Cumulative Impact Analysis in Air Quality Permitting

Learn about and participate in the MassDEP initiative to incorporate cumulative impact analysis into the agency's review of applications for certain air permits and approvals.

Table of Contents

Regulations Proposed

MassDEP has proposed cumulative impact analysis regulations and announced a public comment period and hearing dates - see Public Notice and proposed regulations.

Draft Air Toxics Risk Screening Tool

Draft Massachusetts Air Toxics Risk Screening Tool (MATRiST) – MassDEP has developed a draft spreadsheet tool that can be used in the CIA to estimate cumulative air toxics risks from proposed projects.  Instructions for using the tool are included in the Read Me tab.  A Technical Memorandum describes how the default dispersion factors in the spreadsheet were developed.  See Additional Resources below for Draft MATRiST file and Technical Memorandum.

Additional Resources

What You Need to Know

Cumulative impacts are the total effect of past, present, and future actions on the environment and human health. Evaluating these effects is the focus of cumulative impact analysis (CIA).

Governor Baker in March 2021 signed Chapter 8 of the Acts of 2021, An Act Creating a Next Generation Roadmap for Massachusetts Climate Policy. The Act directed the Department of Environmental Protection (MassDEP) to:

  • Evaluate and seek public comment on incorporating CIA into its review of applications for certain categories of air permits and approvals;
  • Propose regulations for accomplishing this; and
  • Complete these tasks within 18 months of the signed legislation's June 2021 effective date (or by late December 2022).

The Act also gave the Massachusetts Environmental Policy Act (MEPA) Office six months (or by late December 2021) to develop new regulations that would require:

  • Submission of an environmental impact report (EIR) for any project that is likely to cause damage to the environment and is located near an environmental justice (EJ) population;
  • Assessment of potential existing unfair or inequitable burden and related public health consequences; and
  • Analysis of how the proposed project might result in a disproportionate adverse effect on the EJ population.   

See Additional Resources below to learn more about environmental justice communities and populations in Massachusetts. 

Additional Resources

How You Can Participate

MassDEP has proposed regulations for cumulative impact analysis (CIA) and you can participate via the public comment period and hearings. See notice of hearings and proposed CIA regulations at MassDEP Public Hearings & Comment Opportunities.

Over the past 18 months MassDEP has conducted a stakeholder engagement process on incorporating cumulative impact analysis in its review of applications for certain categories of air permits and approvals. See Additional Resources below for the past meeting materials.

Additional Resources

How to Stay Informed

Join the MassDEP email list to receive periodic updates on:

  • The cumulative impact analysis (CIA) regulatory development process;
  • Future stakeholder meetings; and
  • Opportunities for providing input to the agency.

Sign up by following the link in Additional Resources below.

Additional Resources



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