Air Monitoring and Reporting

The Maine Department of Environmental Protection operates and maintains a variety of ambient air monitoring equipment around the state. Some of these instruments operate on a continuous basis and provide hourly averages of pollutants or meteorological data that is used in the evaluation of the air pollutant data. Data may also be collected over a twenty-four hour period such as particulates or it may be collected as a composite over an entire week. Examples of the latter are the atmospheric and mercury deposition monitoring programs. The number of monitoring sites and the pollutants that are monitored may vary from year to year depending on the expected concentrations of the pollutants, the origin of the pollutants and new programs based on changes in existing regulations or the establishment of new regulations. For more information, contact Andy Johnson (207) 480-0906.

Air Monitoring Data including:

Emissions Inventory

  • MAIRIS is a free web based reporting system developed by the Maine Department of Environmental Protection to assist Maine facilities with their annual air emissions reporting requirements. Log in to MAIRIS.

Annual Air Monitoring Plan 2019 (9 MB, pdf) - The Maine Department of Environmental Protection (ME DEP) operates a network of air monitoring sites at locations across the state. ME DEP is required to submit an Annual Ambient Air Quality Monitoring Network Plan to the U.S. Environmental Protection Agency (EPA). This document was subject to a 30-day public comment period before ME DEP submitted it to EPA for review and approval. A draft of the 2019 Annual Air Monitoring Plan was posted on this website in late May, 2018. The comment period concluded at the end of June, 2018. The final plan was submitted to EPA on August 9th, 2018 and it received their approval on October 25th, 2018.

The annual network plan describes to EPA which pollutants and other parameters DEP 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 12 months.

Five Year Assessment of Maine's Ambient Air Monitoring Network (pdf) - The Five Year Monitoring Network Assessment is required by EPA and allows all who are invested in Maine’s air quality to consider DEP’s air monitoring program objectives in the context of “the bigger picture,” and from a vantage point five years into the future. Originally presented to EPA on July 1, 2015 this revision from December 2015 reflects modifications incorporated after receiving many comments and suggestions.