Penobscot County, Maine: drinking water report. Penobscot County in central Maine has about 152,000 residents, with Bangor as the county seat.
Penobscot County in central Maine has about 152,000 residents, with Bangor as the county seat. The Bangor Water District draws from Floods Pond, a pristine glacial lake in neighboring Hancock County. Former Dow Air Force Base (now Bangor International Airport) sits adjacent to the city, and its military history has direct water quality implications.
Dow AFB operated from 1942 to 1968, and the facility used AFFF firefighting foam throughout its military tenure. According to the Maine DEP's 2024 PFAS investigation, monitoring wells at Bangor International Airport show PFOS at 48 ppt – well above the federal MCL of 4 ppt. The contamination plume extends into residential neighborhoods south and east of the airport.
Bangor's Floods Pond supply is among the cleanest drinking water sources in the Northeast – the pond sits in a protected, undeveloped watershed. However, the distribution system in Bangor includes older pipes that may contribute lead. A 2024 Maine CDC lead testing program found that 3% of tested homes in Bangor exceeded the lead action level of 15 ppb.
Bangor has a tale of two water stories – the pristine source at Floods Pond versus the PFAS contamination around the airport and aging distribution infrastructure in the city. Your risk depends heavily on whether you are on the municipal system or a private well near the airport.
Check your water for data at your address. For airport-area well owners, PFAS testing is essential. For city residents, a lead-certified filter addresses the primary in-home concern. Our water filter guide covers both scenarios. Get your detailed report for local data, and visit our Maine page for statewide patterns.
Drinking water is one exposure route. These federal datasets also cover Penobscot County, ME.
The EPA places Penobscot County, ME in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
55% of homes in Penobscot County, ME were built before 1980, and 26% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Penobscot County, ME averages 4.5 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide