Loading water data...
Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Water quality scores for 15 cities in Maine
Across the 15 Maine water systems we track, the average water quality score is 83/100 — 11 points above the U.S. national average of 72/100. 87% of Maine cities (13 of 15) score above that national benchmark, and 9 earn a Grade A for clean, low-contaminant tap water.
The contaminants most commonly flagged in Maine water systems are arsenic (naturally occurring in bedrock), uranium (granite geology) and radon (groundwater). See the full breakdown in our Maine water quality rankings or compare against the cities with the best water quality in America.
See the top 20 cities with the cleanest, safest drinking water
Complete water quality rankings for every city in Maine
21,982 residents
8,797 residents
21,990 residents
22,135 residents
20,400 residents
31,753 residents
20,381 residents
18,697 residents
68,408 residents
24,061 residents
36,221 residents
18,336 residents
15,828 residents
20,278 residents
26,498 residents
Maine's surface water is generally clean and plentiful, but the state has distinctive groundwater challenges. A large share of Maine households rely on private wells, and the state's granite bedrock geology produces naturally elevated arsenic, uranium, and radon in groundwater. Portland Water District's Sebago Lake supply is among the highest-quality surface sources in the country.
Based on our analysis of 15 cities in Maine, the average water quality score is 83/100. 1 cities have water quality scores below 70, indicating potential concerns that residents should be aware of. The highest-rated city is South Portland with a score of 69/100, while Sanford has the most room for improvement at 95/100.
1 of the 15 Maine cities we analyzed score below 70/100. If your city is one of them, a certified filter matched to your local contaminants is the fastest way to reduce exposure. For lead and PFAS, look for an NSF 53 certified filter or a reverse osmosis system.
We may earn a commission when you purchase through our links, at no extra cost to you.
The Portland Water District serves Greater Portland from Sebago Lake, one of only a few large U.S. surface supplies clean enough to be exempt from full filtration. Outside the service-district cities, roughly half of Maine residents depend on private bedrock wells, which dominate the state's water quality profile.
These contaminants have been detected in various Maine water systems
The Maine Drinking Water Program within the Department of Health and Human Services regulates public systems. Maine has been a national leader on PFAS, after contamination was tied to historic spreading of industrial sludge on farmland, and the state has set strict PFAS standards and expanded testing.
Arsenic is the signature private-well concern in Maine, with a significant share of bedrock wells exceeding the federal limit; chronic exposure is linked to cancer and developmental effects. Uranium and radon are also common in well water. PFAS is a serious issue on and near farmland where contaminated sludge was historically applied.
All Maine private-well owners should test for arsenic, uranium, radon, and PFAS at least once and re-test periodically, since these contaminants are tasteless and odorless. Reverse osmosis or anion-exchange systems remove arsenic and uranium; specialized PFAS-certified filters are needed where PFAS is present. Sebago-supplied Portland residents enjoy excellent municipal water.
Most Maine cities have tap water that meets EPA safety standards. With an average score of 83/100 across 15 cities we analyzed, Maine generally has good water quality. However, water quality varies by location, so check your specific city's report.
The most common water quality concerns in Maine include arsenic (naturally occurring in bedrock), uranium (granite geology), radon (groundwater). These contaminants can come from natural sources, industrial activities, or aging infrastructure. Review your city's specific report to see which contaminants affect your area.
Whether you need a water filter depends on your specific location and health concerns. With 1 cities in Maine showing elevated contaminant levels, residents in those areas may benefit from filtration. Look for filters certified by NSF/ANSI to remove the specific contaminants found in your area.
Public water systems in Maine are required to provide annual Consumer Confidence Reports (CCRs) to residents. You can usually find your report on your water utility's website, request it by phone, or access it through the EPA's database. Our city-level reports above summarize key information from these official sources.
Lead can be present in Maine water, primarily from older plumbing infrastructure. Homes built before 1986 may have lead pipes or lead solder. While water treatment plants remove lead, it can leach into water from service lines and home plumbing. Check your city's specific report for lead testing data, and consider having your tap water tested if you live in an older home.
PFAS ("forever chemicals") have been detected in water systems across the United States, including in Maine. These chemicals are associated with industrial sites, military bases, and firefighting foam use. The EPA has set new PFAS limits effective 2024. Check individual Maine city reports for PFAS testing results in your area.
Based on our analysis, South Portland has the highest water quality score in Maine at 69/100 (Grade C+). However, "best" depends on your specific health concerns. View our Best Water Quality in Maine page for a complete ranking.
Public water systems in Maine are required by the EPA to test water regularly. Testing frequency depends on the contaminant: bacteria testing occurs daily to weekly, while chemical contaminants may be tested quarterly or annually. Results are published in annual Consumer Confidence Reports. Our site aggregates this data from EPA's SDWIS database.
Compare water quality across counties and find data for your area