NORTHWEST NATURAL GAS CO
For the period ended Dec 31, 2025. Filed Feb 27, 2026.
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FY2025 · Filed Feb 27, 2026
NWN$51.99-0.1%Stored close · as of Nov 10, 2026
Extracted filing text, with the paragraph anchors used by the comparison.
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Glossary of Terms and Abbreviations
| ACC | Arizona Corporation Commission; the entity that regulates NW Holdings' regulated water and wastewater businesses in Arizona with respect to rates and terms of service, among other matters |
|---|---|
| AFUDC | Allowance for Funds Used During Construction |
| AOCI / AOCL | Accumulated Other Comprehensive Income (Loss) |
| ASC | Accounting Standards Codification |
| ASU | Accounting Standards Update as issued by the FASB |
| Average Weather | The 25-year average of heating degree days based on temperatures established in our last Oregon general rate case |
| Bcf | Billion cubic feet, a volumetric measure of natural gas, where one Bcf is roughly equal to 10 million therms |
| CAP | Compliance Assurance Process with the Internal Revenue Service |
| CCA | Climate Commitment Act enacted by the State of Washington |
| CNG | Compressed Natural Gas |
| CODM | Chief Operating Decision Maker, which for accounting purposes is defined as an individual or group of individuals responsible for the allocation of resources and assessing the performance of the entity's business units |
| Cost of Gas | The delivered cost of natural gas sold to customers, including the cost of gas purchased, gas storage costs, gas reserves costs, gas commodity derivative contracts, pipeline demand costs, seasonal demand cost balancing adjustments, renewable natural gas and its attributes, including renewable thermal certificate costs, and regulatory gas cost deferrals |
| CPP | Climate Protection Program established by the Environmental Quality Commission of the Oregon Department of Environmental Quality |
| Decoupling | A natural gas billing rate mechanism, also referred to as a conservation tariff, which is designed to allow a utility to encourage residential and small commercial customers to conserve energy |
| Degree Day | The number of degrees that the average outdoor temperature falls below or exceeds a base value in a given period of time |
| Demand Cost | A component in NW Natural Gas customer rates representing the cost of securing firm pipeline capacity, whether the capacity is used or not |
| ECRM | Environmental Cost Recovery Mechanism, a billing rate mechanism for recovering prudently incurred environmental site remediation costs allocable to Washington customers through NW Natural Gas customer billings |
| Energy Corp | Northwest Energy Corporation, a wholly-owned subsidiary of Northwest Natural Gas Company |
| EPA | Environmental Protection Agency |
| EPS | Earnings per share |
| ESPP | Employee Stock Purchase Plan |
| FASB | Financial Accounting Standards Board |
| FERC | Federal Energy Regulatory Commission; the entity regulating interstate storage services offered by the Mist gas storage facility |
| Firm Service | Natural gas service offered to customers under contracts or rate schedules that will not be disrupted to meet the needs of other customers |
| FMBs | First Mortgage Bonds |
| General Rate Case | A periodic filing with state or federal regulators to establish billing rates for utility customers |
| GHG | Greenhouse gases |
| GRIP | Gas Reliability Infrastructure Program, a statute authorized by the Railroad Commission of Texas that allows gas utilities to adjust rates annually to recover investment costs between rate cases |
| 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 |
| Interstate Storage Services | The portion of the Mist gas storage facility not used to serve NW Natural Gas customers, instead serving utilities, third-party marketers, and electric generators |
| IPUC | Public Utility Commission of Idaho; the entity that regulates NW Holdings' regulated water businesses in Idaho with respect to rates and terms of service, among other matters |
| IRP | Integrated Resource Plan |
| KB | Kelso-Beaver Pipeline, of which 10% is owned by KB Pipeline Company, a subsidiary of NNG Financial Corporation |
| LNG | 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 |
|---|---|
| LTIP | Long Term Incentive Plan |
| Moody's | Moody's Investors Service, Inc., credit rating agency |
| NAV | Net Asset Value |
| NGD | Natural Gas Distribution, a term used prior to the first quarter of 2025 to describe a segment of Northwest Natural Holding Company and Northwest Natural Gas Company that provided regulated natural gas distribution services to residential, commercial, and industrial customers in Oregon and Southwest Washington |
| NNG Financial | NNG Financial Corporation, a wholly-owned subsidiary of NW Holdings |
| NW Holdings | Northwest Natural Holding Company |
| NW Natural | Northwest Natural Gas Company, a wholly-owned subsidiary of NW Holdings |
| NW Natural Renewables | NW Natural Renewables Holdings, LLC, a wholly-owned subsidiary of NW Holdings |
| NWN Energy | NW Natural Energy, LLC, a wholly-owned subsidiary of NW Holdings |
| NWN Gas Reserves | NWN Gas Reserves LLC, a wholly-owned subsidiary of Energy Corp |
| NWN Gas Storage | NW Natural Gas Storage, LLC, a wholly-owned subsidiary of NWN Energy |
| NWN Gas Utility Margin | A financial measure used by NW Natural's CODM consisting of NWN Gas Utility operating revenues less the associated cost of gas, revenue taxes, and environmental recoveries |
| NWN Water | NW Natural Water Company, LLC, a wholly-owned subsidiary of NW Holdings |
| ODEQ | Oregon Department of Environmental Quality |
| OPEIU | Office and Professional Employees International Union Local No. 11, AFL-CIO, the Union which represents NW Natural's bargaining unit employees |
| OPUC | Public Utility Commission of Oregon; the entity that regulates our Oregon natural gas and regulated water businesses with respect to rates and terms of service, among other matters; the OPUC also regulates the Mist gas storage facility's intrastate storage services |
| PGA | Purchased Gas Adjustment, a regulatory mechanism primarily used to adjust natural gas customer rates to reflect changes in the forecasted cost of gas and differences between forecasted and actual gas costs from the prior year |
| PHMSA | U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration |
| PUCT | Public Utility Commission of Texas; the entity that regulates NW Holdings' regulated water and wastewater businesses in Texas with respect to rates and terms of service, among other matters |
| RNG | Renewable Natural Gas, a source of natural gas derived from organic materials which may be captured, refined, and distributed on natural gas pipeline systems |
| RNG Hold Co | NW Natural RNG Holding Company, LLC, a wholly-owned subsidiary of Northwest Natural Gas Company |
| ROE | Return on Equity, a measure of corporate profitability, calculated as net income or loss divided by average common equity. Authorized ROE refers to the equity rate approved by a regulatory agency for use in determining utility revenue requirements |
| ROR | Rate of Return, a measure of return on utility rate base. Authorized ROR refers to the rate of return approved by a regulatory agency and is generally discussed in the context of ROE and capital structure |
| RRC | Railroad Commission of Texas; the entity that, along with the cities in which SiEnergy operates, regulates SiEnergy's natural gas business |
| RSU | Restricted Stock Unit |
| RTC | Renewable Thermal Certificate |
| S&P | Standard & Poor's Financial Services LLC, a credit rating agency and a subsidiary of S&P Global Inc. |
| Sales Service | Service provided whereby a customer purchases both natural gas commodity supply and transportation from the NW Natural Gas business |
| SiEnergy | SiEnergy Operating, LLC, a wholly-owned subsidiary of Northwest Natural Holding Company |
| SEC | U.S. Securities and Exchange Commission |
| SOFR | Secured Overnight Financing Rate |
| SRRM | Site Remediation and Recovery Mechanism, a billing rate mechanism for recovering prudently incurred environmental site remediation costs allocable to Oregon through NW Natural Gas customer billings, subject to an earnings test |
| Therm | The basic unit of natural gas measurement, equal to one hundred thousand British thermal units |
| 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 |
| TSA | Transportation Security Administration |
|---|---|
| U.S. GAAP | Accounting principles generally accepted in the United States of America |
| WARM | An Oregon billing rate mechanism applied to natural gas residential and commercial customers to adjust for temperature variances from average weather |
| WUTC | Washington Utilities and Transportation Commission, the entity that regulates our Washington natural gas and regulated water businesses with respect to rates and terms of service, among other matters |
The text of this filing, as the company filed it with the SEC, without its images or exhibits. This is not investment advice.