Nitrate Contamination

Nitrate in Massachusetts Drinking Water

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

141

Cities Tested

141

Has Violations

100%

% Has Violations

3.2 violations

State Avg

▼ 0% vs national

vs National

253

Health Violations

Analysis

Nitrate in Massachusetts: what the data shows

Massachusetts has 141 cities with nitrate-related violations. The EPA MCL for nitrate is 10 mg/L (measured as nitrogen). The state has 141 cities with at least one nitrate violation. Nitrate is the most common groundwater contaminant in the United States. It enters water supplies primarily through agricultural fertilizer runoff, septic system leaching, and animal feedlot operations. Rural and agricultural communities face the highest risk. The primary acute health concern is methemoglobinemia ("blue baby syndrome") in infants under six months. Emerging research also links chronic nitrate exposure to thyroid disease, certain cancers, and adverse birth outcomes. Reverse osmosis, ion exchange, and distillation can remove nitrate from drinking water — standard carbon filters do not.

Comparison

Cities exceeding 10 mg/L EPA MCL

Massachusetts

100%

141 of 141 cities

← = Exactly at national rate

National avg

100%

7727 of 7727 cities

City Map

Nitrate data across Massachusetts

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

Worst Offenders

Top 10 cities by nitrate level in Massachusetts

Highest Nitrate levels (violations)

All Cities

All Massachusetts cities ranked by nitrate level

#	City	Level	Violations?	Violations	Grade
1	Chilmark	25 violations	Yes	10	D+
2	Boxborough	18 violations	Yes	14	D+
3	Hinsdale	15 violations	Yes	9	C+
4	Sunderland	11 violations	Yes	8	B
5	Acton	10 violations	Yes	28	F
6	Ware	9 violations	Yes	11	B
7	Carver	9 violations	Yes	23	C-
8	Nantucket	8 violations	Yes	12	D
9	North Attleborough	8 violations	Yes	15	F
10	Leicester	8 violations	Yes	121	D
11	Shirley	8 violations	Yes	18	C
12	Wellfleet	8 violations	Yes	7	C+
13	Plymouth	7 violations	Yes	20	F
14	Milford	7 violations	Yes	15	F
15	Warren	7 violations	Yes	20	C+
16	Holliston	6 violations	Yes	11	C-
17	Townsend	6 violations	Yes	14	B
18	Great Barrington	6 violations	Yes	12	C+
19	Rutland	6 violations	Yes	22	C-
20	Palmer	6 violations	Yes	11	B
21	Belchertown	6 violations	Yes	26	B-
22	West Brookfield	6 violations	Yes	28	B-
23	Brookfield	6 violations	Yes	17	B
24	Mashpee	5 violations	Yes	4	B
25	Tewksbury	5 violations	Yes	3	B
26	Ashburnham	5 violations	Yes	11	B+
27	Southwick	5 violations	Yes	9	A-
28	Tyngsborough	5 violations	Yes	9	C-
29	Sutton	5 violations	Yes	17	B
30	Yarmouth	4 violations	Yes	7	A-
31	Burlington	4 violations	Yes	7	B+
32	Easthampton	4 violations	Yes	8	A
33	Hopkinton	4 violations	Yes	24	B-
34	Norfolk	4 violations	Yes	12	F
35	Halifax	4 violations	Yes	1	C+
36	Spencer	4 violations	Yes	4	B
37	Winchendon	4 violations	Yes	13	A-
38	Barnstable	4 violations	Yes	34	D+
39	Deerfield	4 violations	Yes	9	C+
40	Williamsburg	4 violations	Yes	9	A
41	Northfield	4 violations	Yes	7	A-
42	Marshfield	3 violations	Yes	9	B-
43	Franklin	3 violations	Yes	11	B+
44	Northampton	3 violations	Yes	5	A-
45	Stoughton	3 violations	Yes	13	B
46	Bridgewater	3 violations	Yes	5	C+
47	Wakefield	3 violations	Yes	10	B+
48	Mansfield	3 violations	Yes	6	A-
49	Westford	3 violations	Yes	9	B
50	Holden	3 violations	Yes	18	B
51	Raynham	3 violations	Yes	0	B+
52	Medway	3 violations	Yes	14	B-
53	Norwell	3 violations	Yes	5	B+
54	Merrimac	3 violations	Yes	11	B
55	Dalton	3 violations	Yes	6	A
56	Templeton	3 violations	Yes	0	B+
57	Monson	3 violations	Yes	5	A-
58	Harvard	3 violations	Yes	17	F
59	Bernardston	3 violations	Yes	7	B
60	Cheshire	3 violations	Yes	6	A-
61	Bolton	3 violations	Yes	4	B+
62	Dennis	2 violations	Yes	5	A
63	Billerica	2 violations	Yes	7	B+
64	Amherst	2 violations	Yes	6	A-
65	Braintree	2 violations	Yes	1	B
66	Gloucester	2 violations	Yes	4	A
67	Abington	2 violations	Yes	14	B
68	Wellesley	2 violations	Yes	20	B
69	Chelmsford	2 violations	Yes	1	B-
70	Chatham	2 violations	Yes	19	A
71	Oak Bluffs	2 violations	Yes	18	B+
72	Winchester	2 violations	Yes	5	C-
73	Wilmington	2 violations	Yes	5	A-
74	Provincetown	2 violations	Yes	5	A
75	Gardner	2 violations	Yes	7	A-
76	Hudson	2 violations	Yes	7	F
77	Scituate	2 violations	Yes	10	C
78	Orleans	2 violations	Yes	3	B
79	Amesbury	2 violations	Yes	0	A
80	Kingston	2 violations	Yes	12	C
81	Lynnfield	2 violations	Yes	7	B
82	Millbury	2 violations	Yes	4	C
83	Grafton	2 violations	Yes	25	F
84	Blackstone	2 violations	Yes	9	B+
85	Millis	2 violations	Yes	4	B+
86	Bourne	2 violations	Yes	16	B-
87	Groton	2 violations	Yes	5	B+
88	Groveland	2 violations	Yes	3	A-
89	Hopedale	2 violations	Yes	8	B+
90	Lancaster	2 violations	Yes	30	B-
91	Lee	2 violations	Yes	11	B+
92	Topsfield	2 violations	Yes	8	B+
93	Chester	2 violations	Yes	15	C
94	Dighton	1 violations	Yes	7	D+
95	Lawrence	1 violations	Yes	3	B+
96	Peabody	1 violations	Yes	7	B
97	Leominster	1 violations	Yes	12	B
98	Westfield	1 violations	Yes	7	B+
99	Woburn	1 violations	Yes	5	B+
100	Shrewsbury	1 violations	Yes	3	B+
101	Mattapoisett	1 violations	Yes	9	A
102	Natick	1 violations	Yes	3	B+
103	Andover	1 violations	Yes	2	B+
104	Dracut	1 violations	Yes	5	B
105	West Springfield	1 violations	Yes	7	A
106	Danvers	1 violations	Yes	5	B+
107	Reading	1 violations	Yes	1	A-
108	Bedford	1 violations	Yes	35	B+
109	Walpole	1 violations	Yes	6	A-
110	Canton	1 violations	Yes	11	A-
111	Wareham	1 violations	Yes	22	B
112	Foxborough	1 violations	Yes	11	A-
113	Webster	1 violations	Yes	19	B
114	Greenfield	1 violations	Yes	3	A-
115	Duxbury	1 violations	Yes	4	B+
116	Middleborough	1 violations	Yes	16	B
117	Auburn	1 violations	Yes	16	D+
118	Northborough	1 violations	Yes	10	B
119	Ipswich	1 violations	Yes	8	B
120	North Adams	1 violations	Yes	5	B
121	Wrentham	1 violations	Yes	64	F
122	Hanson	1 violations	Yes	7	B+
123	Pepperell	1 violations	Yes	12	B-
124	Plainville	1 violations	Yes	9	B
125	Ayer	1 violations	Yes	4	B
126	Acushnet	1 violations	Yes	2	A-
127	Edgartown	1 violations	Yes	6	A
128	Williamstown	1 violations	Yes	10	A-
129	Hamilton	1 violations	Yes	11	A-
130	Sterling	1 violations	Yes	11	B
131	Tisbury	1 violations	Yes	9	B+
132	Sturbridge	1 violations	Yes	7	B+
133	Barre	1 violations	Yes	20	C
134	Boylston	1 violations	Yes	11	B
135	Lanesborough	1 violations	Yes	10	A-
136	Shelburne	1 violations	Yes	4	A
137	Egremont	1 violations	Yes	3	A-
138	Hancock	1 violations	Yes	5	A-
139	Worthington	1 violations	Yes	0	B+
140	West Stockbridge	1 violations	Yes	3	A-
141	Mendon	1 violations	Yes	4	A-

FAQ

Frequently asked questions about nitrate in Massachusetts

Is nitrate in Massachusetts tap water dangerous?

Yes — 141 cities in Massachusetts have nitrate-related violations. The EPA MCL is 10 mg/L. Nitrate is especially dangerous for infants under six months, where it can cause methemoglobinemia ("blue baby syndrome"). Adults face lower acute risk, but chronic exposure is linked to thyroid disease and certain cancers.

How can I remove nitrate from my drinking water?

Reverse osmosis, ion exchange, and distillation are effective at removing nitrate. Standard carbon filters (including most pitcher and faucet-mount filters) do NOT remove nitrate. If you rely on a private well in an agricultural area, have your water tested annually for nitrate.

What causes high nitrate levels in Massachusetts water?

Nitrate contamination comes primarily from agricultural fertilizer runoff, septic system leaching, and animal feedlot operations. Rural communities near intensive farming are most at risk. Shallow wells are particularly vulnerable. Heavy rainfall can spike nitrate levels as it washes fertilizer into groundwater and surface water supplies.

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