Reducing Methane (CH4) Emissions from Natural Gas Distribution Mains & Services (310 CMR 7.73)

MassDEP has imposed annually-declining methane (CH4) emission limits on Massachusetts gas operators in 2021, 2022, 2023 and 2024 under the Global Warming Solutions Act.

News & Updates

December 2025

MassDEP has published a 310 CMR 7.73 Program Review Proposal document describing proposed changes to MassDEP’s 310 CMR 7.73: Reducing Methane (CH4) Emissions from Natural Gas Distribution Mains & Services, including an appendix containing calculation of draft emission limits. MassDEP requests written comments by January 9, 2026 by email to [e-mail].

Regulatory Requirements

310 CMR 7.73 requires each gas operator with a Gas System Enhancement Plan (GSEP) order from the Massachusetts Department of Public Utilities (DPU) to annually report emissions from the total miles of mains and service pipelines by material type, and to report the total miles of mains and service pipelines by material type and age. GSEPs detail schedules for replacement of older leak-prone distribution system pipes for each gas operator.

Annual Reporting

Gas operators are required to submit to MassDEP the form and spreadsheet below by April 15 of each year for the previous calendar year. 

Completed documents (or requests for these materials in alternate formats) should be emailed to [e-mail].