Subpart W Guidance: EPA GHG Reporting for Oil and Gas
Subpart W is EPA's greenhouse gas reporting rule for oil and gas: its ten segments, the two 25,000 metric ton tests, what to report, and the rule's 2026 status.
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GHGRP and Subpart W Reporting
Subpart W is the part of EPA's Greenhouse Gas Reporting Program that covers petroleum and natural gas systems. It is a reporting rule, separate from the OOOO emission standards, and changes to one do not change the other.
These posts track what Subpart W still requires, how the reporting deadlines have moved, and how facilities and states report greenhouse gas and methane emissions. They also cover what the published GHGRP data can and cannot tell you about a facility.
Subpart W reporting runs on its own schedule under 40 CFR Part 98, with reporting years and deadlines that EPA has moved. The posts follow those changes as they happen, note which proposals have not been finalized, and explain why state reporting rules still apply while the federal requirement is in question.
15 posts in this topic
Operator-Reported Methane vs Satellite Data: Why They Differ
Satellites usually find more oil and gas methane than reported inventories. The reasons, from abnormal events to detection limits, and how to reconcile the two.
EHS Management Software and What It Cannot Compute
EHS software is a system of record. It handles the documents and dates well, and stores whatever emissions number you give it rather than deriving one.
Default Emission Factors: When Subpart W Still Allows Them
Default emission factors are Subpart W's Calculation Method 4 for natural gas pneumatic devices, and cannot be used for devices measured under Methods 1 to 3.
What Is Subpart W Suspension? State Rules Still Apply
Federal methane reporting faces suspension while Colorado ONGAEIR and New Mexico mandates stay fully enforceable. How multi-state O&G operators should respond.
Inflation Reduction Act: What Is Left for Methane in 2026
The IRA methane charge was not repealed. Its rule was disapproved and the charge moved to 2034. What still binds oil and gas operators, provision by provision.
Greenhouse Gases and CO2e: One Tonne, Three Answers
Which greenhouse gases oil and gas emits, and why the same tonne of methane becomes three different CO2e numbers depending on which published basis you use.
OGMP 2.0 Level 4 and Level 5 Reporting Explained
OGMP 2.0 Level 4 requires source-level measurement. Level 5 adds site-level reconciliation. What each level demands of your emissions data, and why.
Southern Permian Oil Jumped 14% in 2024: Emissions Impact
Southern Permian oil (RRC District 7C) jumped 14% to 186M barrels in 2024. Compliance and ops implications for associated gas and methane intensity.
How to Get a Colorado Operator-Specific Verification Factor
How Colorado operators replace the state default verification factor with an operator-specific one under Reg 7 Part B Section VIII, and when it pays off.
What Colorado's 1.164 Verification Factor Costs Operators
Dollar estimates of the CDPHE State Default Intensity Verification Factor's cost to Colorado upstream operators, with fee and sensitivity analysis.
Methane Intensity Metrics: Why Methodology Matters
Different methane intensity formulas produce different results for the same facility. CATF's 2026 report shows why denominator choice shapes EU compliance.
Colorado ONGAEIR Due June 30: A Practical Filing Checklist
Colorado ONGAEIR report for CY2025 is due June 30, 2026. Which facilities must report, required source categories, and a pre-submission checklist for operators.
Subpart W Proposed Rule: Is GHGRP Reporting Still Required?
The Subpart W proposed rule (90 FR 44591) would pause reporting through RY2034, but it is not final. Facilities still file RY2025 data by March 10, 2027.
GHGRP Subpart W Deadline Moved to March 10, 2027
EPA moved the RY2025 GHGRP filing deadline to March 10, 2027, while a separate proposal to suspend Subpart W reporting through 2034 remains pending.