MassDEP Ambient Air Quality Monitoring Network & Annual Plan

Learn about which pollutants and parameters the agency measures at specific monitoring sites, and why.

News & Updates

July 2022

MassDEP released its Draft 2022 Ambient Air Quality Monitoring Network Plan (see Additional Resources below) for public comment, which it accepted through August 5, 2022. The agency operates a network of 23 ambient air monitoring stations across Massachusetts. Each year, MassDEP is required to submit for U.S. Environmental Protection Agency (EPA) review and approval a document describing the network, pollutants and parameters measured, and recent and planned changes.

Additional Resources for

About the Monitoring Network & Plan

The Massachusetts Department of Environmental Protection (MassDEP) operates a network of 23 ambient air quality monitoring stations at locations across the state. The Wampanoag Tribe of Gay Head (Aquinnah) operates an ozone monitoring station on Martha's Vineyard. Each year, MassDEP is required to submit an Annual Ambient Air Quality Monitoring Network Plan to the U.S. Environmental Protection Agency (EPA). This document and its attachments are subject to a 30-day public comment period before MassDEP submits them to EPA for review and approval.

The annual network plan describes to EPA which pollutants and other parameters MassDEP measures at its various ambient air monitoring sites and why they are measured at those specific locations. It also describes changes in the network - including new and closed locations, and new and discontinued measurements at existing locations - since the last network plan, as well as proposed changes in the network over the next 18 months.

MassDEP also must conduct an assessment of the Massachusetts Ambient Air Quality Monitoring Network every five years to determine whether it meets the objectives defined in EPA regulations.

Air Monitoring Network Sites Map & Table

Zoom in ( + ) and click on the icons to learn about each monitoring station site across Massachusetts.

Legend of Parameter Acronyms

O3 Ozone
CO Carbon Monoxide
SO2 Sulfur Dioxide
NOx Nitric Oxide, including Nitrogen Dioxide
NOy Total Reactive Oxides of Nitrogen
MET Meteorological Parameters
PM10 Particulate Matter (10 microns & smaller)
PM2.5 Fine Particles (2.5 microns & smaller)
VOC Volatile Organic Compounds
TOXICS Toxic Air Pollutants including Carbonyls (Aldehydes), Metals & VOCs
BC Black Carbon
SPEC Speciated Fine Particles
IMPROVE Visibility PM Speciation

2021 Network Plan

The agency finalized its 2021 Ambient Air Quality Monitoring Network Plan on November 23, 2021. If you have questions, please direct them to:

See Additional Resources below for the 2021 Network Plan, its attachments, and MassDEP's response to public comments.

Additional Resources for