McFarland Hill Air Pollutant Research Site - CASTNET Air Monitoring Station in Maine

McFarland Hill Air Pollutant Research Site is an operational air monitoring station located at 567 Eagle Lake Road in Hancock County, Maine, United States. It is part of the Clean Air Status and Trends Network (CASTNET), a national network designed to assess the effectiveness of emission reduction programs under the Clean Air Act. The station is operated by Mactec, Inc. and reports to the U.S. Environmental Protection Agency (EPA). As a CASTNET site, McFarland Hill measures criteria pollutants, atmospheric deposition, and meteorological parameters. The network uses standardized monitoring protocols to ensure data comparability across sites. The station's last reported sample date is December 24, 2024, indicating ongoing data collection. CASTNET sites typically monitor ozone, sulfur dioxide, nitrogen oxides, particulate matter, and wet deposition chemistry. The station's location in a rural area of Maine provides background air quality data representative of the northeastern United States. This data supports research on regional air pollution transport, ecosystem impacts, and compliance with National Ambient Air Quality Standards (NAAQS). The site contributes to the broader U.S. EPA Air Quality System (AQS) and the WMO Global Atmosphere Watch program.

McFarland Hill is situated in a forested region of Maine, far from major urban and industrial sources, making it ideal for monitoring regional background air quality. The site's data helps assess the impact of transported pollutants from upwind regions and the effectiveness of emission controls. Parameters measured include ozone, sulfur dioxide, nitrogen oxides, and particulate matter, which are critical for understanding acid deposition, eutrophication, and visibility impairment in sensitive ecosystems like Acadia National Park.