Arsenic Contamination

Arsenic in Massachusetts Drinking Water

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

Cities Tested

Has Violations

100%

% Has Violations

2.8 violations

State Avg

▼ 0% vs national

vs National

263

Health Violations

Analysis

Arsenic in Massachusetts: what the data shows

Massachusetts has 96 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 96 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

Massachusetts

100%

96 of 96 cities

← = Exactly at national rate

National avg

100%

5489 of 5489 cities

City Map

Arsenic data across Massachusetts

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 Massachusetts

Highest Arsenic levels (violations)

All Cities

All Massachusetts cities ranked by arsenic level

#	City	Level	Violations?	Violations	Grade
1	Leicester	46 violations	Yes	121	D
2	Lee	29 violations	Yes	44	F
3	Harvard	12 violations	Yes	17	F
4	Auburn	9 violations	Yes	16	D+
5	Boxborough	9 violations	Yes	14	D+
6	Lancaster	8 violations	Yes	30	B-
7	Hinsdale	8 violations	Yes	9	C+
8	Shirley	6 violations	Yes	18	C
9	Sunderland	6 violations	Yes	8	B
10	Newton	5 violations	Yes	8	B
11	Westborough	5 violations	Yes	13	D
12	Ayer	5 violations	Yes	4	B
13	Palmer	4 violations	Yes	11	B
14	Nantucket	3 violations	Yes	12	D
15	Oxford	3 violations	Yes	7	C+
16	Great Barrington	3 violations	Yes	12	C+
17	Hatfield	3 violations	Yes	3	A-
18	West Brookfield	3 violations	Yes	28	B-
19	Berlin	3 violations	Yes	4	C
20	Chester	3 violations	Yes	15	C
21	Atkinson	3 violations	Yes	7	C+
22	Lawrence	2 violations	Yes	3	B+
23	Peabody	2 violations	Yes	7	B
24	North Attleborough	2 violations	Yes	15	F
25	Burlington	2 violations	Yes	7	B+
26	Hudson	2 violations	Yes	7	F
27	Greenfield	2 violations	Yes	3	A-
28	Hanover	2 violations	Yes	12	C-
29	Maynard	2 violations	Yes	8	B-
30	Norfolk	2 violations	Yes	12	F
31	Southwick	2 violations	Yes	9	A-
32	Spencer	2 violations	Yes	4	B
33	Hopedale	2 violations	Yes	8	B+
34	Rutland	2 violations	Yes	22	C-
35	Deerfield	2 violations	Yes	9	C+
36	Belchertown	2 violations	Yes	26	B-
37	Warren	2 violations	Yes	20	C+
38	Bernardston	2 violations	Yes	7	B
39	Chilmark	2 violations	Yes	10	D+
40	Beverly	1 violations	Yes	0	A-
41	Plymouth	1 violations	Yes	20	F
42	Attleboro	1 violations	Yes	3	A-
43	Leominster	1 violations	Yes	12	B
44	Westfield	1 violations	Yes	7	B+
45	Woburn	1 violations	Yes	5	B+
46	Chelmsford	1 violations	Yes	1	B-
47	Yarmouth	1 violations	Yes	7	A-
48	Gloucester	1 violations	Yes	4	A
49	Mashpee	1 violations	Yes	4	B
50	Bourne	1 violations	Yes	16	B-
51	Dracut	1 violations	Yes	5	B
52	Bridgewater	1 violations	Yes	5	C+
53	Milford	1 violations	Yes	15	F
54	Danvers	1 violations	Yes	5	B+
55	Wakefield	1 violations	Yes	10	B+
56	Walpole	1 violations	Yes	6	A-
57	Oak Bluffs	1 violations	Yes	18	B+
58	Mansfield	1 violations	Yes	6	A-
59	Winchester	1 violations	Yes	5	C-
60	Wilmington	1 violations	Yes	5	A-
61	Acton	1 violations	Yes	28	F
62	Scituate	1 violations	Yes	10	C
63	Westford	1 violations	Yes	9	B
64	Foxborough	1 violations	Yes	11	A-
65	Somerset	1 violations	Yes	11	B
66	Easthampton	1 violations	Yes	8	A
67	Holliston	1 violations	Yes	11	C-
68	Ashburnham	1 violations	Yes	11	B+
69	Grafton	1 violations	Yes	25	F
70	Lynnfield	1 violations	Yes	7	B
71	Hopkinton	1 violations	Yes	24	B-
72	Blackstone	1 violations	Yes	9	B+
73	Pepperell	1 violations	Yes	12	B-
74	Plainville	1 violations	Yes	9	B
75	Lincoln	1 violations	Yes	8	B+
76	Montague	1 violations	Yes	4	A
77	West Bridgewater	1 violations	Yes	4	A-
78	Williamstown	1 violations	Yes	10	A-
79	Halifax	1 violations	Yes	1	C+
80	Dalton	1 violations	Yes	6	A
81	Tisbury	1 violations	Yes	9	B+
82	Templeton	1 violations	Yes	0	B+
83	Lee	1 violations	Yes	11	B+
84	Dudley	1 violations	Yes	14	B+
85	Hadley	1 violations	Yes	7	A
86	Tyngsborough	1 violations	Yes	9	C-
87	Monson	1 violations	Yes	5	A-
88	Stockbridge	1 violations	Yes	15	B+
89	Carver	1 violations	Yes	23	C-
90	Newbury	1 violations	Yes	4	A
91	Brookfield	1 violations	Yes	17	B
92	Wellfleet	1 violations	Yes	7	C+
93	Whately	1 violations	Yes	0	B+
94	Granby	1 violations	Yes	13	B
95	Erving	1 violations	Yes	3	A
96	Preble (T)	1 violations	Yes	10	C+

FAQ

Frequently asked questions about arsenic in Massachusetts

Is arsenic in Massachusetts tap water a concern?

Yes — 96 cities in Massachusetts 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 Massachusetts?

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 Massachusetts 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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