754,037

$

758,518

$

730,607

$

828,055

53,703

58,692

60,538

58,779

63,044

For the year ended December 31,

Earnings per share of common stock:

Basic

Diluted

Dividends paid per share of common stock

$

1.96

$

2.16

$

2.24

$

2.19

$

1.96

1.86

2.16

1.85

2.24

1.83

2.18

1.79

2.36

2.36

1.75

Total assets, end of period

$

3,076,692

$

3,064,945

$

2,970,911

$

2,813,120

$

2,742,718

Total equity

Long-term debt

780,972

576,700

767,321

621,700

751,872

681,700

729,627

691,700

712,158

641,700

23

 
 
 
 
 
ITEM 7. MANAGEMENT'S DISCUSSION AND 
ANALYSIS OF FINANCIAL CONDITION AND 
RESULTS OF OPERATIONS

The following is management’s assessment of Northwest 
Natural Gas Company’s (NW Natural or the Company) 
financial condition, including the principal factors that affect 
results of operations. The discussion refers to our 
consolidated results for the years ended December 31, 
2015, 2014, and 2013. References in this discussion to 
"Notes" are to the Notes to Consolidated Financial 
Statements in Item 8 of this report.

The consolidated financial statements include NW Natural 
and its direct and indirect wholly-owned subsidiaries 
including: 
•  NW Natural Energy, LLC (NWN Energy); 
•  NW Natural Gas Storage, LLC (NWN Gas Storage);
•  Gill Ranch Storage, LLC (Gill Ranch);
•  NNG Financial Corporation (NNG Financial);
•  Northwest Energy Corporation (Energy Corp); and
•  NW Natural Gas Reserves, LLC (NWN Gas Reserves).

We operate in two primary reportable business segments: 
local gas distribution and gas storage. We also have other 
investments and business activities not specifically related 
to one of these two reporting segments, which we 
aggregate and report as other. We refer to our local gas 
distribution business as the utility, and our gas storage 
segment and other as non-utility. Our utility segment 
includes our NW Natural local gas distribution business, 
NWN Gas Reserves, which is a wholly-owned subsidiary of 
Energy Corp, and the utility portion of our Mist underground 
storage facility in Oregon (Mist). Our gas storage segment 

includes NWN Gas Storage, which is a wholly-owned 
subsidiary of NWN Energy, Gill Ranch, which is a wholly-
owned subsidiary of NWN Gas Storage, the non-utility 
portion of Mist, and asset management services. Other 
includes NWN Energy's equity investment in Trail West 
Holding, LLC (TWH), which is pursuing the development of 
a proposed natural gas pipeline through its wholly-owned 
subsidiary, Trail West Pipeline, LLC (TWP), and NNG 
Financial's equity investment in Kelso-Beaver Pipeline (KB 
Pipeline). For a further discussion of our business segments 
and other, see Note 4.

In addition to presenting the results of operations and 
earnings amounts in total, certain financial measures are 
expressed in cents per share or exclude the after-tax 
regulatory disallowance related to the OPUC's 2015 
environmental order, which are non-GAAP financial 
measures. We present net income and earnings per share 
(EPS) excluding the regulatory disallowance along with the 
U.S. GAAP measures to illustrate the magnitude of this 
disallowance on ongoing business and operational results. 
Although the excluded amounts are properly included in the 
determination of net income and earnings per share under 
U.S. GAAP, we believe the amount and nature of such 
disallowance make period to period comparisons of 
operations difficult or potentially confusing. Financial 
measures are expressed in cents per share as these 
amounts reflect factors that directly impact earnings, 
including income taxes. All references in this section to EPS 
are on the basis of diluted shares (see Note 3). We use 
such non-GAAP financial measures to analyze our financial 
performance because we believe they provide useful 
information to our investors and creditors in evaluating our 
financial condition and results of operations.

24

 
  
EXECUTIVE SUMMARY

We manage our business and strategic initiatives with a 
long-term view of providing natural gas service safely and 
reliably to customers, working with regulators on key policy 
initiatives, and remaining focused on growing our business. 
See "2016 Outlook" below for more information. Highlights 
for the year include:
• 

steady annual customer growth rate at the core utility of 
1.4% at December 31, 2015; 
increased new meter sets installed to approximately 
11,000, which is nearly 4% higher than the prior year;
invested $118.3 million in our distribution system and 
facilities including $19.9 million on SIP, allowing us to 

• 

• 

• 

• 

• 

• 

complete our bare steel replacement; 
continued to make progress on our North Mist gas 
storage expansion project;
decreased residential customer rates approximately 7% 
in Oregon and 14% in Washington with the 2015-16 
PGA effective November 1, 2015; 
ranked first in residential customer satisfaction for large 
gas utilities in the West in the 2015 J.D. Power and 
Associates Study, making 2015 the 14th consecutive 
year of top three rankings; and
increased our dividend, marking the 60th consecutive 
year of increases.

Key financial highlights include: 

In millions, except per share data

Amount

Per Share

Amount

Per Share

Amount

Per Share

2015

2014

2013

Consolidated net income

Adjustments:

$

53.7

$

1.96

$

58.7

$

2.16

$

60.5

$

2.24

Regulatory environmental disallowance, net of taxes $5.9(1)

9.1

0.33

—

—

—

—

Adjusted consolidated net income(1)

Utility margin

Gas storage operating revenues

ROE

$

$

62.8

$

2.29

$

58.7

$

2.16

371.4

21.4

6.9%

$ 366.1

22.2

7.7%

$

$

60.5

$

2.24

353.9

31.1

8.2%

Adjusted ROE(1)
(1)     Regulatory environmental disallowance of $15 million is recorded in utility operations and maintenance expense. Adjusted EPS, net    

8.1%

8.2%

7.7%

income, and ROE are non-GAAP financial measures based on the after-tax disallowance. EPS is calculated using the combined federal and 
state statutory tax rate of 39.5% and 27.4 million diluted shares for the year ended December 31, 2015. 

2015 COMPARED TO 2014. Overall, consolidated net income 
decreased $5.0 million. The decrease was primarily due to 
the $9.1 million after-tax charge related to the regulatory 
disallowance associated with a February 2015 OPUC Order 
in our SRRM docket. Under the Order, we were required to 
forego collection of $15 million, pre-tax, out of the 
approximate $95 million of environmental expenditures and 
associated carrying costs deferred through 2012. This 
charge is reflected in operations and maintenance expense. 
Excluding the charge, net income increased $4.1 million 
primarily due to the following factors:
• 

a $5.3 million increase in utility margin primarily due to 
customer growth and gas cost sharing, offset by the 
effects of warmer weather;  
a $0.9 million decrease in gas storage operating 
revenues as storage was negatively impacted by a 
decrease in storage prices between the 2013-14 and 
2014-15 gas years;
a $5.8 million increase in other income, net related to 
the recognition of equity earnings on deferred 
regulatory asset balances as a result of the OPUC 
SRRM Order; 
a $5.5 million increase in operations and maintenance 
expense mainly due to higher compensation and 
benefits expense; and 
a $1.7 million increase in depreciation and amortization 
expenses due to additional utility capital expenditures.

• 

• 

• 

• 

During 2015, management implemented temporary cost 
saving initiatives to mitigate the effects of warm weather and 
the $15 million regulatory disallowance. These initiatives 
resulted in approximately $5 million of operations and 
maintenance expense savings that are not expected to be 
repeated in the future.

2014 COMPARED TO 2013. Overall, consolidated net income 
decreased $1.8 million. Our net income is most significantly 
impacted by our utility business which had favorable results 
during the year, but increases at the utility were more than 
offset by declines from our gas storage segment. The 
primary factors were: 
• 

a $12.2 million increase in utility margin primarily due to 
customer growth and the rate-base return on our gas 
reserves and other investments; 
a $8.9 million decrease in gas storage operating 
revenues as storage was negatively impacted by re-
contracting certain expiring firm storage capacity at 
lower prices;
a $3.3 million increase in depreciation and amortization 
expenses due to additional utility capital expenditures; 
and
a $2.7 million decrease in other income, net due to 
lower interest income on net deferred regulatory 
balances. 

• 

• 

• 

25

 
 
 
 
 
2016 OUTLOOK

Our near-term outlook and long-term strategic goals for the business are aligned with delivering gas safely and reliably to our 
customers, investing for profitable growth in our core gas distribution and gas storage businesses, and creating new ideas to 
drive growth opportunities. Our 2016 strategy leverages our resources and our history of innovative solutions to continue 
meeting the needs of customers, regulators, and shareholders. We consider the following goals critical in achieving these long-
term goals:   

Deliver Gas

Ensure Safety and Reliability

Grow Our Businesses

Grow Utility Customers

Advance Regulatory Policies and Initiatives

Pursue Strategic Utility Investments

Promote Sustainable Energy Policies

Develop Non-utility Growth Initiatives

SAFETY AND RELIABILITY. Delivering natural gas safely and 
reliably to customers and providing employees with a safe 
work environment are our top priorities. During 2016, we will 
continue to ensure our pipeline system and facilities are well 
maintained, new facility improvements are planned and well 
executed, and business continuity requirements are met. 
Projects planned for 2016 include infrastructure investments 
in high-growth areas such as Clark County, Washington, 
refurbishing our LNG facilities, and continuing to prepare for 
large-scale emergency events such as an earthquake. In 
addition, we will remain proactive regarding investments in 
computer systems and cybersecurity infrastructure.

REGULATION. Constructive regulation supports customers 
receiving quality service at a reasonable cost and the 
Company receiving timely cost recovery and earning a 
reasonable return on shareholder investments. In 2016, we 
will be evaluating our future rate case needs in Oregon and 
Washington, progressing open dockets from 2015, and we 
will also update our Integrated Resource Plan focusing on 
investments needed to support the growth in our region. 
Finally, we will work with regulators to further our shared 
commitment to the environment with continued efforts 
around the carbon solutions programs and providing gas to 
rural communities. 

ENERGY POLICIES. The Pacific Northwest is committed to 
energy conservation, environmental sustainability, and 
reducing carbon emissions. Natural gas is an important 
clean energy resource for our region and the country. In 
2016, we will continue to play an active role in shaping 
energy policies and programs, which reflect the interests of 
our customers, including progressing CNG transportation 
initiatives and working on legislation that supports making 
natural gas available to rural communities. In addition, we 
are working hard with other potentially responsible parties to 
make progress with the EPA on a solution to ensure the 
Portland Harbor Superfund Site cleanup is done in a smart, 
cost effective, and responsible way.

UTILITY CUSTOMERS. We intend to capitalize on natural gas 
as a preferred energy choice in our service territory by 
creating a comprehensive marketing program for rental 
projects that further our penetration in the residential multi-
family housing sector. In addition, we remain focused on 
supporting single-family and commercial markets to grow 
our customer base. Additional growth may also come with 
increased industrial load from new projects in the region and 
proposed legislation that favors lower carbon emissions and 
lower cost energy alternatives, such as natural gas.

KEY UTILITY INVESTMENTS. Investing in new infrastructure, 
operating efficiencies, and marketing opportunities position 
our core business for growth now and well into the future. 

A growth investment for our storage business is the planned 
expansion at Mist to support a gas-fired plant built by 
Portland General Electric (PGE) at their nearby Port 
Westward facility. In early 2016, will be working closely with 
the Oregon Energy Siting Facilities Council to finalize the 
cost estimates and receive a notice to proceed. We expect 
construction to begin in 2016 with an in-service date in the 
winter of 2018-19. 

NON-UTILITY INITIATIVES. We remain focused on creating 
value in our non-utility gas storage business, working to 
identify and contract with higher value customers and 
position ourselves for longer-term improvement in the 
California storage markets. We believe the state’s 
renewable energy policies could strategically shift the value 
of gas storage in California in the future. 

26

DIVIDENDS

Dividend highlights include:  

Per common share

Dividends paid

2015

2014

2013

$

1.86

$

1.85

$

1.83

The Board of Directors declared a quarterly dividend on our 
common stock of $0.4675 cents per share, payable on 
February 12, 2016, to shareholders of record on January 
29, 2016, reflecting an indicated annual dividend rate of 
$1.87 per share.

RESULTS OF OPERATIONS

Regulatory Matters

Regulation and Rates 
UTILITY. Our utility business is subject to regulation by the 
OPUC, WUTC, and FERC with respect to, among other 
matters, rates and terms of service. The OPUC and WUTC 
also regulate the system of accounts and issuance of 
securities by our utility. In 2015, approximately 89% of our 
utility gas volumes and revenues were derived from Oregon 
customers, with the remaining 11% from Washington 
customers. Earnings and cash flows from utility operations 
are largely determined by rates set in general rate cases 
and other proceedings in Oregon and Washington. They are 
also affected by the local economies in Oregon and 
Washington, the pace of customer growth in the residential, 
commercial, and industrial markets, and our ability to remain 
price competitive, control expenses, and obtain reasonable 
and timely regulatory recovery of our utility-related costs, 
including operating expenses and investment costs in utility 
plant and other regulatory assets. See "Most Recent 
General Rate Cases" below.

GAS STORAGE. Our gas storage business is subject to 
regulation by the OPUC, WUTC, CPUC, and FERC with 
respect to, among other matters, rates and terms of service. 
The OPUC and CPUC also regulate the issuance of 
securities and system of accounts. The OPUC and CPUC 
regulate intrastate storage services, and the FERC 
regulates interstate storage services. The OPUC and FERC 
use a maximum cost of service model which allows for gas 
storage prices to be set at or below the cost of service as 
approved by each agency in the last regulatory filing. The 
CPUC regulates Gill Ranch under a market-based rate 
model which allows for the price of storage services to be 
set by the marketplace. In 2015, approximately 72% of our 
storage revenues were derived from FERC, Oregon, and 
Washington regulated operations and approximately 28% 
from California operations.

Most Recent General Rate Cases  
OREGON. Effective November 1, 2012, the OPUC  
authorized rates to customers based on an ROE of 9.5%, 
an overall rate of return of 7.78%, and a capital structure of 
50% common equity and 50% long-term debt. 

WASHINGTON. Effective January 1, 2009, the WUTC 
authorized rates to customers based on an ROE of 10.1% 
and an overall rate of return of 8.4% with a capital structure 
of 51% common equity, 5% short-term debt, and 44% long-
term debt.

FERC. We are required under our Mist interstate storage 
certificate authority and rate approval orders to file every 
five years either a petition for rate approval or a cost and 
revenue study to change or justify maintaining the existing 
rates for our interstate storage services. In December 2013 
we filed a rate petition, which was approved in 2014 and 
allows for the maximum cost-based rates for our interstate 
gas storage services. These rates were effective January 1, 
2014, with the rate changes having no significant impact on 
our revenues.

Regulatory Proceeding Updates
During 2015, we were involved in the regulatory activity 
discussed below. 

ENVIRONMENTAL COST DEFERRAL AND SITE REMEDIATION 
AND RECOVERY MECHANISM (SRRM). In February 2015, the 
OPUC issued an Order regarding the SRRM for recovering 
prudently incurred environmental site remediation costs 
through customer billings, subject to an earnings test. The 
OPUC Order found the following: (1) prudence of all but $33 
thousand of costs incurred through March 31, 2014; (2) 
prudence of approximately $150 million of insurance 
settlement proceeds, with one-third of the proceeds applied 
to costs prior to December 31, 2012 and two-thirds to offset 
future environmental expenses over the next 20 years; (3) 
the disallowance of $15 million out of approximately $95 
million of environmental remediation expenses we had 
deferred from 2003 to 2012 based on the OPUC’s 
determination of how an earnings test should have applied 
during that period; which resulted in a non-cash $15 million 
before tax expense recognized in the first quarter 2015; (4) 
how the SRRM recovery mechanism would allow recovery 
of past and future environmental costs; and (5) an OPUC 
review of the SRRM following its third year of operation. 
This Order also required us to submit a compliance filing 
demonstrating how we would implement the Commission’s 
determinations.

We submitted the required compliance filing demonstrating 
the proposed implementation of the Order and SRRM. In 
September 2015, the OPUC ordered we would not be 
required to establish a secure account for the insurance 
proceeds, rather we would defer proceeds to a regulatory 
liability account until utilized, and we would accrue interest 
to rate payers' benefit at a rate equal to the five-year 
treasury rate plus 100 basis points. See "Rate Mechanisms
—Environmental Cost Deferral and SRRM", Note 15 and 
Note 16.

On January 27, 2016, the OPUC issued an Order 
addressing the remaining outstanding issues in the 
compliance filing. See Note 16 regarding this subsequent 
event. 

27

GAS RESERVES. We filed with the OPUC in February 2015 
seeking cost recovery on additional investments in gas 
reserves. In September 2015, the OPUC adopted an all-
party settlement. See "Rate Mechanisms—Gas Reserves" 
below and Note 11.

PREPAID PENSION ASSET. In August 2015, the OPUC issued 
the final Order related to this docket, which confirmed the 
use of accounting expense for recovery of pension costs, 
but denied the utilities' request to recover the financing 
costs associated with funding our pension plans in advance 
of expense recognition. Although we will not recover the 
financing costs associated with funding our plans, we will 
continue collecting pension expense based on the amounts 
set in our 2003 Oregon general rate case and will continue 
deferring the difference between actual pension expense 
and collected expense in our pension balancing account. 
See "Rate Mechanisms—Pension Cost Deferral and 
Pension Balancing Account" below.

SYSTEM INTEGRITY PROGRAM (SIP). We filed a request to 
extend the SIP program in the fourth quarter of 2014. The 
OPUC considered our renewal request at a public meeting 
in March 2015 and suspended our filing and ordered 
additional process, including involvement of other gas 
utilities in the state, before making a final decision. See 
"Rate Mechanisms—System Integrity Program" below.

HEDGING. In our most recent Integrated Resource Plan, we 
proposed to the OPUC that we engage in continued long-
term gas hedging. The OPUC determined it wanted to 
consider long-term hedging along with a general review of 
overall hedging practices among all gas utilities in the 
state. The OPUC therefore opened a new docket to discuss 
broader gas hedging practices across gas utilities in 
Oregon. Our request for the OPUC to consider long-term 
hedging practices will be considered as part of this 
docket. The OPUC established that this docket will follow 
two phases. The first phase will be focused on an analytical 
review of hedging and hedging practices, followed by a 
second phase regarding potential hedging guidelines. After 
these phases, a status report will be submitted to the 
OPUC, and the remainder of the process will be determined 
at that time.

INTERSTATE STORAGE SHARING. We received an Order 
from the OPUC in March 2015 on their review of the current 
revenue sharing arrangement that allocates a portion of the 
net revenues generated from non-utility Mist storage 
services and third-party asset management services to 
utility customers. The Order requires a third-party cost study 
to be performed and the results of the cost study may 
initiate a new docket or the re-opening of the original 
docket.

CARBON SOLUTIONS PROGRAM. Oregon Senate Bill 844 
(SB 844) required the OPUC to develop rules and programs 
to reduce carbon emissions in Oregon. In June 2015, we 
submitted our first project related to Combined Heat and 
Power (CHP) for OPUC approval. The submitted CHP 
program would pay owners of new commercial- and 
industrial-scale CHP systems for verified carbon emission 
reductions. A final decision regarding CHP is expected in 
the first half of 2016. 

WEATHER NORMALIZATION MECHANISM (WARM). In 
Oregon, WARM is applied to residential and commercial 
customers' bills to adjust for temperature variances from 
average weather. In 2015, the OPUC initiated a review of 
the WARM mechanism as a result of customer complaints 
received this year related to surcharges applied under the 
WARM mechanism due to the record warm weather in our 
service territory during the 2014-15 winter. The OPUC 
review is focused on ensuring the calculations were done 
correctly, and to assess whether any modifications to the 
mechanism are necessary. Based on the scope of this 
proceeding established by the Commission, we do not 
expect this proceeding to significantly reduce the value 
WARM provides to us or our customers in mitigating the 
impact from variations in weather. Since its inception, 
WARM has resulted in a net benefit to customers, providing 
customer bill savings of approximately $9.9 million as of the 
end of the most recent heating season.

Rate Mechanisms
PURCHASED GAS ADJUSTMENT. Rate changes are 
established for the utility each year under PGA mechanisms 
in Oregon and Washington to reflect changes in the 
expected cost of natural gas commodity purchases. This 
includes gas prices under spot purchases as well as 
contract supplies, gas prices hedged with financial 
derivatives, gas prices from the withdrawal of storage 
inventories, the production of gas reserves, interstate 
pipeline demand costs, temporary rate adjustments, which 
amortize balances of deferred regulatory accounts, and the 
removal of temporary rate adjustments effective for the 
previous year.

Each year, we typically hedge gas prices on approximately 
75% of our utility's annual sales requirement based on 
normal weather, including both physical and financial 
hedges. We entered the 2015-16 gas year (November 1, 
2015 - October 31, 2016) hedged at 75% of our forecasted 
sales volumes, including 44% in financial swap and option 
contracts and 31% in physical gas supplies. For further 
discussion see "Regulatory Matters—Rate Mechanisms—
Purchased Gas Adjustment" above.

In addition to the amount hedged for the current gas 
contract year, we are also hedged in future years at 
approximately 16% for the 2016-17 gas year and between 
5% and 14% for annual requirements over the following five 
gas years as of December 31, 2015. Our hedge levels are 
subject to change based on actual load volumes, which 
depend to a certain extent on weather, economic conditions, 
and estimated gas reserve production. Also, our storage 
inventory levels may increase or decrease with storage 
expansion, changes in storage contracts with third parties, 
and/or storage recall by the utility. 

Under the current PGA mechanism in Oregon, there is an 
incentive sharing provision whereby we are required to 
select each year either an 80% deferral or a 90% deferral of 
higher or lower actual gas costs compared to estimated 
PGA prices, such that the impact on current earnings from 
the incentive sharing is either 20% or 10% of the difference 
between actual and estimated gas costs, respectively. For 
the 2014-15 and 2015-16 gas years, we selected the 90% 
and 80% deferral option, respectively. Under the 
Washington PGA mechanism, we defer 100% of the higher 

28

or lower actual gas costs, and those gas cost differences 
are passed on to customers through the annual PGA rate 
adjustment. 

We filed our PGA in September 2015 and received OPUC 
and WUTC approval in October 2015. PGA rate changes 
were effective November 1, 2015. The rate changes 
decreased the average monthly bills of residential 
customers by approximately 7% and 14% in Oregon and 
Washington, respectively. The decrease in Oregon reflected 
customers' portion of adjustments for changes in wholesale 
natural gas costs, offset by adjustments related to the 
decoupling mechanism, environmental costs, and additional 
annual adjustments based on ongoing orders with the 
OPUC. Washington rates reflected the full effect of changes 
in wholesale natural gas costs and some additional annual 
adjustments based on ongoing orders with the WUTC.

EARNINGS TEST REVIEW. We are subject to an annual 
earnings review in Oregon to determine if the utility is 
earning above its authorized ROE threshold. If utility 
earnings exceed a specific ROE level, then 33% of the 
amount above that level is required to be deferred or 
refunded to customers. Under this provision, if we select the 
80% deferral gas cost option, then we retain all of our 
earnings up to 150 basis points above the currently 
authorized ROE. If we select the 90% deferral option, then 
we retain all of our earnings up to 100 basis points above 
the currently authorized ROE. We selected the 90% deferral 
option for the 2013-14 and 2014-15 PGA years, and we 
selected the 80% deferral option for the 2015-16 PGA year. 
The ROE threshold is subject to adjustment annually based 
on movements in long-term interest rates. For calendar 
years 2013, 2014, and 2015, the ROE threshold was 
10.58%, 10.66%, and 10.60%, respectively. There were no 
refunds required for 2013 and 2014. We do not expect a 
refund for 2015 based on our results and anticipate filing the 
2015 test in May 2016. 

GAS RESERVES. In 2011 the OPUC approved the Encana 
gas reserves transaction to provide long-term gas price 
protection for our utility customers and determined our costs 
under the agreement would be recovered, on an ongoing 
basis through our annual PGA mechanism. Gas produced 
from our interests is sold at then prevailing market prices, 
and revenues from such sales, net of associated operating 
and production costs and amortization, are credited to our 
cost of gas. The cost of gas, including a carrying cost for the 
rate base investment, is included in our annual Oregon PGA 
filing, which allows us to recover these costs through 
customer rates. Our net investment under the original 
agreement earns a rate of return and provides long-term 
price protection for our utility customers. 

In March 2014, we amended the original gas reserves 
agreement in response to Encana's sale of its interest in the 
Jonah field located in Wyoming to Jonah Energy. Under the 
amendment, we ended the drilling program with Encana, but 
increased our working interests in our assigned sections of 
the Jonah field and we retained the right to invest in new 
wells with Jonah Energy.

In 2014, we elected to participate in some of the additional 
wells drilled in the Jonah field under our amended gas 
reserves agreement with Jonah Energy and may have the 

29

opportunity to participate in more wells in the future. We 
filed an application requesting regulatory deferral in Oregon 
for these additional investments, which was granted in April 
2015. In September 2015, the OPUC adopted an all-party 
settlement, under which volumes produced under the 
amended agreement are included in our Oregon PGA 
beginning November 1, 2015 at a fixed rate of $0.4725 per 
therm, which approximates the 10-year hedge rate plus 
financing costs at the inception of the investment. 

DECOUPLING. In Oregon, we have a decoupling 
mechanism. Decoupling is intended to break the link 
between utility earnings and the quantity of gas consumed 
by customers, removing any financial incentive by the utility 
to discourage customers’ efforts to conserve energy.
The Oregon decoupling mechanism was reauthorized and 
the baseline expected usage per customer was set in the 
2012 Oregon general rate case. This mechanism employs a 
use-per-customer decoupling calculation, which adjusts 
margin revenues to account for the difference between 
actual and expected customer volumes. The margin 
adjustment resulting from differences between actual and 
expected volumes under the decoupling component is 
recorded to a deferral account, which is included in the 
annual PGA filing. In Washington, customer use is not 
covered by such a tariff. See "Business Segments—Local 
Gas Distribution Utility Operations" below.

WEATHER NORMALIZATION TARIFF. In Oregon, we have an 
approved weather normalization mechanism, which is 
applied to residential and commercial customer bills. This 
mechanism is designed to help stabilize the collection of 
fixed costs by adjusting residential and commercial 
customer billings based on temperature variances from 
average weather, with rate decreases when the weather is 
colder than average and rate increases when the weather is 
warmer than average. The mechanism is applied to bills 
from December through May of each heating season. The 
mechanism adjusts the margin component of customers’ 
rates to reflect average weather, which uses the 25-year 
average temperature for each day of the billing period. Daily 
average temperatures and 25-year average temperatures 
are based on a set point temperature of 59 degrees 
Fahrenheit for residential customers and 58 degrees 
Fahrenheit for commercial customers. This weather 
normalization mechanism was reauthorized in the 2012 
Oregon general rate case without an expiration date. 
Residential and commercial customers in Oregon are 
allowed to opt out of the weather normalization mechanism, 
and as of December 31, 2015, 9% of total customers had 
opted out. We do not have a weather normalization 
mechanism approved for residential and commercial 
Washington customers, which account for about 11% of 
total customers. See "Business Segments—Local Gas 
Distribution Utility Operations" below.

INDUSTRIAL TARIFFS. The OPUC and WUTC have 
approved tariffs covering utility service to our major 
industrial customers, including terms, which are intended to 
give us certainty in the level of gas supplies we need to 
acquire to serve this customer group. The terms include, 
among other things, an annual election period, special 
pricing provisions for out-of-cycle changes, and a 
requirement that industrial customers complete the term of 
their service election under our annual PGA tariff.

 
 SYSTEM INTEGRITY PROGRAM (SIP). In the past, we have 
had the approval of the OPUC for specific accounting 
treatment and cost recovery for our SIP, which is an 
integrated safety program that consolidates the bare steel 
replacement program, the transmission pipeline integrity 
management program, and the distribution integrity 
management program related to pipeline safety rules 
adopted by the U.S. Department of Transportation’s Pipeline 
and Hazardous Materials Safety Administration (PHMSA). 
We recorded these costs as capital expenditures, 
accumulated the costs over each 12-month period, and 
recovered the revenue requirement associated with these 
costs, subject to audit, through rate changes effective with 
the Oregon annual PGA. Our SIP costs were tracked into 
rates annually, with the first $4 million of capital costs 
subject to regulatory lag and annual rate-base recovery 
capped at $12 million. Costs above the cap could also be 
approved with written consent of the OPUC staff and other 
interested parties and approval of the OPUC.

During 2013, the OPUC approved a temporary two-year 
extension, beginning in November 2012, of our capital 
expenditure tracking mechanism to recover capital costs 
related to SIP and authorized a total increase of $13.7 
million above the cap during the extension period. 
Regulatory authority for SIP expired October 31, 2014, 
although the bare steel replacement portion of the 
mechanism remained in place until the end of 2015. We 
filed a request to extend the SIP program in the fourth 
quarter of 2014 and upon consideration of our request in 
March of 2015, the OPUC ordered an additional process 
and evaluation with other gas utilities in the state before 
making a final decision. In the interim, we will recover our 
remaining bare steel replacement costs through the 
2015-16 PGA, and we expect system integrity capital costs 
not tracked through our SIP mechanism would be included 
in rate base in our next rate case.  

ENVIRONMENTAL COST DEFERRAL AND SRRM. In Oregon, 
we have a SRRM through which we track and have the 
ability to recover prudently incurred past deferred and future 
environmental remediation costs allocable to Oregon, 
subject to an earnings test. 

The SRRM defines three classes of deferred environmental 
remediation expense:
• 

Pre-review - This class of costs represents remediation 
spend that has not yet been deemed prudent by the 
OPUC. Carrying costs on these remediation expenses 
are recorded at our authorized cost of capital. We 
anticipate the prudence review for annual costs and 
approval of the earnings test prescribed by the OPUC 
to occur by the third quarter of the following year. 
Post-review - This class of costs represents 
remediation spend that has been deemed prudent and 
allowed after applying the earnings test, but is not yet 
included in amortization. We earn a carrying cost on 
these amounts at a rate equal to the five-year treasury 
rate plus 100 basis points. 
Amortization - This class of costs represents amounts 
included in current customer rates for collection and is 
generally calculated as one-fifth of the post-review 
deferred balance. We earn a carrying cost equal to the 
amortization rate determined annually by the OPUC, 
which approximates a short-term borrowing rate. We 

• 

• 

included $8.4 million of deferred remediation expense 
approved by the OPUC for collection during the 
2015-2016 PGA year.

The earnings test is an annual review of our adjusted Utility 
ROE compared to our authorized Utility ROE, which is 
currently 9.5%. To apply the earnings test first we must 
determine what if any costs are subject to the test through 
the following calculation:

Annual spend
Less: $5 million base rate rider(1)
          Prior year carry-over(2)
          $5 million insurance + interest on insurance

Total deferred annual spend subject to earnings test

Less: over-earnings adjustment, if any
Add:  deferred interest on annual spend(3)
Total amount transferred to post-review
(1)   Base rate rider went into Oregon customer rates beginning 

November 1, 2015.

(2)   Prior year carry-over results when the prior year amount 

transferred to post-review is negative.  The negative amount is 
carried over to offset annual spend in the following year. 
(3)   Deferred interest is added to annual spend to the extent the 

spend is recoverable. 

If the adjusted Utility ROE is greater than the authorized 
Utility ROE, then we could be required to expense up to the 
amount that results in the Utility earning its authorized ROE. 
For 2015, we have performed this test, which will be 
submitted to the OPUC in May 2016, and have concluded 
that there is no earnings test adjustment for 2015.  

The WUTC has also previously authorized the deferral of 
environmental costs, if any, that are appropriately allocated 
to Washington customers. This Order was effective in 
January 2011 with cost recovery and a carrying charge to 
be determined in a future proceeding. 

PENSION COST DEFERRAL AND PENSION BALANCING 
ACCOUNT. Effective January 1, 2011, the OPUC approved 
our request to defer annual pension expenses above the 
amount set in rates, with recovery of these deferred 
amounts through the implementation of a balancing 
account, which includes the expectation of higher and lower 
pension expenses in future years. Our recovery of these 
deferred balances includes accrued interest on the account 
balance at the utility’s authorized rate of return, which is 
currently 7.78%. Future years’ deferrals will depend on 
changes in plan assets and projected benefit liabilities 
based on a number of key assumptions, and our pension 
contributions. Pension expense deferrals, including interest,  
were $8.2 million, $4.6 million, and $9.1 million in 2015, 
2014 and 2013, respectively. See "Application of Critical 
Accounting Policies and Estimates" below. 

CUSTOMER CREDITS FOR GAS STORAGE SHARING. On an 
annual basis, we credit amounts to Oregon and Washington 
customers as part of our regulatory incentive sharing 
mechanism related to net revenues earned from Mist gas 
storage and asset management activities. Generally 
amounts are credited to Oregon customers in June, while 
credits are given to customers in Washington through 

30

 
reductions in rates through the annual PGA filing in 
November. 

The following table presents the credits to customers: 

In millions

Oregon utility
customer credit

Washington utility
customer credit

2015

2014

2013

$

9.6

$

11.4

$

0.8

0.8

8.8

0.5

Business Segments - Local Gas Distribution Utility 
Operations
Utility margin results are primarily affected by customer 
growth, revenues from rate-base additions, and, to a certain 
extent, by changes in delivered volumes due to weather and 
customers’ gas usage patterns because a significant portion 
of our utility margin is derived from natural gas sales to 
residential and commercial customers. In Oregon, we have 
a conservation tariff (also called the decoupling 
mechanism), which adjusts utility margin up or down each 
month through a deferred regulatory accounting adjustment 
designed to offset changes resulting from increases or 
decreases in average use by residential and commercial 
customers. We also have a weather normalization tariff in 
Oregon, which adjusts customer bills up or down to offset 
changes in utility margin resulting from above- or below-
average temperatures during the winter heating season.
Both mechanisms are designed to reduce the volatility of 
customer bills and our utility’s earnings. See "Regulatory 
Matters—Rate Mechanisms" above. 

Utility segment highlights include:  

Dollars and therms in
millions, except EPS data

2015

2014

2013

Utility net income

$

53.4

$

58.6

$

EPS - utility segment

1.95

2.15

54.9

2.03

Gas sold and delivered
(in therms)
Utility margin(1)
353.9
(1) See Utility Margin Table below for a reconciliation and additional 

1,146

1,029

371.4

1,093

366.1

$

$

$

detail. 

2015 COMPARED TO 2014. The primary factors contributing 
to the $5.2 million or $0.20 per share decrease in utility net 
income were as follows:
• 

the $15 million pre-tax charge, or $9.1 million after-tax 
charge, for the regulatory disallowance associated with 
the February 2015 OPUC Order on the recovery of past 
environmental cost deferrals. This charge is reflected in 
operations and maintenance expense;
a $5.3 million increase in utility margin primarily due to:
a $4.4 million increase from customer growth; 
a $5.3 million increase from gas cost incentive 
sharing resulting from lower gas prices than 
those estimated in the PGA; partially offset by

• 

an approximate $4.0 million decrease due to lower 
customer usage from warmer weather, which 
impacts utility margins from our Washington 
customers where we do not have a weather 
normalization mechanism in place, and from our 
Oregon customers who opted out of weather 
normalization.

a $6.6 million increase in other income, net, primarily 
due to the recognition of the equity earnings on 
deferred environmental expenditures as a result of the 
February order; 
a $7.2 million increase in operations and maintenance 
expense, excluding the environmental disallowance, 
primarily due to an increase in compensation and 
benefit expense; and 
a net $0.4 million increase in other expenses related to 
increased depreciation expense from additional capital 
investments and an increase in general taxes from 
higher Oregon property tax expense, offset by a 
decrease in interest expense due to debt redemptions 
made during the year. 

• 

• 

• 

Total utility volumes sold and delivered in 2015 decreased 
6% over 2014 primarily due to the impact of warmer 
weather. 

2014 COMPARED TO 2013. The primary factors contributing 
to the $3.7 million or $0.12 per share increase in net income 
were as follows:
• 

a $12.2 million net increase in utility margin primarily 
due to:

a $16.6 million increase from customer growth in 
residential and commercial customers, industrial 
margins, and added rate-base returns on certain 
investments, including gas reserves; partially offset 
by
a $2.1 million increase in loss from gas cost 
incentive sharing mainly resulting from higher gas 
prices and volumes than those estimated in the 
PGA; and
the remaining decrease was primarily due to 
warmer weather as measured by heating degree 
days, in Washington, which does not have a 
weather normalization mechanism in place, and 
the effect of warmer weather on margin for Oregon 
customers that opt out of weather normalization.

• 

• 

• 

a $3.2 million increase in depreciation expense due to 
additional capital expenditures;
a $3.0 million decrease in operations and maintenance 
expense; and
a $2.1 million decrease in other income, net primarily 
due to lower interest income on regulatory deferred 
account balances. 

Total utility volumes sold and delivered in 2014 decreased 
5% over 2013 primarily due to the impact of warmer 
weather on residential and commercial use. 

31

                                                                                                                                                                                                                              
UTILITY MARGIN TABLE. The following table summarizes the composition of utility gas volumes, revenues, and cost of sales: 

In thousands, except degree day and customer data

2015

2014

2013

Utility volumes (therms):

Residential and commercial sales

Industrial sales and transportation

570,728

457,884

620,903

472,087

671,906

474,525

Total utility volumes sold and delivered

1,028,612

1,092,990

1,146,431

Favorable/(Unfavorable)

2015 vs.
2014

2014 vs.
2013

(50,175)

(14,203)

(64,378)

(51,003)

(2,438)

(53,441)

Utility operating revenues:

Residential and commercial sales

Industrial sales and transportation

Other revenues

Less: Revenue taxes

Total utility operating revenues

Less: Cost of gas

Less: Environmental remediation expense

Utility margin

Utility margin:(1)

Residential and commercial sales

Industrial sales and transportation

Miscellaneous revenues

Gain (loss) from gas cost incentive sharing

Other margin adjustments

Utility margin

Degree days
Average(2)

Actual
Percent colder (warmer) than average weather(2)

Customers - end of period:

Residential customers

Commercial customers

Industrial customers

$ 644,835

$ 672,440

$ 673,250

$ (27,605)

$

(810)

71,495

3,914

18,034

702,210

327,305

3,513

73,992

3,983

18,837

731,578

365,490

—

68,880

4,054

19,002

727,182

373,298

—

$ 371,392

$ 366,088

$ 353,884

$ 334,134

$ 334,247

$ 321,608

30,081

3,913

3,182

82

29,982

4,329

(2,135)

(335)

28,335

4,308

(41)

(326)

(2,497)

5,112

(69)

(803)

(29,368)

38,185

(3,513)

(71)

(165)

4,396

7,808

—

$

$

5,304

$ 12,204

(113)

$ 12,639

99

(416)

5,317

417

1,647

21

(2,094)

(9)

$ 371,392

$ 366,088

$ 353,884

$

5,304

$ 12,204

4,240

3,458

4,240

3,792

4,240

4,379

—

(9)%

—

(13)%

(18)%

(11)%

3%

646,841

637,411

66,584

1,003

66,304

929

628,634

65,321

918

9,430

8,777

280

74

983

11

Total number of customers

714,428

704,644

694,873

9,784

9,771

Customer growth:

Residential customers

Commercial customers

Industrial customers

Total customer growth

1.5 %

0.4 %

8.0 %

1.4 %

1.4 %

1.5 %

1.2 %

1.4 %

(1)  Amounts reported as margin for each category of customers are operating revenues, which are net of revenue taxes, less cost of gas and 

environmental remediation expense.

(2)  Average weather represents the 25-year average degree days, as determined in our 2012 Oregon general rate case.

32

Residential and Commercial Sales
The primary factors that impact results of operations in the 
residential and commercial markets are customer growth, 
seasonal weather patterns, energy prices, competition from 
other energy sources, and economic conditions in our 
service areas. The impact of weather on margin is 
significantly reduced through our weather normalization 
mechanism in Oregon; approximately 80% of our total 
customers are covered under this mechanism. The 
remaining customers either opt out of the mechanism or are 
located in Washington, which does not have a similar 
mechanism in place. For more information on our weather 
mechanism, see "Regulatory Matters—Rate Mechanisms—
Weather Normalization Tariff" above.

Residential and commercial sales highlights include:

In millions

Volumes (therms):

Residential sales

Commercial sales

Total volumes

Operating revenues:

2015

2014

2013

350.9

219.8

570.7

381.5

239.4

620.9

418.6

253.3

671.9

Residential sales

$

424.6

$

441.5

$

447.4

Commercial sales

220.2

230.9

225.9

Total operating
revenues

Utility margin:

Residential:

Sales

Weather normalization

Decoupling

Total residential utility
margin

Commercial:

Sales

Weather normalization

Decoupling

Total commercial utility
margin

$

644.8

$

672.4

$

673.3

$

211.6

$

223.6

$

234.1

14.0

7.2

5.1

4.0

(9.0)

2.6

232.8

232.7

227.7

84.8

5.8

10.7

91.6

2.2

7.7

92.1

(4.0)

5.8

101.3

101.5

93.9

Total utility margin

$

334.1

$

334.2

$

321.6

2015 COMPARED TO 2014. The primary factors contributing 
to changes in the residential and commercial markets were 
as follows:
• 

sales volumes decreased 50.2 million therms, or 8%, 
primarily reflecting 9% warmer weather, which was 
partially offset by customer growth;
operating revenues decreased $27.6 million, due to the 
8% decrease in sales volumes, as well as a 2% 
decrease in average gas rates over last year; and
utility margin decreased $0.1 million, due to warmer 
weather, almost entirely offset by increases from 
commercial and residential customer growth.

• 

• 

2014 COMPARED TO 2013. The primary factors contributing 
to changes in the residential and commercial markets were 
as follows:
• 

sales volumes decreased 51.0 million therms, or 8%, 
primarily reflecting 13% warmer weather, which was 

• 

33

• 

• 

partially offset by customer growth and a record 
February cold weather event;
operating revenues decreased $0.8 million, due to the 
8% decrease in sales volumes, which was partially 
offset by a 4% increase in average gas rates over last 
year; and
utility margin increased $12.6 million, or 4%, primarily 
related to customer growth, added loads under higher 
commercial rate schedules, and added rate-base 
returns from our gas reserves and other investments, 
partially offset by the effect of warmer weather on our 
Washington customers and Oregon customers that 
opted out of the weather normalization mechanism. 

Industrial Sales and Transportation
Industrial customers have the option of purchasing sales or 
transportation services from the utility. Under the sales 
service, the customer buys the gas commodity from the 
utility. Under the transportation service, the customer buys 
the gas commodity directly from a third-party gas marketer 
or supplier. Our gas commodity cost is primarily a pass-
through cost to customers; therefore, our profit margins are 
not materially affected by an industrial customer's decision 
to purchase gas from us or from third parties. Industrial and 
large commercial customers may also select between firm 
and interruptible service options, with firm services generally 
providing higher profit margins compared to interruptible 
services. To help manage gas supplies, our industrial tariffs 
are designed to provide some certainty regarding industrial 
customers' volumes by requiring an annual service election 
on November 1, special charges for changes between 
elections, and in some cases, a minimum or maximum 
volume requirement before changing options. 

Industrial sales and transportation highlights include:

In millions

Volumes (therms):

2015

2014

2013

Industrial - firm sales

32.4

34.0

34.3

Industrial - firm
transportation

Industrial - interruptible
sales

Industrial - interruptible
transportation

Total volumes

Utility margin:

Industrial - sales and
transportation

144.0

153.6

144.5

70.2

76.4

59.5

211.3

457.9

208.1

472.1

236.2

474.5

$

30.1

$

30.0

$

28.3

2015 COMPARED TO 2014. The primary factors contributing 
to changes in the industrial sales and transportation markets 
were as follows:
• 

sales and transportation volumes decreased by 14.2 
million therms due to lower usage from warmer weather 
and lower demand from a few large volume 
transportation customers on lower margin rate 
schedules;
utility margin increased $0.1 million, primarily due to an 
increase in industrial customers under higher margin 
rate schedules partially offset by higher fee revenue in 
the prior year from increased usage during the cold 
weather event in February 2014.

2014 COMPARED TO 2013. The primary factors contributing 
to changes in the industrial sales and transportation markets 
were as follows:
• 

sales and transportation volumes decreased by 2.4 
million therms due to lower usage by large volume 
interruptible transportation customers on lower margin 
rate schedules;
utility margin increased $1.6 million, or 6% primarily 
due to volume growth under higher margin rate 
schedules and other customer charges stemming from 
the extreme cold weather event in February 2014.

• 

Other Revenues
Other revenues include miscellaneous fee income as well 
as regulatory revenue adjustments, which reflect current 
period deferrals to and prior year amortizations from 
regulatory asset and liability accounts, except for gas cost 
deferrals which flow through cost of gas. Decoupling 
amortizations and other regulatory amortizations from prior 
year deferrals are included in revenues from residential, 
commercial and industrial firm customers.

Other revenue for 2015, 2014, and 2013 remained flat year-
over-year as expected.

In millions

2015

2014

2013

Other revenues

$

3.9

$

4.0

$

4.1

Cost of Gas
Cost of gas as reported by the utility includes gas 
purchases, gas withdrawn from storage inventory, gains and 
losses from commodity hedges, pipeline demand costs, 
seasonal demand cost balancing adjustments, regulatory 
gas cost deferrals, gas reserves costs, and company gas 
use. The OPUC and WUTC generally require natural gas 
commodity costs to be billed to customers at the actual cost 
incurred, or expected to be incurred, by the utility. Customer 
rates are set each year so that if cost estimates were met 
we would not earn a profit or incur a loss on gas commodity 
purchases; however, in Oregon we have an incentive 
sharing mechanism which has been described under 
"Regulatory Matters—Rate Mechanisms—Purchased Gas 
Adjustment" above. In addition to the PGA incentive sharing 
mechanism, gains and losses from hedge contracts entered 
into after annual PGA rates are effective for Oregon 
customers are also required to be shared and therefore may 
impact net income. Further, we also have a regulatory 
agreement whereby we earn a rate of return on our 
investment in the gas reserves acquired under the original 
agreement with Encana and include gas from our amended 
gas reserves agreement at a fixed rate of $0.4725 per 
therm, which are also reflected in utility margin. See 
"Application of Critical Accounting Policies and Estimates—
Accounting for Derivative Instruments and Hedging 
Activities" below.

Cost of gas highlights include:

Dollars and therms in
millions

2015

2014

2013

Cost of gas

$

327.3

$

365.5

$

373.3

Volumes sold (therms)

660

716

766

Average cost of gas
(cents per therm)

Gain (loss) from gas cost
incentive sharing

$

0.50

$

0.51

$

0.49

3.2

(2.1)

—

2015 COMPARED TO 2014. Cost of gas decreased $38.2 
million, or 10% primarily due to an 8% decrease in sales 
volume reflecting warmer weather during the year as well as 
a 2% decrease in average cost of gas reflecting lower 
market prices for natural gas. 

2014 COMPARED TO 2013. Cost of gas decreased $7.8 
million, or 2% primarily due to a 7% decrease in sales 
volume reflecting warmer weather during the year, partially 
offset by a 4% increase in average cost of gas collected 
through rates. 

During the extreme cold weather event in February 2014, 
we experienced a record sendout and consequently, the 
higher volumes of gas purchased at that time resulted in a 
margin loss of $2.1 million in 2014 compared to a margin 
gain of $3.2 million for 2015 as prices were lower due to the 
record warmer weather, particularly in the first quarter of 
2015. The effect on net income from our gas cost incentive 
sharing mechanism for 2013 was a pre-tax loss in margin of 
less than $0.1 million. For a discussion of our gas cost 
incentive sharing mechanism, see “Regulatory Matters—
Rate Mechanisms—Purchased Gas Adjustment” above.

Business Segments - Gas Storage
Our gas storage segment primarily consists of the non-utility 
portion of our Mist underground storage facility in Oregon 
and our 75% undivided ownership interest in the Gill Ranch 
underground storage facility in California. 

At Mist, we provide gas storage services to customers in the 
interstate and intrastate markets primarily using storage 
capacity that has been developed in advance of core utility 
customers’ requirements. We also contract with an 
independent energy marketing company to provide asset 
management services using our utility and non-utility 
storage and transportation capacity, the results of which are 
included in the gas storage businesses segment. Pre-tax 
income from gas storage at Mist and asset management 
services is subject to revenue sharing with core utility 
customers. Under this regulatory incentive sharing 
mechanism, we retain 80% of pre-tax income from Mist gas 
storage services and asset management services when the 
underlying costs of the capacity being used are not included 
in our utility rates, and 33% of pre-tax income from such 
storage and asset management services when the capacity 
being used is included in utility rates. The remaining 20% 
and 67%, respectively, are credited to a deferred regulatory 
account for credit to our core utility customers. See 
"Regulatory Matters—Open Regulatory Proceedings" above 
for information regarding an open docket related to this 
incentive sharing mechanism.

34

Our 75% undivided ownership interest in the Gill Ranch 
facility is held by our wholly-owned subsidiary Gill Ranch, 
LLC, which is also the operator of the facility. Our portion of 
the facility is 15 Bcf of gas storage capacity. Gill Ranch 
commenced operations at the end of 2010, with the first full 
storage injection season beginning on April 1, 2011. We 
also contract with an independent energy marketing 
company to provide asset management services at Gill 
Ranch. See also Note 4.

Gas storage segment highlights include:

In millions, except EPS
data

Gas storage net income
(loss)

EPS - gas storage
segment
Operating revenues

Operating expenses

2015

2014

2013

$

0.2

$

(0.4) $

5.6

0.01

21.4

16.3

(0.01)

22.2

18.2

0.21

31.1

16.4

2015 COMPARED TO 2014. Our gas storage segment net 
income increased $0.6 million primarily due to the following 
offsetting factors:
• 

a $0.9 million decrease in operating revenues, primarily 
due to a decrease in storage prices between the 
2013-14 and 2014-15 gas storage years; and 
a $1.9 million decrease in operating expenses primarily 
due to lower repair and power costs at our Gill Ranch 
facility. 

• 

2014 COMPARED TO 2013. Our gas storage segment net 
income decreased $5.9 million primarily due to the following 
factors:
• 

an $8.9 million decrease in operating revenues, 
primarily reflecting recontracting expiring storage 
capacity at lower prices as the gas storage market 
prices remain at historic lows; and 
a $1.8 million increase in operating expenses primarily 
due to higher repair and power costs at our Gill Ranch 
facility. 

• 

Our Mist gas storage facility benefits from limited 
competition from other Pacific Northwest storage facilities 
primarily because of its geographic location.

Over the past few years, market prices for natural gas 
storage, particularly in California, were negatively affected 
by the abundant supply of natural gas, low volatility of 
natural gas prices, and surplus gas storage capacity. In 
addition, storage prices were further affected by extreme 
cold weather during the 2013-14 winter, which resulted in a 
significant decline in storage levels, a rise in spot gas 
prices, and lower storage values due to a flatter forward 
price curve for the 2014-15 gas storage year. We re-
contracted certain expiring storage capacity for the 2014-15 
gas storage year with shorter-term contracts at lower market 
prices than in previous years. These trends accounted for 
most of the decline in gas storage operating revenues. 

Prices for the 2015-16 and 2016-17 gas years have shown 
improvement, however remain low relative to the pricing in 
our original long-term contracts, which ended primarily in 
the 2013-14 gas storage year. In the future, we may see an 
improvement in gas storage values and an increase in the 

35

demand for natural gas driven by a number of factors, 
including changes in electric generation triggered by 
California's renewable portfolio standards, an increase in 
use of alternative fuels to meet carbon reduction targets, 
recovery of the California economy, growth of domestic 
industrial manufacturing, potential exports of liquefied 
natural gas from the west coast, and other favorable storage 
market conditions in and around California. These factors, if 
they occur, may contribute to higher summer/winter natural 
gas price spreads, gas price volatility, and gas storage 
values. We are continuing to explore opportunities to 
increase revenues through enhanced services for storage 
customers and capitalizing on opportunities that fit our 
business-risk profile.  Should storage values not improve in 
the future, this could have a negative impact on our future 
cash flows and could result in impairment of our Gill Ranch 
gas storage facility.  Refer to Note 2 for more information 
regarding our accounting for impairment of long-lived 
assets.

Other
Other primarily consists of NNG Financial's equity 
investment in KB Pipeline, an equity investment in TWH, 
which has invested in the Trail West pipeline project, and 
other miscellaneous non-utility investments and business 
activities. There were no significant changes in our other 
activities in 2015. See Note 4 and Note 12 for further details 
on other activities and our investment in TWH.

Consolidated Operations

Operations and Maintenance
Operations and maintenance highlights include:

In millions

2015

2014

2013

Operations and maintenance

$ 157.5

$ 137.0

$ 136.6

2015 COMPARED TO 2014. Operations and maintenance 
expense increased $20.5 million, primarily due to the 
following factors:
• 

the $15 million pre-tax charge for the regulatory 
disallowance associated with the February 2015 OPUC 
Order on the recovery of past environmental cost 
deferrals. We also expensed an additional $1 million 
related to the Order; and
a $5.5 million increase in compensation and benefit 
expense, including increased employee incentive 
expense, retirement expense, and health care costs, as 
well as higher wage rates under the new union labor 
contract, which became effective June 1, 2014; offset 
by
a $1.9 million decrease primarily related to 2014 repair 
and power costs at our Gill Ranch gas storage facility.

• 

• 

During 2015, management implemented temporary cost 
saving initiatives to mitigate the effects of warm weather and 
the $15 million regulatory disallowance. These initiatives 
resulted in approximately $5 million of operations and 
maintenance expense savings that are not expected to be 
repeated in the future.

2014 COMPARED TO 2013. Operations and maintenance 
expense increased $0.4 million, primarily due to the 
following factors:
• 

a $2.4 million increase from additional repair and power 
costs at our Gill Ranch storage facility;
a $1.5 million increase in professional service costs 
related to our ongoing growth initiatives;
a $0.4 million increase in bad debt expense at the utility 
due to lower comparable amounts in 2013 driven by a 
decrease in our allowance for uncollectible accounts in 
the first quarter of 2013; and
Partially offsetting the above factors was a $3.9 million 
decrease in utility payroll and other costs.

• 

• 

• 

Other Income, Net
Other income, net highlights include:

In millions

2015

2014

2013

Gains from company-
owned life insurance

$

Interest income

Loss from equity
investments

Net interest income on
deferred regulatory
accounts

Other non-operating

$

2.2

0.1

$

2.0

0.1

2.5

0.1

(0.1)

(0.2)

(0.1)

8.2

(2.7)

2.4

(2.4)

4.5

(2.3)

4.7

Total other income, net

$

7.7

$

1.9

$

Delinquent customer receivable balances continue to 
remain at historically low levels. The utility's bad debt 
expense as a percent of revenues was 0.1% for 2015 and 
2014.

In addition to fluctuations in operation and maintenance 
expense reported above, we have OPUC approval to defer 
certain utility pension costs in excess of what is currently 
recovered in customer rates. This pension cost deferral is 
recorded to a regulatory balancing account, which stabilizes 
the amount of operations and maintenance expense each 
year. For the years ended December 31, 2015, 2014 and 
2013 we deferred pension expenses totaling $8.2 million, 
$4.6 million and $9.1 million, respectively. As a result, 
increased pension costs had a minimal effect on operations 
and maintenance expense in 2015 and 2014, with the 
increase principally related to the costs allocated to our 
Washington operations, which are not covered by the 
pension balancing account. For further explanation of the 
pension balancing account, see Note 8 and “Regulatory 
Matters—Rate Mechanisms—
Pension Cost Deferral and Prepaid Pension Assets,” above 
for further explanation of the pension balancing account.

Depreciation and Amortization
Depreciation and amortization highlights include:

In millions

2015

2014

2013

Depreciation and amortization

$

80.9

$

79.2

$

75.9

2015 COMPARED TO 2014. Depreciation and amortization 
expense increased by $1.7 million due to utility plant 
additions that included natural gas transmission and 
distribution system investments and computer software.

2014 COMPARED TO 2013. Depreciation and amortization 
expense increased by $3.3 million due to an increase in 
utility depreciation expense from system investments, 
resource center improvements, and gas storage facilities 
enhancements.  

2015 COMPARED TO 2014. Other income, net, increased $5.8 
million primarily due to the recognition of the equity 
component in interest income from our deferred 
environmental expenses. We realized the equity earnings of 
these deferred regulatory asset balances as a result of the 
OPUC SRRM Order we received in February 2015. 

2014 COMPARED TO 2013. Other income, net, decreased 
$2.7 million primarily due to lower interest income on net 
deferred regulatory balances as a result of insurance 
proceeds credited to regulatory balances for environmental 
costs. Our regulatory environmental deferred cost account 
subject to interest accruals changed from a net regulatory 
asset balance of $56 million at December 31, 2013 to a net 
regulatory liability balance of approximately $30 million at 
December 31, 2014 due to insurance proceeds received in 
2014 exceeding amounts spent.

Interest Expense, Net 
Interest expense, net highlights include:

In millions

2015

2014

2013

Interest expense, net

$

42.5

$

44.6

$

45.2

2015 COMPARED TO 2014. Interest expense, net of amounts 
capitalized, decreased $2.1 million primarily due to the 
redemption of $40 million of utility First Mortgage Bonds 
(FMBs) in June 2015, $60 million of utility FMBs in 2014, 
and the retirement of $20 million of Gill Ranch's debt in 
June 2014. This was partially offset by the early retirement 
of $20 million of Gill Ranch's debt in December 2015, which 
included a make whole interest provision. 

2014 COMPARED TO 2013.  Interest expense, net of amounts 
capitalized, decreased $0.6 million primarily due to the 
redemptions of debt in 2014 of $50 million of utility FMBs in 
July 2014 and $10 million in September 2014, and the 
retirement of $20 million of debt pursuant to Gill Ranch's 
amended loan agreement in June 2014.

36

Income Tax Expense
Income tax expense highlights include:

In millions

2015

2014

2013

Income tax expense

$ 35.8

$ 41.6

$ 41.7

Effective tax rate

40.0%

41.5%

40.8%

2015 COMPARED TO 2014. The decrease in the effective 
income tax rate reflects the benefits of depletion deductions 
from our gas reserves activity.

2014 COMPARED TO 2013. The increase in the effective 
income tax rate was primarily the result of a $0.6 million 
income tax charge in 2014 related to a higher statutory tax 
rate in Oregon, which required the revaluation of deferred 
tax balances. 

FINANCIAL CONDITION

Capital Structure
One of our long-term goals is to maintain a strong 
consolidated capital structure, generally consisting of 45% 
to 50% common stock equity and 50% to 55% long-term 
and short-term debt, and with a target utility capital structure 
of 50% common stock and 50% long-term debt. When 
additional capital is required, debt or equity securities are 
issued depending on both the target capital structure and 
market conditions. These sources of capital are also used to 
fund long-term debt retirements and short-term commercial 
paper maturities. See "Liquidity and Capital Resources" 
below and Note 7. 

Achieving the target capital structure and maintaining 
sufficient liquidity to meet operating requirements are 
necessary to maintain attractive credit ratings and provide 
access to capital markets at reasonable costs. Our 
consolidated capital structure was as follows:

Common stock equity

Long-term debt

Short-term debt, including current
maturities of long-term debt

Total

December 31,

2015

2014

47.2%

46.1%

34.9

17.9

37.4

16.5

100.0%

100.0%

Liquidity and Capital Resources 
At December 31, 2015 we had $4.2 million of cash and cash 
equivalents compared to $9.5 million at December 31, 2014. 
We did not have restricted cash at December 31, 2015 
compared to $3.0 million in restricted cash at December 31, 
2014 held as collateral for the long-term debt outstanding at 
Gill Ranch, which we redeemed in December 2015. In order 
to maintain sufficient liquidity during periods when capital 
markets are volatile, we may elect to maintain higher cash 
balances and add short-term borrowing capacity. In 
addition, we may also pre-fund utility capital expenditures 
when long-term fixed rate environments are attractive. As a 
regulated entity, our issuance of equity securities and most 
forms of debt securities are subject to approval by the 
OPUC and WUTC. Our use of retained earnings is not 
subject to those same restrictions.

37

For the utility segment, the short-term borrowing 
requirements typically peak during colder winter months 
when the utility borrows money to cover the lag between 
natural gas purchases and bill collections from customers. 
Our short-term liquidity for the utility is primarily provided by 
cash balances, internal cash flow from operations, proceeds 
from the sale of commercial paper notes, as well as 
available cash from multi-year credit facilities, short-term 
credit facilities, company-owned life insurance policies, and 
the sale of long-term debt. Utility long-term debt proceeds 
are primarily used to finance utility capital expenditures, 
refinance maturing debt of the utility, and provide temporary 
funding for other general corporate purposes of the utility. 

Based on our current debt ratings (see "Credit Ratings" 
below), we have been able to issue commercial paper and 
long-term debt at attractive rates and have not needed to 
borrow or issue letters of credit from our back-up credit 
facility. In the event we are not able to issue new debt due 
to adverse market conditions or other reasons, we expect 
our near-term liquidity needs can be met using internal cash 
flows or, for the utility segment, drawing upon our committed 
credit facility. We also have a universal shelf registration 
statement filed with the SEC for the issuance of secured 
and unsecured debt or equity securities, subject to market 
conditions and certain regulatory approvals. As of 
December 31, 2015, we have Board authorization to issue 
up to $325 million of additional FMBs. We also have OPUC 
approval to issue up to $325 million of additional long-term 
debt for approved purposes.

In the event our senior unsecured long-term debt ratings are 
downgraded, or our outstanding derivative position exceeds 
a certain credit threshold, our counterparties under 
derivative contracts could require us to post cash, a letter of 
credit, or other forms of collateral, which could expose us to 
additional cash requirements and may trigger increases in 
short-term borrowings while we were in a net loss position. 
We were not near the threshold for posting collateral at 
December 31, 2015. However, if the credit risk-related 
contingent features underlying these contracts were 
triggered on December 31, 2015, assuming our long-term 
debt ratings dropped to non-investment grade levels, we 
could have been required to post $21.2 million of collateral 
to our counterparties. See "Credit Ratings" below and Note 
13. 

Other items that may have a significant impact on our 
liquidity and capital resources include pension contribution 
requirements, expiration of bonus tax depreciation, 
environmental expenditures and insurance recoveries. 

PENSION CONTRIBUTIONS. We expect to make significant 
contributions to our company-sponsored defined benefit 
plan, which is closed to new employees, over the next 
several years until we are fully funded under the Pension 
Protection Act rules, including the new rules issued under 
the Moving Ahead for Progress in the 21st Century Act 
(MAP-21) and the Highway and Transportation Funding Act 
of 2014 (HATFA). See "Application of Critical Accounting 
Policies—Accounting for Pensions and Postretirement 
Benefits" below. 

 
  
  
BONUS DEPRECIATION. Regarding income tax, 50 percent 
bonus depreciation was available for a large portion of our 
capital expenditures in 2013, 2014 and 2015 for both federal 
and Oregon. This generated an income tax net operating 
loss (NOL) in 2013, and reduced taxable income in 2014 
and 2015, providing cash flow benefits. The Federal 
Protecting Americans From Tax Hikes Act of 2015 became 
law on December 17, 2015 and extended federal bonus 
depreciation through 2019.

ENVIRONMENTAL EXPENDITURES. Concerning 
environmental expenditures, we expect to continue using 
cash resources to fund our environmental liabilities. In 2015, 
we received an Order from the OPUC  regarding our SRRM 
and began recovering amounts through utility rates in 
November 2015. These expenditures are uncertain as to the 
amount and timing. See Note 15, Note 16, and "Results of 
Operations—Regulatory Matters—Environmental Costs" 
above.

GAS STORAGE. Short-term liquidity for the gas storage 
segment is supported by cash balances, internal cash flow 
from operations, external financing, and equity contributions 
from its parent company. 

The amount and timing of our Gill Ranch facility's cash flows 
from year to year are uncertain, as the majority of these 
storage contracts are currently short-term. We have seen 
slightly higher contract prices for the 2015-16 and 2016-17 
storage years, but overall prices are still lower than the long-
term contracts that expired at the end of the 2013-14 
storage year. While we expect continuing challenges for Gill 
Ranch in 2016, we do not anticipate material changes in our 
ability to access sources of cash for short-term liquidity.

In November 2011, Gill Ranch issued $40 million of senior 
collateralized debt, with a fixed interest rate of 7.75% on 
$20 million and a variable interest rate on the remaining $20 
million, with an original maturity date of November 30, 2016. 
Under the debt agreement, Gill Ranch was subject to 

certain covenants and restrictions. We amended this 
agreement twice, which resulted in repayment of the $20 
million variable-rate outstanding debt during the second 
quarter of 2014, suspension of the EBITDA covenant 
requirement through the maturity date, and maintenance of 
a debt reserve account, which was fixed at $4.5 million as of 
June 30, 2015. In addition, under the amended agreement, 
Gill Ranch was required to receive common equity 
contributions from its parent NWN Gas Storage of at least 
$2 million by August 31, 2015 and complied with this 
requirement. On December 18, 2015, Gill Ranch repaid the 
$20 million of fixed-rate senior secured debt using available 
cash and cash flows from operations, including cash from 
intercompany receivables. 

CONSOLIDATED LIQUIDITY. Based on several factors, 
including our current credit ratings, our commercial paper 
program, current cash reserves, committed credit facilities, 
and our expected ability to issue long-term debt in the 
capital markets, we believe our liquidity is sufficient to meet 
anticipated near-term cash requirements, including all 
contractual obligations, investing, and financing activities 
discussed below.

DIVIDEND POLICY. We have paid quarterly dividends on our 
common stock each year since stock was first issued to the 
public in 1951. Annual common stock dividend payments 
per share, adjusted for stock splits, have increased each 
year since 1956. The declarations and amount of future 
dividends will depend upon our earnings, cash flows, 
financial condition and other factors. The amount and timing 
of dividends payable on our common stock is at the sole 
discretion of our Board of Directors.

OFF-BALANCE SHEET ARRANGEMENTS. Except for certain 
lease and purchase commitments, we have no material off-
balance sheet financing arrangements. See "Contractual 
Obligations" below.

38

Contractual Obligations
The following table shows our contractual obligations at December 31, 2015 by maturity and type of obligation:

Payments Due in Years Ending December 31,

In millions

2016

2017

2018

2019

2020

Thereafter

Total

Short-term debt maturities

$

270.0

$

— $

— $

— $

— $

— $

Long-term debt maturities

Interest on long-term debt
Postretirement benefit payments(1)

Capital leases

Operating leases
Gas purchases(2)

Gas pipeline capacity commitments
Other purchase commitments(3)
Other long-term liabilities(4)

25.0

34.2

23.6

0.6

5.4

61.5

83.2

0.1

16.5

40.0

32.1

24.1

0.1

5.4

—

79.4

—

—

22.0

29.2

25.0

—

5.3

—

75.8

—

—

30.0

28.6

26.1

—

5.3

—

75.7

—

—

75.0

24.4

28.4

—

2.8

—

72.1

—

—

409.7

177.5

145.8

—

30.5

—

340.0

—

—

270.0

601.7

326.0

273.0

0.7

54.7

61.5

726.2

0.1

16.5

Total

$

520.1

$

181.1

$

157.3

$

165.7

$

202.7

$

1,103.5

$

2,330.4

(1)  Postretirement benefit payments primarily consists of two items: (1) estimated qualified defined benefit pension plan payments, which are 
funded by plan assets and future cash contributions, and (2) required payments to the Western States multiemployer pension plan due to 
our withdrawal from the plan in December 2013. See Note 8.

(2)  Gas purchases include contracts which use price formulas tied to monthly index prices. The commitment amounts presented incorporate 

the December 2015 first of month index price for each supply basin from which gas is purchased. For a summary of gas purchase and gas 
pipeline capacity commitments, see Note 14.

(3)  Other purchase commitments primarily consist of base gas requirements and remaining balances under existing purchase orders. 
(4)  Other long-term liabilities includes accrued vacation liabilities for management employees and deferred compensation plan liabilities for 
executives and directors. The timing of these payments are uncertain; however, these payments are unlikely to all occur in the next 12 
months.

In addition to known contractual obligations listed in the 
above table, we have also recognized liabilities for future 
environmental remediation or action. The exact timing of 
payments beyond 12 months with respect to those liabilities 
cannot be reasonably estimated due to numerous 
uncertainties surrounding the course of environmental 
remediation and the preliminary nature of site investigations. 
See Note 15 for a further discussion of environmental 
remediation cost liabilities.

At December 31, 2015, 598 of our utility employees were 
members of the Office and Professional Employees 
International Union (OPEIU) Local No. 11. In May 2014, our 
union employees ratified a new labor agreement (Joint 
Accord) that expires on November 30, 2019. The Joint 
Accord includes the following items: an average annualized 
compensation increase of 4% effective June 1, 2014, which 
includes a 7.9% wage increase to better reflect current 
market competitive wages, offset by a reduction in bonus 
pay opportunities for union employees; and a scheduled 3% 
wage increase effective December 1 each year thereafter, 
beginning in 2015 with the potential for up to an additional 
3% per year based on wage inflation at or above 4%. The 
Joint Accord also maintains competitive health benefits, 
including a 15% to 20% premium cost sharing by 
employees, job flexibility, and other flexibility provisions for 
the Company. 

Short-Term Debt
Our primary source of utility short-term liquidity is from the 
sale of commercial paper and bank loans. In addition to 
issuing commercial paper or bank loans to meet working 
capital requirements, including seasonal requirements to 
finance gas purchases and accounts receivable, short-term 
debt may also be used to temporarily fund utility capital 
requirements. Commercial paper and bank loans are 
periodically refinanced through the sale of long-term debt or 
equity securities. Our outstanding commercial paper, which 
is sold through two commercial banks under an issuing and 
paying agency agreement, is supported by one or more 
unsecured revolving credit facilities. See “Credit 
Agreements” below. In the fourth quarter of 2015, we 
entered into a short-term credit facility loan totaling $50 
million, as a short-term bridge through our peak heating 
season, which was repaid on February 4, 2016. 

At December 31, 2015 and 2014, our utility had short-term 
debt outstanding of $270.0 million and $234.7 million, 
respectively.  The effective interest rate on short-term debt 
outstanding at December 31, 2015 and 2014 was 0.6% and 
0.4%, respectively. 

39

 
 
 
 
Credit Ratings
Our credit ratings are a factor of our liquidity, potentially 
affecting our access to the capital markets including the 
commercial paper market. Our credit ratings also have an 
impact on the cost of funds and the need to post collateral 
under derivative contracts. The following table summarizes 
our current debt ratings from S&P and Moody’s:

Commercial paper (short-term debt)

Senior secured (long-term debt)

Senior unsecured (long-term debt)

Corporate credit rating

Ratings outlook

S&P

Moody's

A-1

AA-

n/a

A+

P-2

A1

A3

n/a

Stable

Stable

The above credit ratings are dependent upon a number of 
factors, both qualitative and quantitative, and are subject to 
change at any time. The disclosure of or reference to these 
credit ratings is not a recommendation to buy, sell or hold 
NW Natural securities. Each rating should be evaluated 
independently of any other rating.

Maturity and Redemption of Long-Term Debt
The following debentures were retired:

In millions

Utility First Mortgage Bonds

Years Ended December 31,

2015

2014

2013

3.95% Series B due 2014

$

— $

8.26% Series B due 2014

4.70% Series B due 2015

Subsidiary Debt

Variable-rate

Fixed-rate

—

40

40

—

20

60

$

$

50

10

—

60

20

—

80

$

$

—

—

—

—

—

—

—

Credit Agreements
We have a $300 million credit agreement, with a feature that 
allows the Company to request increases in the total 
commitment amount, up to a maximum of $450 million. The 
maturity date of the agreement is December 20, 2019. 

All lenders under the agreement are major financial 
institutions with committed balances and investment grade 
credit ratings as of December 31, 2015 as follows:

In millions

Lender rating, by category

Loan Commitment

AA/Aa

A/A

BBB/Baa

Total

$

$

234

66

—

300

Based on credit market conditions, it is possible one or 
more lending commitments could be unavailable to us if the 
lender defaulted due to lack of funds or insolvency; 
however, we do not believe this risk to be imminent due to 
the lenders' strong investment-grade credit ratings.

Our credit agreement permits the issuance of letters of 
credit in an aggregate amount of up to $100 million. Any 
principal and unpaid interest amounts owed on borrowings 
under the credit agreements is due and payable on or 
before the maturity date. There were no outstanding 
balances under this credit agreement at December 31, 2015 
or 2014. The credit agreement requires us to maintain a 
consolidated indebtedness to total capitalization ratio of 
70% or less. Failure to comply with this covenant would 
entitle the lenders to terminate their lending commitments 
and accelerate the maturity of all amounts outstanding. We 
were in compliance with this covenant at December 31, 
2015 and 2014, with consolidated indebtedness to total 
capitalization ratios of 52.8% and 53.9%, respectively.

The agreement also requires us to maintain credit ratings 
with Standard & Poor's (S&P) and Moody's Investors 
Service, Inc. (Moody’s) and notify the lenders of any change 
in our senior unsecured debt ratings or senior secured debt 
ratings, as applicable, by such rating agencies. A change in 
our debt ratings by S&P or Moody’s is not an event of 
default, nor is the maintenance of a specific minimum level 
of debt rating a condition of drawing upon the credit 
agreement. Rather, interest rates on any loans outstanding 
under the credit agreements are tied to debt ratings and 
therefore, a change in the debt rating would increase or 
decrease the cost of any loans under the credit agreements 
when ratings are changed. See "Credit Ratings" below.

40

 
 
 
 
 
 
 
Cash Flows

Operating Activities
Changes in our operating cash flows are primarily affected 
by net income, changes in working capital requirements, 
and other cash and non-cash adjustments to operating 
results. 

Operating activity highlights include:

In millions

2015

2014

2013

Cash provided by operating
activities

$ 184.7

$ 215.7

$ 176.4

2015 COMPARED TO 2014. The significant factors 
contributing to the $31.0 million decrease in operating cash 
flows were as follows:
• 

a decrease of $99.4 million in deferred environmental 
recoveries, net of expenditures, reflecting the receipt of 
insurance settlements during 2014;
an increase of $55.0 million from changes in deferred 
gas costs balances, which reflected lower actual gas 
prices than prices embedded in the PGA compared to 
the prior year;
an increase of $15.0 million from regulatory 
disallowance of prior environmental cost deferrals in 
2015;
a decrease of $5.3 million from a non-cash recognition 
of interest income on deferred environmental expenses 
related to our SRRM order; 
a net decrease of $3.6 million from changes in working 
capital related to receivables, inventories and accounts 
payable due to warmer weather in 2015 compared to 
2014; and
an increase of $1.8 million from changes in regulatory 
balances, other assets and liabilities, and accrued 
taxes.

2014 COMPARED TO 2013. The significant factors 
contributing to the $39.3 million increase in operating cash 
flows were as follows:
• 

an increase of $105.5 million in deferred environmental 
recoveries, net of expenditures reflecting the receipt of 
insurance settlements during 2014;
an increase of $41.0 million from changes in the 
accounts receivable balance, primarily due to colder 
weather in December 2013.
a decrease of $24.1 million from changes in inventory 
balances due to refilling gas storage inventory after 
colder weather in December 2013; 
a decrease of $48.1 million from changes in regulatory 
balances, an increase in pension liabilities, and an 
increase in prepaids;
a decrease of $21.7 million in deferred taxes due to the 
utilization of NOL carryforwards; and
a decrease of $17.9 million from changes in deferred 
gas costs balances, which reflected higher actual gas 
prices than prices embedded in the PGA compared to 
the prior year.

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

During the year ended December 31, 2015, we contributed 
$14.1 million to our utility's qualified defined benefit pension 
plan, compared to $10.5 million for 2014 and $9.1 million for 
2013. The amounts and timing of future contributions will 

41

depend on market interest rates and investment returns on 
the plans’ assets. See Note 8.

Bonus depreciation of 50% has been available for federal 
and Oregon purposes in 2013, 2014 and 2015. This 
generated an income tax NOL in 2013, and reduced taxable 
income in 2014 and 2015, providing cash flow benefits. 
Bonus depreciation for 2014 and 2015 was not enacted until 
December 19, 2014 and December 17, 2015, respectively. 
In both cases it was extended retroactively back to January 
1 of the respective year. As a result, estimated income tax 
payments were made throughout 2014 and 2015 without the 
benefit of bonus depreciation for the year. This delayed the 
cash flow benefit of bonus depreciation and contributed to 
the income tax receivable of $7.9 million and $1.0 million as 
of December 31, 2015 and 2014, respectively. As a result of 
the Federal Protecting Americans From Tax Hikes Act of 
2015, bonus depreciation is now available in years 2016 
through 2019.

We have lease and purchase commitments relating to our 
operating activities that are financed with cash flows from 
operations. For information on cash flow requirements 
related to leases and other purchase commitments, see 
“Financial Condition—Contractual Obligations” above and 
Note 14.

Investing Activities
Investing activity highlights include:

In millions

2015

2014

2013

Total cash used in investing
activities

Capital expenditures

Utility gas reserves

$ 115.3

$ 144.3

$ 182.1

118.3

1.5

120.1

26.8

138.9

54.1

2015 COMPARED TO 2014. The $29.0 million decrease in 
cash used in investing activities was primarily due to lower 
utility gas reserves investments compared to 2014; see 
Note 11.  

2014 COMPARED TO 2013. The $37.8 million decrease in 
cash used in investing activities was primarily due to lower 
investments in capital expenditures and utility gas reserves 
as NW Natural ended its original drilling program with 
Encana in 2014; see Note 11.  

Over the five-year period 2016 through 2020, total utility 
capital expenditures are estimated to be between $850 and 
$950 million, including the Company's proposed investment 
in an expansion of our Mist gas storage facility as well as 
continued refurbishments of the Newport Liquefied Natural 
Gas (LNG) facility in Oregon over the next three years with 
an expected investment of approximately $25 million, and 
upgrading distribution infrastructure in Clark County, 
Washington, which could total approximately $25 million 
over the next five years. The estimated level of utility capital 
expenditures over the next five years reflects assumptions 
for continued customer growth, technology investments, 
distribution system maintenance and improvements, and 
gas storage facilities maintenance. Most of the required 
funds are expected to be internally generated over the five-
year period, and any remaining funding will be obtained 
through a combination of long-term debt and equity security 

issuances, with short-term debt and bridge financing 
providing liquidity. 

In 2016, utility capital expenditures are estimated to be 
between $155 and $175 million, and non-utility capital 
investments are estimated to be less than $5 million. Gas 
storage segment capital expenditures in 2016 are expected 
to be paid from working capital and additional equity 
contributions from NW Natural as needed.

Financing Activities
Financing activity highlights include:

In millions

2015

2014

2013

Total cash (used in) provided
by financing activities

$

(74.7) $

(71.3) $

6.3

Change in short-term debt

Change in long-term debt

35.3

(60.0)

46.5

(80.0)

(2.1)

50.0

2015 COMPARED TO 2014. The $3.4 million increase in cash 
used in financing activities was primarily due to redeeming 
$20 million less debt in 2015 compared to 2014. Offsetting 
this, we issued $11.2 million less of net commercial paper 
and short-term loans in 2015 compared to 2014.

2014 COMPARED TO 2013. The $77.6 million decrease in 
cash provided by financing activities was primarily due to 
using the proceeds from our insurance settlements of $103 
million to redeem $60 million of long-term utility debt. In 
addition, Gill Ranch retired $20 million of variable interest 
rate debt.

Pension Cost and Funding Status of Qualified 
Retirement Plans
Pension costs are determined in accordance with 
accounting standards for compensation and retirement 
benefits. See “Application of Critical Accounting Policies and 
Estimates – Accounting for Pensions and Postretirement 
Benefits” below. Pension expense for our qualified defined 
benefit plan, which is allocated between operation and 
maintenance expenses, capital expenditures, and the 
deferred regulatory balancing account, totaled $20.8 million 
in 2015, an increase of $6.6 million from 2014. The fair 
market value of pension assets in this plan decreased to 
$249.3 million at December 31, 2015 from $279.2 million at 
December 31, 2014. The decrease was due to a loss on 
plan assets of $9.6 million plus $14.1 million in employer 
contributions, offset by benefit payments of $34.3 million.

We make contributions to the company-sponsored qualified 
defined benefit pension plan based on actuarial 
assumptions and estimates, tax regulations and funding 
requirements under federal law. Our qualified defined 
benefit pension plan was underfunded by $162.5 million at 
December 31, 2015. We plan to make contributions during 
2016 of $14.5 million. See Note 8 for further pension 
disclosures.

Ratios of Earnings to Fixed Charges
For the years ended December 31, 2015, 2014, and 2013, 
our ratios of earnings to fixed charges, computed using the 
method outlined by the SEC, were 3.00, 3.13, and 3.16, 
respectively. For this purpose, earnings consist of net 
income before taxes plus fixed charges, and fixed charges 
consist of interest on all indebtedness, the amortization of 
debt expense and discount or premium and the estimated 
interest portion of rentals charged to income. See Exhibit 12 
for the detailed ratio calculation.

Contingent Liabilities
Loss contingencies are recorded as liabilities when it is 
probable that a liability has been incurred and the amount of 
the loss is reasonably estimable in accordance with 
accounting standards for contingencies. See “Application of 
Critical Accounting Policies and Estimates” below. At 
December 31, 2015, we had a net regulatory asset of $85.9 
million for deferred environmental costs, which includes 
deferred payments and interest of $51.8 million, $125.0 
million for additional costs expected to be paid in the future, 
and the remaining amortization to be collected in 2016 of 
$6.8 million, partially offset by $96.5 million of insurance 
recoveries and $1.2 million of a tariff rider collected in 2015 
to be applied to deferred costs. If it is determined that future 
customer rate recovery of such costs are not probable, then 
the costs will be charged to expense in the period such 
determination is made.  See Note 15, Note 16, and "Results 
of Operations—Regulatory Matters—Rate Mechanisms—
Environmental Costs" above.

New Accounting Pronouncements 
For a description of recent accounting pronouncements that 
may have an impact on our financial condition, results of 
operations or cash flows, see Note 2.

42

  
APPLICATION OF CRITICAL ACCOUNTING POLICIES 
AND ESTIMATES

In preparing our financial statements in accordance with 
GAAP, management exercises judgment in the selection 
and application of accounting principles, including making 
estimates and assumptions that affect reported amounts of 
assets, liabilities, revenues, expenses and related 
disclosures in the financial statements. Management 
considers our critical accounting policies to be those which 
are most important to the representation of our financial 
condition and results of operations and which require 
management’s most difficult and subjective or complex 
judgments, including accounting estimates that could result 
in materially different amounts if we reported under different 
conditions or used different assumptions. Our most critical 
estimates and judgments include accounting for:
•  regulatory accounting;
•  revenue recognition;
•  derivative instruments and hedging activities;
•  pensions and postretirement benefits;
•  income taxes;
•  environmental contingencies; and
•  impairment of long-lived assets.

Management has discussed its current estimates and 
judgments used in the application of critical accounting 
policies with the Audit Committee of the Board. Within the 
context of our critical accounting policies and estimates, 
management is not aware of any reasonably likely events or 
circumstances that would result in materially different 
amounts being reported. For a description of recent 
accounting pronouncements that could have an impact on 
our financial condition, results of operations or cash flows, 
see Note 2.

Regulatory Accounting
Our utility is regulated by the OPUC and WUTC, which 
establish the rates and rules governing utility services 
provided to customers, and, to a certain extent, set forth 
special accounting treatment for certain regulatory 
transactions. In general, we use the same accounting 
principles as non-regulated companies reporting under 
GAAP. However, authoritative guidance for regulated 
operations (regulatory accounting) requires different 
accounting treatment for regulated companies to show the 
effects of such regulation. For example, we account for the 
cost of gas using a PGA deferral and cost recovery 
mechanism, which is submitted for approval annually to the 
OPUC and WUTC. See "Results of Operations—Regulatory 
Matters—Rate Mechanisms—Purchased Gas Adjustment" 
above. There are other expenses and revenues that the 
OPUC or WUTC may require us to defer for recovery or 
refund in future periods. Regulatory accounting requires us 
to account for these types of deferred expenses (or deferred 
revenues) as regulatory assets (or regulatory liabilities) on 
the balance sheet. When we are allowed to recover these 
regulatory assets from, or are required to refund regulatory 
liabilities to, customers, we recognize the expense or 
revenue on the income statement at the same time we 
realize the adjustment to amounts included in utility rates 
charged to customers.

The conditions we must satisfy to adopt the accounting policies 
and practices of regulatory accounting include:
an independent regulator sets rates;
• 
the regulator sets the rates to cover specific costs of 
• 
delivering service; and
the service territory lacks competitive pressures to reduce 
rates below the rates set by the regulator. 

• 

Because our utility satisfies all three conditions, we continue 
to apply regulatory accounting to our utility operations. 
Future accounting changes, regulatory changes or changes 
in the competitive environment could require us to 
discontinue the application of regulatory accounting for 
some or all of our regulated businesses. This would require 
the write-off of those regulatory assets and liabilities that 
would no longer be probable of recovery from or refund to 
customers. 

Based on current accounting and regulatory competitive 
conditions, we believe it is reasonable to expect continued 
application of regulatory accounting for our utility activities. 
Further, it is reasonable to expect the recovery or refund of 
our regulatory assets and liabilities at December 31, 2015 
through future customer rates. If we should determine all or 
a portion of these regulatory assets or liabilities no longer 
meet the criteria for continued application of regulatory 
accounting, then we would be required to write-off the net 
unrecoverable balances against earnings in the period such 
determination is made. The net balance in regulatory asset 
and liability accounts as of December 31, 2015 and 2014 
was an asset of $70.7 million and $101.2 million, 
respectively. See Note 2.

Revenue Recognition 
Utility and non-utility revenues, which are derived primarily 
from the sale, transportation, and storage of natural gas, are 
recognized upon the delivery of gas commodity or services 
rendered to customers. 

Accrued Unbilled Revenue 
For a description of our policy regarding accrued unbilled 
revenue for both the utility and non-utility revenues, see 
Note 2. The following table presents changes in key metrics 
if the estimated percentage of unbilled volume at December 
31 was adjusted up or down by 1%:

In millions

Unbilled revenue increase (decrease)
Utility margin increase (decrease)(1)

Net income increase (decrease)
(1) 

Includes impact of regulatory mechanisms including decoupling 
mechanism.

2015

Up 1%

Down 1%

$

0.5

$

(0.5)

—

—

—

—

Derivative Instruments and Hedging Activities  
Our gas acquisition and hedging policies set forth guidelines 
for using financial derivative instruments to support prudent 
risk management strategies. These policies specifically 
prohibit the use of derivatives for trading or speculative 
purposes. We enter into financial derivative contracts to 
hedge a portion of our utility’s natural gas sales 
requirements. These contracts include swaps, options, and 
combinations of option contracts. We primarily use these 
derivative financial instruments to manage commodity price 

43

 
  
variability. A small portion of our derivative hedging strategy 
involves foreign currency exchange contracts. 

Derivative instruments are recorded on our balance sheet at 
fair value. If certain regulatory conditions are met, then the 
derivative instrument fair value is recorded together with an 
offsetting entry to a regulatory asset or liability account 
pursuant to regulatory accounting (see Note 2, "Industry 
Regulation"), and no unrealized gain or loss is recognized in 
current income. The gain or loss from the fair value of a 
derivative instrument subject to regulatory deferral is 
included in the recovery from, or refund to, utility customers 
in future periods (see "Regulatory Accounting", above). If a 
derivative contract is not subject to regulatory deferral, then 
the accounting treatment for unrealized gains and losses is 
recorded in accordance with accounting standards for 
derivatives and hedging (see Note 2, "Derivatives” and 
"Industry Regulation") which is either in current income or in 
accumulated other comprehensive income or loss (AOCI or 
AOCL). Our derivative contracts outstanding at December 
31, 2015 were measured at fair value using models or other 
market accepted valuation methodologies derived from 
observable market data. Our estimate of fair value may 
change significantly from period-to-period depending on 
market conditions and prices. These changes may have an 
impact on our results of operations, but the impact would 
largely be mitigated due to the majority of our derivative 
activities being subject to regulatory deferral treatment. For 
estimated fair value of unrealized gains and losses, see 
Note 13.

The following table summarizes the amount of gains and 
losses realized from commodity price transactions for the 
last three years:

In millions

2015

2014

2013

Net utility gain (loss) on:

Commodity

Swaps

Options

$

(37.7) $

10.5

$

(11.0)

—

—

—

Total net gain (loss)
realized

$

(37.7) $

10.5

$

(11.0)

Realized gains and losses from commodity hedges shown 
above were recorded as decreases or increases to cost of 
gas, respectively, and were included in our annual PGA 
rates.

Pensions and Postretirement Benefits
We maintain a qualified non-contributory defined benefit 
pension plan, non-qualified supplemental pension plans for 
eligible executive officers and certain key employees, and 
other postretirement employee benefit plans covering 
certain non-union employees. We also have a qualified 
defined contribution plan (Retirement K Savings Plan) for all 
eligible employees. Only the qualified defined benefit 
pension plan and Retirement K Savings Plan have plan 
assets, which are held in qualified trusts to fund the 
respective retirement benefits. The qualified defined benefit 
retirement plan for union and non-union employees was 
closed to new participants several years ago. These plans 
are not available to employees at any of our subsidiary 
companies. Non-union and union employees hired or re-
hired after December 31, 2006 and 2009, respectively, and 

44

employees of NW Natural subsidiaries are provided an 
enhanced Retirement K Savings Plan benefit. The 
postretirement Welfare Benefit Plan for non-union 
employees was also closed to new participants several 
years ago.

Net periodic pension and postretirement benefit costs 
(retirement benefit costs) and projected benefit obligations 
(benefit obligations) are determined using a number of key 
assumptions including discount rates, rate of compensation 
increases, retirement ages, mortality rates and an expected 
long-term return on plan assets. See Note 8. These key 
assumptions have a significant impact on the pension 
amounts recorded and disclosed. Retirement benefit costs 
consist of service costs, interest costs, the amortization of 
actuarial gains, losses and prior service costs, the expected 
returns on plan assets and, in part, on a market-related 
valuation of assets, if applicable. The market-related asset 
valuation reflects differences between expected returns and 
actual investment returns, which we recognize over a three-
year period or less from the year in which they occur, 
thereby reducing year-to-year volatility in retirement benefit 
costs.

Accounting standards also require balance sheet 
recognition of the overfunded or underfunded status of 
pension and postretirement benefit plans in AOCI or AOCL, 
net of tax, based on the fair value of plan assets compared 
to the actuarial value of future benefit obligations. However, 
the retirement benefit costs related to our qualified defined 
benefit pension and postretirement benefit plans are 
generally recovered in utility rates, which are set based on 
accounting standards for pensions and postretirement 
benefit expenses.  We received approval from the OPUC to 
recognize the overfunded or underfunded status as a 
regulatory asset or regulatory liability based on expected 
rate recovery, rather than including it as AOCI or AOCL 
under common equity. See "Regulatory Accounting" above 
and Note 2, "Industry Regulation".

In 2011, we received regulatory approval from the OPUC 
and began deferring a portion of our pension expense 
above or below the amount set in rates to a regulatory 
balancing account on the balance sheet. At December 31, 
2015, the cumulative amount deferred for future pension 
cost recovery was $43.7 million. The regulatory balancing 
account includes the recognition of accrued interest on the 
account balance at the utility's authorized rate of return, with 
the equity portion of this interest being deferred until 
amounts are collected in rates. 

A number of factors, as discussed above, are considered in 
developing pension and postretirement benefit assumptions. 
For the December 31, 2015 measurement date, we 
reviewed and updated the following key assumptions:
• 

our weighted-average discount rate assumptions for 
pensions went from 3.85% for 2014 to 4.21% for 2015, 
and our weighted-average discount rate assumptions 
for other postretirement benefits went from 3.74% for 
2014 to 4.00% for 2015. The new rate assumptions 
were determined for each plan based on a matching of 
benchmark interest rates to the estimated cash flows, 
which reflect the timing and amount of future benefit 
payments. Benchmark interest rates are drawn from the 
Citigroup Above Median Curve, which consists of high 

  
quality bonds rated AA- or higher by S&P or Aa3 or 
higher by Moody’s;
our expected annual rate of future compensation 
increases, which decreased slightly to a range of 3.25% 
to 4.50%;
our expected long-term return on qualified defined 
benefit plan assets, which remained unchanged at a 
rate of 7.50%; 
our mortality rate assumptions were updated to the new 
Society of Actuaries Scale MP-2015, which projects a 
mortality detriment compared to the previous table 
used, thereby decreasing benefit plan liabilities; and
other key assumptions, which were based on actual 
plan experience and actuarial recommendations.

• 

• 

• 

• 

At December 31, 2015, our net pension liability (benefit 
obligations less market value of plan assets) for the 
qualified defined benefit plan decreased $9.5 million 
compared to 2014. The decrease in our net pension liability 
is primarily due to the $39.4 million decrease in our pension 
benefit obligation, offset by a decrease of $29.8 million in 
plan assets. The liability for non-qualified plans decreased 
$2.3 million, and the liability for other postretirement benefits 
decreased $1.0 million in 2015.

We determine the expected long-term rate of return on plan 
assets by averaging the expected earnings for the target 
asset portfolio. In developing our expected return, we 
analyze historical actual performance and long-term return 
projections, which gives consideration to the current asset 
mix and our target asset allocation. As of December 31, 
2015, the actual annualized returns on plan assets, net of 
management fees, for the past one-year, five-years, and 10-
years were (3.2%), 4.7%, and 4.0%, respectively.

We believe our pension assumptions to be appropriate 
based on plan design and an assessment of market 
conditions. However, the following shows the sensitivity of 
our retirement benefit costs and benefit obligations to 
changes in certain actuarial assumptions:

Change in
Assumption

(0.25)%

Impact on
2015
Retirement
Benefit
Costs

Impact on
Retirement
Benefit
Obligations
at Dec. 31,
2015

$

1.3

$

—

0.1

14.4

1.0

1.0

(0.25)

0.7

N/A

Dollars in millions

Discount rate:

Qualified defined
benefit plans

Non-qualified plans

Other
postretirement
benefits

Expected long-term
return on plan assets:

Qualified defined
benefit plans

In July 2012, President Obama signed into law the MAP-21 
Act. This legislation changed several provisions affecting 
pension plans, including temporary funding relief and 
Pension Benefit Guaranty Corporation (PBGC) premium 
increases, which reduces the level of minimum required 
contributions in the near-term but generally increases 
contributions in the long-run as well as increasing the 

45

operational costs of running a pension plan. Prior to the 
MAP-21 Act, we were using interest rates based on a 24-
month average yield of investment grade corporate bonds 
(also referred to as "segment rate") to calculate minimum 
contribution requirements. MAP-21 Act established a new 
minimum and maximum corridor for segment rates based 
on a 25-year average of bond yields, which is to be used in 
calculating contribution requirements. In August 2014, 
HATFA was signed and extends certain aspects of MAP-21 
as well as modifies the phase-out periods for the limitations. 
As a result we anticipate lower contributions over the next 
five years with contributions increasing thereafter.

Income Taxes

Valuation Allowances 
We recognize deferred tax assets to the extent that we 
believe these assets are more likely than not to be realized. 
In making such a determination, we consider the available 
positive and negative evidence, including future reversals of 
existing taxable temporary differences, projected future 
taxable income, tax-planning strategies, and results of 
recent operations. The most significant deferred tax asset 
currently recorded is for alternative minimum tax credits. We 
have determined that we are more likely than not to realize 
all recorded deferred tax assets as of December 31, 2015. 
See Note 9.

Uncertain Tax Benefits 
The calculation of our tax liabilities involves dealing with 
uncertainties in the application of complex tax laws and 
regulations in the jurisdictions in which we operate. A tax 
benefit from a material uncertain tax position will only be 
recognized when it is more likely than not that the position, 
or some portion thereof, will be sustained upon examination, 
including resolution of any related appeals or litigation 
processes, on the basis of the technical merits. The 
Company participates in the Compliance Assurance 
Process (CAP) with the Internal Revenue Service (IRS). 
Under the CAP program the Company works with the IRS to 
identify and resolve material tax matters before the federal 
income tax return is filed each year. No reserves for 
uncertain tax benefits were recorded during 2013, 2014, or 
2015. See Note 9.

Regulatory Matters 
Regulatory tax assets and liabilities are recorded to the 
extent we believe they will be recoverable from, or refunded 
to, customers in future rates. At December 31, 2015 and 
2014, we have regulatory income tax assets of $47.4 million 
and $51.8 million, respectively, representing future rate 
recovery of deferred tax liabilities resulting from differences 
in utility plant financial statement and tax basis and utility 
plant removal costs. These deferred tax liabilities, and the 
associated regulatory income tax assets, are currently being 
recovered through customer rates. See Note 2.

Tax Legislation 
When significant proposed or enacted changes in income 
tax rules occur we consider whether there may be a 
material impact to our financial position, results of 
operations, cash flows, or whether the changes could 
materially affect existing assumptions used in making 
estimates of tax related balances. 

The final tangible property regulations applicable to all 
taxpayers were issued on September 13, 2013 and were 
generally effective for taxable years beginning on or after 
January 1, 2014. In addition, procedural guidance related to 
the regulations was issued under which taxpayers may 
make accounting method changes to comply with the 
regulations. We have evaluated the regulations and do not 
anticipate any material impact. However, unit-of-property 
guidance applicable to natural gas distribution networks has 
not yet been issued and is expected in 2016. We will further 
evaluate the effect of these regulations after this guidance is 
issued, but believe our current method is materially 
consistent with the new regulations and do not expect these 
regulations to have a material effect on our financial 
statements.

The Federal Protecting Americans From Tax Hikes Act of 
2015 became law on December 17, 2015 and extended 
federal bonus depreciation through 2019. See "Financial 
Conditions—Cash Flows" above.

Environmental Contingencies  
We account for environmental liabilities in accordance with 
accounting standards under the loss contingency guidance 
when it is probable that a liability has been incurred and the 
amount of the loss is reasonably estimable. For a complete 
discussion of our environmental policy refer to Note 2. For a 
discussion of our current environmental sites and liabilities 
refer to Note 15 and "Contingent Liabilities" above. In 
addition, for information regarding the regulatory treatment 
of these costs and our regulatory recovery mechanism, see 
"Results of Operations—Rate Matters—Rate Mechanisms
—Environmental Costs" above.

Impairment of Long-Lived Assets
We review the carrying value of long-lived assets whenever 
events or changes in circumstances indicate the carrying 
amount of the assets might not be recoverable. Factors that 
would necessitate an impairment assessment of long-lived 
assets include a significant adverse change in the extent or 
manner in which the asset is used, a significant adverse 
change in legal factors or business climate that could affect 
the value of the asset, or a significant decline in the 
observable market value or expected future cash flows of 
the asset, among others. 

When such factors are present, we assess the recoverability 
by determining whether the carrying value of the asset will 
be recovered through expected future cash flows.  An asset 
is determined to be impaired when the carrying value of the 
asset exceeds the expected undiscounted future cash flows 
from the use and eventual disposition of the asset.  If an 
impairment is indicated, we record an impairment loss for 
the difference between the carrying value and the fair value 
of the long-lived assets.  Fair value is estimated using 
appropriate valuation methodologies, which may include an 
estimate of discounted cash flows.

We determined there were no long-lived asset impairments 
in 2015; however our Gill Ranch Storage facility within our 
Gas Storage Segment was reviewed for impairment.  The 
undiscounted cash flows are in excess of the carrying value 
of the asset and no impairment was indicated. The cash 
flows assume a recovery of storage pricing and the ability to 
contract with higher value customers.  Accordingly, if 

46

storage pricing does not improve and/or new higher value 
customers are not obtained, future analysis may result in an 
impairment of these long-lived assets.

ITEM 7A. QUANTITATIVE AND QUALITATIVE 
DISCLOSURES ABOUT MARKET RISK

We are exposed to various forms of market risk including 
commodity supply risk, commodity price risk, interest rate 
risk, foreign currency risk, credit risk and weather risk. The 
following describes our exposure to these risks.

Commodity Supply Risk
We enter into spot, short-term, and long-term natural gas 
supply contracts, along with associated pipeline 
transportation contracts, to manage our commodity supply 
risk. Historically, we have arranged for physical delivery of 
an adequate supply of gas, including gas in our Mist storage 
and off-system storage facilities, to meet expected 
requirements of our core utility customers. Our long-term 
gas supply contracts are primarily index-based and subject 
to monthly re-pricing, a strategy that is intended to 
substantially mitigate credit exposure to our physical gas 
counterparties. Notional amounts under physical gas 
contracts were $7.0 million and $4.8 million as of December 
31, 2015 and 2014, respectively.

Commodity Price Risk
Natural gas commodity prices are subject to market 
fluctuations due to unpredictable factors including weather, 
pipeline transportation congestion, drilling technologies, 
market speculation, and other factors that affect supply and 
demand. We manage commodity price risk with financial 
swaps and physical gas reserves from a long-term 
investment in working interests in gas leases operated by 
Jonah Energy. These financial hedge contracts and gas 
reserves volumes are generally included in our annual PGA 
filing for recovery, subject to a regulatory prudence review.  
Notional amounts under financial derivative contracts were 
$95.5 million and $108.4 million as of December 31, 2015 
and 2014, respectively. The fair value of financial swaps as 
of December 31, 2015 was an unrealized loss of $23.2 
million with future cash flows of $19.8 million in 2016, $2.7 
million in 2017 and $0.7 million in 2018.  

Interest Rate Risk
We are exposed to interest rate risk primarily associated 
with new debt financing needed to fund capital 
requirements, including future contractual obligations and 
maturities of long-term and short-term debt. Interest rate risk 
is primarily managed through the issuance of fixed-rate debt 
with varying maturities. We may also enter into financial 
derivative instruments, including interest rate swaps, options 
and other hedging instruments, to manage and mitigate 
interest rate exposure.  We did not have any interest rate 
swaps outstanding as of December 31, 2015 or 2014.

Foreign Currency Risk
The costs of certain pipeline and off-system storage 
services purchased from Canadian suppliers are subject to 
changes in the value of the Canadian currency in relation to 
the U.S. currency. Foreign currency forward contracts are 
used to hedge against fluctuations in exchange rates for our 
commodity-related demand and reservation charges paid in 
Canadian dollars. Notional amounts under foreign currency 

  
  
  
forward contracts were $9.0 million and $12.2 million as of 
December 31, 2015 and 2014, respectively.  If all of the 
foreign currency forward contracts had been settled on 
December 31, 2015, a loss of $0.4 million would have been 
realized. See Note 13.

Credit Risk
Credit Exposure to Natural Gas Suppliers 
Certain gas suppliers have either relatively low credit ratings 
or are not rated by major credit rating agencies. To manage 
this supply risk, we purchase gas from a number of different 
suppliers at liquid exchange points. We evaluate and 
monitor suppliers’ creditworthiness and maintain the ability 
to require additional financial assurances, including 
deposits, letters of credit, or surety bonds, in case a supplier 
defaults. In the event of a supplier’s failure to deliver 
contracted volumes of gas, the regulated utility would need 
to replace those volumes at prevailing market prices, which 
may be higher or lower than the original transaction prices. 
We expect these costs would be subject to our PGA sharing 
mechanism discussed above. Since most of our commodity 
supply contracts are priced at the daily or monthly market 
index price tied to liquid exchange points, and we have 
adequate storage flexibility, we believe it is unlikely a 
supplier default would have a material adverse effect on our 
financial condition or results of operations.

Credit Exposure to Financial Derivative Counterparties 
Based on estimated fair value at December 31, 2015, our 
overall credit exposure relating to commodity contracts is 
considered immaterial as it reflects amounts owed to 
financial derivative counterparties (see table below). 
However, changes in natural gas prices could result in 
counterparties owing us money. Therefore, our financial 
derivatives policy requires counterparties to have at least an 
investment-grade credit rating at the time the derivative 
instrument is entered into and specific limits on the contract 
amount and duration based on each counterparty’s credit 
rating. Due to potential changes in market conditions and 
credit concerns, we continue to enforce strong credit 
requirements. We actively monitor and manage our 
derivative credit exposure and place counterparties on hold 
for trading purposes or require cash collateral, letters of 
credit, or guarantees as circumstances warrant. As of 
December 31, 2015, we do not have any actual derivative 
credit risk exposure for amounts financial derivative 
counterparties owe to us.

The following table summarizes our overall financial swap 
and option credit exposure, based on estimated fair value, 
and the corresponding counterparty credit ratings. The table 
uses credit ratings from S&P and Moody’s, reflecting the 
higher of the S&P or Moody’s rating or a middle rating if the 
entity is split-rated with more than one rating level 
difference:

In most cases, we also mitigate the credit risk of financial 
derivatives by having master netting arrangements with our 
counterparties which provide for making or receiving net 
cash settlements. Generally, transactions of the same type 
in the same currency that have settlement on the same day 
with a single counterparty are netted and a single payment 
is delivered or received depending on which party
is due funds.

Additionally we have master contracts in place with each 
of our derivative counterparties that include provisions for 
posting or calling for collateral. Generally we can obtain 
cash or marketable securities as collateral with one day’s 
notice. We use various collateral management strategies to 
reduce liquidity risk. The collateral provisions vary by 
counterparty but are not expected to result in the significant 
posting of collateral, if any. We have performed stress tests 
on the portfolio and concluded the liquidity risk from 
collateral calls is not material. Our derivative credit exposure 
is primarily with investment grade counterparties rated AA-/
Aa3 or higher. Contracts are diversified across 
counterparties to reduce credit and liquidity risk.

Credit Exposure to Insurance Companies
Our credit exposure to insurance companies for loss or 
damage claims could be material. We regularly monitor the 
financial condition of insurance companies who provide 
general liability insurance policy coverage to NW Natural 
and its predecessors.

Weather Risk 
We have a weather normalization mechanism in Oregon; 
however, we are exposed to weather risk primarily from our 
regulated utility business. A large percentage of our utility 
margin is volume driven, and current rates are based on an 
assumption of average weather. Our weather normalization 
mechanism in Oregon is for residential and commercial 
customers, which is intended to stabilize the recovery of our 
utility’s fixed costs and reduce fluctuations in customers’ 
bills due to colder or warmer than average weather. 
Customers in Oregon are allowed to opt out of the weather 
normalization mechanism. As of December 31, 2015, 
approximately 9% of our Oregon customers had opted out. 
In addition to the Oregon customers opting out, our 
Washington residential and commercial customers account 
for approximately 11% of our total customer base and are 
not covered by weather normalization. The combination of 
Oregon and Washington customers not covered by a 
weather normalization mechanism is 20% of all residential 
and commercial customers. See "Results of Operations—
Regulatory Matters—Rate Mechanism—Weather 
Normalization Tariff" above.

In millions

AA/Aa

A/A

Total

$

Financial Derivative Position by Credit Rating
Unrealized Fair Value Loss

2015

2014

(20.0)

(3.2)

(23.2) $

(27.2)

(3.4)

(30.6)

47

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

TABLE OF CONTENTS

1.

2.

3.

4.

5.

Management's Report on Internal Control Over Financial Reporting

Report of Independent Registered Public Accounting Firm

Consolidated Financial Statements:

Consolidated Statements of Comprehensive Income for the Years Ended December 31, 2015, 2014, and 2013

Consolidated Balance Sheets at December 31, 2015 and 2014

Consolidated Statements of Shareholders’ Equity for the Years Ended December 31, 2015, 2014, and 2013

Consolidated Statements of Cash Flows for the Years Ended December 31, 2015, 2014, and 2013

Notes to Consolidated Financial Statements

Quarterly Financial Information (Unaudited)

Supplementary Data for the Years Ended December 31, 2015, 2014, and 2013:

Financial Statement Schedule

Schedule II – Valuation and Qualifying Accounts and Reserves

Supplemental Schedules Omitted

Page

49

50

51

52

54

55

56

85

85

All other schedules are omitted because of the absence of the conditions under which they are required or because the required 
information is included elsewhere in the financial statements.

48

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
MANAGEMENT’S REPORT ON INTERNAL CONTROL OVER FINANCIAL REPORTING

Management is responsible for establishing and maintaining adequate internal control over financial reporting as defined in 
Rules 13a-15(f) or 15d-15(f) under the Securities Exchange Act of 1934, as amended. Our internal control over financial 
reporting is designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of 
financial statements for external purposes in accordance with generally accepted accounting principles in the United States of 
America (GAAP). Our internal control over financial reporting includes those policies and procedures that:

(i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions 
involving company assets;

(ii) provide reasonable assurance that transactions are recorded as necessary to permit the preparation of financial statements 
in accordance with GAAP, and that receipts and expenditures are being made only in accordance with authorizations of 
management and the Board of Directors; and

(iii) provide reasonable assurance regarding prevention or timely detection of the unauthorized acquisition, use or disposition of 
our assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements or fraud. 
Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate 
because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Management assessed the effectiveness of our internal control over financial reporting as of December 31, 2015. In making this 
assessment, management used the criteria set forth by the Committee of Sponsoring Organizations of the Treadway 
Commission (COSO) in Internal Control-Integrated Framework (2013).

Based on our assessment and those criteria, management has concluded that we maintained effective internal control over 
financial reporting as of December 31, 2015.

The effectiveness of internal control over financial reporting as of December 31, 2015 has been audited by 
PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in their report which appears in this 
annual report.

/s/ Gregg S. Kantor        
Gregg S. Kantor
Chief Executive Officer

/s/ Gregory C. Hazelton 
Gregory C. Hazelton
Senior Vice President, Chief Financial Officer, and Treasurer

February 26, 2016

49

 
 
 
  
 
 
 
 
  
 
REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Board of Directors and Shareholders of
Northwest Natural Gas Company:

In our opinion, the consolidated financial statements listed in the accompanying index present fairly, in all material respects, the 
financial position of Northwest Natural Gas Company and its subsidiaries at December 31, 2015 and 2014, and the results of 
their operations and its cash flows for each of the three years in the period ended December 31, 2015 in conformity with 
accounting principles generally accepted in the United States of America. In addition, in our opinion, the financial statement 
schedule listed in the accompanying index presents fairly, in all material respects, the information set forth therein when read in 
conjunction with the related consolidated financial statements. Also in our opinion, the Company maintained, in all material 
respects, effective internal control over financial reporting as of December 31, 2015, based on criteria established in Internal 
Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission 
(COSO). The Company's management is responsible for these financial statements, for maintaining effective internal control 
over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the 
accompanying Management's Report on Internal Control over Financial Reporting. Our responsibility is to express opinions on 
these financial statements, on the financial statement schedule, and on the Company's internal control over financial reporting 
based on our integrated audits. We conducted our audits in accordance with the standards of the Public Company Accounting 
Oversight Board (United States). Those standards require that we plan and perform the audits to obtain reasonable assurance 
about whether the financial statements are free of material misstatement and whether effective internal control over financial 
reporting was maintained in all material respects. Our audits of the financial statements included examining, on a test basis, 
evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and 
significant estimates made by management, and evaluating the overall financial statement presentation. Our audit of internal 
control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk 
that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on 
the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. 
We believe that our audits provide a reasonable basis for our opinions.

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the 
reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally 
accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that 
(i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions 
of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit 
preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and 
expenditures of the company are being made only in accordance with authorizations of management and directors of the 
company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or 
disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, 
projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate 
because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

/s/ PricewaterhouseCoopers LLP

Portland, Oregon
February 26, 2016 

50

 
  
 
 
 
NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

In thousands, except per share data

Operating revenues

Operating expenses:

Cost of gas

Operations and maintenance

Environmental remediation

General taxes

Depreciation and amortization

Total operating expenses

Income from operations

Other income, net

Interest expense, net

Income before income taxes

Income tax expense

Net income

Other comprehensive income:

Change in employee benefit plan liability, net of taxes of ($988) for 2015, $2,857
for 2014, and ($1,304) for 2013
Amortization of non-qualified employee benefit plan liability, net of taxes of ($883)
for 2015, ($438) for 2014, and ($608) for 2013

Comprehensive income

Average common shares outstanding:

Basic

Diluted

Earnings per share of common stock:

Basic

Diluted

Dividends declared per share of common stock

Year Ended December 31,

2015

2014

2013

$ 723,791

$ 754,037

$ 758,518

327,305

157,521

3,513

30,281

80,923

599,543

124,248

7,747

42,539

89,456

35,753

53,703

365,490

136,982

—

29,407

79,193

611,072

142,965

1,933

44,563

373,298

136,613

—

29,956

75,905

615,772

142,746

4,669

45,172

100,335

102,243

41,643

58,692

41,705

60,538

1,561

1,353

(4,364)

1,998

646

935

$

56,617

$

54,974

$

63,471

27,347

27,417

27,164

27,223

26,974

27,027

$

$

1.96

1.96

1.86

$

2.16

2.16

1.85

2.24

2.24

1.83

See Notes to Consolidated Financial Statements

51

NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED BALANCE SHEETS

In thousands

Assets:

Current assets:

Cash and cash equivalents

Accounts receivable

Accrued unbilled revenue

Allowance for uncollectible accounts

Regulatory assets

Derivative instruments

Inventories

Gas reserves

Income taxes receivable

Deferred tax assets

Other current assets

Total current assets

Non-current assets:

Property, plant, and equipment

Less: Accumulated depreciation

Total property, plant, and equipment, net

Gas reserves

Regulatory assets

Derivative instruments

Other investments

Restricted cash

Other non-current assets

Total non-current assets

Total assets

As of December 31,

2015

2014

$

4,211

$

68,228

57,987

(870)

69,178

2,719

70,868

17,094

7,900

—

34,748

332,063

9,534

69,818

57,963

(969)

68,562

243

77,832

20,020

1,000

23,785

34,772

362,560

3,089,380

2,992,560

906,717

870,967

2,182,663

2,121,593

114,552

370,711

27

68,066

—

8,610

129,280

368,908

—

68,238

3,000

11,366

2,744,629

2,702,385

$

3,076,692

$

3,064,945

See Notes to Consolidated Financial Statements

52

NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED BALANCE SHEETS

In thousands

Liabilities and equity:

Current liabilities:

Short-term debt

Current maturities of long-term debt

Accounts payable

Taxes accrued

Interest accrued

Regulatory liabilities

Derivative instruments

Other current liabilities

Total current liabilities

Long-term debt

Deferred credits and other non-current liabilities:

Deferred tax liabilities

Regulatory liabilities

Pension and other postretirement benefit liabilities

Derivative instruments

Other non-current liabilities

Total deferred credits and other non-current liabilities

Commitments and contingencies (see Note 14 and Note 15)

Equity:

Common stock - no par value; authorized 100,000 shares; issued and outstanding 27,427
and 27,284 at December 31, 2015 and 2014, respectively

Retained earnings

Accumulated other comprehensive loss

Total equity

Total liabilities and equity

See Notes to Consolidated Financial Statements

As of December 31,

2015

2014

$

270,035

$

234,700

25,000

73,219

10,420

5,873

29,927

22,092

41,148

477,714

576,700

530,021

339,287

223,105

3,447

145,446

40,000

91,366

10,031

6,079

19,105

29,894

38,235

469,410

621,700

530,965

317,205

236,735

3,515

118,094

1,241,306

1,206,514

—

—

383,144

404,990

(7,162)

780,972

375,117

402,280

(10,076)

767,321

$

3,076,692

$

3,064,945

53

 
NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY

In thousands

Balance at December 31, 2012

   Comprehensive income

   Dividends on common stock

   Tax expense from employee stock plans

   Stock-based compensation

   Issuance of common stock

Balance at December 31, 2013

   Comprehensive income (loss)

   Dividends on common stock

   Tax expense from employee stock plans

   Stock-based compensation

   Issuance of common stock

Balance at December 31, 2014

   Comprehensive income

   Dividends on common stock

   Tax expense from employee stock plans

   Stock-based compensation

   Issuance of common stock

Balance at December 31, 2015

Common
Stock

Retained
Earnings

Accumulated
Other
Comprehensive
Income (Loss)

Total
Equity

$

356,571

$

382,347

$

(9,291) $

729,627

—

—

(242)

2,169

6,051

364,549

—

—

(117)

1,646

9,039

375,117

—

—

(118)

3,277

4,868

60,538

(49,204)

—

—

—

393,681

58,692

(50,093)

—

—

—

402,280

53,703

(50,993)

—

—

—

2,933

—

—

—

—

(6,358)

(3,718)

—

—

—

—

(10,076)

2,914

—

—

—

—

63,471

(49,204)

(242)

2,169

6,051

751,872

54,974

(50,093)

(117)

1,646

9,039

767,321

56,617

(50,993)

(118)

3,277

4,868

$

383,144

$

404,990

$

(7,162) $

780,972

See Notes to Consolidated Financial Statements

54

NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED STATEMENTS OF CASH FLOWS

In thousands

Operating activities:

Net income

Adjustments to reconcile net income to cash provided by operations:

Depreciation and amortization

Regulatory amortization of gas reserves

Deferred tax liabilities, net

Qualified defined benefit pension plan expense

Contributions to qualified defined benefit pension plans

Deferred environmental (expenditures) recoveries, net

Regulatory disallowance of prior environmental cost deferrals

Interest income on deferred environmental expenses

Amortization of environmental remediation

Other

Changes in assets and liabilities:

Receivables, net

Inventories

Taxes accrued

Accounts payable

Interest accrued

Deferred gas costs

Other, net

Cash provided by operating activities

Investing activities:

Capital expenditures

Utility gas reserves

Proceeds from sale of assets

Restricted cash

Other

Cash used in investing activities

Financing activities:

Common stock issued, net

Long-term debt issued

Long-term debt retired

Change in short-term debt

Cash dividend payments on common stock

Other

Cash (used in) provided by financing activities

(Decrease) increase in cash and cash equivalents

Cash and cash equivalents, beginning of period

Cash and cash equivalents, end of period

Supplemental disclosure of cash flow information:

Interest paid, net of capitalization

Income taxes paid, net of refunds

See Notes to Consolidated Financial Statements

55

Year Ended December 31,

2015

2014

2013

$ 53,703

$ 58,692

$ 60,538

80,923

17,991

26,972

5,697

79,193

19,335

24,772

4,984

75,905

11,089

46,483

5,666

(14,120)

(10,500)

(11,700)

(10,568)

88,849

(16,679)

15,000

(5,322)

3,513

3,709

2,373

6,964

(6,541)

(17,175)

(206)

—

—

—

—

—

—

1,853

(2,580)

14,948

(26,094)

(17,163)

1,709

(2,020)

(1,024)

6,933

286

7,422

1,150

31,918

(23,114)

(5,245)

(10,143)

(24,857)

23,216

184,688

215,657

176,390

(118,320)

(120,092)

(138,924)

(1,549)

(26,798)

(54,077)

410

3,000

1,161

175

1,000

1,392

8,638

—

2,231

(115,298)

(144,323)

(182,132)

3,875

—

8,986

—

(60,000)

(80,000)

5,964

50,000

—

35,335

46,500

(2,050)

(49,243)

(50,093)

(49,204)

(4,680)

3,336

(74,713)

(71,271)

(5,323)

9,534

63

9,471

$

4,211

$

9,534

$

1,580

6,290

548

8,923

9,471

$ 39,634

$ 42,602

$ 44,022

17,306

19,445

870

2. SIGNIFICANT ACCOUNTING POLICIES

Use of Estimates 
The preparation of financial statements in conformity with 
generally accepted accounting principles in the United 
States of America (GAAP) requires management to make 
estimates and assumptions that affect reported amounts in 
the consolidated financial statements and accompanying 
notes. Actual amounts could differ from those estimates, and 
changes would most likely be reported in future periods. 
Management believes the estimates and assumptions used 
are reasonable.

Industry Regulation  
Our principal businesses are the distribution of natural gas, 
which is regulated by the OPUC and WUTC, and natural gas 
storage services, which are regulated by either the FERC or 
the CPUC, and to a certain extent by the OPUC and WUTC. 
Accounting records and practices of our regulated 
businesses conform to the requirements and uniform system 
of accounts prescribed by these regulatory authorities in 
accordance with U.S. GAAP. Our businesses regulated by 
the OPUC, WUTC, and FERC earn a reasonable return on 
invested capital from approved cost-based rates, while our 
business regulated by the CPUC earns a return to the extent 
we are able to charge competitive prices above our costs 
(i.e. market-based rates).

In applying regulatory accounting principles, we capitalize or 
defer certain costs and revenues as regulatory assets and 
liabilities pursuant to orders of the OPUC or WUTC, which 
provide for the recovery of revenues or expenses from, or 
refunds to, utility customers in future periods, including a 
return or a carrying charge in certain cases.

NORTHWEST NATURAL GAS 
COMPANY
NOTES TO CONSOLIDATED FINANCIAL 
STATEMENTS

1. ORGANIZATION AND PRINCIPLES OF 
CONSOLIDATION

The accompanying consolidated financial statements 
represent the consolidated results of Northwest Natural Gas 
Company (NW Natural or the Company) and all companies 
we directly or indirectly control, either through majority 
ownership or otherwise. We have two core businesses: our 
regulated local gas distribution business, referred to as the 
utility segment, which serves residential, commercial, and 
industrial customers in Oregon and southwest Washington; 
and our gas storage businesses, referred to as the gas 
storage segment, which provides storage services for 
utilities, gas marketers, electric generators, and large 
industrial users from facilities located in Oregon and 
California. In addition, we have investments and other non-
utility activities we aggregate and report as other. 

Our core utility business assets and operating activities are 
largely included in the parent company, NW Natural. Our 
direct and indirect wholly-owned subsidiaries include NW 
Natural Energy, LLC (NWN Energy), NW Natural Gas 
Storage, LLC (NWN Gas Storage), Gill Ranch Storage, LLC 
(Gill Ranch), NNG Financial Corporation (NNG Financial), 
Northwest Energy Corporation (Energy Corp), and NW 
Natural Gas Reserves, LLC (NWN Gas Reserves). 
Investments in corporate joint ventures and partnerships we 
do not directly or indirectly control, and for which we are not 
the primary beneficiary, are accounted for under the equity 
method, which includes NWN Energy’s investment in Trail 
West Holdings, LLC (TWH) and NNG Financial's investment 
in Kelso-Beaver (KB) Pipeline. NW Natural and its affiliated 
companies are collectively referred to herein as NW Natural. 
The consolidated financial statements are presented after 
elimination of all intercompany balances and transactions, 
except for amounts required to be included under regulatory 
accounting standards to reflect the effect of such regulation. 
In this report, the term “utility” is used to describe our 
regulated gas distribution business, and the term “non-
utility” is used to describe our gas storage businesses and 
other non-utility investments and business activities.

Certain prior year balances in our consolidated financial 
statements and notes have been reclassified to conform 
with the current presentation. These reclassifications had no 
effect on our prior year’s consolidated results of operations, 
financial condition, or cash flows.

56

 
  
 
At December 31, the amounts deferred as regulatory assets 
and liabilities were as follows:

In thousands

Current:

Regulatory Assets

2015

2014

Unrealized loss on derivatives(1)

$ 22,092

$ 29,889

Gas costs
Environmental costs(2)
Decoupling(3)
Other(4)

Total current

Non-current:

Unrealized loss on derivatives(1)
Pension balancing(5)

Income taxes

Pension and other postretirement
benefit liabilities
Environmental costs(2)

Gas costs
Other(4)

8,717

9,270

18,775

10,324

21,794

—

7,505

9,374

$ 69,178

$ 68,562

$

3,447

$

3,515

43,748

43,049

32,541

47,427

184,223

201,845

76,584

1,949

17,711

58,859

5,971

18,750

Total non-current

$ 370,711

$ 368,908

In thousands

Current:

Gas costs
Unrealized gain on derivatives(1)
Other(4)

Total current

Non-current:

Gas costs
Unrealized gain on derivatives(1)
Accrued asset removal costs(6)
Other(4)

Regulatory Liabilities

2015

2014

$ 14,157

$

5,700

2,659

240

13,111

13,165

$ 29,927

$ 19,105

$

8,869

$

2,507

27

—

327,047

311,238

3,344

3,460

Total non-current
$ 317,205
(1)  Unrealized gains or losses on derivatives are non-cash items 
and, therefore, do not earn a rate of return or a carrying 
charge. These amounts are recoverable through utility rates as 
part of the annual Purchased Gas Adjustment (PGA) 
mechanism when realized at settlement.

$ 339,287

(2)  Environmental costs relate to specific sites approved for 

regulatory deferral by the OPUC and WUTC. In Oregon, we 
earn a carrying charge on cash amounts paid, whereas 
amounts accrued but not yet paid do not earn a carrying 
charge until expended. We also accrue a carrying charge on 
insurance proceeds for amounts owed to customers. In 
Washington, a carrying charge related to deferred amounts will 
be determined in a future proceeding. Current environmental 
costs represent remediation costs management expects to 
collect from customers in the next 12 months. Amounts 
included in this estimate are still subject to a prudence and 
earnings test review by the OPUC and do not include the $5 
million base rate rider. The amounts allocable to Oregon are 
recoverable through utility rates, subject to an earnings test. 
See Note 15.  
This deferral represents the margin adjustment resulting from 
differences between actual and expected volumes. 

(3) 

57

(4) 

(5) 

These balances primarily consist of deferrals and amortizations 
under approved regulatory mechanisms. The accounts being 
amortized typically earn a rate of return or carrying charge. 
The deferral of certain pension expenses above or below the 
amount set in rates was approved by the OPUC, with recovery 
of these deferred amounts through the implementation of a 
balancing account, which includes the expectation of lower net 
periodic benefit costs in future years. Deferred pension 
expense balances include accrued interest at the utility’s 
authorized rate of return, with the equity portion of interest 
income recognized when amounts are collected in rates. 
(6)  Estimated costs of removal on certain regulated properties are 
collected through rates. See "Accounting Policies—Plant, 
Property, and Accrued Asset Removal Costs" below.  

The amortization period for our regulatory assets and 
liabilities ranges from less than one year to an 
indeterminable period. Our regulatory deferrals for gas costs 
payable are generally amortized over 12 months beginning 
each November 1 following the gas contract year during 
which the deferred gas costs are recorded. Similarly, most of 
our other regulatory deferred accounts are amortized over 
12 months. However, certain regulatory account balances, 
such as income taxes, environmental costs, pension 
liabilities, and accrued asset removal costs, are large and 
tend to be amortized over longer periods once we have 
agreed upon an amortization period with the respective 
regulatory agency.

We believe all costs incurred and deferred at December 31, 
2015 are prudent. We annually review all regulatory assets 
and liabilities for recoverability and more often if 
circumstances warrant. If we should determine that all or a 
portion of these regulatory assets or liabilities no longer meet 
the criteria for continued application of regulatory 
accounting, then we would be required to write off the net 
unrecoverable balances in the period such determination is 
made. 

Environmental Regulatory Accounting 
On February 20, 2015, the OPUC issued an Order (2015 
Order) addressing outstanding implementation items related 
to the Site Remediation and Recovery Mechanism (SRRM). 
Under the Order, $15 million of $95 million in total 
environmental remediation expenses deferred through 2012 
were disallowed. The OPUC found the $95 million to be 
prudent but disallowed the $15 million from rate recovery 
based on its determination of how an earnings test should 
apply to years between 2003 and 2012, with adjustments for 
other factors the OPUC deemed relevant. We recognized the 
$15 million pre-tax disallowance, or $9.1 million after-tax 
charge, during the first quarter of 2015. The charge was 
recorded in operations and maintenance expense. Also, as a 
result of the order, we recognized $5.3 million pre-tax of 
interest income related to the equity earnings on our 
deferred environmental expenses. 

On January 27, 2016, the OPUC issued an Order 
addressing the outstanding issues. In November 2015, we 
began collecting revenues from customers through the 
SRRM. These collections are included in utility operating 
revenues and are offset by environmental remediation 
expense included in operating expense. See Note 15 and 
Note 16 regarding our SRRM. 

New Accounting Standards

Recently Adopted Accounting Pronouncement
PRESENTATION OF DEFERRED TAXES. On November 
20, 2015, the FASB (Financial Accounting Standards Board) 
issued ASU 2015-17, "Balance Sheet Classification of 
Deferred Taxes." The ASU requires deferred tax liabilities 
and assets to be classified as noncurrent in a classified 
statement of financial position. The new requirements are 
effective for us beginning January 1, 2017 and may be 
applied either prospectively to all deferred tax liabilities and 
assets or retrospectively to all periods presented. We have 
early adopted the change in accounting principle on a 
prospective basis, and it is reflected within our consolidated 
balance sheet for the period ended December 31, 2015. 
Prior periods were not retrospectively adjusted. 

Recently Issued Accounting Pronouncements
BENEFIT PLAN ACCOUNTING. On July 31, 2015, the 
FASB issued ASU 2015-12, "Plan Accounting: Defined 
Benefit Pension Plans, Defined Contribution Pension Plans, 
and Health and Welfare Benefit Plans." The ASU outlines a 
three part update. Only part two of the update is applicable 
for us, which simplifies the investment disclosure 
requirements for employee benefit plans by allowing certain 
disclosures at an aggregated level, reducing the number of 
ways assets must be grouped and analyzed, and no longer 
requiring investment strategy disclosures for certain 
investments. The new requirements are effective for us 
beginning January 1, 2016, with early adoption permitted. 
We will be required to apply the disclosure guidance 
retrospectively and do not expect the ASU to materially affect 
our financial statements and disclosures.

FAIR VALUE MEASUREMENT. On May 1, 2015, the FASB 
issued ASU 2015-07, "Disclosures for Investments in Certain 
Entities That Calculate Net Asset Value per Share (or its 
Equivalent)." The ASU removes the requirement to 
categorize within the fair value hierarchy all investments for 
which fair value is measured using the net asset value per 
share practical expedient and also removes certain 
disclosure requirements. The new requirements are effective 
for us beginning January 1, 2016 with retrospective 
application to all periods presented required and early 
adoption permitted. We do not expect the ASU to materially 
affect our financial statements and disclosures. 

INTANGIBLES - GOODWILL AND OTHER - INTERNAL-
USE SOFTWARE. On April 15, 2015 the FASB issued ASU 
2015-05, "Customer’s Accounting for Fees Paid in a Cloud 
Computing Arrangement." The ASU provides customers 
guidance on how to determine whether a cloud computing 
arrangement includes a software license. The new 
requirements are effective for us beginning January 1, 2016. 
The ASU can be applied prospectively or retrospectively and 
early adoption is permitted. We intend to apply the guidance 
prospectively and do not expect the ASU to materially affect 
our financial statements and disclosures. 

DEBT ISSUANCE COSTS. On April 7, 2015, the FASB 
issued ASU 2015-03, "Simplifying the Presentation of Debt 
Issuance Costs," which requires the presentation of debt 
issuance costs in the balance sheet as a direct deduction 
from the associated debt liability. The new requirements are 

58

effective for us beginning January 1, 2016. The new 
guidance will be applied on a retrospective basis. We do not 
expect the ASU to materially affect our financial statements 
and disclosures.

REVENUE RECOGNITION. On May 28, 2014, the FASB 
issued ASU 2014-09 "Revenue From Contracts with 
Customers." The underlying principle of the guidance 
requires entities to recognize revenue depicting the transfer 
of goods or services to customers at amounts the entity is 
expected to be entitled to in exchange for those goods or 
services. The model provides a five-step approach to 
revenue recognition: (1) identify the contract(s) with the 
customer; (2) identify the separate performance obligations 
in the contract(s); (3) determine the transaction price; (4) 
allocate the transaction price to separate performance 
obligations; and (5) recognize revenue when, or as, each 
performance obligation is satisfied. The new requirements 
prescribe either a full retrospective or simplified transition 
adoption method. On August 12, 2015, the FASB deferred 
the effective date by one year to January 1, 2018 for annual 
reporting periods beginning after December 15, 2017. The 
FASB also permitted early adoption of the standard, but not 
before the original effective date of January 1, 2017. We are 
currently assessing the effect of this standard on our 
financial statements and disclosures. 

Accounting Policies

Plant, Property, and Accrued Asset Removal Costs 
Plant and property are stated at cost, including capitalized 
labor, materials and overhead. In accordance with regulatory 
accounting standards, the cost of acquiring and constructing 
long-lived plant and property generally includes an 
allowance for funds used during construction (AFUDC) or 
capitalized interest. AFUDC represents the regulatory 
financing cost incurred when debt and equity funds are used 
for construction (see “AFUDC” below). When constructed 
assets are subject to market-based rates rather than cost-
based rates, the financing costs incurred during construction 
are included in capitalized interest in accordance with U.S. 
GAAP, not as regulatory financing costs under AFUDC.

In accordance with long-standing regulatory treatment, our 
depreciation rates consist of three components: one based 
on the average service life of the asset, a second based on 
the estimated salvage value of the asset, and a third based 
on the asset’s estimated cost of removal. We collect, through 
rates, the estimated cost of removal on certain regulated 
properties through depreciation expense, with a 
corresponding offset to accumulated depreciation. These 
removal costs are non-legal obligations as defined by 
regulatory accounting guidance. Therefore, we have 
included these costs as non-current regulatory liabilities 
rather than as accumulated depreciation on our consolidated 
balance sheets. In the rate setting process, the liability for 
removal costs is treated as a reduction to the net rate base 
on which the regulated utility has the opportunity to earn its 
allowed rate of return.

The costs of utility plant retired or otherwise disposed of are 
removed from utility plant and charged to accumulated 
depreciation for recovery or refund through future rates. 
Gains from the sale of regulated assets are generally 

 
deferred and refunded to customers. For non-utility assets, 
we record a gain or loss upon the disposal of the property, 
and the gain or loss is recorded in operating income in the 
consolidated statements of comprehensive income.

Our provision for depreciation of utility property, plant, and 
equipment is recorded under the group method on a straight-
line basis with rates computed in accordance with 
depreciation studies approved by regulatory authorities. The 
weighted-average depreciation rate for utility assets in 
service was approximately 2.8% for 2015, 2014, and 2013, 
reflecting the approximate weighted-average economic life of 
the property. This includes 2015 weighted-average 
depreciation rates for the following asset categories: 2.7% 
for transmission and distribution plant, 2.2% for gas storage 
facilities, 4.6% for general plant, and 2.7% for intangible and 
other fixed assets.

AFUDC. Certain additions to utility plant include AFUDC, 
which represents the net cost of debt and equity funds used 
during construction. AFUDC is calculated using actual 
interest rates for debt and authorized rates for ROE, if 
applicable. If short-term debt balances are less than the total 
balance of construction work in progress, then a composite 
AFUDC rate is used to represent interest on all debt funds, 
shown as a reduction to interest charges, and on ROE 
funds, shown as other income. While cash is not 
immediately recognized from recording AFUDC, it is realized 
in future years through rate recovery resulting from the 
higher utility cost of service. Our composite AFUDC rate was 
0.4% in 2015, and 0.3% in 2014 and 2013, respectively.

IMPAIRMENT OF LONG-LIVED ASSETS. We review the 
carrying value of long-lived assets whenever events or 
changes in circumstances indicate the carrying amount of 
the assets may not be recoverable. Factors that would 
necessitate an impairment assessment of long-lived assets 
include a significant adverse change in the extent or manner 
in which the asset is used, a significant adverse change in 
legal factors or business climate that could affect the value of 
the asset, or a significant decline in the observable market 
value or expected future cash flows of the asset, among 
others. 

When such factors are present, we assess the recoverability 
by determining whether the carrying value of the asset will 
be recovered through expected future cash flows. An asset 
is determined to be impaired when the carrying value of the 
asset exceeds the expected undiscounted future cash flows 
from the use and eventual disposition of the asset. If an 
impairment is indicated, we record an impairment loss for the 
difference between the carrying value and the fair value of 
the long-lived assets. Fair value is estimated using 
appropriate valuation methodologies, which may include an 
estimate of discounted cash flows.

We determined there were no long-lived asset impairments 
in 2015; however our Gill Ranch Storage facility within our 
Gas Storage Segment was reviewed for impairment. The 
undiscounted cash flows are in excess of the carrying value 
of the asset and no impairment was indicated. The cash 
flows assume a recovery of storage pricing and the ability to 
contract with higher value customers. Accordingly, if storage 
pricing does not improve and/or new higher value customers 

59

are not obtained, future analysis may result in an impairment 
of these long-lived assets.

Cash and Cash Equivalents  
For purposes of reporting cash flows, cash and cash 
equivalents include cash on hand plus highly liquid 
investment accounts with original maturity dates of three 
months or less. At December 31, 2015 and 2014, 
outstanding checks of approximately $2.5 million and $5.5 
million, respectively, were included in accounts payable.

Revenue Recognition and Accrued Unbilled Revenue
Utility revenues, derived primarily from the sale and 
transportation of natural gas, are recognized upon delivery of 
the gas commodity or service to customers. Revenues 
include accruals for gas delivered but not yet billed to 
customers based on estimates of deliveries from meter 
reading dates to month end (accrued unbilled revenue). 
Accrued unbilled revenue is dependent upon a number of 
factors that require management’s judgment, including total 
gas receipts and deliveries, customer use by billing cycle, 
and weather factors. Accrued unbilled revenue is reversed 
the following month when actual billings occur. Our accrued 
unbilled revenue at December 31, 2015 and 2014 was $58.0 
million.

Non-utility revenues are derived primarily from the gas 
storage segment. At our Mist underground storage facility, 
revenues are primarily firm service revenues in the form of 
fixed monthly reservation charges. At our Gill Ranch facility, 
firm storage services resulting from short-term and long-term 
contracts are typically recognized in revenue ratably over the 
term of the contract regardless of the actual storage capacity 
utilized. In addition, we also have asset management service 
revenue from an independent energy marketing company 
that optimizes commodity, storage, and pipeline capacity 
release transactions. Under this agreement, guaranteed 
asset management revenue is recognized using a straight-
line, pro-rata methodology over the term of each contract. 
Revenues earned above the guaranteed amount are 
recognized as they are earned. 

Revenue Taxes 
Revenue-based taxes are primarily franchise taxes, which 
are collected from customers and remitted to taxing 
authorities. Revenue taxes are included in operating 
revenues in the statement of comprehensive income. 
Revenue taxes were $18.0 million, $18.8 million, and $19.0 
million for 2015, 2014, and 2013, respectively.  

Accounts Receivable and Allowance for Uncollectible 
Accounts 
Accounts receivable consist primarily of amounts due for 
natural gas sales and transportation services to utility 
customers, plus amounts due for gas storage services. We 
establish an allowance for uncollectible accounts (allowance) 
for trade receivables, including accrued unbilled revenue, 
based on the aging of receivables, collection experience of 
past due account balances including payment plans, and 
historical trends of write-offs as a percent of revenues. A 
specific allowance is established and recorded for large 
individual customer receivables when amounts are identified 
as unlikely to be partially or fully recovered. Inactive 
accounts are written-off against the allowance after they are 

  
 
120 days past due or when deemed uncollectible. 
Differences between our estimated allowance and actual 
write-offs will occur based on a number of factors, including 
changes in economic conditions, customer creditworthiness, 
and natural gas prices. The allowance for uncollectible 
accounts is adjusted quarterly, as necessary, based on 
information currently available.

Inventories  
Utility gas inventories, which consist of natural gas in storage 
for the utility, are stated at the lower of average cost or net 
realizable value. The regulatory treatment of utility gas 
inventories provides for cost recovery in customer rates. 
Utility gas inventories injected into storage are priced in 
inventory based on actual purchase costs. Utility gas 
inventories withdrawn from storage are charged to cost of 
gas during the current period at the weighted-average 
inventory cost.

Gas storage inventories, which primarily represent 
inventories at the Gill Ranch storage facility, mainly consist 
of natural gas received as fuel-in-kind from storage 
customers. Gas storage inventories are valued at the lower 
of average cost or net realizable value. Cushion gas is not 
included in our inventory balances, is recorded at original 
cost, and classified as a long-term plant asset.

Materials and supplies inventories consist of both utility and 
non-utility inventories and are stated at the lower of average 
cost or net realizable value.

Our utility and gas storage inventories totaled $59.3 million 
and $68.0 million at December 31, 2015 and 2014, 
respectively. At December 31, 2015 and 2014, our materials 
and supplies inventories totaled $11.6 million and $9.8 
million, respectively.

Gas Reserves
Gas reserves are payments to acquire and produce natural 
gas reserves. Gas reserves are stated at cost, adjusted for 
regulatory amortization, with the associated deferred tax 
benefits recorded as liabilities on the balance sheet. The 
current portion is calculated based on expected gas 
deliveries within the next fiscal year. We recognize regulatory 
amortization of this asset on a volumetric basis calculated 
using the estimated gas reserves and the estimated therms 
extracted and sold each month. The amortization of gas 
reserves is recorded to cost of gas along with gas production 
revenues and production costs. See Note 11.

Derivatives  
Derivatives are measured at fair value and recognized as 
either assets or liabilities on the balance sheet. Changes in 
the fair value of the derivatives are recognized currently in 
earnings unless specific regulatory or hedge accounting 
criteria are met. Accounting for derivatives and hedges 
provides an exception for contracts intended for normal 
purchases and normal sales for which physical delivery is 
probable. In addition, certain derivative contracts are 
approved by regulatory authorities for recovery or refund 
through customer rates. Accordingly, the changes in fair 
value of these approved contracts are deferred as regulatory 
assets or liabilities pursuant to regulatory accounting 
principles. Our financial derivatives generally qualify for 

60

deferral under regulatory accounting. Our index-priced 
physical derivative contracts also qualify for regulatory 
deferral accounting treatment.
Derivative contracts entered into for utility requirements after 
the annual PGA rate has been set and during the PGA year 
are subject to the PGA incentive sharing mechanism. In 
Oregon we participate in a PGA sharing mechanism under 
which we are required to select either an 80% or 90% 
deferral of higher or lower gas costs such that the impact on 
current earnings from the gas cost sharing is either 20% or 
10% of gas cost differences compared to PGA prices, 
respectively. For the PGA year in Oregon beginning 
November 1, 2015, we selected the 80% deferral of gas cost 
differences, and for the PGA years in Oregon beginning 
November 1, 2014, and 2013, we selected a 90% deferral of 
gas cost differences. In Washington, 100% of the differences 
between the PGA prices and actual gas costs are deferred. 
See Note 13.

Our financial derivatives policy sets forth the guidelines for 
using selected derivative products to support prudent risk 
management strategies within designated parameters. Our 
objective for using derivatives is to decrease the volatility of 
gas prices, earnings, and cash flows without speculative risk. 
The use of derivatives is permitted only after the risk 
exposures have been identified, are determined to exceed 
acceptable tolerance levels, and are determined necessary 
to support normal business activities. We do not enter into 
derivative instruments for trading purposes.

Fair Value  
In accordance with fair value accounting, we use the 
following fair value hierarchy for determining inputs for our 
debt, pension plan assets, and our derivative fair value 
measurements:
• 

Level 1: Valuation is based on quoted prices for identical 
instruments traded in active markets;
Level 2: Valuation is based on quoted prices for similar 
instruments in active markets, quoted prices for identical 
or similar instruments in markets that are not active, and 
model-based valuation techniques for which all 
significant assumptions are observable in the market; 
and
Level 3: Valuation is generated from model-based 
techniques that use significant assumptions not 
observable in the market. These unobservable 
assumptions reflect our own estimates of assumptions 
market participants would use in valuing the asset or 
liability.

• 

• 

When developing fair value measurements, it is our policy to 
use quoted market prices whenever available, or to 
maximize the use of observable inputs and minimize the use 
of unobservable inputs when quoted market prices are not 
available. Fair values are primarily developed using industry-
standard models that consider various inputs including: (a) 
quoted future prices for commodities; (b) forward currency 
prices; (c) time value; (d) volatility factors; (e) current market 
and contractual prices for underlying instruments; (f) market 
interest rates and yield curves; (g) credit spreads; and (h) 
other relevant economic measures.

Income Taxes  
We account for income taxes under the asset and liability 
method, which requires the recognition of deferred tax 
assets and liabilities for the expected future tax 
consequences of events that have been included in the 
financial statements. Under this method, deferred tax assets 
and liabilities are determined on the basis of the differences 
between the financial statement and tax basis of assets and 
liabilities using enacted tax rates in effect for the year in 
which the differences are expected to reverse. The effect of 
a change in tax rates on deferred tax assets and liabilities is 
recognized in income in the enactment date period unless a 
regulatory Order specifies deferral of the effect of the change 
in tax rates over a longer period of time.  

Deferred income tax assets and liabilities are also 
recognized for temporary differences where the deferred 
income tax benefits or expenses have previously been 
flowed through in the ratemaking process of the regulated 
utility. Regulatory tax assets and liabilities are recorded on 
these deferred tax assets and liabilities to the extent the 
Company believes they will be recoverable from or refunded 
to customers in future rates. At December 31, 2015 and 
2014, regulatory income tax assets of $47.4 million and 
$51.8 million, respectively, were recorded, a portion of which 
is recorded in current assets. These regulatory income tax 
assets primarily represent future rate recovery of deferred 
tax liabilities, resulting from differences in utility plant 
financial statement and tax bases and utility plant removal 
costs, which were previously flowed through for rate making 
purposes and to take into account the additional future 
taxes, which will be generated by that recovery. These 
deferred tax liabilities, and the associated regulatory income 
tax assets, are currently being recovered through customer 
rates. 

Deferred investment tax credits on utility plant additions, 
which reduce income taxes payable, are deferred for 
financial statement purposes and amortized over the life of 
the related plant. 

The Company recognizes interest and penalties related to 
unrecognized tax benefits, if any, within income tax expense 
and accrued interest and penalties within the related tax 
liability line in the consolidated balance sheets. No accrued 
interest or penalties for uncertain tax benefits have been 
recorded. See Note 9. 

Environmental Contingencies  
Loss contingencies are recorded as liabilities when it is 
probable a liability has been incurred and the amount of the 
loss is reasonably estimable in accordance with accounting 
standards for contingencies. Estimating probable losses 
requires an analysis of uncertainties that often depend upon 
judgments about potential actions by third parties. Accruals 
for loss contingencies are recorded based on an analysis of 
potential results. 

With respect to environmental liabilities and related costs, 
we develop estimates based on a review of information 
available from numerous sources, including completed 
studies and site specific negotiations. It is our policy to 
accrue the full amount of such liability when information is 
sufficient to reasonably estimate the amount of probable 
liability. When information is not available to reasonably 
estimate the probable liability, or when only the range of 
probable liabilities can be estimated and no amount within 
the range is more likely than another, it is our policy to 
accrue at the low end of the range. Accordingly, due to 
numerous uncertainties surrounding the course of 
environmental remediation and the preliminary nature of 
several site investigations, in some cases, we may not be 
able to reasonably estimate the high end of the range of 
possible loss. In those cases we have disclosed the nature 
of the potential loss and the fact that the high end of the 
range cannot be reasonably estimated. See Note 15.

Subsequent Events
See Note 16 for information regarding the resolution of the 
environmental SRRM docket.

61

3. EARNINGS PER SHARE

Basic earnings per share are computed using net income and the weighted average number of common shares outstanding for 
each period presented. Diluted earnings per share are computed in the same manner, except it uses the weighted average 
number of common shares outstanding plus the effects of the assumed exercise of stock options and the payment of estimated 
stock awards from other stock-based compensation plans that are outstanding at the end of each period presented. Antidilutive 
stock awards are excluded from the calculation of diluted earnings per common share. Diluted earnings per share are calculated 
as follows:

In thousands, except per share data

Net income

Average common shares outstanding - basic

Additional shares for stock-based compensation plans (See Note 6)

Average common shares outstanding - diluted

Earnings per share of common stock - basic

Earnings per share of common stock - diluted

Additional information:

Antidilutive shares

4. SEGMENT INFORMATION

We primarily operate in two reportable business segments: 
local gas distribution and gas storage. We also have other 
investments and business activities not specifically related 
to one of these two reporting segments, which are 
aggregated and reported as other. We refer to our local gas 
distribution business as the utility, and our gas storage 
segment and other as non-utility. Our utility segment also 
includes the utility portion of our Mist underground storage 
facility in Oregon and NWN Gas Reserves, which is a 
wholly-owned subsidiary of Energy Corp. Our gas storage 
segment includes NWN Gas Storage, which is a wholly-
owned subsidiary of NWN Energy, Gill Ranch, which is a 
wholly-owned subsidiary of NWN Gas Storage, the non-
utility portion of Mist, and all third-party asset management 
services. Other includes NNG Financial and NWN Energy's 
equity investment in TWH, which is pursuing development 
of a cross-Cascades transmission pipeline project. 

Local Gas Distribution
Our local gas distribution segment is a regulated utility 
principally engaged in the purchase, sale, and delivery of 
natural gas and related services to customers in Oregon 
and southwest Washington. As a regulated utility, we are 
responsible for building and maintaining a safe and reliable 
pipeline distribution system, purchasing sufficient gas 
supplies from producers and marketers, contracting for firm 
and interruptible transportation of gas over interstate 
pipelines to bring gas from the supply basins into our 
service territory, and re-selling the gas to customers subject 
to rates, terms, and conditions approved by the OPUC or  
WUTC. Gas distribution also includes taking customer-
owned gas and transporting it from interstate pipeline 
connections, or city gates, to the customers’ end-use 
facilities for a fee, which is approved by the OPUC or 
WUTC. Approximately 89% of our customers are located in 
Oregon and 11% in Washington. On an annual basis, 
residential and commercial customers typically account for 
around 60% of our utility’s total volumes delivered and 90% 
of our utility’s margin. Industrial customers largely account 
for the remaining volumes and utility margin. A small 
amount of utility margin is also derived from miscellaneous 

62

2015

2014

2013

$

53,703

$

58,692

$

27,347

70

27,417

27,164

59

27,223

$

$

1.96

1.96

$

$

2.16

2.16

$

$

60,538

26,974

53

27,027

2.24

2.24

12

18

26

services, gains or losses from an incentive gas cost sharing 
mechanism, and other service fees.

Industrial sectors we serve include: pulp, paper, and other 
forest products; the manufacture of electronic, 
electrochemical and electrometallurgical products; the 
processing of farm and food products; the production of 
various mineral products; metal fabrication and casting; the 
production of machine tools, machinery and textiles; the 
manufacture of asphalt, concrete and rubber; printing and 
publishing; nurseries; government and educational 
institutions; and electric generation. No individual customer 
or industry group accounts for over 10% of our utility 
revenues or utility margins.

Gas Storage
Our gas storage segment includes natural gas storage 
services provided to customers primarily from two 
underground natural gas storage facilities, our Gill Ranch 
gas storage facility, and the non-utility portion of our Mist 
gas storage facility. In addition to earning revenue from 
customer storage contracts, we also use an independent 
energy marketing company to provide asset management 
services for utility and non-utility capacity, the results of 
which are included in this business segment. 

Mist Gas Storage Facility
Earnings from non-utility assets at our Mist facility in 
Oregon are primarily related to firm storage capacity 
revenues. Earnings for the Mist facility also include 
revenue, net of amounts shared with utility customers, from 
management of utility assets at Mist and upstream capacity 
when not needed to serve utility customers. We retain 80% 
of the pre-tax income from these services when the costs of 
the capacity have not been included in utility rates, or 33% 
of the pre-tax income when the costs have been included in 
utility rates. The remaining 20% and 67%, respectively, are 
recorded to a deferred regulatory account for crediting back 
to utility customers. 

Gill Ranch Gas Storage Facility
Gill Ranch has a joint project agreement with Pacific 
Gas and Electric Company (PG&E) to own and operate the 
Gill Ranch underground natural gas storage facility near 
Fresno, California. Gill Ranch has a 75% undivided 
ownership interest in the facility and is also the operator of 
the facility, which offers storage services to the California 
market at market-based rates, subject to CPUC regulation 
including, but not limited to, service terms and conditions 
and tariff regulations. Although this is a jointly owned 
property, each owner is independently responsible for 
financing its share of the Gill Ranch natural gas storage 
facility. Revenues are primarily related to firm storage 
capacity as well as asset management revenues. 

Other
We have non-utility investments and other business 
activities, which are aggregated and reported as other. 

Other primarily consists of an equity method investment in 
TWH, which was formed to build and operate an interstate 
gas transmission pipeline in Oregon (TWP) and other 
pipeline assets in NNG Financial. For more information on 
TWP, see Note 12. Other also includes some corporate 
operating and non-operating revenues and expenses that 
cannot be allocated to utility operations.

NNG Financial's assets primarily consist of an active, 
wholly-owned subsidiary which owns a 10% interest in an 
18-mile interstate natural gas pipeline. NNG Financial’s 
total assets were $0.7 million and $0.8 million at December 
31, 2015 and 2014, respectively.

Segment Information Summary
Inter-segment transactions were insignificant for the periods presented. The following table presents summary financial 
information concerning the reportable segments:

In thousands

2015

Utility

Gas Storage

Other

Total

Operating revenues

$

702,210

$

21,356

$

225

$

Depreciation and amortization

Income from operations

Net income

Capital expenditures

74,410

119,215

53,391

115,272

6,513

5,032

174

3,048

—

1

138

—

723,791

80,923

124,248

53,703

118,320

Total assets at December 31, 2015

2,800,018

261,750

14,924

3,076,692

2014

Operating revenues

$

731,578

$

22,235

$

224

$

Depreciation and amortization

Income from operations

Net income (loss)

Capital expenditures

72,660

138,711

58,587

117,322

6,533

3,987

(364)

2,770

—

267

469

—

754,037

79,193

142,965

58,692

120,092

Total assets at December 31, 2014

2,775,011

273,813

16,121

3,064,945

2013

Operating revenues

$

727,182

$

31,112

$

224

$

—

11

49

—

758,518

75,905

142,746

60,538

138,924

16,447

2,970,911

Depreciation and amortization

Income from operations

Net income

Capital expenditures

Total assets at December 31, 2013

69,420

128,066

54,920

137,466

2,644,367

6,485

14,669

5,569

1,458

310,097

63

 
Utility Margin
Utility margin is a financial measure consisting of utility operating revenues, which are reduced by revenue taxes, the associated 
cost of gas, and environmental recovery revenues. The cost of gas purchased for utility customers is generally a pass-through 
cost in the amount of revenues billed to regulated utility customers. Environmental recovery revenues represent collections 
received from customers through our environmental recovery mechanism in Oregon. These collections are offset by the 
amortization of environmental liabilities, which is presented as environmental remediation expense in our operating expenses. 
By subtracting cost of gas and environmental remediation expense from utility operating revenues, utility margin provides a key 
metric used by our chief operating decision maker in assessing the performance of the utility segment. The gas storage segment 
and other emphasize growth in operating revenues as opposed to margin because they do not incur a product cost (i.e. cost of 
gas sold) like the utility and, therefore, use operating revenues and net income to assess performance.

The following table presents additional segment information concerning utility margin:

In thousands

Utility margin calculation:

Utility operating revenues (1)

Less: Utility cost of gas

          Environmental remediation expense

Utility margin

2015

2014

2013

$

$

702,210

$

731,578

$

327,305

3,513

365,490

—

727,182

373,298

—

371,392

$

366,088

$

353,884

(1)   Utility operating revenues include environmental recovery revenues, which are collections received from customers through our 

environmental recovery mechanism in Oregon, offset by environmental remediation expense. 

Summary of Changes in Common Stock
The following table shows the changes in the number of 
shares of our common stock issued and outstanding:

In thousands

Balance, December 31, 2012

   Sales to employees under ESPP

Stock-based compensation

   Sales to shareholders under DRPP

Balance, December 31, 2013

   Sales to employees under ESPP

Stock-based compensation

   Sales to shareholders under DRPP

Balance, December 31, 2014

   Sales to employees under ESPP

Stock-based compensation

   Sales to shareholders under DRPP

Balance, December 31, 2015

Shares

26,917

16

42

100

27,075

24

83

102

27,284

19

78

46

27,427

5. COMMON STOCK

Common Stock
As of December 31, 2015 and 2014, we had 100 million 
shares of common stock authorized. As of December 31, 
2015, we had reserved 78,857 shares for issuance of 
common stock under the Employee Stock Purchase Plan 
(ESPP) and 297,879 shares under our Dividend 
Reinvestment and Direct Stock Purchase Plan (DRPP).  At 
the Company's election, shares sold through our DRPP may 
be purchased in the open market or through original 
issuance of shares reserved for issuance under the DRPP. 
In July 2015 we moved DRPP to open market purchases.

The Restated Stock Option Plan (SOP) was terminated with 
respect to new grants in 2012; however, options granted 
before the Restated SOP was terminated will remain 
outstanding until the earlier of their expiration, forfeiture, or 
exercise. There were 352,688 options outstanding at 
December 31, 2015, which were granted prior to termination 
of the plan. 

Stock Repurchase Program
We have a share repurchase program under which we may 
purchase our common shares on the open market or 
through privately negotiated transactions. We currently have 
Board authorization through May 2016 to repurchase up to 
an aggregate of the greater of 2.8 million shares or $100 
million. No shares of common stock were repurchased 
pursuant to this program during the year ended December 
31, 2015. Since the plan’s inception in 2000, a total of 2.1 
million shares have been repurchased at a total cost of 
$83.3 million.

64

6. STOCK-BASED COMPENSATION

Our stock-based compensation plans are designed to 
promote stock ownership in NW Natural by employees and 
officers. These compensation plans include a Long-Term 
Incentive Plan (LTIP), an ESPP, and a Restated SOP. 

Long-Term Incentive Plan
The LTIP is intended to provide a flexible, competitive 
compensation program for eligible officers and key 
employees. Under the LTIP, shares of common stock are 
authorized for equity incentive grants in the form of stock, 
restricted stock, restricted stock units, stock options, or 
performance shares. An aggregate of 850,000 shares were 
authorized for issuance as of December 31, 2015. Shares 
awarded under the LTIP may be purchased on the open 
market or issued as original shares. 

Of the 850,000 shares of common stock authorized for LTIP 
awards at December 31, 2015, there were 186,979 shares 
available for issuance under any type of award and 250,000 
shares available for option grants. This assumes market, 
performance, and service based grants currently 
outstanding are awarded at the target level. There were no 
outstanding grants of restricted stock or stock options under 
the LTIP at December 31, 2015 or 2014. The LTIP stock 
awards are compensatory awards for which compensation 
expense is based on the fair value of stock awards, with 
expense being recognized over the performance and 
vesting period of the outstanding awards.

Performance Shares
Since the LTIP’s inception in 2001, performance shares, 
which incorporate market, performance, and service-based 
factors, have been granted annually with three-year 
performance periods. The following table summarizes 
performance share expense information:

Dollars in thousands

Estimated award:

2013-2015 grant(3)

Actual award:

2012-2014 grant

2011-2013 grant

Shares(1) 

Expense 
During Award 
Year(2)

Total
Expense
for Award

8,465

$

312

$

1,240

8,621

9,819

582

390

1,821

960

(1)  

In addition to common stock shares, a participant also 
receives a dividend equivalent cash payment equal to the 
number of shares of common stock received on the award 
payout multiplied by the aggregate cash dividends paid per 
share during the performance period. 

(2)   Amount represents the expense recognized in the third year of 

(3) 

the vesting period noted above.
This represents the estimated number of shares to be 
awarded as of December 31, 2015 as certain performance 
share measures had been achieved. Amounts are subject to 
change with final payout amounts authorized by the Board of 
Directors in February 2016.

The aggregate number of performance shares granted and outstanding at the target and maximum levels were as follows:

Dollars in thousands

Performance Period

Performance Share Awards Outstanding

Target

Maximum

2015

Expense

Cumulative Expense

December 31, 2015

2013-15

2014-16

2015-17

Total

34,100

39,725

43,950

117,775

68,200

$

312

$

79,450

87,900

235,550

$

632

853

1,797

1,240

1,250

853

For the 2013-2015 performance period, awards will be 
based on total shareholder return (TSR factor) relative to a 
peer group of gas distribution companies over the three-
year performance period and on performance results 
achieved relative to specific core and non-core strategies 
(strategic factor). In addition to the TSR and strategic 
factors, the 2014-2016 and 2015-2017 performance period 
awards also included weighting for EPS and Return on 
Invested Capital (ROIC) factors. Compensation expense is 
recognized in accordance with accounting standards for 
stock-based compensation and calculated based on 
performance levels achieved and an estimated fair value 
using the Monte-Carlo method. The weighted-average grant 
date fair value of unvested shares at December 31, 2015 
and 2014 was $49.09 and $42.06 per share, 
respectively. The weighted-average grant date fair value of 
shares vested during the year was $46.64 per share and for 
shares granted during the year was $51.78 per share. As of 
December 31, 2015, there was $2.3 million of unrecognized 
compensation expense related to the unvested portion of 

performance awards expected to be recognized through 
2017. 

Restricted Stock Units
In 2012, the Company began granting RSUs under the LTIP 
instead of stock options under the Restated SOP.   
Generally, the RSUs awarded are forfeitable and include a 
performance-based threshold as well as a vesting period of 
4 years from the grant date. Upon vesting, the RSU holder 
is issued one share of common stock plus a cash payment 
equal to the total amount of dividends paid per share 
between the grant date and vesting date of that portion of 
the RSU. The fair value of an RSU is equal to the closing 
market price of the Company's common stock on the grant 
date. During 2015, total RSU expense was $1.3 million 
compared to $0.9 million in 2014. As of December 31, 2015, 
there was $2.6 million of unrecognized compensation cost 
from grants of RSUs, which is expected to be recognized 
over a period extending through 2019. 

65

 
Information regarding the RSU activity is summarized as 
follows:

Number
of
RSUs

Weighted -
Average
Price Per 
RSU

Nonvested, December 31, 2012

24,864

$

Granted

Vested

Forfeited

Nonvested, December 31, 2013

Granted

Vested

Forfeited

Nonvested, December 31, 2014

Granted

Vested

Forfeited

Nonvested, December 31, 2015

25,748

(5,455)

(590)

44,567

38,765

(12,060)

(478)

70,794

37,264

(19,003)

(468)

88,587

47.57

45.38

48.01

46.58

46.27

42.19

46.52

45.47

44.00

46.29

44.81

44.99

44.78

Restated Stock Option Plan
The Restated SOP was terminated for new option grants in 
2012; however, options granted before the plan terminated 
will remain outstanding until the earlier of their expiration, 
forfeiture, or exercise. Any new grants of stock options 
would be made under the LTIP.

Options under the Restated SOP were granted to officers 
and key employees designated by a committee of our Board 
of Directors. All options were granted at an option price 
equal to the closing market price on the date of grant and 
may be exercised for a period up to 10 years and seven 
days from the date of grant. Option holders may exchange 
shares they have owned for at least 6 months, valued at the 
current market price, to purchase shares at the option price.

Information regarding the Restated SOP activity is 
summarized as follows:

Weighted -
Average
Price Per 
Share

Intrinsic
Value
(In millions)

Option
Shares

Balance outstanding,
December 31, 2012

529,925

$

42.22

$

Exercised

Forfeited

Balance outstanding,
December 31, 2013

Exercised

Forfeited

Balance outstanding,
December 31, 2014
Exercised

Forfeited

Balance outstanding
and exercisable,
December 31, 2015

(33,800)

(3,975)

492,150

(69,662)

(6,400)

416,088

(62,900)

(500)

32.16

43.72

42.89

39.82

43.59

43.40

39.96

45.74

352,688

44.00

1.3

0.3

n/a

0.6

0.5

n/a

2.7

0.5

n/a

2.3

During 2015, cash of $2.5 million was received for stock 
options exercised and $0.1 million related tax expense was 
recognized.  During 2015, 2014, and 2013, the total fair 
value of options that vested was $0.2 million, $0.4 million 
and $0.5 million, respectively. The weighted average 
remaining life of options exercisable and outstanding at 
December 31, 2015 was 3.6 years.

Employee Stock Purchase Plan
The ESPP allows employees to purchase common stock at 
85% of the closing price on the trading day immediately 
preceding the initial offering date, which is set annually. 
Each eligible employee may purchase up to $21,227 worth 
of stock through payroll deductions over a 12-month period, 
with shares issued at the end of the 12-month subscription 
period.

Stock-Based Compensation Expense
Stock-based compensation expense is recognized as 
operations and maintenance expense or is capitalized as 
part of construction overhead. The following table 
summarizes the financial statement impact of stock-based 
compensation under our LTIP, Restated SOP and ESPP:

In thousands

2015

2014

2013

Operations and maintenance
expense, for stock-based
compensation

$ 2,673 $ 2,309 $ 1,876

Income tax benefit

(1,012)

(861)

(765)

Net stock-based compensation
effect on net income

$ 1,661 $ 1,448 $ 1,111

Amounts capitalized for stock-based
compensation

$

661 $

597 $

331

7. DEBT

Short-Term Debt
Our primary source of short-term funds is from the sale of 
commercial paper and bank loans. In addition to issuing 
commercial paper or bank loans to meet seasonal working 
capital requirements, short-term debt is used temporarily to 
fund capital requirements. Commercial paper and bank 
loans are periodically refinanced through the sale of long-
term debt or equity securities. Our commercial paper 
program is supported by one or more committed credit
facilities. 

In the fourth quarter of 2015, we entered into a short-term 
credit facility loan totaling $50 million, as a short-term bridge 
through our peak heating season, which was repaid on 
February 4, 2016. 

At December 31, 2015, total short-term debt outstanding 
was $270 million, which includes $220 million of commercial 
paper and a $50 million credit facility. At December 31, 2014 
total short-term debt outstanding was $234.7 million, which 
was comprised entirely of commercial paper. The weighted 
average interest rate at December 31, 2015 and 2014 was 
0.6% and 0.4%, respectively. 

66

 
The carrying cost of our commercial paper approximates fair 
value using Level 2 inputs, due to the short-term nature of 
the notes. See Note 2 for a description of the fair value 
hierarchy. At December 31, 2015, our commercial paper had 
a maximum maturity of 77 days and an average maturity of 
36 days. 

We have a $300 million credit agreement, with a feature that 
allows us to request increases in the total commitment 
amount up to a maximum amount of $450 million. The 
maturity of the agreement is December 20, 2019. We have 
a letter of credit of $100 million. Any principal and unpaid 
interest owed on borrowings under the agreement is due 
and payable on or before the expiration date. There were no 
outstanding balances under the agreement and no letters of 
credit issued or outstanding at December 31, 2015 and 
2014.

The credit agreement requires that we maintain credit 
ratings with Standard & Poor’s (S&P) and Moody’s Investors 
Service, Inc. (Moody’s) and notify the lenders of any change 
in our senior unsecured debt ratings or senior secured debt 
ratings, as applicable, by such rating agencies. A change in 
our debt ratings is not an event of default, nor is the 
maintenance of a specific minimum level of debt rating a 
condition of drawing upon the credit facility. However, 
interest rates on any loans outstanding under the credit 
facility are tied to debt ratings, which would increase or 
decrease the cost of any loans under the credit facility when 
ratings are changed.

The credit agreement also requires us to maintain a 
consolidated indebtedness to total capitalization ratio of 
70% or less. Failure to comply with this covenant would 
entitle the lenders to terminate their lending commitments 
and accelerate the maturity of all amounts outstanding. We 
were in compliance with this covenant at December 31, 
2015 and 2014.

Long-Term Debt
The issuance of first mortgage bonds (FMBs), which 
includes our medium-term notes, under the Mortgage and 
Deed of Trust (Mortgage) is limited by eligible property, 
adjusted net earnings and other provisions of the Mortgage. 
The Mortgage constitutes a first mortgage lien on 
substantially all of our utility property. 

Maturities and Outstanding Long-Term Debt
Retirement of long-term debt for each of the 12-month 
periods through December 31, 2020 and thereafter are as 
follows: 

In thousands

Year

2016
2017
2018
2019
2020
Thereafter

$

25,000
40,000
22,000
30,000
75,000
409,700

67

The following table presents our debt outstanding as of 
December 31:

In thousands

First Mortgage Bonds

4.70 % Series B due 2015
5.15 % Series B due 2016
7.00 % Series B due 2017
6.60 % Series B due 2018
8.31 % Series B due 2019
7.63 % Series B due 2019
5.37 % Series B due 2020
9.05 % Series A due 2021
3.176 % Series B due 2021
3.542% Series B due 2023
5.62 % Series B due 2023
7.72 % Series B due 2025
6.52 % Series B due 2025
7.05 % Series B due 2026
7.00 % Series B due 2027
6.65 % Series B due 2027
6.65 % Series B due 2028
7.74 % Series B due 2030
7.85 % Series B due 2030
5.82 % Series B due 2032
5.66 % Series B due 2033
5.25 % Series B due 2035
4.00 % due 2042

2015

2014

—
25,000
40,000
22,000
10,000
20,000
75,000
10,000
50,000
50,000
40,000
20,000
10,000
20,000
20,000
19,700
10,000
20,000
10,000
30,000
40,000
10,000
50,000
601,700

40,000
25,000
40,000
22,000
10,000
20,000
75,000
10,000
50,000
50,000
40,000
20,000
10,000
20,000
20,000
19,700
10,000
20,000
10,000
30,000
40,000
10,000
50,000
641,700

Subsidiary Senior Secured Debt

Gill Ranch debt due 2016

Less: Current maturities

Total long-term debt

—
601,700
25,000
$ 576,700

20,000
661,700
40,000
$ 621,700

Subsidiary Senior Secured Debt
On December 18, 2015, Gill Ranch repaid $20 million of 
fixed-rate senior secured debt outstanding with an interest 
rate of 7.75%, which included a make whole interest 
provision using available cash and cash flows from 
operations, including cash from intercompany receivables. 

Retirements of Long-Term Debt
The utility redeemed $40 million of FMBs with a coupon rate 
of 4.70% in June 2015. 

Fair Value of Long-Term Debt
Our outstanding debt does not trade in active markets. We 
estimate the fair value of our debt using utility companies 
with similar credit ratings, terms, and remaining maturities to 
our debt that actively trade in public markets. These 
valuations are based on Level 2 inputs as defined in the fair 
value hierarchy. See Note 2. 

The following table provides an estimate of the fair value of 
our long-term debt, including current maturities of long-term 
debt, using market prices in effect on the valuation date: 

In thousands

December 31,

2015

2014

Carrying amount

$

601,700

$

Estimated fair value

667,168

661,700

756,808

 
8. PENSION AND OTHER POSTRETIREMENT BENEFIT COSTS 

We maintain a qualified non-contributory defined benefit pension plan, non-qualified supplemental pension plans for eligible 
executive officers and other key employees, and other postretirement employee benefit plans. We also have qualified defined 
contribution plans (Retirement K Savings Plan) for all eligible employees. The qualified defined benefit pension plan and 
Retirement K Savings Plan have plan assets, which are held in qualified trusts to fund retirement benefits. Effective January 1, 
2007 and 2010, the qualified defined benefit retirement plans and postretirement benefits for non-union employees and union 
employees, respectively, were closed to new participants. These plans were not available to employees of our non-utility 
subsidiaries. Non-union and union employees hired or re-hired after December 31, 2006 and 2009, respectively, and employees 
of NW Natural subsidiaries are provided an enhanced Retirement K Savings Plan benefit.

The following table provides a reconciliation of the changes in benefit obligations and fair value of plan assets, as applicable, for 
the pension and other postretirement benefit plans, excluding the Retirement K Savings Plan, and a summary of the funded 
status and amounts recognized in the consolidated balance sheets as of December 31:

In thousands

Reconciliation of change in benefit obligation:

Obligation at January 1

Service cost

Interest cost
Plan amendments(1)

Net actuarial (gain) loss

Benefits paid

Obligation at December 31

Reconciliation of change in plan assets:

Fair value of plan assets at January 1

Actual return on plan assets

Employer contributions

Benefits paid

Postretirement Benefit Plans

Pension Benefits

Other Benefits

2015

2014

2015

2014

$

487,278

$

391,089

$

32,072

$

28,754

8,267

18,360

—

(32,354)

(35,923)

7,213

18,198

—

90,710

(19,932)

527

1,179

(3,435)

2,724

(2,018)

483

1,252

—

3,454

(1,871)

$

445,628

$

487,278

$

31,049

$

32,072

$

279,164

$

267,062

$

(9,599)

15,696

(35,923)

19,957

12,077

(19,932)

— $

—

2,018

(2,018)

—

—

1,871

(1,871)

—

Fair value of plan assets at December 31

$

249,338

$

279,164

$

— $

Funded status at December 31
(32,072)
(1)   We amended our qualified defined benefit pension plan to establish a health retirement account (HRA) plan for participants. The HRA plan 

(208,114) $

(196,290) $

(31,049) $

$

permits participants to obtain reimbursement of health care expenses on a nontaxable basis, and the amendment is effective April 1, 2016.   

Our qualified defined benefit pension plan has an aggregate benefit obligation of $411.8 million and $451.2 million at December 
31, 2015 and 2014, respectively, and fair values of plan assets of $249.3 million and $279.2 million, respectively. 

The following table presents amounts realized through regulatory assets or in other comprehensive loss (income) for the years 
ended December 31:

Regulatory Assets

Other Comprehensive Loss (Income)

Pension Benefits

Other Postretirement Benefits

Pension Benefits

In thousands

2015

2014

2013

2015

2014

2013

2015

2014

2013

Net actuarial loss (gain)

$

419

$ 83,027

$ (51,892) $ 2,724

$

3,454

$

(4,283) $

(2,549) $

7,221

$

(3,302)

Amortization of:

Prior service cost

Actuarial loss

(230)

(230)

(230)

(16,372)

(9,823)

(16,744)

(197)

(554)

(197)

(221)

(197)

(733)

—

7

7

(2,236)

(1,091)

(1,550)

Total

$ (16,183) $ 72,974

$ (68,866) $ 1,973

$

3,036

$

(5,213) $

(4,785) $

6,137

$

(4,845)

68

 
The following table presents amounts recognized in regulatory assets and accumulated other comprehensive loss (AOCL) at 
December 31:

In thousands

Prior service cost (credit)

Net actuarial loss

Total

Regulatory Assets

AOCL

Pension Benefits

Other Postretirement Benefits

Pension Benefits

2015

2014

2015

2014

2015

2014

$

$

406

$

637

$

(3,143) $

488

$

1

$

176,894

192,846

10,067

7,898

11,870

177,300

$

193,483

$

6,924

$

8,386

$

11,871

$

2

16,604

16,606

The following table presents amounts recognized in AOCL and the changes in AOCL related to our non-qualified employee 
benefit plans:

In thousands

Beginning balance

Amounts reclassified to AOCL

Amounts reclassified from AOCL:

Amortization of prior service costs

Amortization of actuarial losses

Total reclassifications before tax

Tax (benefit) expense

Total reclassifications for the period

Ending balance

In 2016, an estimated $13.3 million will be amortized from 
regulatory assets to net periodic benefit costs, consisting of 
$13.5 million of actuarial losses, and $0.2 million of prior 
service credits. A total of $1.3 million will be amortized from 
AOCL to earnings related to actuarial losses in 2016.

Our assumed discount rate for the pension plan and other 
postretirement benefit plans was determined independently 
based on the Citigroup Above Median Curve (discount rate 
curve), which uses high quality corporate bonds rated AA- 
or higher by S&P or Aa3 or higher by Moody’s. The discount 
rate curve was applied to match the estimated cash flows in 
each of our plans to reflect the timing and amount of 
expected future benefit payments for these plans.

Our assumed expected long-term rate of return on plan 
assets for the qualified pension plan was developed using a 
weighted average of the expected returns for the target 
asset portfolio. In developing the expected long-term rate of 
return assumption, consideration was given to the historical 
performance of each asset class in which the plans’ assets 
are invested and the target asset allocation for plan assets.

Our investment strategy and policies for qualified pension 
plan assets held in the retirement trust fund were approved 
by our retirement committee, which is composed of senior 
management with the assistance of an outside investment 
consultant. The policies set forth the guidelines and 
objectives governing the investment of plan assets. Plan 
assets are invested for total return with appropriate 
consideration for liquidity, portfolio risk and return 
expectations. All investments are expected to satisfy the 
prudent investments rule under the Employee Retirement 
Income Security Act of 1974. The approved asset classes 
may include cash and short-term investments, fixed income, 
common stock and convertible securities, absolute and real 

Year Ended December 31,

2015

2014

$

$

(10,076) $

2,549

—

2,236

4,785

(1,871)

2,914

(7,162) $

(6,358)

(7,221)

(7)

1,091

(6,137)

2,419

(3,718)

(10,076)

return strategies, real estate, and investments in NW 
Natural securities. Plan assets may be invested in 
separately managed accounts or in commingled or mutual 
funds. Investment re-balancing takes place periodically as 
needed, or when significant cash flows occur, in order to 
maintain the allocation of assets within the stated target 
ranges. The retirement trust fund is not currently invested in 
NW Natural securities.

The following table presents the pension plan asset target 
allocation at December 31, 2015:

Asset Category

U.S. large cap equity

U.S. small/mid cap equity

Non-U.S. equity

Emerging markets equity

Long government/credit

High yield bonds

Emerging market debt

Real estate funds

Absolute return strategy

 Target Allocation

18.0%

10.0

18.0

5.0

20.0

5.0

5.0

7.0

12.0

Our non-qualified supplemental defined benefit plan 
obligations were $33.8 million and $36.1 million at 
December 31, 2015 and 2014, respectively. These plans 
are not subject to regulatory deferral, and the changes in 
actuarial gains and losses, prior service costs and transition 
assets, or obligations are recognized in AOCL, net of tax 
until they are amortized as a component of net periodic 
benefit cost. These are unfunded, non-qualified plans with 
no plan assets; however, we indirectly fund a significant 
portion of our obligations with company- and trust-owned life 
insurance and other assets.

69

 
 
 
Our other postretirement benefit plans are unfunded plans 
but are subject to regulatory deferral. The actuarial gains 
and losses, prior service costs and transition assets or 
obligations for these plans are recognized as a regulatory 
asset. 

Net periodic benefit costs consist of service costs, interest 
costs, the amortization of actuarial gains and losses and

the expected returns on plan assets, which are based in 
part on a market-related valuation of assets. The market-
related valuation reflects differences between expected 
returns and actual investment returns with the differences 
recognized over a three-year or less period from the year in 
which they occur, thereby reducing year-to-year net periodic 
benefit cost volatility.

The following table provides the components of net periodic benefit cost for the Company's pension and other postretirement 
benefit plans for the years ended December 31: 

In thousands

Service cost

Interest cost

Expected return on plan assets

Amortization of prior service costs

Amortization of net actuarial loss

Net periodic benefit cost

Amount allocated to construction
Amount deferred to regulatory balancing account(1)

Pension Benefits

Other Postretirement Benefits

2015

2014

2013

2015

2014

2013

$

8,267

$

7,213

$

8,698

$

527

$

483

$

18,360

(20,676)

231

18,609

24,791

(6,834)

(8,241)

18,198

16,400

1,179

1,252

(19,496)

(18,721)

223

10,914

17,052

(4,625)

(4,578)

223

18,294

24,894

(6,712)

(9,115)

—

197

554

2,457

(808)

—

—

197

221

2,153

(702)

—

656

1,157

—

197

734

2,744

(856)

—

Net amount charged to expense

$

9,716

$

7,849

$

9,067

$

1,649

$

1,451

$

1,888

(1)   The deferral of defined benefit pension expenses above or below the amount set in rates was approved by the OPUC, with recovery of 

these deferred amounts through the implementation of a balancing account. The balancing account includes the expectation of higher net 
periodic benefit costs than costs recovered in rates in the near-term with lower net periodic benefit costs than costs recovered in rates 
expected in future years. Deferred pension expense balances include accrued interest at the utility’s authorized rate of return, with the  
equity portion of the interest recognized when amounts are collected in rates. See Note 2.

Net periodic benefit costs are reduced by amounts capitalized to utility plant based on approximately 25% to 35% payroll 
overhead charge. In addition, a certain amount of net periodic benefit costs are recorded to the regulatory balancing account for 
pensions. Net periodic pension cost less amounts charged to capital accounts and regulatory balancing accounts are expenses 
recognized in earnings.

The following table provides the assumptions used in measuring periodic benefit costs and benefit obligations for the years 
ended December 31:

Pension Benefits

Other Postretirement Benefits

2015

2014

2013

2015

2014

2013

Assumptions for net periodic benefit cost:

Weighted-average discount rate

3.82%

4.71%

3.84%

3.74%

4.45%

3.56%

Rate of increase in compensation

3.25-5.0%

3.25-5.0%

3.25-5.0%

Expected long-term rate of return

7.50%

7.50%

7.50%

n/a

n/a

n/a

n/a

n/a

n/a

Assumptions for year-end funded status:

Weighted-average discount rate

4.21%

3.85%

4.73%

4.00%

3.74%

4.45%

Rate of increase in compensation

3.25-4.5%

3.25-5.0%

3.25-5.0%

Expected long-term rate of return

7.50%

7.50%

7.50%

n/a

n/a

n/a

n/a

n/a

n/a

70

 
 
 
 
 
 
 
 
(MAP-21) legislation changed several provisions affecting 
pension plans, including temporary funding relief and 
Pension Benefit Guaranty Corporation (PBGC) premium 
increases, which reduces the level of minimum required 
contributions in the near-term but generally increases 
contributions in the long-run and increases the operational 
costs of running a pension plan. In 2014, the Highway and 
Transportation Funding Act (HATFA) was signed and 
extends certain aspects of MAP-21 as well as modifies the 
phase-out periods for the limitations.  

Our qualified defined benefit pension plan is currently 
underfunded by $162.5 million at December 31, 2015. 
Including the impacts of MAP-21 and HATFA, we made 
cash contributions totaling $14.1 million to our qualified 
defined benefit pension plan for 2015. During 2016, we 
expect to make contributions of approximately $14.5 million 
to this plan.

Multiemployer Pension Plan
In addition to the Company-sponsored defined benefit plans 
presented above, prior to 2014 we contributed to a 
multiemployer pension plan for our utility's union employees 
known as the Western States Office and Professional 
Employees International Union Pension Fund (Western 
States Plan). The plan's employer identification number is 
94-6076144. Effective December 22, 2013, we withdrew 
from the plan, which was a noncash transaction. Vested 
participants will receive all benefits accrued through the 
date of withdrawal. As the plan was underfunded at the time 
of withdrawal, we were assessed a withdrawal liability of 
$8.3 million, plus interest, which requires NW Natural to pay 
$0.6 million each year to the plan for 20 years beginning in 
July 2014. The cost of the withdrawal liability was deferred 
to a regulatory account on the balance sheet. 

We made payments of $0.6 million for 2015, and as of 
December 31, 2015 the liability balance was $7.8 million. 
For 2014 and 2013, contributions to the plan were $0.4 
million and $0.5 million, respectively, which was 
approximately 4% to 5% of the total contributions to the plan 
by all employer participants in those years.

Defined Contribution Plan
The Retirement K Savings Plan is a qualified defined 
contribution plan under Internal Revenue Code Section   
401(k). Employer contributions totaled $3.7 million, $3.4 
million, and $2.2 million for 2015, 2014, and 2013, 
respectively. The Retirement K Savings Plan includes an 
Employee Stock Ownership Plan. 

Deferred Compensation Plans
The supplemental deferred compensation plans for eligible 
officers and senior managers are non-qualified plans. These 
plans are designed to enhance the retirement savings of 
employees and to assist them in strengthening their 
financial security by providing an incentive to save and 
invest regularly. 

The assumed annual increase in health care cost trend 
rates used in measuring other postretirement benefits as of 
December 31, 2015 was 7.50% for both pre- and post-65 
populations. These trend rates apply to both medical and 
prescription drugs. Medical costs and prescription drugs are 
assumed to decrease gradually each year to a rate of 
4.75% by 2024.

Assumed health care cost trend rates can have a significant 
effect on the amounts reported for the health care plans; 
however, other postretirement benefit plans have a cap on 
the amount of costs reimbursable from the Company. A one 
percentage point change in assumed health care cost trend 
rates would have the following effects:

In thousands

1% Increase

1% Decrease

Effect on net periodic
postretirement health care
benefit cost

Effect on the accumulated
postretirement benefit obligation

$

100

$

(74)

742

(665)

We review mortality assumptions annually and will update 
for material changes as necessary. In 2015, we adopted the 
Society of Actuaries Scale MP-2015, which projects a 
mortality detriment compared to the previous table used, 
thereby decreasing benefit plan liabilities. 

The following table provides information regarding employer 
contributions and benefit payments for the qualified pension 
plan, non-qualified pension plans and other postretirement 
benefit plans for the years ended December 31, and 
estimated future contributions and payments:

In thousands

Pension Benefits

Other Benefits

$

12,077

$

Employer Contributions:

2014

2015

2016 (estimated)

Benefit Payments:

2013

2014

2015

Estimated Future Benefit Payments:

2016

2017

2018

2019

2020

15,696

16,695

18,855

19,932

35,923

21,589

22,028

22,974

23,950

26,242

1,871

2,018

2,035

1,895

1,871

2,018

2,035

2,060

2,073

2,132

2,178

2021-2025

134,736

11,068

Employer Contributions to Company-Sponsored 
Defined Benefit Pension Plans
We make contributions to our qualified defined benefit 
pension plans based on actuarial assumptions and 
estimates, tax regulations and funding requirements under 
federal law. The Pension Protection Act of 2006 (the Act) 
established funding requirements for defined benefit plans. 
The Act establishes a 100% funding target over seven years 
for plan years beginning after December 31, 2008. In 2012 
the Moving Ahead for Progress in the 21st Century Act 

71

 
 
 
 
Fair Value
Below is a description of the valuation methodologies used 
for assets measured at fair value. In cases where the 
pension plan is invested through a collective trust fund or 
mutual fund, our custodian uses the fund's market value. 
The custodian also provides the market values for 
investments directly owned.

U.S. LARGE CAP EQUITY and U.S. SMALL/MID CAP 
EQUITY. These are level 1 and 2 assets. The level 1 assets 
consist of directly held stocks and mutual funds with a 
readily determinable fair value, including a published net 
asset value (NAV). The level 2 assets consist of mutual 
funds where NAV is not published but the investment can be 
readily disposed of at NAV or market value. Directly held 
stocks are valued at the closing price reported in the active 
market on which the individual security is traded, and 
mutual funds are valued at NAV. This asset class includes 
investments primarily in U.S. common stocks.

NON-U.S. EQUITY. These are level 1 and 2 assets. The level 
1 assets consist of directly held stocks, and the level 2 
assets consist of a commingled trust where the NAV/unit 
price is not published but the investment can be readily 
disposed of at the NAV/unit price. Directly held stocks are 
valued at the closing price reported in the active market on 
which the individual security is traded, and the commingled 
trust is valued at the unit price of the trust. This asset class 
includes investments primarily in foreign equity common 
stocks.

EMERGING MARKETS EQUITY. This is a level 2 asset 
consisting of an open-end mutual fund where the NAV price 
is not published but the investment can be readily disposed 
of at the NAV. This asset class includes investments 
primarily in common stocks in emerging markets.

FIXED INCOME. This is a level 2 asset consisting of a mutual 
fund, valued at NAV, where NAV is not published, but the 
investment can be readily disposed of at the NAV. This 
asset class includes investments primarily in investment 
grade debt and fixed income securities.

LONG GOVERNMENT/CREDIT. These are level 1 and 2 
assets. The level 1 assets consist of a fixed-income mutual 
fund with readily determinable fair value, including a 
published NAV. The level 2 assets consist of a commingled 
trust and directly held fixed-income securities whose values 
are determined by closing prices if available and by matrix 
prices for illiquid securities. This asset class includes long 
duration fixed income investments primarily in U.S. 
treasuries, U.S. government agencies, municipal securities, 
mortgage-backed securities, asset-backed securities, as 
well as U.S. and international investment-grade corporate 
bonds.

HIGH YIELD BONDS. This is a level 2 asset consisting of a 
limited partnership where valuation is not published but the 
investment can be readily disposed of at market value. This 
asset class includes investments primarily in high yield 
bonds.

EMERGING MARKET DEBT. This is a level 1 asset consisting 
of a mutual fund with a readily determinable fair value, 
including a published NAV. This asset class includes 
investments primarily in emerging market debt. 

REAL ESTATE FUNDS. This is a level 1 asset consisting of a 
mutual fund with a readily determinable fair value, including 
a published NAV. This asset class includes investments 
primarily in real estate investment trust (REIT) equity 
securities globally. 

ABSOLUTE RETURN STRATEGY. This is a level 2 asset 
consisting of a hedge fund of funds where the valuation is 
not published but the investment can be readily disposed of 
at unit price. The hedge fund of funds is valued at the 
weighted average value of investments in various hedge 
funds, which in turn are valued at the closing price of the 
underlying securities. This asset class primarily includes 
investments in common stocks and fixed income securities. 

REAL RETURN STRATEGY. This is a Level 1 asset 
representing a mutual fund with a readily determinable fair 
value, including a published NAV. This asset class includes 
an investment in a broad range of assets primarily including 
fixed income, high-yield bonds and emerging market debt.

CASH AND CASH EQUIVALENTS. This is a Level 2 asset 
representing mutual funds without published NAV's but the 
investment can be readily disposed of at the NAV. The 
mutual funds are valued at the NAV of the shares held by 
the plan at the valuation date. This asset class includes 
money market mutual funds.

The preceding valuation methods may produce a fair value 
calculation that is not indicative of net realizable value or 
reflective of future fair values. Although we believe these 
valuation methods are appropriate and consistent with other 
market participants, the use of different methodologies or 
assumptions to determine the fair value of certain financial 
instruments could result in a different fair value 
measurement at the reporting date.

Investment securities are exposed to various financial risks 
including interest rate, market and credit risks. Due to the 
level of risk associated with certain investment securities, it 
is reasonably possible that changes in the values of our 
investment securities will occur in the near term and such 
changes could materially affect our investment account 
balances and the amounts reported as plan assets available 
for benefit payments.

72

  
  
The following table presents the fair value of plan assets, including outstanding receivables and liabilities, of the retirement trust 
fund:

In thousands

Investments

U.S. large cap equity

U.S. small/mid cap equity

Non-U.S. equity

Emerging markets equity

Long government/credit

High yield bonds

Emerging market debt

Real estate funds

Absolute return strategy

Cash and cash equivalents

Total investments

Investments

U.S. large cap equity

U.S. small/mid cap equity

Non-U.S. equity

Emerging markets equity

Fixed income

Long government/credit

High yield bonds

Emerging market debt

Real estate funds

Absolute return strategy

Real return strategy

Cash and cash equivalents

Total investments

Receivables

Accrued interest and dividend income

Due from broker for securities sold

Total receivables

Liabilities

Due to broker for securities purchased

Total investment in retirement trust

December 31, 2015

Level 1

Level 2

Level 3

Total

$

44,528

$

23,495

20,725

—

—

—

7,746

17,261

—

—

— $

—

22,823

11,120

48,456

12,298

—

—

36,758

4,116

— $

—

—

—

—

—

—

—

—

—

44,528

23,495

43,548

11,120

48,456

12,298

7,746

17,261

36,758

4,116

$

113,755

$

135,571

$

— $

249,326

December 31, 2014

Level 1

Level 2

Level 3

Total

$

39,405

$

122

$

— $

27,172

16,369

—

—

40,584

—

9,133

18,890

—

8,308

—

85

17,221

7,145

598

40,235

13,087

—

—

37,065

—

1,720

—

—

—

—

—

—

—

—

—

—

—

39,527

27,257

33,590

7,145

598

80,819

13,087

9,133

18,890

37,065

8,308

1,720

$

159,861

$

117,278

$

— $

277,139

December 31,

2015

2014

486

$

88

574

$

510

1,694

2,204

562

249,338

$

$

179

279,164

  $

  $

  $

  $

73

 
 
 
 
 
 
 
 
 
 
 
 
 
 
9. INCOME TAX

The following table provides a reconciliation between 
income taxes calculated at the statutory federal tax rate and 
the provision for income taxes reflected in the consolidated 
statements of comprehensive income for December 31:

Dollars in thousands

2015

2014

2013

Income taxes at federal
statutory rate

Increase (decrease):

Current state income tax,
net of federal tax benefit

Amortization of investment
tax credits

Differences required to be
flowed-through by
regulatory commissions

Gains on company and
trust-owned life insurance

Other, net

Total provision for income
taxes

$ 31,310

$ 35,117

$ 35,785

4,195

4,666

4,674

(118)

(201)

(271)

2,357

2,357

2,357

(766)

(1,225)

(689)

393

(864)

24

$ 35,753

$ 41,643

$ 41,705

Effective tax rate

40.0%

41.5%

40.8%

The decrease in the effective income tax rate for 2015 
compared to 2014 was primarily due to the benefits of 
depletion deductions from gas reserves activity. The 
increase from 2014 compared to 2013 was primarily the 
result of a $0.6 million income tax charge in 2014 related to 
a higher statutory tax rate in Oregon, which required the 
revaluation of deferred tax balances. 

The provision (benefit) for current and deferred income 
taxes consists of the following at December 31:

In thousands

Current

   Federal

   State

Deferred

   Federal

   State

2015

2014

2013

$ 10,558

$ 14,823

$

61

24

10,619

14,847

(62)

(11)

(73)

18,729

18,635

6,405

8,161

25,134

26,796

35,109

6,669

41,778

Total provision for
income taxes

$ 35,753

$ 41,643

$ 41,705

The following table summarizes the total provision (benefit) 
for income taxes for the utility and non-utility business 
segments for December 31:

In thousands

Utility:

   Current

   Deferred

Deferred investment tax
credits

Non-utility business
segments:

   Current

   Deferred

2015

2014

2013

$ 15,890

$ 24,317

$

(73)

20,834

19,518

38,073

(118)

(201)

(271)

36,606

43,634

37,729

(5,271)

4,418

(853)

(9,470)

7,479

(1,991)

—

3,976

3,976

Total provision for income
taxes

$ 35,753

$ 41,643

$ 41,705

The following table summarizes the tax effect of significant 
items comprising our deferred income tax accounts at 
December 31:

In thousands

Deferred tax liabilities:

   Plant and property

   Regulatory income tax assets

   Regulatory liabilities

   Non-regulated deferred tax liabilities

      Total

Deferred tax assets:

Pension and postretirement
obligations

Alternative minimum tax credit
carryforward

   Loss and credit carryforwards

      Total

2015

2014

$ 408,342

$ 386,732

47,427

46,400

49,683

51,805

55,776

48,683

$ 551,852

$ 542,996

$

4,666

$

6,537

16,699

514

21,879

16,788

12,657

35,982

Deferred income tax liabilities, net

529,973

507,014

Deferred investment tax credits

48

166

Deferred income taxes and investment
tax credits

$ 530,021

$ 507,180

Management assesses the available positive and negative 
evidence to estimate if sufficient taxable income will be 
generated to utilize the existing deferred tax assets. Based 
upon this assessment, we have determined we are more 
likely than not to realize all deferred tax assets recorded as 
of December 31, 2015.

74

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
10. PROPERTY, PLANT, AND EQUIPMENT

The following table sets forth the major classifications of our 
property, plant, and equipment and accumulated 
depreciation at December 31:

In thousands

2015

2014

Utility plant in service

$2,745,485

$2,661,097

Utility construction work in progress

39,288

24,886

Less: Accumulated depreciation

867,377

836,510

Utility plant, net

Non-utility plant in service

Non-utility construction work in
progress

Less: Accumulated depreciation

1,917,396

1,849,473

296,839

297,295

7,768

39,340

9,282

34,457

Non-utility plant, net

265,267

272,120

Total property, plant, and equipment

$2,182,663

$2,121,593

Capital expenditures in accrued
liabilities

$

8,985

$

8,757

The weighted average depreciation rate was 2.8% for utility 
assets and 2.2% for non-utility assets in 2015, 2014, and 
2013.

Accumulated depreciation does not include the accumulated 
provision for asset removal costs of $327.0 million and 
$311.2 million at December 31, 2015 and 2014, 
respectively. These accrued asset removal costs are 
reflected on the balance sheet as regulatory liabilities. See 
Note 2. During 2014, we acquired $1.3 million of equipment 
under capital leases. In 2015, we did not acquire any 
equipment under capital leases. 

The Company estimates it has Oregon net operating loss 
(NOL) carryforwards of $3.9 million at December 31, 2015. 
The NOL carryforwards will be carried forward to reduce our 
current tax liability in future years. We anticipate that we will 
be able to utilize the NOL carryforwards before they begin to 
expire in 2028. Alternative minimum tax (AMT) credits of 
$16.7 million, general business credits of $0.3 million, and 
charitable contribution carryforwards of $2.3 million are also 
available. The AMT credits do not expire, and we anticipate 
fully using the general business credits and charitable 
contribution carryforwards before they begin to expire in 
2033 and 2016, respectively.

As a result of certain realization requirements prescribed in 
the accounting guidance for income taxes, the tax benefit of 
statutory depletion is recognized no earlier than the year in 
which the depletion is deductible on the Company’s federal 
income tax return. Income tax expense was decreased by 
$0.9 million in 2015 as a result of realizing deferred 
depletion benefit from 2013 and 2014. This benefit is 
included in Other in the statutory rate reconciliation table.

Uncertain tax positions are accounted for in accordance 
with accounting standards that require management’s 
assessment of the anticipated settlement outcome of 
material uncertain tax positions taken in a prior year, or 
planned to be taken in the current year. Until such positions 
are sustained, we would not recognize the uncertain tax 
benefits resulting from such positions. No reserves for 
uncertain tax positions existed as of December 31, 2015, 
2014, or 2013.

The Company’s examination by the Internal Revenue 
Service (IRS) for tax years 2009 through 2011 was 
completed during the first quarter of 2014. The examination 
did not result in a material change to the returns as 
originally filed or previously adjusted for net operating loss 
carrybacks. The IRS Compliance Assurance Process (CAP) 
examinations of the 2013 and 2014 tax years were 
completed in the first and fourth quarters of 2015, 
respectively. There were no material changes to these 
returns as filed. The 2015 year is currently under IRS CAP 
examination. The Company’s 2016 CAP application has 
been accepted by the IRS. Under the CAP program the 
Company works with the IRS to identify and resolve material 
tax matters before the tax return is filed each year. As of 
December 31, 2015, tax year 2012 remains open for federal 
examination, and tax years 2012 through 2015 remain open 
for state examination. 

75

 
 
11. GAS RESERVES

We have invested $188 million through our gas reserves 
program in the Jonah Field located in Wyoming as of 
December 31, 2015. Gas reserves are stated at cost, net of 
regulatory amortization, with the associated deferred tax 
benefits recorded as liabilities on the balance sheet. Our 
investment in gas reserves provides long-term price 
protection for utility customers and currently incorporates 
two agreements: the original agreement with Encana Oil & 
Gas (USA) Inc. under which we invested $178 million and 
the amended agreement with Jonah Energy LLC under 
which an additional $10 million was invested.

We entered into our original agreements with Encana in 
2011 under which we hold working interests in certain 
sections of the Jonah Field. Gas produced in these sections 
is sold at prevailing market prices, and revenues from such 
sales, net of associated operating and production costs and 
amortization, are credited to the utility's cost of gas. The 
cost of gas, including a carrying cost for the rate base 
investment, is included in our annual Oregon PGA filing, 
which allows us to recover these costs through customer 
rates. Our net investment under the original agreement 
earns a rate of return. 

In March 2014, we amended the original gas reserves 
agreement in order to facilitate Encana's proposed sale of 
its interest in the Jonah field to Jonah Energy. Under the 
amendment, we ended the drilling program with Encana, 
but increased our working interests in our assigned 
sections of the Jonah field. We also retained the right to 
invest in new wells with Jonah Energy. The amended 
agreements allow us to invest in additional wells on a well-
by-well basis with drilling costs and resulting gas volumes 
shared at our amended proportionate working interest for 
each well in which we invest. We elected to participate in 
some of the additional wells drilled in 2014, and may have 
the opportunity to participate in more wells in the future. 

In September 2015, the OPUC adopted an all-party 
settlement, under which volumes produced from the 
additional wells drilled in 2014 are included in our Oregon 
PGA beginning November 1, 2015 at a fixed rate of 
$0.4725 per therm, which approximates the 10-year hedge 
rate plus financing costs at the inception of the investment. 

Gas reserves acted to hedge the cost of gas
for approximately 11% and 10% of our utility's gas supplies 
for the years ended December 31, 2015 and 2014, 
respectively. 

The following table outlines our net gas reserves 
investment at December 31:

In thousands

2015

2014

Gas reserves, current

$

17,094

$

20,020

Gas reserves, non-current

170,453

167,190

Less: Accumulated amortization

55,901

37,910

Total gas reserves(1)

Less: Deferred taxes on gas reserves
Net investment in gas reserves(1)

131,646

149,300

27,203

18,551

$ 104,443

$ 130,749

(1)   Our investment in additional wells included in total gas 

reserves was $8.0 million ($4.3 million net of deferred taxes) 
and $9.2 million ($8.4 million net of deferred taxes) at 
December 31, 2015 and December 31, 2014, respectively. 

Our investment is included on our balance sheet under gas 
reserves with our maximum loss exposure limited to our 
current investment balance.

12. INVESTMENTS

Investments include financial investments in life insurance 
policies, which are accounted for at cash surrender value, 
net of policy loans, and equity investments in certain 
partnerships and limited liability companies, which are 
accounted for under the equity method. The following table 
summarizes our other investments at December 31:

In thousands

2015

2014

Investments in life insurance policies

$ 52,308

$ 52,366

Investments in gas pipeline

Other

13,866

13,962

1,892

1,910

   Total other investments

$ 68,066

$ 68,238

Investment in Life Insurance Policies
We have invested in key person life insurance contracts to 
provide an indirect funding vehicle for certain long-term 
employee and director benefit plan liabilities. The amount in 
the above table is reported at cash surrender value, net of 
policy loans.

Investments in Gas Pipeline
TWP, a wholly-owned subsidiary of TWH, is pursuing the 
development of a new gas transmission pipeline that would 
provide an interconnection with our utility distribution 
system. NWN Energy, a wholly-owned subsidiary of NW 
Natural owns 50% of TWH, and 50% is owned by 
TransCanada American Investments Ltd., an indirect wholly-
owned subsidiary of TransCanada Corporation.  

76

VIE Analysis
TWH is a VIE, with our investment in TWP reported under 
equity method accounting. We have determined we are not 
the primary beneficiary of TWH’s activities as we only have 
a 50% share of the entity and there are no stipulations that 
allow us a disproportionate influence over it. Our 
investments in TWH and TWP are included in other 
investments on our balance sheet. If we do not develop this 
investment, then our maximum loss exposure related to 
TWH is limited to our equity investment balance, less our 
share of any cash or other assets available to us as a 50% 
owner. Our investment balance in TWH was $13.4 million at 
December 31, 2015 and 2014. 

Impairment Analysis
Our investments in nonconsolidated entities accounted for 
under the equity method are reviewed for impairment at 
each reporting period and following updates to our 
corporate planning assumptions. If it is determined a loss in 
value is other than temporary, a charge is recognized for the 
difference between the investment’s carrying value and its 
estimated fair value. Fair value is based on quoted market 
prices when available or on the present value of expected 
future cash flows. Differing assumptions could affect the 
timing and amount of a charge recorded in any period.

In 2011, TWP withdrew its original application with the 
FERC for a proposed natural gas pipeline in Oregon and 
informed FERC that it intended to re-file an application to 
reflect changes in the project scope aligning the project with 
the region’s current and future gas infrastructure needs. 
TWP continues working with customers in the Pacific  
Northwest to further understand their gas transportation 
needs and determine the commercial support for a revised 
pipeline proposal. A new FERC certificate application is 
expected to be filed to reflect a revised scope based on 
these regional needs.

Our equity investment was not impaired at December 31, 
2015 as the fair value of expected cash flows from planned 
development exceeded our remaining equity investment of 
$13.4 million at December 31, 2015. However, if we learn 
that the project is not viable or will not go forward, then we 
could be required to recognize a maximum charge of up to 
approximately $13.4 million based on the current amount of 
our equity investment, net of cash and working capital at 
TWP. We will continue to monitor and update our 
impairment analysis as required.

13. DERIVATIVE INSTRUMENTS

We enter into financial derivative contracts to hedge a 
portion of our utility’s natural gas sales requirements. These 
contracts include swaps, options and combinations of option 
contracts. We primarily use these derivative financial 
instruments to manage commodity price variability. A small 
portion of our derivative hedging strategy involves foreign 
currency exchange contracts. 

We enter into these financial derivatives, up to prescribed 
limits, primarily to hedge price variability related to our 
physical gas supply contracts as well as to hedge spot 
purchases of natural gas. The foreign currency forward 
contracts are used to hedge the fluctuation in foreign 
currency exchange rates for pipeline demand charges paid 
in Canadian dollars. 

In the normal course of business, we also enter into 
indexed-price physical forward natural gas commodity 
purchase contracts and options to meet the requirements of 
utility customers. These contracts qualify for regulatory 
deferral accounting treatment. 

We also enter into exchange contracts related to the third-
party asset management of our gas portfolio, some of which 
are derivatives that do not qualify for hedge accounting or 
regulatory deferral, but are subject to our regulatory sharing 
agreement. These derivatives are recognized in operating 
revenues in our gas storage segment, net of amounts 
shared with utility customers. 

Notional Amounts
The following table presents the absolute notional amounts 
related to open positions on our derivative instruments:

In thousands

Natural gas (in therms):

Financial

Physical

Foreign exchange

At December 31,

2015

2014

346,875

287,475

404,645

420,980

$ 9,025

$ 12,230

Purchased Gas Adjustment (PGA)
Derivatives entered into by the utility for the procurement or 
hedging of natural gas for future gas years generally receive 
regulatory deferral accounting treatment. Derivative 
contracts entered into after the start of the PGA period are 
subject to our PGA incentive sharing mechanism in Oregon. 
In general, our commodity hedging for the current gas year 
is completed prior to the start of the upcoming gas year, and 
hedge prices are reflected in our weighted-average cost of 
gas in the PGA filing. As of November 1, 2015, we reached 
our target hedge percentage of approximately 75% for the 
2015-16 gas year. These hedge prices were included in the 
PGA filings and qualified for regulatory deferral.

77

                                                                                    
Unrealized and Realized Gain/Loss
The following table reflects the income statement presentation for the unrealized gains and losses from our derivative 
instruments: 

In thousands

Expense to cost of gas

Operating revenues
 Less:
 Amounts deferred to regulatory accounts on balance sheet

December 31, 2015

December 31, 2014

Natural gas
commodity

Foreign
exchange

Natural gas
commodity

Foreign
exchange

$

(22,600) $

226

(419) $
—

(32,784) $
—

22,434

419

32,782

(382)
—

382

—

Total gain (loss) in pre-tax earnings

$

60

$

— $

(2) $

UNREALIZED GAIN/LOSS. Outstanding derivative instruments related to regulated utility operations are deferred in accordance 
with regulatory accounting standards. The cost of foreign currency forward and natural gas derivative contracts are recognized 
immediately in the cost of gas; however, costs above or below the amount embedded in the current year PGA are subject to a 
regulatory deferral tariff and therefore, are recorded as a regulatory asset or liability. 

REALIZED GAIN/LOSS. We realized net losses of $37.7 million and net gains of $10.5 million for the years ended December 
31, 2015 and 2014, respectively, from the settlement of natural gas financial derivative contracts. Realized gains and losses are 
recorded in cost of gas, deferred through our regulatory accounts, and amortized through customer rates in the following year. 

Credit Risk Management of Financial Derivatives 
Instruments
No collateral was posted with or by our counterparties as of 
December 31, 2015 or 2014. We attempt to minimize the 
potential exposure to collateral calls by counterparties 
to manage our liquidity risk. Counterparties generally allow a 
certain credit limit threshold before requiring us to post 
collateral against loss positions. Given our counterparty 

Our financial derivative instruments are subject to master 
netting arrangements; however, they are presented on a 
gross basis in our statement of financial position. The 
Company and its counterparties have the ability to set-off 
their obligations to each other under specified 
circumstances. Such circumstances may include a 
defaulting party, a credit change due to a merger affecting 
either party, or any other termination event.

credit limits and portfolio diversification, we have not been 
subject to collateral calls in 2015 or 2014. Our collateral call 
exposure is set forth under credit support agreements, 
which generally contain credit limits. We could also be 
subject to collateral call exposure where we have agreed to 
provide adequate assurance, which is not specific as to the 
amount of credit limit allowed, but could potentially require 
additional collateral in the event of a material adverse  
change. 

Based upon current commodity financial swap and option 
contracts outstanding, which reflect unrealized losses of 
$23.2 million at December 31, 2015, we have estimated the 
level of collateral demands, with and without potential 
adequate assurance calls, using current gas prices and 
various credit downgrade rating scenarios for NW Natural as 
follows:

Credit Rating Downgrade Scenarios

(Current
Ratings) 
A+/A3

BBB+/
Baa1

BBB/
Baa2

BBB-/
Baa3

Specul-
ative

$

— $ — $ — $4,852

$ 21,185

—

—

— 4,164

15,497

In thousands

With
Adequate
Assurance
Calls

Without
Adequate
Assurance
Calls

If netted by counterparty, our derivative position would result 
in an asset of $2.7 million and a liability of $25.5 million as 
of December 31, 2015. As of December 31, 2014, our 
derivative position would have resulted in an asset of $0.2 
million and a liability of $33.4 million.

We are exposed to derivative credit and liquidity risk 
primarily through securing fixed price natural gas commodity 
swaps to hedge the risk of price increases for our natural 
gas purchases made on behalf of customers. We utilize 
master netting arrangements through International Swaps 
and Derivatives Association contracts to minimize this risk 
along with collateral support agreements with counterparties 
based on their credit ratings. In certain cases we require 
guarantees or letters of credit from counterparties to meet 
our minimum credit requirement standards.
Our financial derivatives policy requires counterparties to 
have a certain investment-grade credit rating at the time the 
derivative instrument is entered into, and the policy specifies 
limits on the contract amount and duration based on each 
counterparty’s credit rating. We do not speculate with 
derivatives; instead, we use derivatives to hedge our 
exposure above risk tolerance limits. Any increase in market 
risk created by the use of derivatives should be offset by the 
exposures they modify.

We actively monitor our derivative credit exposure and place 
counterparties on hold for trading purposes or require other 
forms of credit assurance, such as letters of credit, cash 
collateral or guarantees as circumstances warrant. Our 
ongoing assessment of counterparty credit risk includes 

78

  
14. COMMITMENTS AND CONTINGENCIES

Leases
We lease land, buildings and equipment under agreements 
that expire in various years, including a 99-year land lease 
that extends through 2108. Rental expense under operating 
leases was $5.5 million, $5.9 million, and $5.1 million for the 
years ended December 31, 2015, 2014, and 2013, 
respectively. The following table reflects the future minimum 
lease payments due under non-cancelable leases at 
December 31, 2015. These commitments relate principally 
to the lease of our office headquarters, underground gas 
storage facilities and computer equipment.

In thousands

Operating
leases

Capital
leases

$

5,417

$

564

$

5,363

5,348

5,313

2,765

30,475

156

3

—

—

—

Minimum
lease
payments

5,981

5,519

5,351

5,313

2,765

30,475

$

54,681

$

723

$

55,404

2016

2017

2018

2019

2020

Thereafter

   Total

Gas  Purchase  and  Pipeline  Capacity  Purchase  and 
Release Commitments
We have signed agreements providing for the reservation of 
firm pipeline capacity under which we are required to make 
fixed monthly payments for contracted capacity. The pricing 
component of the monthly payment is established, subject 
to change, by U.S. or Canadian regulatory bodies. In 
addition, we have entered into long-term sale agreements to 
release firm pipeline capacity. We also enter into short-term 
and long-term gas purchase agreements. 

consideration of credit ratings, credit default swap spreads, 
bond market credit spreads, financial condition, government 
actions and market news. We use a Monte-Carlo simulation 
model to estimate the change in credit and liquidity risk from 
the volatility of natural gas prices. The results of the model 
are used to establish earnings-at-risk trading limits. Our 
credit risk for all outstanding financial derivatives at 
December 31, 2015 extends to March 2018.

We could become materially exposed to credit risk with one 
or more of our counterparties if natural gas prices 
experience a significant increase. If a counterparty were to 
become insolvent or fail to perform on its obligations, we 
could suffer a material loss; however, we would expect such 
a loss to be eligible for regulatory deferral and rate recovery, 
subject to a prudence review. All of our existing 
counterparties currently have investment-grade credit 
ratings.

Fair Value
In accordance with fair value accounting, we include non-
performance risk in calculating fair value adjustments. This 
includes a credit risk adjustment based on the credit 
spreads of our counterparties when we are in an unrealized 
gain position, or on our own credit spread when we are in an 
unrealized loss position. The inputs in our valuation models 
include natural gas futures, volatility, credit default swap 
spreads and interest rates. Additionally, our assessment of 
non-performance risk is generally derived from the credit 
default swap market and from bond market credit spreads. 
The impact of the credit risk adjustments for all outstanding 
derivatives was immaterial to the fair value calculation at 
December 31, 2015. As of December 31, 2015 and 2014, 
the net fair value was a liability of $22.8 million and a liability 
of $33.2 million, respectively, using significant other 
observable, or level 2, inputs. No level 3 inputs were used in 
our derivative valuations, and there were no transfers 
between level 1 or level 2 during the years ended December 
31, 2015 and 2014. See Note 2.

79

 
 
The aggregate amounts of these agreements were as 
follows at December 31, 2015:

In thousands

2016

2017

2018

2019

2020

Thereafter

   Total

Less: Amount
representing
interest

Total at present
value

Gas
Purchase
Agreements

Pipeline
Capacity
Purchase
Agreements

Pipeline
Capacity
Release
Agreements

$

61,464

$

79,487

$

3,739

—

—

—

—

—

61,464

79,370

75,796

75,683

72,091

340,027

722,454

—

—

—

—

—

3,739

123

110,899

11

$

61,341

$

611,555

$

3,728

Our total payments for fixed charges under capacity 
purchase agreements were $85.2 million for 2015, $94.3 
million for 2014, and $98.2 million for 2013. Included in the 
amounts were reductions for capacity release sales of $4.4 
million for 2015, $4.8 million for 2014, and $4.5 million for 
2013. In addition, per-unit charges are required to be paid 

based on the actual quantities shipped under the 
agreements. In certain take-or-pay purchase commitments, 
annual deficiencies may be offset by prepayments subject 
to recovery over a longer term if future purchases exceed 
the minimum annual requirements.

Environmental Matters
Refer to Note 15 for a discussion of environmental 
commitments and contingencies.

15. ENVIRONMENTAL MATTERS

We own, or previously owned, properties that may require 
environmental remediation or action. We estimate the range 
of loss for environmental liabilities based on current 
remediation technology, enacted laws and regulations, 
industry experience gained at similar sites and an 
assessment of the probable level of involvement and 
financial condition of other potentially responsible parties 
(PRPs). When amounts are prudently expended related to 
site remediation, we have a recovery mechanism in place to 
collect 96.68% of remediation costs from Oregon 
customers, and we are allowed to defer environmental 
remediation costs allocated to customers in Washington 
annually until they are reviewed for prudence at a 
subsequent proceeding. 

Our sites are subject to the remediation process prescribed 
by the Environmental Protection Agency (EPA) and the 
Department of Environmental Quality (ODEQ). The process 
begins with a remedial investigation (RI) to determine the 
nature and extent of contamination and then a risk 
assessment (RA) to establish whether the contamination at 
the site poses unacceptable risks to humans and the 
environment. Next, a feasibility study (FS) or an engineering 
evaluation/cost analysis (EE/CA) evaluates various remedial 
alternatives. It is at this point in the process when we are 
able to estimate a range of remediation costs and record a 
reasonable potential remediation liability, or make an 
adjustment to our existing liability. From this study, the 
regulatory agency selects a remedy and issues a Record of 
Decision (ROD). 

After the ROD is issued, we negotiate a consent decree or 
consent judgment for designing and implementing the 
remedy. We have the ability to further refine estimates of 
remediation liabilities at that time. 

Remediation may include treatment of contaminated media 
such as sediment, soil and groundwater, removal and 
disposal of media, or institutional controls such as legal 
restrictions on future property use. Following construction of 
the remedy, the EPA and ODEQ also have requirements for 
ongoing maintenance, monitoring and other post-
remediation care that may continue for many years. Where 
appropriate and reasonably known, we will provide for these 
costs in our remediation liabilities described above.

Due to the numerous uncertainties surrounding the course 
of environmental remediation and the preliminary nature of 
several site investigations, in some cases, we may not be 
able to reasonably estimate the high end of the range of 
possible loss. In those cases, we have disclosed the nature 
of the possible loss and the fact that the high end of the 
range cannot be reasonably estimated where a range of 
potential loss is available. Unless there is an estimate within 
the range of possible losses that is more likely than other 
cost estimates within that range, we record the liability at the 
low end of this range. It is likely changes in these estimates 
and ranges will occur throughout the remediation process 
for each of these sites due to our continued evaluation and 
clarification concerning our responsibility, the complexity of 
environmental laws and regulations and the determination 
by regulators of remediation alternatives. In addition to 
remediation costs, we could also be subject to Natural 
Resource Damages (NRD) claims. We will assess the 
likelihood and probability of each claim and recognize a 
liability if deemed appropriate.  As of December 31, 2015, 
we have not received any material NRD claims.  

80

Environmental Sites
The following table summarizes information regarding liabilities related to environmental sites, which are recorded in other 
current liabilities and other noncurrent liabilities on the balance sheet at December 31: 

In thousands

Portland Harbor site:

Gasco/Siltronic Sediments

Other Portland Harbor

Gasco Upland site

Siltronic Upland site

Central Service Center site

Front Street site

Oregon Steel Mills

Total

PORTLAND HARBOR SITE. The Portland Harbor is an 
EPA listed Superfund site that is approximately 10 miles 
long on the Willamette River and is adjacent to NW 
Natural's Gasco uplands and the Siltronic uplands sites. We 
are a PRP to the Superfund site and have joined with some 
of the other PRPs (the Lower Willamette Group or LWG) to 
develop a Portland Harbor Remedial Investigation/
Feasibility Study (RI/FS), which we submitted to the EPA in 
2012. In August 2015, the EPA issued its own Draft 
Feasibility Study (Draft FS) for comment. The EPA Draft FS 
provides a new range of remedial costs for the entire 
Portland Harbor Superfund Site, which includes the Gasco/
Siltronic Sediment site, discussed below. The range of 
present value costs estimated by the EPA for various 
remedial alternatives for the entire Portland Harbor, as 
provided by the EPA's Draft FS, is $791 million to $2.45 
billion. The range provided in the EPA's Draft FS is based 
on cost alternatives the EPA estimates to have an accuracy 
between -30% and +50% of actual costs, depending on the 
scope of work. While the EPA's Draft FS provides a higher 
range of costs than the LWG's submission in 2012, our 
potential liability is still a portion of the costs of the remedy 
the EPA will select for the entire Portland Harbor Superfund 
site. The cost of that remedy is expected to be allocated 
among more than 100 PRPs. We are participating in a non-
binding allocation process in an effort to settle this potential 
liability. The new EPA Draft FS does not provide any 
additional clarification around allocation of costs. 

We manage our liability related to the Superfund site as two 
distinct remediation projects, the Gasco/Siltronic Sediments 
and Other Portland Harbor projects.

Current Liabilities

Non-Current Liabilities

2015

2014

2015

2014

$

2,229

$

1,767

$

42,641

$

38,019

1,972

10,599

951

25

1,155

—

1,934

9,535

957

171

1,020

—

5,073

52,117

337

—

7,748

179

4,338

37,117

348

—

122

179

$

16,931

$

15,384

$

108,095

$

80,123

Gasco/Siltronic Sediments. In 2009, NW Natural and Siltronic 
Corporation entered into a separate Administrative Order on 
Consent with the EPA to evaluate and design specific 
remedies for sediments adjacent to the Gasco uplands and 
Siltronic uplands sites. We submitted a draft EE/CA to the 
EPA in May 2012 to provide the estimated cost of potential 
remedial alternatives for this site. At this time, the estimated 
costs for the various sediment remedy alternatives in the 
draft EE/CA as well as costs for the additional studies and 
design work needed before the clean-up can occur, and for 
regulatory oversight throughout the clean-up range from 
$44.9 million to $350 million. We have recorded a liability of 
$44.9 million for the sediment clean-up, which reflects the 
low end of the range. At this time, we believe sediments at 
this site represent the largest portion of our liability related to 
the Portland Harbor site, discussed above. 

Other Portland Harbor. NW Natural incurs costs related to its 
membership in the LWG. NW Natural also incurs costs 
related to natural resource damages from these sites. The 
Company and other parties have signed a cooperative 
agreement with the Portland Harbor Natural Resource 
Trustee council to participate in a phased natural resource 
damage assessment to estimate liabilities to support an 
early restoration-based settlement of natural resource 
damage claims. Natural resource damage claims may arise 
only after a remedy for clean-up has been settled. We have 
recorded a liability for these claims which is at the low end 
of the range of the potential liability; the high end of the 
range cannot be reasonably estimated at this time. This 
liability is not included in the range of costs provided in the 
draft FS for the Portland Harbor or noted above.

81

GASCO UPLANDS SITE. A predecessor of NW Natural 
owned a former gas manufacturing plant that was closed in 
1958 (Gasco site) and is adjacent to the Portland Harbor 
site described above. The Gasco site has been under 
investigation by us for environmental contamination under 
the ODEQ Voluntary Clean-Up Program. It is not included in 
the range of remedial costs for the Portland Harbor site 
noted above. We manage the Gasco site in two parts, the 
uplands portion and the groundwater source control action. 

We submitted a revised Remedial Investigation Report for 
the uplands to ODEQ in May 2007. In March 2015, ODEQ 
approved the RA NW Natural submitted in 2010, enabling us 
to begin work on the FS in 2016. We have recognized a 
liability for the remediation of the uplands portion of the site 
which is at the low end of the range of potential liability; the 
high end of the range cannot be reasonably estimated at 
this time.

In September 2013, we completed construction of a 
groundwater source control system, including a water 
treatment station, at the Gasco site. We are working with 
ODEQ on monitoring the effectiveness of the system and at 
this time it is unclear what, if any, additional actions ODEQ 
may require subsequent to the initial testing of the system or 
as part of the final remedy for the uplands portion of the 
Gasco site. We have estimated the cost associated with the 
ongoing operation of the system and have recognized a 
liability which is at the low end of the range of potential cost. 
We cannot estimate the high end of the range at this time 
due to the uncertainty associated with the duration of 
running the water treatment station, which is highly 
dependent on the remedy determined for both the upland 
portion as well as the final remedy for our Gasco sediment 
exposure.  

Beginning November 1, 2013, capital asset costs of $19.0 
million for the Gasco water treatment station were placed 
into rates with OPUC approval. The OPUC deemed these 
costs prudent. Beginning November 1, 2014, the OPUC 
approved the application of $2.5 million from insurance 
proceeds plus interest to reduce the total amount of Gasco 
capital costs to be recovered through rate base. A portion of 
these proceeds was noncash in 2014.

OTHER SITES. In addition to those sites above, we have 
environmental exposures at four other sites: Siltronic, 
Central Service Center, Front Street and Oregon Steel Mills. 
Due to the uncertainty of the design of remediation, 
regulation, timing of the remediation and in the case of the 
Oregon Steel Mills site, pending litigation, liabilities for each 
of these sites have been recognized at their respective low 
end of the range of potential liability; the high end of the 
range could not be reasonably estimated at this time. 

Siltronic Upland. A portion of the Siltronic property adjacent 
to the Gasco site was formerly owned by Portland Gas and 
Coke, NW Natural's predecessor. We are currently 
conducting an investigation of manufactured gas plant 
wastes on the uplands at this site for the ODEQ. 

Central Service Center site. We are currently performing an 
environmental investigation of the property under the 
ODEQ's Independent Cleanup Pathway. This site is on 

82

ODEQ's list of sites with confirmed releases of hazardous 
substances, and cleanup is necessary. 

Front Street site. The Front Street site was the former 
location of a gas manufacturing plant we operated (the 
former Portland Gas Manufacturing site, or PGM).  At 
ODEQ’s request, we conducted a sediment and source 
control investigation and provided findings to ODEQ.  In 
December 2015, we completed a FS on the former Portland 
Gas Manufacturing site. The FS provided a range of $7.6 
million to $12.9 million for remedial costs. We have recorded 
a liability at the low end of the range of possible loss as no 
alternative in the range is considered more likely than 
another. Further, we have recognized an additional liability 
of $1.3 million for additional studies and design costs as well 
as regulatory oversight throughout the clean-up that will be 
required to assist in ODEQ making a remedy selection and 
completing a design. 

Oregon Steel Mills site. Refer to the “Legal Proceedings,” 
below.

Site Remediation and Recovery Mechanism
We have a SRRM through which we track and have the 
ability to recover past deferred and future prudently incurred 
environmental remediation costs allocable to Oregon, 
subject to an earnings test. 

REGULATORY ACTIVITIES. An Order from the OPUC in 
February 2015 deemed certain environmental remediation 
expenses and associated carrying costs deferred through 
March 31, 2014 prudent. Our settlement with insurance 
carriers resulting in insurance proceeds received was also 
deemed prudent in the Order. Under the Order, we were 
required to forgo the collection of $15 million out of 
approximately $95 million of environmental remediation 
expenses and associated carrying costs we had deferred 
through 2012. The OPUC disallowed this amount from rate 
recovery based on its determination of how an earnings test 
should apply to amounts deferred from 2003 to 2012, with 
adjustments for other factors the OPUC deemed relevant. 
See Note 2 for information regarding the regulatory 
disallowance of past deferred costs under the Order 
received from the OPUC in February 2015.

We submitted the required compliance filing demonstrating 
the proposed implementation of the Order and SRRM in 
March 2015. In September 2015, as a result of discussions 
with the parties, we withdrew our original compliance filing 
and submitted a revised filing. The parties raised three 
issues with our proposed implementation of the Order. First, 
the parties asserted that interest on the $15 million charge 
should be separately disallowed, in addition to the specified 
$15 million. This interest would total approximately $2.8 
million. Second, the parties raised issues with how the state 
allocation rates from the Order are applied to our 
environmental remediation sites. Third, a customer group 
disagreed with our treatment of expenses put into the 
SRRM amortization account. 

In addition, we requested clarification from the OPUC 
regarding the amount of Oregon-allocated insurance 
proceeds to be held in a secured account. In September 

 
 
 
2015, the OPUC resolved the issue by adopting an all-party 
settlement, which provided that we did not need to obtain a 
secured account. Instead, under the order, insurance 
proceeds used to offset future environmental expenses will 
accrue interest at a rate equal to the five-year treasury rate 
plus 100 basis points. Currently, Oregon-allocated insurance 
proceeds total approximately $93 million on a pre-tax basis.

On January 27, 2016, the OPUC issued an Order 
addressing the outstanding issues. See Note 16 regarding 
this subsequent event. 

COLLECTIONS FROM CUSTOMERS. The SRRM provides 
us with the ability to recover past deferred and future 
prudently incurred environmental remediation costs 
allocable to Oregon, subject to an earnings test. The SRRM 
created three classes of deferred environmental remediation 
expense:
•  Pre-review - This class of costs represents remediation 
spend that has not yet been deemed prudent by the 
OPUC. Carrying costs on these remediation expenses are 
recorded at our authorized cost of capital. The Company 
anticipates the prudence review for annual costs and 
approval of the earnings test prescribed by the OPUC to 
occur by the third quarter of the following year. 

•  Post-review - This class of costs represents remediation 
spend that has been deemed prudent and allowed after 
applying the earnings test, but is not yet included in 
amortization. We earn a carrying cost on these amounts 
at a rate equal to the five-year treasury rate plus 100 
basis points. 

•  Amortization - This class of costs represents amounts 
included in current customer rates for collection and is 
generally calculated as one-fifth of the post-review 
deferred balance. We earn a carrying cost equal to the 
amortization rate determined annually by the OPUC, 
which approximates a short-term borrowing rate. We 
included $8.4 million of deferred remediation expense 
approved by the OPUC for collection during the 
2015-2016 PGA year.

In addition to the collection amount noted above, the Order 
also provides for the annual collection of $5 million from 
Oregon customers through a tariff rider. As we collect 
amounts from customers, we recognize these collections as 
revenue and separately amortize our deferred regulatory 
asset balance through operating expense. 

We received total environmental insurance proceeds of 
approximately $150 million as a result of settlements from 
our litigation that was dismissed in July 2014. Under the 
OPUC Order, one-third of the Oregon allocated proceeds 
were applied to costs deferred through 2012, and the 
remaining two-thirds will be applied to costs over the next 20 
years. Annually, the Order provided for the application of $5 
million of insurance proceeds against deferred remediation 
expense deemed prudent in the same annual period; annual 
amounts not utilized are carried forward to apply against 
future prudently incurred costs. We accrue interest on the 
insurance proceeds in the customer’s favor at a rate equal 
to the five-year treasury rate plus 100 basis points. As of 
December 31, 2015, we have applied $53.2 million of 
insurance proceeds to prudently incurred remediation costs. 

83

The following table presents information regarding the total 
amount of cash paid for environmental sites and the total 
regulatory asset deferred as of December 31:

In thousands

Cash paid

Total regulatory asset deferral(1)

Current regulatory assets(2)

2015

2014

$ 124,325

$ 113,740

85,854

9,270

76,584

58,859

—

58,859

Long-term regulatory assets
(1)  

Includes cash paid, remaining liability and interest, net of 
insurance reimbursement, amounts collected from customers, 
and amounts reclassified to utility plant for the water treatment 
station.

(2)  Environmental costs relate to specific sites approved for 

regulatory deferral by the OPUC and WUTC. In Oregon, we 
earn a carrying charge on cash amounts paid, whereas 
amounts accrued but not yet paid do not earn a carrying 
charge until expended. We also accrue a carrying charge on 
insurance proceeds for amounts owed to customers. In 
Washington, a carrying charge related to deferred amounts will 
be determined in a future proceeding. Current environmental 
costs represent remediation costs management expects to 
collect from customers in the next 12 months. Amounts 
included in this estimate are still subject to a prudence and 
earnings test review by the OPUC and do not include the $5 
million base rate rider. The Oregon amounts are recoverable 
through utility rates, subject to an earnings test.

ENVIRONMENTAL EARNINGS TEST. The Order directed 
us to implement an annual environmental earnings test for 
our prudently incurred remediation expense. Prudently 
incurred Oregon allocated annual remediation expense and 
interest in excess of the $5 million tariff rider and $5 million 
insurance proceeds application plus interest on the 
insurance proceeds are recoverable through the SRRM, to 
the extent the utility earns at or below our authorized Return 
On Equity (ROE). To the extent the utility earns more than 
its authorized ROE in a year, the utility is required to cover 
environmental expenses and interest on expenses greater 
than the $10 million (plus interest from insurance proceeds) 
with those earnings that exceed its authorized ROE. 

Under the Order, the OPUC will revisit the deferral and 
amortization of future remediation expenses, as well as the 
treatment of remaining insurance proceeds three years from 
the original Order, or earlier if the Company gains greater 
certainty about its future remediation costs, to consider 
whether adjustments to the mechanism may be appropriate.  

WASHINGTON DEFERRAL. In Washington, cost recovery 
and carrying charges on amounts deferred for costs 
associated with services provided to Washington customers 
will be determined in a future proceeding. Annually, we 
review all regulatory assets for recoverability or more often if 
circumstances warrant. If we should determine all or a 
portion of these regulatory assets no longer meet the criteria 
for continued application of regulatory accounting, then we 
would be required to write off the net unrecoverable 
balances against earnings in the period such a 
determination is made.

Legal Proceedings
NW Natural is subject to claims and litigation arising in the 
ordinary course of business. Although the final outcome of 
any of these legal proceedings cannot be predicted with 
certainty, including the matter described below, we do not 
expect that the ultimate disposition of any of these matters 
will have a material effect on our financial condition, results 
of operations or cash flows. See also Part I, Item 3, “Legal 
Proceedings.”

OREGON STEEL MILLS SITE. In 2004, NW Natural was 
served with a third-party complaint by the Port of Portland 
(the Port) in a Multnomah County Circuit Court case, 
Oregon Steel Mills, Inc. v. The Port of Portland. The Port 
alleges that in the 1940s and 1950s petroleum wastes 
generated by our predecessor, Portland Gas & Coke 
Company, and 10 other third-party defendants, were 
disposed of in a waste oil disposal facility operated by the 
United States or Shaver Transportation Company on 
property then owned by the Port and now owned by Evraz 
Oregon Steel Mills. The complaint seeks contribution for 
unspecified past remedial action costs incurred by the Port 
regarding the former waste oil disposal facility as well as a 
declaratory judgment allocating liability for future remedial 
action costs. No date has been set for trial. Although the 
final outcome of this proceeding cannot be predicted with 
certainty, we do not expect the ultimate disposition of this 
matter will have a material effect on our financial condition, 
results of operations or cash flows. For additional 
information regarding other commitments and 
contingencies, see Note 14.

16. SUBSEQUENT EVENT 

On January 27, 2016, the Public Utility Commission of 
Oregon (OPUC) issued an Order (2016 OPUC Order) 
deciding the three issues raised as a result of our required 
Site Remediation Recovery Mechanism (SRRM) compliance 
filing. The OPUC ordered: (1) the disallowance of $2.8 
million of interest earned on the previously disallowed 
environmental expenditures amounts; (2) the allocation of 
96.68% of environmental remediation costs for all 
environmental sites to Oregon; and (3) our treatment of 
$13.8 million of expenses put into the SRRM amortization 
account was correct and in compliance with prior OPUC 
orders. 

Under a prior OPUC order we were required to forgo 
collection of $15 million out of approximately $95 million of 
environmental remediation expenses and associated 
carrying costs that the Company had deferred through 2012 
based on the OPUC’s determination of how an earnings test 
should apply to amounts deferred from 2003 to 2012, with 
adjustments for other factors the OPUC deemed relevant.  
We recognized interest of approximately $2.8 million on the 
$15 million charge after that time. This interest is shown as 
a regulatory asset in our financial statements, and the 
disallowance will result in a $2.8 million pre-tax charge in 
the first quarter of 2016. Consistent with our accounting 
policy for recognition of regulatory actions, we recognize the 
financial impacts in the period in which the order was 
received. 

With respect to allocation of 96.68% of environmental 
remediation costs to Oregon, we currently have a deferral 
order in Washington to defer environmental costs and 
insurance proceeds; however, recovery of those costs has 
not yet been determined. We have deferred costs for certain 
sites that only served Oregon customers and have, as a 
result of this order, determined it appropriate to reserve 
against 3.32% of these deferrals until resolution of recovery 
in Washington can be determined. The total reserve amount 
is approximately $0.5 million and will be recorded in the first 
quarter of 2016 in accordance with the Company’s policy. 
Consistent with our compliance filing filed in September 
2015, the OPUC also ordered the same allocation factors 
should be applied to insurance proceeds, resulting in the 
application of 96.68% of the Company’s recovered 
insurance proceeds to Oregon.  

With respect to a third issue raised in the proceeding by a 
customer group that the Company should not be allowed to 
apply and recover portions of the SRRM amounts in 2013, 
2014, and 2015 because that would constitute retroactive 
ratemaking, the OPUC ordered in the Company’s favor.  
The OPUC ordered our treatment of $13.8 million of 
expenses put into the SRRM amortization account, to be 
amortized over five years, was correct and complied with 
the original order. For more information regarding our 
SRRM, see Note 15.  

84

NORTHWEST NATURAL GAS COMPANY
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)

Quarter ended

In thousands, except share data

March 31

June 30

September 30

December 31

2015

Operating revenues

Net income (loss)

Basic earnings (loss) per share(1)

Diluted earnings (loss) per share(1)

2014

Operating revenues

Net income (loss)

Basic earnings (loss) per share(1)

Diluted earnings (loss) per share(1)

$

261,665

$

138,280

$

93,128

$

28,486

1.04

1.04

2,197

0.08

0.08

(6,685)

(0.24)

(0.24)

$

293,386

$

133,169

$

87,199

$

37,884

1.40

1.40

1,071

0.04

0.04

(8,733)

(0.32)

(0.32)

230,718

29,705

1.08

1.08

240,283

28,470

1.05

1.04

(1)   Quarterly earnings (loss) per share are based upon the average number of common shares outstanding during each quarter. Variations in 

earnings between quarterly periods are due primarily to the seasonal nature of our business. 

NORTHWEST NATURAL GAS COMPANY
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES

COLUMN A

COLUMN B

COLUMN C

Additions

COLUMN D

COLUMN E

Deductions

In thousands (year ended December 31)

2015

Reserves deducted in balance sheet from
assets to which they apply:

Allowance for uncollectible accounts

2014

Reserves deducted in balance sheet from
assets to which they apply:

Allowance for uncollectible accounts

2013

Reserves deducted in balance sheet from
assets to which they apply:

Allowance for uncollectible accounts

$

$

$

Balance at
beginning of
period

Charged to
costs and
expenses

Charged to
other accounts

Net write-offs

Balance at end
of period

969

$

760

$

— $

859

$

870

1,656

$

599

$

— $

1,286

$

969

2,518

$

199

$

— $

1,061

$

1,656

85

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ITEM 9. CHANGES IN AND DISAGREEMENTS 
WITH ACCOUNTANTS ON ACCOUNTING AND 
FINANCIAL DISCLOSURE

None.

ITEM 9A. CONTROLS AND PROCEDURES

(a) Evaluation of Disclosure Controls and Procedures

Our management, under the supervision and with the 
participation of our Chief Executive Officer and Chief 
Financial Officer, has completed an evaluation of the 
effectiveness of the design and operation of our disclosure 
controls and procedures (as defined in Rules 13a-15(e) and 
15d-15(e) of the Securities Exchange Act of 1934, as 
amended (the Exchange Act)). Based upon this evaluation, 
our Chief Executive Officer and Chief Financial Officer have 
concluded that, as of the end of the period covered by this 
report, our disclosure controls and procedures were 
effective to ensure that information required to be disclosed 
by us and included in our reports filed or submitted under 
the Exchange Act is recorded, processed, summarized and 
reported within the time periods specified in the Securities
and Exchange Commission (SEC) rules and forms and that 
such information is accumulated and communicated to 
management, including the Chief Executive Officer and 
Chief Financial Officer, as appropriate to allow timely 
decisions regarding required disclosure.

(b) Changes in Internal Control Over Financial Reporting

Our management is responsible for establishing and 
maintaining adequate internal control over financial 
reporting, as such term is defined in the Exchange Act Rule 
13a-15(f).

There have been no changes in our internal control over 
financial reporting that occurred during the quarter ended 
December 31, 2015 that have materially affected, or are 
reasonably likely to materially affect, our internal control 
over financial reporting. The statements contained in Exhibit 
31.1 and Exhibit 31.2 should be considered in light of, and 
read together with, the information set forth in this Item 9(a).

ITEM 9B. OTHER INFORMATION

On February 24, 2016, the Organization and Executive 
Compensation Committee of the Company’s Board of 
Directors approved, and the Company entered into, an 
amendment to the Long Term Incentive Award Agreement 
dated February 25, 2015 between the Company and Gregg 
S. Kantor, Chief Executive Officer of the Company. The 
amendment changes the minimum age to qualify for a pro-
rated payment on retirement under the agreement from 60 
to 55. The Company has previously announced that Mr. 
Kantor intends to retire as an employee of the Company on 
December 31, 2016, which is four months before his 60th 
birthday. Accordingly, the effect of the amendment will be to 
make Mr. Kantor eligible for a pro rata payout of his 
2015-2017 performance share award upon his planned 
retirement. Assuming retirement on December 31, 2016, the 
pro-rated target number of shares of Company common 
stock under this award will be 9,500 shares, and the award 
can payout between 0% and 200% of target based on 
Company performance. The same change was made in the 
agreement for Mr. Kantor’s 2016-2018 performance share 
award granted on February 24, 2016. Assuming retirement 
on December 31, 2016, the pro-rated target number of 
shares of Company common stock under this award will be 
2,525 shares, and this award also can payout between 0% 
and 200% of target based on Company performance.

86

 
 
 
 
 
PART III

ITEM 10. DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE
The "Information Concerning Nominees and Continuing Directors", "Corporate Governance", and "Section 16(a) Beneficial 
Ownership Reporting Compliance" contained in our definitive Proxy Statement for the May 26, 2016 Annual Meeting of 
Shareholders is hereby incorporated by reference.

Name

Gregg S. Kantor

Age at
Dec. 31, 2015
58

David H. Anderson

Gregory C. Hazelton

Lea Anne Doolittle

MardiLyn Saathoff

David R. Williams

Grant M. Yoshihara

C. Alex Miller

Ngoni Murandu

Shawn M. Filippi

Kimberly A. Heiting

Thomas J. Imeson

Margaret D. Kirkpatrick

Brody J. Wilson

David A. Weber

54

51

60

59

62

60

58

41

43

46

65

60

36

56

Positions held during last five years

Chief Executive Officer (2009-  ); President (2009-2015); President and Chief
Operating Officer (2007-2008); Executive Vice President (2006-2007); Senior Vice
President, Public and Regulatory Affairs (2003-2006).

President and Chief Operating Officer (2016-  ); Executive Vice President and Chief
Operating Officer (2014-2015); Executive Vice President Operations and Regulation
(2013-2014); Senior Vice President and Chief Financial Officer (2004-2013).

Senior Vice President, Chief Financial Officer and Treasurer (2016-  ); Senior Vice
President and Chief Financial Officer (2015-2016); Vice President of Finance,
Treasurer and Controller, Hawaiian Electric Industries, Inc. (2013-2015); Managing
Director, UBS Investment Bank, Global Power and Utilities Group; Associate
Director, UBS Investment Bank, Global Power and Utilities Group (2011-2013);
Executive Director, UBS Investment Bank, Global Power and Utilities Group
(2008-2011).

Senior Vice President and Chief Administrative Officer (2013-  ); Senior Vice
President (2008-2013); Vice President, Human Resources (2000-2007).

Senior Vice President, General Counsel and Regulation (2016-  )Senior Vice
President and General Counsel (2015-2016); Vice President Legal, Risk and
Compliance (2013-2014); Deputy General Counsel (2010-2013); Chief Governance
Officer and Corporate Secretary (2008-2014).

Vice President, Utility Services (2007-  ); Director of Utility Operations, Districts and
Managed Labor Relations (2004-2006).

Vice President, Utility Operations (2007-  ); Managing Director, Utility Services
(2005-2006); Director, Utility Services (2004-2005).

Vice President Regulation and Treasurer (2013-2016); Vice President, Finance and
Regulation (2009-2013); Assistant Treasurer (2008-2013); General Manager of
Rates and Regulatory Affairs (2002-2009).

Vice President and Chief Information Officer (2016-  ); Chief Information Officer
(2014-2016); Vice President and Chief Information Officer, NANA Development
Corporation (2010-2014).

Vice President, Chief Compliance Officer and Corporate Secretary (2016-  ); Vice
President and Corporate Secretary (2015-2016); Senior Legal Counsel (2011-2014);
Assistant Corporate Secretary (2010-2014); Associate Legal Counsel (2005-2010).

Vice President, Communications and Chief Marketing Officer (2015-  ); Chief
Marketing & Communications Officer (2013-2014); Chief Corporate Communications
Officer (2011-2013); Communications Director (2005-2011).
Vice President of Public Affairs (2014-  ); Director of Public Affairs, Port of Portland
(2006-2014).

Senior Vice President, Environmental Policy and Affairs (2015); Senior Vice
President and General Counsel (2013-2014); Vice President and General Counsel
(2005-2013).

Chief Accounting Officer, Controller and Assistant Treasurer (2016-  ); Controller
(2013-2015); Acting Controller (2013); Accounting Director (2012-2013); Senior
Manager, PriceWaterhouseCoopers LLP (2009-2012); Manager,
PriceWaterhouseCoopers LLP (2007-2009).

President and Chief Executive Officer, NW Natural Gas Storage, LLC and Gill
Ranch Storage, LLC (2012-  ); Interim President and Chief Executive Officer, NW
Natural Gas Storage LLC, and Gill Ranch Storage, LLC (2011-2012); Chief
Operating Officer NW Natural Gas Storage, LLC and Gill Ranch Storage LLC
(November 2010 - January 2011); Managing Director of Information Services and
Chief Information Officer (2005 - 2011); Director of Information Services and Chief
Information Officer (2001-2005).

Each executive officer serves successive annual terms; present terms end on May 26, 2016. There are no family relationships 
among our executive officers, directors or any person chosen to become one of our officers or directors. 

NW Natural has adopted a Code of Ethics (Code) applicable to all employees and officers that is available on our website at 
www.nwnatural.com. We intend to disclose on our website at www.nwnatural.com any amendments to the Code or waivers of 
the Code for executive officers.

87

ITEM 11. EXECUTIVE COMPENSATION

The information concerning "Executive Compensation", "Report of the Organization and Executive Compensation Committee", 
and "Compensation Committee Interlocks and Insider Participation" contained in our definitive Proxy Statement for the May 26, 
2016 Annual Meeting of Shareholders is hereby incorporated by reference. Information related to Executive Officers as of 
December 31, 2015 is reflected in Part III, Item 10, above.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND 
RELATED STOCKHOLDER MATTERS

The following table sets forth information regarding compensation plans under which equity securities of NW Natural are 
authorized for issuance as of December 31, 2015 (see Note 6 to the Consolidated Financial Statements):

Plan Category

Equity compensation plans approved by security holders:
LTIP Performance Share Awards (Target Award)(1)(2)
LTIP Restricted Stock Units (Target Award)(1)(2)
LTIP Stock Options(3)

Restated Stock Option Plan

Employee Stock Purchase Plan

Equity compensation plans not approved by security holders:

Executive Deferred Compensation Plan (EDCP)(4)
Directors Deferred Compensation Plan (DDCP)(4)
Deferred Compensation Plan for Directors and Executives (DCP)(5)

Total

(a)

(b)

(c)

Number of securities
to be issued upon
exercise of
outstanding options,
warrants and rights

Weighted-average
exercise price of
outstanding options,
warrants and rights

Number of securities
remaining available
for future issuance
under equity
compensation plans
(excluding securities
reflected in column
(a))

117,775

88,587

—

352,688

$

20,726

1,251

48,370

149,485

778,882

n/a

n/a

—

44.00

40.51

n/a

n/a

n/a

393,210

393,210

643,210

—

58,131

n/a

n/a

n/a

701,341

(1)  Shares issued pursuant to Performance Share Awards and Restricted Stock Units under the LTIP do not include an exercise price, but are 
payable when the award criteria are satisfied. If the maximum awards were paid pursuant to the Performance Share Awards outstanding at 
December 31, 2015, the number of shares shown in column (a) would increase by 117,775 shares and the number of shares shown in 
column (c) would decrease by the same amount of shares.
The aggregate 393,210 shares are available for future issuance under the LTIP as Restricted Stock Units, Performance Share Awards, or 
stock options. An additional 250,000 shares are available for LTIP Stock Option Issuance at December 31, 2015, but those additional 
shares are not available for issuance of LTIP Restricted Stock Units or Performance Share Awards. 

(2) 

(3)  Shares balance includes 393,210 shares available for future issuance under the LTIP as Restricted Stock Units, Performance Share 

Awards, or stock options; and an additional 250,000 shares available for LTIP Stock Option Issuance only at December 31, 2015, and are 
not available for issuance of LTIP Restricted Stock Units or Performance Share Awards. 

(4)  Prior to January 1, 2005, deferred amounts were credited, at the participant’s election, to either a “cash account” or a “stock account.” If 
deferred amounts were credited to stock accounts, such accounts were credited with a number of shares of NW Natural common stock 
based on the purchase price of the common stock on the next purchase date under our Dividend Reinvestment and Direct Stock Purchase 
Plan, and such accounts were credited with additional shares based on the deemed reinvestment of dividends. Cash accounts are credited 
quarterly with interest at a rate equal to Moody’s Average Corporate Bond Yield plus two percentage points, subject to a 6% minimum rate. 
At the election of the participant, deferred balances in the stock accounts are payable after termination of Board service or employment in a 
lump sum, in installments over a period not to exceed 10 years in the case of the DDCP, or 15 years in the case of the EDCP, or in a 
combination of lump sum and installments. Amounts credited to stock accounts are payable solely in shares of common stock and cash for 
fractional shares, and amounts in the above table represent the aggregate number of shares credited to participant's stock accounts. We 
have contributed common stock to the trustee of the Umbrella Trusts such that the Umbrella Trusts hold approximately the number of 
shares of common stock equal to the number of shares credited to all participants’ stock accounts.

(5)  Effective January 1, 2005, the EDCP and DDCP were closed to new participants and replaced with the DCP. The DCP continues the basic 
provisions of the EDCP and DDCP under which deferred amounts are credited to either a “cash account” or a “stock account.” Stock 
accounts represent a right to receive shares of NW Natural common stock on a deferred basis, and such accounts are credited with 
additional shares based on the deemed reinvestment of dividends. Effective January 1, 2007, cash accounts are credited quarterly with 
interest at a rate equal to Moody’s Average Corporate Bond Yield. Our obligation to pay deferred compensation in accordance with the 
terms of the DCP will generally become due on retirement, death, or other termination of service, and will be paid in a lump sum or in 
installments of five, 10, or 15 years as elected by the participant in accordance with the terms of the DCP. Amounts credited to stock 
accounts are payable solely in shares of common stock and cash for fractional shares, and amounts in the above table represent the 
aggregate number of shares credited to participant's stock accounts. We have contributed common stock to the trustee of the Supplemental 
Trust such that this trust holds approximately the number of common shares equal to the number of shares credited to all participants' stock 
accounts. The right of each participant in the DCP is that of a general, unsecured creditor of the Company.

88

  
 
 
 
 
 
The information captioned “Beneficial Ownership of Common Stock by Directors and Executive Officers” and "Security 
Ownership of Common Stock of Certain Beneficial Owners" contained in our definitive Proxy Statement for the May 26, 2016 
Annual Meeting of Shareholders is incorporated herein by reference.

ITEM 13. CERTAIN RELATIONSHIPS AND 
RELATED TRANSACTIONS, AND DIRECTOR 
INDEPENDENCE

The information captioned "Transactions with Related 
Persons" and "Corporate Governance" in the Company’s 
definitive Proxy Statement for the May 26, 2016 Annual 
Meeting of Shareholders is hereby incorporated by 
reference.

ITEM 14. PRINCIPAL ACCOUNTANT FEES AND 
SERVICES

The information captioned "2015 and 2014 Audit Firm Fees" 
in the Company’s definitive Proxy Statement for the May 26, 
2016 Annual Meeting of Shareholders is hereby 
incorporated by reference.

89

 
 
ITEM 15. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

(a)  The following documents are filed as part of this report:

PART IV

1.  A list of all Financial Statements and Supplemental Schedules is incorporated by reference to Item 8.

2.  List of Exhibits filed:

Reference is made to the Exhibit Index commencing on page 92.

90

  
 
SIGNATURES

Pursuant  to  the  requirements  of  Section  13  or  15(d)  of  the 
Securities  Exchange  Act  of  1934,  the  registrant  has  duly 
caused  this  report  to  be  signed  on  its  behalf  by  the 
undersigned, thereunto duly authorized.

NORTHWEST NATURAL GAS COMPANY

By: /s/ Gregg S. Kantor
Gregg S. Kantor
Chief Executive Officer
Date: February 26, 2016      

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons 
on behalf of the registrant and in the capacities and on the date indicated.

Signature

Title

Date

/s/ Gregg S. Kantor

Gregg S. Kantor

Chief Executive Officer

/s/ Gregory C. Hazelton

Gregory C. Hazelton

Senior Vice President, Chief Financial Officer and
Treasurer

/s/ Brody J. Wilson   

Brody J. Wilson

Chief Accounting Officer, Controller and Assistant
Treasurer

Principal Executive Officer and Director

February 26, 2016

Principal Financial Officer

February 26, 2016

Principal Accounting Officer

February 26, 2016

/s/ Timothy P. Boyle 

Timothy P. Boyle 

/s/ Martha L. Byorum     

Martha L. Byorum

/s/ John D. Carter     

John D. Carter

/s/ Mark S. Dodson

Mark S. Dodson

/s/ C. Scott Gibson

C. Scott Gibson

/s/ Tod R. Hamachek

Tod R. Hamachek

/s/ Jane L. Peverett 

Jane L. Peverett 

/s/ Kenneth Thrasher  

Kenneth Thrasher

/s/ Malia H. Wasson

Malia H. Wasson

  Director

  Director

  Director

  Director

  Director

  Director

  Director

  Director

  Director

91

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February 26, 2016

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NORTHWEST NATURAL GAS COMPANY
 Exhibit Index to Annual Report on Form 10-K
For the Fiscal Year Ended December 31, 2015 

Exhibit Number                                                        Document

*3a.

*3b.

*4a.

*4b.

*4c.

*4d.

*4e.

*4f.

*4g.

*4h.

*4i.

*4j.

Restated Articles of Incorporation, as filed and effective May 31, 2006 and amended June 3, 2008 (incorporated
herein by reference to Exhibit 3.1 to Form 10-Q for the quarter ended June 30, 2008, File No. 1-15973).

Bylaws as amended May 22, 2014 (incorporated herein by reference to Exhibit 3.1 to Form 8-K dated May 22, 2014,
File No. 1-15973).

Copy of Mortgage and Deed of Trust, dated as of July 1, 1946, to Bankers Trust and R. G. Page (to whom Stanley
Burg is now successor), Trustees (incorporated herein by reference to Exhibit 7(j) in File No. 2-6494); and copies of
Supplemental Indentures Nos. 1 through 14 to the Mortgage and Deed of Trust, dated respectively, as of June 1,
1949, March 1, 1954, April 1, 1956, February 1, 1959, July 1, 1961, January 1, 1964, March 1, 1966, December 1,
1969, April 1, 1971, January 1, 1975, December 1, 1975, July 1, 1981, June 1, 1985 and November 1, 1985
(incorporated herein by reference to Exhibit 4(d) in File No. 33-1929); Supplemental Indenture No. 15 to the Mortgage
and Deed of Trust, dated as of July 1, 1986 (filed as Exhibit 4(c) in File No. 33-24168); Supplemental Indentures Nos.
16, 17 and 18 to the Mortgage and Deed of Trust, dated, respectively, as of November 1, 1988, October 1, 1989 and
July 1, 1990 (incorporated herein by reference to Exhibit 4(c) in File No. 33-40482); Supplemental Indenture No. 19 to
the Mortgage and Deed of Trust, dated as of June 1, 1991 (incorporated herein by reference to Exhibit 4(c) in File No.
33-64014); and Supplemental Indenture No. 20 to the Mortgage and Deed of Trust, dated as of June 1, 1993
(incorporated herein by reference to Exhibit 4(c) in File No. 33-53795).

Copy of Indenture, dated as of June 1, 1991, between the Company and Bankers Trust Company, Trustee, relating to
the Company’s Unsecured Medium-Term Notes (incorporated herein by reference to Exhibit 4(e) in File No.
33-64014).

Officers’ Certificate dated June 12, 1991 creating Series A of the Company’s Unsecured Medium-Term Notes
(incorporated herein by reference to Exhibit 4e. to Form 10-K for 1993, File No. 0-994).

Officers’ Certificate dated June 18, 1993 creating Series B of the Company’s Unsecured Medium-Term Notes
(incorporated herein by reference to Exhibit 4f. to Form 10-K for 1993, File No. 0-994).

Officers’ Certificate dated January 17, 2003 relating to Series B of the Company’s Unsecured Medium-Term Notes
and supplementing the Officers’ Certificate dated June 18, 1993 (incorporated herein by reference to Exhibit 4f.(1) to
Form 10-K for 2002, File No. 1-15973).

Form of Secured Medium-Term Notes, Series B (incorporated herein by reference to Exhibit 4.1 to Form 8-K dated
October 4, 2004, File No. 1-15973).

Form of Unsecured Medium-Term Notes, Series B (incorporated herein by reference to Exhibit 4.2 to Form 8-K dated
October 4, 2004, File No. 1-15973).

Twenty-First Supplemental Indenture, providing, among other things, for First Mortgage Bonds, 4.00% Series Due 
2042, dated as of October 15, 2012, by and between Northwest Natural Gas Company, Deutsche Bank Trust 
Company Americas (formerly known as Bankers Trust Company), and Stanley Burg (Successor to R.G. Page and 
J.C. Kennedy) (incorporated herein by reference to Exhibit 4.1 to Form 8-K dated October 26, 2012, File No.1-15973).

Form of Credit Agreement among Northwest Natural Gas Company and the parties thereto, with JPMorgan Chase
Bank, N.A. as administrative agent and U.S. Bank, N.A. and Wells Fargo Bank, N.A. as co-syndication agents, dated
as of December 20, 2012 (incorporated herein by reference to Exhibit 4.1 to Form 8-K dated December 20, 2012, File
No.1-15973).

Form of Letter Agreement, between each of JPMorgan Chase Bank, N.A., Bank of America, N.A., Canadian Imperial
Bank of Commerce, Royal Bank of Canada, TD Bank, N.A., Union Bank, N.A., US Bank, N.A., and Wells Fargo Bank,
N.A., with JPMorgan Chase Bank, N.A. as Administrative Agent, extending the maturity date of the Credit Agreement
between Northwest Natural Gas Company and each financial institution, effective as of December 20, 2013
(incorporated herein by reference to Exhibit 4k to Form 10-K for 2013, File No. 1-15973).

92

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*4k. 

*4l. 

*10a

Form of Letter Agreement, between each of JPMorgan Chase Bank, N.A., Bank of America, N.A., Canadian Imperial
Bank of Commerce, Royal Bank of Canada, TD Bank, N.A., Union Bank, N.A., US Bank, N.A., and Wells Fargo Bank,
N.A., with JPMorgan Chase Bank, N.A. as Administrative Agent, extending the maturity date of the Credit Agreement
between Northwest Natural Gas Company and each financial institution, effective as of December 20, 2014
(incorporated herein by reference to Exhibit 4m to Form 10-K for 2014, File No. 1-15973).

First Amendment to Credit Agreement, between the Company JPMorgan Chase Bank, N.A., Bank of America, N.A.,
Canadian Imperial Bank of Commerce, Royal Bank of Canada, TD Bank, N.A., Union Bank, N.A., US Bank, N.A., and
Wells Fargo Bank, N.A., with JPMorgan Chase Bank, N.A. as Administrative Agent, dated as of December 20, 2014
(incorporated herein by reference to Exhibit 4n to Form 10-K for 2014, File No. 1-15973).

Carry and Earning Agreement by and between Encana Oil & Gas (USA) Inc. and Northwest Natural Gas Company,
dated effective as of May 1, 2011, and First Amendment to Carry and Earning Agreement dated March 11, 2011
(incorporated herein by reference to Exhibit 10.1 to Form 10-Q for the quarter ended March 31, 2011, File No.
1-15973). †

*10b

Second Amendment to Carry and Earning Agreement by and between Encana Oil and Gas (USA) Inc. and NWN Gas
Reserves, LLC., dated as of March 7, 2014 (incorporated herein by reference to Exhibit 10 to Form 10-Q for the
quarter ended March 31, 2014, File No. 1-15973).

12

21

23

Statement re computation of ratios of earnings to fixed charges.

Subsidiaries of Northwest Natural Gas Company.

Consent of PricewaterhouseCoopers LLP.

31.1

Certification of Principal Executive Officer Pursuant to Rule 13a-14(a)/15-d-14(a), Section 302 of the Sarbanes-Oxley
Act of 2002.

31.2

Certification of Principal Financial Officer Pursuant to Rule 13a-14(a)/15-d-14(a), Section 302 of the Sarbanes-Oxley
Act of 2002.

32.1

Certification of Principal Executive Officer and Principal Financial Officer Pursuant to Section 906 of the Sarbanes-
Oxley Act of 2002.

Executive Compensation Plans and Arrangements:

*10c.

Executive Supplemental Retirement Income Plan 2010 Restatement (incorporated herein by reference to Exhibit 10b.
to Form 10-K for 2009, File No. 1-15973).

*10d.

Supplemental Executive Retirement Plan, 2011 Restatement (incorporated herein by reference to Exhibit 10.1 to
Form 10-Q for the quarter ended September 30, 2011, File No. 1-15973).

*10e.

Northwest Natural Gas Company Supplemental Trust, effective January 1, 2005, restated as of December 15, 2005
(incorporated herein by reference to Exhibit 10.7 to Form 8-K dated December 16, 2005, File No. 1-15973).

*10f.

Northwest Natural Gas Company Umbrella Trust for Directors, effective January 1, 1991, restated as of December 15,
2005 (incorporated herein by reference to Exhibit 10.5 to Form 8-K dated December 16, 2005, File No. 1-15973).

*10g.

Northwest Natural Gas Company Umbrella Trust for Executives, effective January 1, 1988, restated as of December
15, 2005 (incorporated herein by reference to Exhibit 10.6 to Form 8-K dated December 16, 2005, File No. 1-15973).

*10h.

Restated Stock Option Plan, as amended effective December 14, 2006 (incorporated herein by reference to Exhibit
10c. to Form 10-K for 2006, File No. 1-15973).

93

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*10i.

Form of Restated Stock Option Plan Agreement (incorporated herein by reference to Exhibit 10h. to Form 10-K for
2009, File No. 1-15973).

*10j.

Executive Deferred Compensation Plan, effective as of January 1, 1987, restated as of February 26, 2009
(incorporated herein by reference to Exhibit 10e. to Form 10-K for 2008, File No. 1-15973).

*10k.

Directors Deferred Compensation Plan, effective June 1, 1981, restated as of February 26, 2009 (incorporated herein
by reference to Exhibit 10f. to Form 10-K for 2008, File No. 1-15973).

*10l.

Deferred Compensation Plan for Directors and Executives effective January 1, 2005, restated as of September 24,
2015 (incorporated herein by reference to Exhibit 10a to Form 10-Q for the quarter ended September 30, 2015).

*10m.

Form of Indemnity Agreement as entered into between the Company and each director and certain executive officers
(incorporated herein by reference to Exhibit 10l. to Form 10-K for 2009, File No. 1-15973).

*10n.

Form of Indemnity Agreement as entered into between the Company and certain executive officers (incorporated
herein by reference to Exhibit 10l.(1) to Form 10-K for 2009, File No. 1-15973).

*10o.

Non-Employee Directors Stock Compensation Plan, as amended effective December 15, 2005 (incorporated herein
by reference to Exhibit 10.2 to Form 8-K dated December 16, 2005, File No. 1-15973).

10p.

Executive Annual Incentive Plan, effective February 23, 2012, as amended effective January 1, 2016.

*10q.

Form of Change in Control Severance Agreement between the Company and each executive officer (incorporated
herein by reference to Exhibit 10o. to Form 10-K for 2008, File No. 1-15973).

*10r.

Northwest Natural Gas Company Long-Term Incentive Plan, as amended and restated effective May 24, 2012
(incorporated herein by reference to Exhibit 10r to Form 10-K for 2012, File No. 1-15973).

*10s.

Severance Agreement between Northwest Natural Gas Company and an executive officer, dated as of June 30, 2015
(incorporated herein by reference to Exhibit 10.1 to Form 8-K dated June 24, 2015).

*10t.

Form of Long-Term Incentive Award Agreement under the Long Term Incentive Plan (2013-2015) (incorporated herein
by reference to Exhibit 10v. to Form 10K for 2012, File No. 1-15973).

*10u.

Form of Long-Term Incentive Award Agreement under the Long Term Incentive Plan (2014-2016) (incorporated herein
by reference to Exhibit 10v. to Form 10-K for 2013, File No. 1-15973).

*10v.

Form of Long-Term Incentive Award Agreement under the Long Term Incentive Plan (2015-2017) (incorporated by
reference to Exhibit 10w to Form 10-K for 2014, File No. 1-15973).

10w.

Form of  Long-Term Incentive Award Agreement under the Long Term Incentive Plan (2016-2018).

10x.

10y.

*10z.

Form of Long-Term Incentive Award Agreement under the Long Term Incentive Plan between the Company and an
Executive Officer (2016-2018).

Agreement to Amend the Long-Term Incentive Award Agreement, under the Long-Term Incentive Plan dated February
25, 2016 by and between the Company and an executive officer.

Form of Consent dated December 14, 2006 entered into by each executive officer with respect to amendments to the
Executive Supplemental Retirement Income Plan, the Supplemental Executive Retirement Plan and certain change in
control severance agreements (incorporated herein by reference to Exhibit 10.1 to Form 8-K dated December 19,
2006, File No. 1-15973).

94

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*10aa. Consent to Amendment of Deferred Compensation Plan for Directors and Executives, dated February 28, 2008

entered into by each executive officer (incorporated herein by reference to Exhibit 10bb to Form 10-K for 2007, File
No. 1-15973).

10bb.

Form of Restricted Stock Unit Award Agreement under Long-Term Incentive Plan (2016).

*10cc. Form of Restricted Stock Unit Award Agreement under the Long-Term Incentive Plan (2013) (incorporated herein by

reference to Exhibit 10aa. to Form 10-K for 2012, File No. 1-15978).

*10dd. Form of Restricted Stock Unit Award Agreement under the Long-Term Incentive Plan (2012) (incorporated herein by

reference to Exhibit 10.1 to Form 8-K dated December 20, 2011, File No. 1-15973).

*10ee. Form of Special Restricted Stock Unit Award Agreement under the Long-Term Incentive Plan between the Company
and an executive officer (incorporated herein by reference to Exhibit 10cc. to Form 10-Q for the period ending
September 30, 2013, File No. 1-15973).

*10ff.

Form of Special Restricted Stock Unit Award Agreement under the Long-Term Incentive Plan between the Company
and an executive officer. (incorporated herein by reference to Form 10-Q for the quarter ended March 31, 2014, File
No. 1-15973).

*10gg. Form of Special Retention Restricted Stock Unit Award Agreement between the Company and an executive officer,

dated as of June 30, 2015 (incorporated herein by reference to Exhibit 10.2 to Form 8-K dated June 24, 2015).

*10hh. Hire-On Bonus Agreement between the Company and an executive officer, dated as of June 30, 2015 (incorporated

herein by reference to Exhibit 10.3 to Form 8-K dated June 24, 2015).

10ii.

Annual Incentive Plan for NW Natural Gas Storage, LLC, as amended effective January 1, 2016.

10jj.

Long-Term Incentive Plan for NW Natural Gas Storage, LLC, as amended effective January 1, 2016.

101.

The following materials from Northwest Natural Gas Company's Annual Report on Form 10-K for the fiscal year ended 
December 31, 2015, formatted in Extensible Business Reporting Language (XBRL):

(i) Consolidated Statements of Income;
(ii) Consolidated Balance Sheets;
(iii) Consolidated Statements of Cash Flows; and
(iv) Related notes.

 *Incorporated herein by reference as indicated

† Certain portions of the exhibit have been omitted based upon a request for confidential treatment filed by us with the Securities 
and Exchange Commission. The omitted portions of the exhibit have been separately filed by us with the Securities and 
Exchange Commission. 

95

 
 
 
 
NORTHWEST NATURAL GAS COMPANY 
Ratios of Earnings to Fixed Charges 
(Unaudited)

EXHIBIT 12

In thousands, except share data

Fixed Charges, as defined:

Interest on Long-Term Debt
Other Interest
Amortization of Debt Discount and Expense
Interest Portion of Rentals
Total Fixed Charges, as defined

Earnings, as defined:

Net Income
Taxes on Income
Fixed Charges, as above
Total Earnings, as defined

Ratios of Earnings to Fixed Charges

Year Ended December 31,

2015

2014

2013

2012

2011

$

$

37,918
3,173
1,760
1,976
44,827

$

40,066
2,718
1,963
2,302
47,049

$

40,825
2,709
1,877
1,910
47,321

$

39,175
2,314
1,848
1,864
45,201

37,515
2,976
1,729
2,213
44,433

53,703
35,753
44,827
$ 134,283
3.00

58,692
41,643
47,049
$ 147,384
3.13

60,538
41,705
47,321
$ 149,564
3.16

58,779
43,403
45,201
$ 147,383
3.26

63,044
42,825
44,433
$ 150,302
3.38

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

EXHIBIT 23

We hereby consent to the incorporation by reference in the Registration Statement on Form 
333-120955, 333-134973, 333-139819, 333-180350 and 333-187005) and in the Registration Statement on Form S-3 (No. 
333-192641) of Northwest Natural Gas Company of our report dated February 26, 2016 relating to the consolidated financial 
statements, financial statement schedule and the effectiveness of internal control over financial reporting, which appears in this 
Form 

(Nos. 333-70218, 333-100885, 

/s/ PricewaterhouseCoopers LLP

Portland, Oregon
February 26, 2016 

 
CERTIFICATION

I, Gregg S. Kantor, certify that:

EXHIBIT 31.1

1.           I have reviewed this annual report on Form 10-K of Northwest Natural Gas Company;

2.           Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material 
fact necessary to make the statements made, in light of the circumstances under which such statements were made, not 
misleading with respect to the period covered by this report;

3.           Based on my knowledge, the financial statements, and other financial information included in this report, fairly present 
in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods 
presented in this report;

4.           The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and 
procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined 
in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under 
our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made 
known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed 
under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of 
financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our 
conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report 
based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the 
registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially 
affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.           The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over 
financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons 
performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting 
which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial 
information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the 
registrant’s internal control over financial reporting.

Date:          February 26, 2016 

/s/ Gregg S. Kantor                                                   
Gregg S. Kantor
Chief Executive Officer

CERTIFICATION

I, Gregory C. Hazelton, certify that:

EXHIBIT 31.2

1.           I have reviewed this annual report on Form 10-K for Northwest Natural Gas Company;

2.           Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material 
fact necessary to make the statements made, in light of the circumstances under which such statements were made, not 
misleading with respect to the period covered by this report;

3.           Based on my knowledge, the financial statements, and other financial information included in this report, fairly present 
in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods 
presented in this report;

4.           The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and 
procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined 
in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under 
our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made 
known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed 
under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of 
financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our 
conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report 
based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the 
registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially 
affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.           The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over 
financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons 
performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting 
which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial 
information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the 
registrant’s internal control over financial reporting.

Date:          February 26, 2016 

/s/ Gregory C. Hazelton                                                                
Gregory C. Hazelton
Senior Vice President, Chief Financial Officer, and Treasurer

NORTHWEST NATURAL GAS COMPANY
Certificate Pursuant to Section 906
of Sarbanes – Oxley Act of 2002

EXHIBIT 32.1

Each of the undersigned, GREGG S. KANTOR, Chief Executive Officer, and GREGORY C. HAZELTON, the Senior Vice 
President, Chief Financial Officer, and Treasurer of NORTHWEST NATURAL GAS COMPANY (the Company), DOES HEREBY 
CERTIFY that:

1.           The Company’s Annual Report on Form 10-K for the year ended December 31, 2015 (the Report) fully complies with 
the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2.           Information contained in the Report fairly presents, in all material respects, the financial condition and results of 
operations of the Company.

IN WITNESS WHEREOF, each of the undersigned has caused this instrument to be executed this 26th day of 

February 2016.

/s/ Gregg S. Kantor                                                      
Gregg S. Kantor
Chief Executive Officer

/s/ Gregory C. Hazelton                                                        
Gregory C. Hazelton
Senior Vice President,
Chief Financial Officer, and
Treasurer

A signed original of this written statement required by Section 906 of the Sarbanes-Oxley Act of 2002 has been provided to 
Northwest Natural Gas Company and will be retained by Northwest Natural Gas Company and furnished to the Securities and 
Exchange Commission or its staff upon request.

 
 
 
INVESTOR AND SHAREHOLDER INFORMATION

CORPORATE INFORMATION

Nikki Sparley

Director, Investor Relations
Toll free (800) 422-4012, Ext. 2530 
Direct (503) 721-2530
nikki.sparley@nwnatural.com

Chu Lee

Manager, Shareholder Services 
Toll free (800) 422-4012, Ext. 2402 
Direct (503) 220-2402
chu.lee@nwnatural.com

Stock transfer agent and registrar

For common stock:
American Stock Transfer & Trust Company
6201 15th Avenue
Brooklyn, NY 11219
(888) 777-0321
web: amstock.com
email: info@amstock.com

Trustee and bond paying agent 

For bond issues:
Deutsche Bank Trust Company Americas
60 Wall Street
New York, NY 10005
(800) 735-7777

COMMUNITY & SUSTAINABILITY REPORT 
Learn more about NW Natural’s community involvement and philanthropic contributions, environmental 

stewardship, employee safety efforts and other company initiatives. 

View the Community & Sustainability Annual Report at nwnatural.com/aboutnwnatural/community.

LOW-INCOME PROGRAMS 
NW Natural helps low-income customers manage their bills through a variety of programs. Shareholders  

and customers support the Gas Assistance Program (GAP), which supplements the federal and 

state assistance programs. In addition, the Oregon Low-Income Gas Assistance Program (OLGA) 

uses public purpose fees to help low-income customers pay their utility bills. The Oregon Low-Income 

Energy Efficiency Program (OLIEE), also paid for by public purpose charges, helps customers in need 

acquire high-efficiency equipment and weatherization.

View the Low-Income Programs at nwnatural.com/residential.

ENERGY-EFFICIENCY PROGRAMS 
NW Natural partners with Energy Trust of Oregon to offer our Oregon and Washington customers 

energy-efficiency programs and services. Learn more about the results of these programs and the 

benefits to our customers. 

View the Energy Trust of Oregon Annual Report at nwnatural.com/residential.

220 nw second avenue
portland, oregon 97209
nwnatural.com
nyse: nwn

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