Arsenic Contamination

Arsenic in Maine Drinking Water

Ranked by arsenic violation count · Data from EPA SDWIS & UCMR

Cities Tested

Has Violations

100%

% Has Violations

3.7 violations

State Avg

▼ 0% vs national

vs National

141

Health Violations

Analysis

Arsenic in Maine: what the data shows

Maine has 36 cities with arsenic-related violations on record. Arsenic contamination is a federal MCL violation at levels above 10 µg/L (10 ppb). The state has 36 cities with at least one arsenic violation. Arsenic enters drinking water primarily through erosion of natural deposits, particularly in western states with arsenite-bearing geology. Industrial sources include mining runoff, glass manufacturing, and semiconductor production. Groundwater systems are significantly more likely to have arsenic issues than surface water systems. Long-term arsenic exposure above the MCL increases the risk of bladder, lung, and skin cancer, as well as cardiovascular disease and diabetes. Reverse osmosis and specialized arsenic-removal media are the most effective point-of-use treatment options.

Comparison

Cities exceeding 10 µg/L EPA MCL

Maine

100%

36 of 36 cities

← = Exactly at national rate

National avg

100%

5489 of 5489 cities

City Map

Arsenic data across Maine

Each dot is a city with arsenic violation data. Cities with at least one arsenic-related violation are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by arsenic level in Maine

Highest Arsenic levels (violations)

All Cities

All Maine cities ranked by arsenic level

#	City	Level	Violations?	Violations	Grade
1	Scarborough	20 violations	Yes	26	C
2	Hancock	18 violations	Yes	30	D
3	Princeton	11 violations	Yes	34	D
4	Abbot	9 violations	Yes	17	B-
5	Castine	8 violations	Yes	10	C+
6	Kennebunkport	6 violations	Yes	12	D+
7	Bucksport	6 violations	Yes	8	C-
8	Camden	5 violations	Yes	9	B-
9	South Berwick	5 violations	Yes	31	B+
10	South Berwick	5 violations	Yes	11	B+
11	Brownville	5 violations	Yes	10	C
12	Limerick	3 violations	Yes	9	B
13	Waterville	2 violations	Yes	8	F
14	Topsham	2 violations	Yes	17	C+
15	Augusta	2 violations	Yes	7	B+
16	Orono	2 violations	Yes	12	B-
17	Mars Hill	2 violations	Yes	58	D+
18	Limestone	2 violations	Yes	95	D
19	North Haven	2 violations	Yes	58	B
20	Scarborough	1 violations	Yes	0	B
21	Scarborough	1 violations	Yes	7	B
22	Waterville	1 violations	Yes	8	C
23	Bangor	1 violations	Yes	3	B
24	Camden	1 violations	Yes	4	C
25	Sanford	1 violations	Yes	16	B-
26	Clifton	1 violations	Yes	26	F
27	Lisbon	1 violations	Yes	3	A-
28	Houlton	1 violations	Yes	5	C
29	Caribou	1 violations	Yes	26	C
30	Damariscotta	1 violations	Yes	33	B-
31	Greenville	1 violations	Yes	2	A
32	Milton	1 violations	Yes	3	B+
33	Milton	1 violations	Yes	2	A-
34	St George	1 violations	Yes	1	B+
35	Princeton	1 violations	Yes	4	B
36	Charleston	1 violations	Yes	4	B

FAQ

Frequently asked questions about arsenic in Maine

Is arsenic in Maine tap water a concern?

Yes — 36 cities in Maine have arsenic-related violations on record. The EPA MCL for arsenic is 10 µg/L. Even at levels below the MCL, long-term arsenic exposure has been linked to cancer and cardiovascular disease.

How can I remove arsenic from my drinking water in Maine?

Reverse osmosis (RO) systems are the most effective at removing arsenic, typically reducing it by 90% or more. Specialized arsenic-removal media (such as iron-based adsorption filters) are also highly effective. Standard carbon filters and pitcher filters do NOT effectively remove arsenic. If your water comes from a private well, have it tested for arsenic.

Where does arsenic in Maine water come from?

Arsenic enters drinking water primarily through natural erosion of arsenic-bearing rock formations. It is most common in groundwater systems in the western United States, parts of the Midwest, and New England. Industrial sources include mining, smelting, and agricultural pesticide residues. Groundwater sources are far more likely to contain arsenic than surface water.

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