About the Monitoring Network & Plan
The Massachusetts Department of Environmental Protection (MassDEP) operates a network of 24 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 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.
2025 Network Plan
Draft Plan and Attachments
- Draft 2025 Air Monitoring Network Plan
- 2025 Attachments 2 - 3: Site measurements & measurement methods
Public Notice: English | Haitian Creole | Khmer | Portuguese | Spanish | Simple Chinese | Traditional Chinese
MassDEP will accept public comments on this draft Network Plan until July 7, 2025. Comments should be sent via email or mail to:Sean Dunn
MassDEP Air Assessment Branch
Senator William X. Wall Experiment Station
37 Shattuck Street
Lawrence, MA 01843-1398
Sean.M.Dunn@mass.gov
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
| Acronym | Meaning |
|---|---|
| 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 |