Copper Contamination

Copper in Maine Drinking Water

Ranked by 90th percentile copper level (mg/L) · Data from EPA SDWIS & UCMR

Cities Tested

Exceeds Limit

100%

% Exceeds Limit

2.269 mg/L

State Avg

▼ 0% vs national

vs National

141

Health Violations

Analysis

Copper in Maine: what the data shows

Maine has 81 cities with copper monitoring data. The state average 90th percentile copper level is 2.269 mg/L, compared to 28.808 mg/L nationally — better than the national average. 81 cities exceed the EPA action level of 1.3 mg/L. Copper in drinking water typically comes from corrosion of copper pipes and plumbing fixtures, particularly in older homes. The EPA action level of 1.3 mg/L is the 90th percentile threshold — if more than 10% of tap samples exceed it, utilities must take corrective action including adjusting water chemistry to reduce corrosivity. Short-term copper exposure above the action level can cause gastrointestinal distress. Long-term exposure at elevated levels is associated with liver and kidney damage. Flushing your tap for 30 seconds before use and using an NSF 53-certified filter can reduce copper exposure.

Comparison

Cities exceeding 1.3 mg/L EPA Action Level

Maine

100%

81 of 81 cities

← = Exactly at national rate

National avg

100%

3953 of 3953 cities

City Map

Copper data across Maine

Each dot is a city, colored by overall water quality grade. Cities with copper levels above the 1.3 mg/L EPA action level are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by copper level in Maine

Highest Copper levels (mg/L)

All Cities

All Maine cities ranked by copper level

#	City	Level	Exceeds?	Violations	Grade
1	Scarborough	9.000 mg/L	Yes	26	C
2	Calais	5.490 mg/L	Yes	4	A-
3	Harrison	5.400 mg/L	Yes	1	B+
4	Stonington	5.260 mg/L	Yes	39	B-
5	Alfred	4.300 mg/L	Yes	6	B-
6	Sanford	4.210 mg/L	Yes	16	B-
7	West Paris	4.000 mg/L	Yes	8	C+
8	Presque Isle	3.400 mg/L	Yes	24	C+
9	Clifton	3.020 mg/L	Yes	26	F
10	Milo	3.010 mg/L	Yes	59	B
11	Augusta	3.000 mg/L	Yes	7	B+
12	Sandy River Plt	2.800 mg/L	Yes	5	A-
13	Sandy River Plt	2.800 mg/L	Yes	5	A-
14	Sandy River Plt	2.800 mg/L	Yes	5	A-
15	Sandy River Plt	2.800 mg/L	Yes	5	A-
16	St George	2.690 mg/L	Yes	1	B+
17	Mount Desert	2.580 mg/L	Yes	19	B-
18	Scarborough	2.500 mg/L	Yes	7	B
19	Waterville	2.460 mg/L	Yes	8	C
20	Waterville	2.460 mg/L	Yes	6	B-
21	Waterville	2.460 mg/L	Yes	8	F
22	Waterville	2.460 mg/L	Yes	1	B
23	Waterville	2.460 mg/L	Yes	1	B
24	Lewiston	2.420 mg/L	Yes	5	A-
25	Kennebunkport	2.350 mg/L	Yes	12	D+
26	Waldoboro	2.330 mg/L	Yes	11	B-
27	Brownville	2.320 mg/L	Yes	10	C
28	Gardiner	2.310 mg/L	Yes	3	B-
29	Caribou	2.230 mg/L	Yes	26	C
30	Skowhegan	2.210 mg/L	Yes	4	B-
31	Bath	2.200 mg/L	Yes	14	A-
32	Boothbay	2.150 mg/L	Yes	3	A-
33	Kingfield	2.110 mg/L	Yes	4	B+
34	Anson	2.080 mg/L	Yes	34	B
35	Anson	2.080 mg/L	Yes	34	B
36	Anson	2.080 mg/L	Yes	34	B
37	Freeport	2.070 mg/L	Yes	13	A-
38	Newport	2.070 mg/L	Yes	54	B+
39	Monmouth	2.070 mg/L	Yes	2	B+
40	Hartland	2.040 mg/L	Yes	33	A-
41	Bowdoinham	2.030 mg/L	Yes	1	A
42	North Berwick	1.940 mg/L	Yes	2	B-
43	Orono	1.920 mg/L	Yes	12	B-
44	Scarborough	1.830 mg/L	Yes	0	B
45	Mechanic Falls	1.830 mg/L	Yes	0	B+
46	Eastport	1.810 mg/L	Yes	42	B
47	Eastport	1.810 mg/L	Yes	42	B
48	Waterboro	1.800 mg/L	Yes	10	B
49	Fort Kent	1.800 mg/L	Yes	4	C+
50	Bingham	1.730 mg/L	Yes	8	B-
51	Bingham	1.730 mg/L	Yes	5	B+
52	Limerick	1.710 mg/L	Yes	9	B
53	Bath	1.700 mg/L	Yes	19	B-
54	Fryeburg	1.700 mg/L	Yes	3	A-
55	Oxford	1.700 mg/L	Yes	1	A
56	Clinton	1.670 mg/L	Yes	1	B+
57	Ashland	1.600 mg/L	Yes	20	A-
58	Eagle Lake	1.600 mg/L	Yes	40	B+
59	Rumford	1.560 mg/L	Yes	0	B+
60	Gray	1.540 mg/L	Yes	2	B-
61	Northport	1.510 mg/L	Yes	4	B+
62	Northport	1.510 mg/L	Yes	9	B-
63	Strong	1.510 mg/L	Yes	0	A-
64	Topsham	1.500 mg/L	Yes	17	C+
65	Bridgton	1.500 mg/L	Yes	5	D
66	Fort Fairfield	1.500 mg/L	Yes	10	B+
67	Limestone	1.470 mg/L	Yes	95	D
68	Vinalhaven	1.470 mg/L	Yes	36	C+
69	Farmington	1.460 mg/L	Yes	1	B
70	Bucksport	1.435 mg/L	Yes	8	C-
71	Paris	1.430 mg/L	Yes	6	A-
72	Bethel	1.430 mg/L	Yes	0	B
73	Dexter	1.420 mg/L	Yes	4	B+
74	Avon	1.410 mg/L	Yes	22	A-
75	Avon	1.410 mg/L	Yes	22	A-
76	Old Town	1.400 mg/L	Yes	1	A-
77	Pittsfield	1.400 mg/L	Yes	4	B+
78	Lubec	1.400 mg/L	Yes	6	B+
79	Carrabassett Vl	1.400 mg/L	Yes	14	C+
80	North Haven	1.400 mg/L	Yes	58	B
81	Scarborough	1.360 mg/L	Yes	5	B-

FAQ

Frequently asked questions about copper in Maine

Is copper in Maine drinking water safe?

81 cities in Maine exceed the EPA action level of 1.3 mg/L for copper. The state average is 2.269 mg/L. Copper levels are highest in homes with copper plumbing, particularly when water sits in pipes overnight. Flushing the tap before use significantly reduces copper in drinking water.

What causes high copper levels in Maine tap water?

Copper typically leaches from copper pipes and brass fittings within homes, not from the water source itself. Corrosive (low pH or soft) water accelerates this leaching. Water utilities with high copper readings are required to adjust water chemistry to reduce corrosivity. You can reduce exposure by flushing your tap for 30 seconds before use.

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