EPA Greenhouse Gas Reporting Program (GHGRP) Rulemaking
EPA has proposed a reconsideration of the GHGRP that would eliminate reporting requirements for most source categories and suspend reporting obligations for the remaining Subpart W (Petroleum and Natural Gas Systems) segments until reporting year 2034. Under the proposal, the natural gas distribution segment would be removed from the program entirely, while the other Subpart W segments would not be required to submit GHGRP reports until 2034. EPA has stated that, if the proposal is finalized as proposed, no industries would be required to submit GHGRP reports containing 2025 emissions data.
Based on EPA’s current proposal and stated regulatory intent, it is anticipated that GHG reporting under the GHGRP will not be required this year. Companies should continue to monitor EPA’s rulemaking process and any final agency actions; however, the current expectation is that annual GHGRP reporting obligations will be suspended and no reporting submission will be necessary for the current reporting cycle.
Background on 40 CFR Part 98 Subpart W
Historically, the annual EPA GHGRP reporting deadline is one of the most significant compliance milestones for companies operating within the petroleum and natural gas sector. Facilities subject to 40 CFR Part 98 Subpart W (Petroleum and Natural Gas Systems) are required to collect, calculate, and report greenhouse gas (GHG) emissions data to the U.S. Environmental Protection Agency (EPA) on an annual basis. Reports are generally due by March 31 following the reporting year, unless EPA issues a reporting-year-specific extension.
For this reporting year, EPA has granted a year-specific extension, with the deadline to submit being October 30, 2026[1].
For many operators, preparing a complete and accurate Subpart W submission involves much more than simply compiling emissions data. The reporting process requires coordination across operations, engineering, environmental, production accounting, and compliance teams to ensure that required information is collected, validated, and reported in accordance with EPA requirements.
As reporting deadlines approach, companies should evaluate the status of their data collection efforts, review emission calculations, and identify any potential gaps that could affect the quality or completeness of their submissions.
Understanding Subpart W Reporting Requirements
Subpart W applies to numerous segments of the petroleum and natural gas industry, including[2]:
- Onshore petroleum and natural gas production
- Onshore petroleum and natural gas production
- Onshore gathering and boosting systems
- Onshore natural gas processing facilities
- Onshore natural gas transmission compression
- Underground natural gas storage
- Liquefied natural gas (LNG) storage
- LNG import and export facilities
- Natural gas distribution systems
- Onshore natural gas transmission pipeline
The regulation requires operators to calculate and report methane (CH₄), carbon dioxide (CO₂), and, where applicable, nitrous oxide (N₂O) emissions from various emission sources and equipment categories[3]. Depending on the segment, reporting may involve direct measurements, engineering calculations, emission factors, population counts, activity data, and other prescribed methodologies.
What Information Must Be Reported?
Subpart W requires more than a facility-level emissions total. Operators must submit detailed operational and emissions-related information through EPA’s electronic Greenhouse Gas Reporting Tool (e-GGRT). Required information often includes:
Equipment and Asset Inventories
Companies may need to report equipment counts and operational information for equipment such as:
- Pneumatic controllers
- Pneumatic pumps
- Compressors
- Storage vessels
- Dehydrators
- Well completions and workovers
- Combustion equipment
- Flares
- Blowdown equipment
- Other segment-specific emission sources
Activity Data
Activity data frequently serves as the foundation for emissions calculations and may include:
- Production volumes
- Throughput data
- Operating hours
- Fuel usage
- Equipment populations
- Venting activities
- Compressor operating information
- Facility operational status information
Emissions Calculations
Operators must calculate emissions using methodologies prescribed by EPA. Depending on the emissions source, calculations may be based on:
- Direct measurement
- Site-specific testing
- Instrument monitoring
- Engineering calculations
- Emission factors
- Population-based methodologies
- Process data and operational records
Supporting Records
In addition to the submitted report, facilities must maintain records supporting reported values, methodologies, assumptions, and calculations. Documentation should be maintained in a manner that allows EPA auditors or inspectors to verify reported information if questions arise following report submission.
Data Collection Across Multiple Systems
Required data often resides in multiple locations, including:
- Production databases
- SCADA systems
- Environmental management systems
- Maintenance records
- Asset inventories
- Accounting systems
Compiling this information into a single reporting framework can be time-consuming and resource-intensive.
Changing Asset Inventories
Acquisitions, divestitures, new drilling programs, facility modifications, and equipment replacements can complicate annual reporting efforts. Operators must ensure that equipment inventories and facility boundaries accurately reflect current operations.
Quality Assurance and Quality Control
Even small data errors can lead to significant reporting discrepancies. Common issues include:
- Incorrect equipment counts
- Data entry errors
- Improper emission factor selection
- Misapplied calculation methodologies
- Missing supporting documentation
A comprehensive QA/QC review can help identify errors before submission.
Why Early Preparation Matters
Organizations that begin assembling data early are generally better positioned to:
- Resolve data gaps before submission deadlines
- Improve data quality and consistency
- Reduce reporting uncertainties
- Minimize the need for report revisions
- Decrease compliance risk
- Improve internal understanding of emissions drivers
Waiting until the weeks immediately preceding the reporting deadline often increases the likelihood of rushed calculations, incomplete documentation, and avoidable reporting errors.
How Trinity Can Help
Trinity Consultants has extensive experience supporting petroleum and natural gas operators with greenhouse gas reporting programs, including Subpart W compliance.
Our team can assist with every phase of the reporting process, including:
Applicability Evaluations
We help organizations determine:
- Whether facilities are subject to Subpart W
- Which industry segments apply
- Applicable reporting requirements
- Reporting boundaries and responsibilities
Data Collection and Management
Our consultants work with facility personnel to:
- Identify required datasets
- Develop data collection templates
- Consolidate information from multiple sources
- Improve data management processes
Emissions Calculations
We can perform or review:
- Equipment-specific calculations
- Segment-level emissions analyses
- Emission factor applications
- Engineering calculations
- Methane emissions estimates
QA/QC Reviews
Our independent review process helps identify:
- Calculation errors
- Data inconsistencies
- Missing activity data
- Documentation gaps
- Potential e-GGRT reporting issues
e-GGRT Reporting Support
We assist clients with:
- Data entry
- Report preparation
- Submission review
- Report updates and corrections
- Regulatory interpretation questions
Call to Action
The annual Subpart W reporting deadline arrives quickly, and successful reporting depends on accurate data collection, thorough QA/QC reviews, and a clear understanding of EPA requirements. Beginning preparation early can help reduce compliance risk and avoid last-minute challenges.
Whether your organization needs assistance with emissions calculations, data validation, report preparation, or overall program management, Trinity’s team can provide practical and efficient support throughout the reporting process.
If you would like to discuss Subpart W reporting obligations or evaluate your reporting readiness, please contact Michael Brown at [email protected] or your local Trinity Consultants office to discuss how we can support your reporting and compliance objectives.
[1] 40 CFR Part 98 Subpart W Reporting Deadline
[2] § 98.230 Definition of the source category.
[3] § 98.232 GHGs to report.
