What Is ONGAEIR? Colorado’s O&G Emissions Reporting Program

ONGAEIR is Colorado’s mandatory oil and gas emissions reporting program, requiring covered facilities to submit annual greenhouse gas and methane emission inventories to CDPHE by June 30 each year, per Colorado AQCC Regulation 7, Part B . Administered by CDPHE’s Air Pollution Control Division, ONGAEIR operates independently of the federal GHGRP Subpart W program; operators above both programs’ applicability thresholds must file with CDPHE and EPA separately .

This post is for informational purposes only and does not constitute legal or compliance advice. Consult qualified legal counsel or a compliance professional for guidance specific to your operations and jurisdiction.

What Is ONGAEIR?

ONGAEIR stands for Oil and Natural Gas Sector Emission Inventory and Reporting [1]. Colorado’s Air Pollution Control Division administers the program under the authority of Colorado AQCC Regulation 7, Part B . Covered facilities submit annual emission inventories reporting methane, volatile organic compounds, and other regulated pollutants from O&G equipment and operations at each facility location [1].

ONGAEIR Requires Annual Facility-Level Emissions Inventories by June 30

ONGAEIR reporting begins with a facility-level equipment inventory [1]. Operators document each emission source at a covered facility, including pneumatic controllers, storage tanks, fugitive emission components, and combustion equipment, per the source categories in Regulation 7, Part B . Emissions for each source category are calculated using EPA emission factors or source-specific measurement data, depending on the category and the operator’s chosen methodology . Completed reports are submitted electronically to CDPHE’s Air Pollution Control Division by June 30 for the prior calendar year .

Who Must File ONGAEIR

Colorado AQCC Regulation 7, Part B requires O&G operators to report ONGAEIR emissions for each facility that meets applicable production or throughput thresholds, including oil and gas wells, production facilities, and midstream operations above CDPHE’s specified reporting levels [1]. Operators should confirm current thresholds directly against the latest Regulation 7 Part B text, as thresholds are subject to regulatory revision. Facilities above the applicable thresholds must file annually regardless of whether they also report under a federal program .

ONGAEIR and GHGRP Subpart W: Two Separate Obligations

ONGAEIR and GHGRP Subpart W are independent programs with separate deadlines, thresholds, and calculation requirements . Filing under one does not satisfy the other .

GHGRP Subpart W is the federal program, administered by EPA under 40 CFR Part 98, with an annual reporting deadline of March 31 . It applies to petroleum and natural gas systems facilities emitting 25,000 metric tons CO2e or more annually . ONGAEIR’s applicability criteria are established in Colorado AQCC Regulation 7, Part B and differ from the federal threshold in scope, source category definitions, and calculation methodologies .

For operators managing both obligations, the GHGRP March 31 deadline arrives first, followed by the ONGAEIR June 30 deadline three months later [2]. The later ONGAEIR deadline can fall into the shadow of the larger federal preparation effort if compliance teams exhaust their bandwidth on Subpart W first .

How to Correct Errors in a Filed ONGAEIR Report

Errors identified after submission are addressed through a formal amendment process administered by CDPHE’s Air Pollution Control Division, per CDPHE ONGAEIR program procedures . Operators should contact CDPHE directly to confirm current amendment requirements and any procedural consequences before initiating a correction .

Self-identified corrections submitted proactively may involve lower administrative burden than corrections identified through agency review . An agency-identified error opens questions about good-faith compliance that a self-reported correction forecloses .

Frequently Asked Questions

Does ONGAEIR allow operators to use EPA default emission factors, or is source-specific data required?

ONGAEIR accepts both EPA default emission factors and source-specific data for calculating facility-level emissions [1]. Operators typically use Regulation 7 Part B emission factor tables for standard source categories such as pneumatic controllers, storage tanks, and fugitive emission components [1]. Source-specific measurement data may be required for certain source types or can be used voluntarily to improve accuracy beyond default factor estimates [1]. Operators should consult CDPHE’s current Regulation 7 Part B guidance for applicable factor requirements and any updates to source category calculation methods .

What operational data do I need to complete an ONGAEIR equipment inventory?

Operators need a complete list of all O&G equipment at each reportable facility, including wells, separators, tanks, compressors, pneumatic controllers, and other emission sources defined in Regulation 7, Part B [1]. Effective dates for any equipment additions, retirements, or modifications during the reporting year must be documented, along with production throughput volumes for source categories where emissions scale with production [1]. Mid-year equipment changes are the most time-sensitive input because effective dates determine the months of emissions attributed to each piece of equipment . Operators should begin compiling equipment inventory data well before the June 30 annual filing deadline to allow time for data reconciliation .

What are the consequences of missing the ONGAEIR filing deadline?

Facilities that fail to submit ONGAEIR by June 30, or that submit with material errors, may be subject to enforcement action by CDPHE under Colorado’s air quality enforcement program, per Colorado AQCC Regulation 7, Part B . Specific penalty amounts and enforcement procedures are established in CDPHE’s enforcement program and depend on the nature, duration, and circumstances of the violation [1]. Operators who have missed a filing deadline or received a notice of violation should consult qualified legal counsel .

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Sources

  1. Colorado AQCC Regulation 7, Part B. Colorado Air Quality Control Commission. Oil and Natural Gas Sector Emission Inventory and Reporting. 5 CCR 1001-9. Colorado Secretary of State, Code of Colorado Regulations. Cited for ONGAEIR program authority, applicability criteria, source category definitions, equipment and calculation requirements, annual filing deadline (June 30), amendment procedures, and enforcement provisions throughout.

  2. CDPHE ONGAEIR Program. Colorado Department of Public Health and Environment, Air Pollution Control Division. ONGAEIR Program Guidance and Reporting Instructions. Available at cdphe.colorado.gov. Cited for annual filing deadline (June 30), electronic submission procedures, amendment process, and program administration.

  3. U.S. Environmental Protection Agency. Greenhouse Gas Reporting Program (GHGRP): Petroleum and Natural Gas Systems (Subpart W). 40 CFR Part 98, Subpart W; 40 CFR § 98.2. U.S. Code of Federal Regulations. Cited for GHGRP Subpart W program authority, annual filing deadline (March 31), applicability threshold (25,000 metric tons CO2e annually), and administration by EPA.

References

  1. Colorado AQCC Regulation 7, Part B.
  2. Colorado AQCC Regulation 7, Part B; 40 CFR Part 98, Subpart W.