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National Drinking Water Database


Total trihalomethanes (TTHMs) in Maine


Total trihalomethanes constitute the sum of four disinfection byproducts: chloroform, bromodichloromethane, dibromochloromethane, and bromoform. [read more]

The Most Polluted Communities in Maine

178 water utilities reported detecting Total trihalomethanes (TTHMs) in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average Total trihalomethanes (TTHMs) level

RankSystem Population Served Positive test results of total reported tests Average Level
(Range)
1Newport Water District
Newport, ME
1,59025 of 25131.85 ppb
(32.9 to 224 ppb)
2Loring Utilities
Limestone, ME
1,40923 of 23110.83 ppb
(16 to 187 ppb)
3Southwest Harbor Water Dept.
Southwest Harbor, ME
2,38016 of 16110.46 ppb
(36.3 to 179 ppb)
4Anson Water District
North Anson, ME
1,63014 of 1490.28 ppb
(62.1 to 153 ppb)
5Jackman Utility District
Jackman, ME
1,06023 of 2588.17 ppb
(0 to 182 ppb)
6Canton Water District
Canton, ME
28520 of 2183.14 ppb
(0 to 152 ppb)
7Milo Water District
Milo, ME
1,68821 of 2580.83 ppb
(0 to 224 ppb)
8Passamaquoddy Water District
Eastport, ME
1,87025 of 2576.39 ppb
(7.1 to 150 ppb)
9Eagle Lake Water & Sewer Dist.
Eagle Lake, ME
67829 of 3574.29 ppb
(0 to 232 ppb)
10Madison Water District
Madison, ME
2,92328 of 2868.08 ppb
(13 to 143 ppb)

Health Based Limits for Total trihalomethanes (TTHMs)

StandardDescriptionLevel
One in one million (10-6) Cancer RiskThe concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 1,000,000. Source: U.S. Environmental Protection Agency.9.8 ppb
EPA Human Health Water Quality CriteriaWater quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.11.5 ppb
Maximum Contaminant Limit (MCL)The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.80 ppb
Lifetime health-based limit, non-cancer riskConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency.130 ppb
One in ten thousand (10-4) Cancer RiskThe concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 10,000. Source: U.S. Environmental Protection Agency.980 ppb
Drinking Water Equivalent LevelA lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.1835 ppb
Children's health-based limit for 10-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.4860 ppb
Children's health-based limit for 1-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.10600 ppb

Violation Summary for Total trihalomethanes (TTHMs) in Maine

Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in Maine since 2004

Violation TypeNumber of Violations
Over maximum contaminant level, Average143
Monitoring and Reporting Disinfection Byproduct Rule16