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MassDEP Source Registration & Greenhouse Gas Reporting

Facilities which meet established regulatory criteria, exceed specific operating parameters or fall within certain categories are required to file. MassDEP may also direct others to report even if they might not otherwise be required to do so.

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News & Updates

Forms for the 2025 reporting year are now available.  We also have posted a new list of filers with deadlines (updated January 13, 2026).   We will be sending email notices to responsible officials, facility contacts, and preparers as in previous years.

DEADLINES: Filing deadlines for 2026 (for 2025 data) are the deadlines in the current regulations (310 CMR 7.12 and 7.71).

NOTE:  The GHG reporting deadlines have been revised to match the Source Registration reporting deadlines.  Facilities that are subject to Source Registration will file both Source Registration and GHG reports according to their Source Registration deadline (see 310 CMR 7.71(4)).  

CORRECTIONS:  If you need to file a correction for a previous year, please contact us first.  Corrections need to be filed before starting a new report.  Corrections also require filing a full report for all units for the year being corrected to ensure total emission values are correct.

Questions?

Email: baw.edep@mass.gov

Experiencing Delays or Difficulties with Printing?

Please see: Printing Guidance: Source Registration/Greenhouse Gas Reporting

Who Needs to File & When

Source Registration is due annually or every three years, depending on the facility. Greenhouse Gas Emissions Reports are due annually.

Which report(s) a given facility needs to file is determined by established regulatory criteria, operating parameters, or operational categories.

Source Registration

Facilities required to file are those that:

  • Have potential emissions or heat input capacities above thresholds specified at 310 CMR 7.00: Air Pollution Control (see 310 CMR 7.12: U Source Registration),
  • Fall within certain categories (e.g. most incinerators), or
  • MassDEP directs to file even if they do not meet regulatory criteria.
     

Greenhouse Gas Emissions Reporting

Facilities required to report are those that:

  • Are regulated under Title V of the federal Clean Air Act and Appendix C of 310 CMR 7.00: Air Pollution Control, or
  • Emit more than 5,000 tons per year of Carbon Dioxide Equivalent (CO2e).

In some cases, facilities are required to submit both SR and GHG reports.

Key Actions

Search Source Registration & Greenhouse Gas Filers List  Login to eDEP Online Filing 

References You Will Need

Once you login to the eDEP Online Filing system, you will need to enter or confirm information about your facility, its operations and emissions, including the following specific references. Links to all of these references are available in Additional Resources below.

  • Source Classification Code (SCC): Categorizes air pollution sources and associated emission factors, if available.
  • North American Industry Classification System (NAICS) Code: Categorizes business activity.
  • Emission Factors: eDEP uses these to automatically calculate combustion unit emissions based on the SCC you enter, or you may perform your own calculations.
  • Greenhouse Gas Emission Factors: Source- and fuel-specific inputs for calculating GHG emissions.
  • EPA Unit Type Code: Identifies the emissions unit activity.
  • EPA Material Type Code: Identifies the material or fuel processed. For fuel burning devices, this code is based on the SCC you enter.
  • EPA Air Pollution Control Device Code: Identifies the control equipment used to achieve emissions reductions.

If your facility has never filed a Source Registration before, it may first need to be added to the MassDEP database. Please email baw.edep@mass.gov with the facility's name, physical and mailing addresses, federal taxpayer identification number, and contact information. MassDEP will reply with eDEP Online Filing system instructions.

Additional Resources

Open file,  MassDEP Source Classification Codes Spreadsheet
Open file,  EPA Source Classification Codes
Open file,  NAICS Keyword Search
Open file,  EPA Clearinghouse for Inventories & Emissions Factors
Open XLS file, 345 KB,  Greenhouse Gas Emission Factors (English, XLS 345 KB)
Open XLS file, 53.5 KB,  EPA Unit Type Codes (English, XLS 53.5 KB)
Open XLS file, 81 KB,  EPA Material Type Codes (English, XLS 81 KB)
Open XLS file, 40.5 KB,  EPA Air Pollution Control Device Codes (English, XLS 40.5 KB)

How to File

Use the eDEP Online Filing system to submit your Source Registration (SR) annual or triennial report and/or Greenhouse Gas Emissions (GHG) annual report. Please note that if you are a new eDEP user, you will need to create an account first.

See Additional Resources below for:

  • A Quick Start guide, which is essential reading if you are a new SR and/or GHG filer, and provides time-saving steps for all users.
  • Field-by-Field Instructions on how to complete and file your SR-Only, GHG-Only, or Combined SR/GHG Report.
  • Tips from the Help Desk, including answers to common questions and how to handle unusual facility types and insignificant non-reportable uses.
  • What's New with the SR/GHG Forms, describing changes in the SR-Only, GHG-Only, or Combined SR/GHG reporting packages.

Key Actions

How to use eDEP Online Filing  Login to eDEP Online Filing 

Additional Resources

Open PDF file, 158.43 KB,  Quick Start: What you must know to file (English, PDF 158.43 KB)
Open PDF file, 2.55 MB,  SR-Only or Combined SR/GHG Field-by-Field Instructions (English, PDF 2.55 MB)
Open PDF file, 1.03 MB,  GHG Reporting Only Field-by-Field Instructions (English, PDF 1.03 MB)
Open PDF file, 335.57 KB,  Tips from the SR Help Desk (English, PDF 335.57 KB)
Open PDF file, 133.76 KB,  What's New with the SR/GHG Forms (English, PDF 133.76 KB)

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