Manganese Contamination

Manganese in Massachusetts Drinking Water

Ranked by max manganese detected (µg/L) · UCMR 4 data (2018–2020) · Data from EPA SDWIS & UCMR

161

Cities Tested

Over SMCL

39%

% Over SMCL

131.6 µg/L

State Avg

▲ 21% vs national

vs National

263

Health Violations

Analysis

Manganese in Massachusetts: what the data shows

Massachusetts has 161 cities with manganese data from the EPA's UCMR 4 program (2018–2020). Manganese exceeded the 50 µg/L EPA secondary MCL in 63 of those cities. The state average max detected level is 131.6 µg/L. Manganese occurs naturally in groundwater and surface water. Elevated levels are common in areas with iron-rich geology and in systems that draw from reservoirs with low dissolved oxygen. The secondary MCL of 50 µg/L is based on aesthetic concerns (taste, staining), but health-based guidelines suggest neurological effects at higher concentrations. Emerging research links chronic manganese exposure in drinking water to neurodevelopmental effects in children, including reduced IQ and behavioral issues. Oxidation filtration and water softeners are effective at removing manganese from household water.

Comparison

Cities exceeding 50 µg/L EPA Secondary MCL

Massachusetts

39%

63 of 161 cities

→ ▲ 21% above national rate (worse)

National avg

18%

729 of 4068 cities

City Map

Manganese data across Massachusetts

Each dot is a city with UCMR 4 manganese testing data. Cities where manganese exceeds the 50 µg/L EPA secondary MCL are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by manganese level in Massachusetts

Highest Manganese levels (µg/L)

All Cities

All Massachusetts cities ranked by manganese level

#	City	Level	Over SMCL?	Violations	Grade
1	Randolph	2550.0 µg/L	Over SMCL	8	B+
2	Swansea	1490.0 µg/L	Over SMCL	12	B+
3	Grafton	1350.0 µg/L	Over SMCL	25	F
4	Easton	1180.0 µg/L	Over SMCL	3	A-
5	Acton	1090.0 µg/L	Over SMCL	28	F
6	Ipswich	657.0 µg/L	Over SMCL	8	B
7	Natick	587.0 µg/L	Over SMCL	3	B+
8	Chelmsford	584.0 µg/L	Over SMCL	1	B-
9	Dracut	551.8 µg/L	Over SMCL	5	B
10	Foxborough	550.0 µg/L	Over SMCL	11	A-
11	Norton	460.0 µg/L	Over SMCL	10	B+
12	Yarmouth	429.0 µg/L	Over SMCL	7	A-
13	Scituate	413.0 µg/L	Over SMCL	10	C
14	Middleborough	400.0 µg/L	Over SMCL	16	B
15	Pembroke	331.0 µg/L	Over SMCL	16	A
16	Attleboro	325.0 µg/L	Over SMCL	3	A-
17	Medway	293.0 µg/L	Over SMCL	14	B-
18	Upton	277.9 µg/L	Over SMCL	9	C
19	Maynard	247.0 µg/L	Over SMCL	8	B-
20	Bridgewater	222.0 µg/L	Over SMCL	5	C+
21	Somerset	222.0 µg/L	Over SMCL	11	B
22	Medfield	220.0 µg/L	Over SMCL	14	B+
23	Easthampton	215.0 µg/L	Over SMCL	8	A
24	Franklin	204.0 µg/L	Over SMCL	11	B+
25	Uxbridge	204.0 µg/L	Over SMCL	2	A-
26	Marshfield	199.0 µg/L	Over SMCL	9	B-
27	Leominster	197.0 µg/L	Over SMCL	12	B
28	Salisbury	193.0 µg/L	Over SMCL	0	A-
29	Sharon	189.0 µg/L	Over SMCL	5	D+
30	Fairhaven	183.0 µg/L	Over SMCL	9	A
31	Wareham	180.0 µg/L	Over SMCL	22	B
32	Ware	167.6 µg/L	Over SMCL	11	B
33	Brockton	159.0 µg/L	Over SMCL	5	A-
34	Norwell	153.0 µg/L	Over SMCL	5	B+
35	Braintree	142.0 µg/L	Over SMCL	1	B
36	Dartmouth	141.0 µg/L	Over SMCL	16	C+
37	Plymouth	130.0 µg/L	Over SMCL	20	F
38	Kingston	128.0 µg/L	Over SMCL	12	C
39	Andover	127.0 µg/L	Over SMCL	2	B+
40	Provincetown	127.0 µg/L	Over SMCL	5	A
41	Barnstable	125.0 µg/L	Over SMCL	34	D+
42	Holden	119.0 µg/L	Over SMCL	18	B
43	Duxbury	118.0 µg/L	Over SMCL	4	B+
44	Mansfield	115.0 µg/L	Over SMCL	6	A-
45	Norfolk	114.7 µg/L	Over SMCL	12	F
46	North Reading	109.0 µg/L	Over SMCL	9	A-
47	Webster	97.4 µg/L	Over SMCL	19	B
48	Weymouth	93.4 µg/L	Over SMCL	6	A
49	Gardner	93.2 µg/L	Over SMCL	7	A-
50	Shrewsbury	87.6 µg/L	Over SMCL	3	B+
51	Whitman	81.2 µg/L	Over SMCL	5	A-
52	Winchester	75.5 µg/L	Over SMCL	5	C-
53	Chatham	73.6 µg/L	Over SMCL	19	A
54	Danvers	66.4 µg/L	Over SMCL	5	B+
55	Westfield	61.9 µg/L	Over SMCL	7	B+
56	Milton	61.7 µg/L	Over SMCL	6	B+
57	Newburyport	58.6 µg/L	Over SMCL	3	A-
58	Pittsfield	58.4 µg/L	Over SMCL	2	A-
59	Saugus	55.6 µg/L	Over SMCL	10	A-
60	Sandwich	55.2 µg/L	Over SMCL	13	A
61	Sudbury	54.3 µg/L	Over SMCL	10	B-
62	Worcester	50.8 µg/L	Over SMCL	3	B
63	Concord	50.2 µg/L	Over SMCL	4	B+
64	Gloucester	49.5 µg/L	No	4	A
65	Southbridge	48.6 µg/L	No	3	A
66	North Adams	46.4 µg/L	No	5	B
67	Hudson	45.3 µg/L	No	7	F
68	Beverly	45.0 µg/L	No	0	A-
69	Salem	45.0 µg/L	No	0	A-
70	Westborough	44.6 µg/L	No	13	D
71	New Bedford	43.8 µg/L	No	2	A-
72	Peabody	43.0 µg/L	No	7	B
73	Hingham	42.3 µg/L	No	2	C+
74	Fitchburg	39.5 µg/L	No	9	B+
75	Billerica	37.9 µg/L	No	7	B+
76	Mashpee	36.5 µg/L	No	4	B
77	Holbrook	35.4 µg/L	No	15	B+
78	Dighton	34.7 µg/L	No	7	D+
79	Dennis	33.6 µg/L	No	5	A
80	Oak Bluffs	33.0 µg/L	No	18	B+
81	Auburn	31.6 µg/L	No	16	D+
82	Northborough	31.2 µg/L	No	10	B
83	Lawrence	30.5 µg/L	No	3	B+
84	Clinton	30.1 µg/L	No	17	A-
85	Stoughton	30.0 µg/L	No	13	B
86	Holyoke	28.7 µg/L	No	0	A-
87	Lowell	27.5 µg/L	No	5	B+
88	Amherst	27.0 µg/L	No	6	A-
89	Athol	26.6 µg/L	No	3	A
90	Milford	26.3 µg/L	No	15	F
91	Orleans	25.9 µg/L	No	3	B
92	Hanover	25.4 µg/L	No	12	C-
93	Westford	25.1 µg/L	No	9	B
94	Methuen	23.9 µg/L	No	1	A
95	Ashland	22.9 µg/L	No	7	A-
96	Wrentham	21.8 µg/L	No	64	F
97	Walpole	21.1 µg/L	No	6	A-
98	Seekonk	20.8 µg/L	No	7	A-
99	Bedford	19.6 µg/L	No	35	B+
100	Wakefield	19.2 µg/L	No	10	B+
101	Wilmington	19.0 µg/L	No	5	A-
102	Brewster	18.8 µg/L	No	1	B+
103	Bellingham	18.5 µg/L	No	21	B-
104	Bourne	18.3 µg/L	No	16	B-
105	Marlborough	18.0 µg/L	No	5	A-
106	Wayland	16.3 µg/L	No	11	B+
107	Greenfield	16.0 µg/L	No	3	A-
108	Harwich	15.8 µg/L	No	3	A+
109	Abington	15.4 µg/L	No	14	B
110	Tisbury	14.6 µg/L	No	9	B+
111	Burlington	14.4 µg/L	No	7	B+
112	East Bridgewater	14.3 µg/L	No	6	B+
113	East Longmeadow	14.3 µg/L	No	5	A-
114	Taunton	13.8 µg/L	No	1	B+
115	Springfield	13.2 µg/L	No	11	B+
116	Cambridge	12.6 µg/L	No	2	B+
117	Chelsea	12.5 µg/L	No	17	A-
118	Haverhill	12.0 µg/L	No	1	C
119	Woburn	11.9 µg/L	No	5	B+
120	Stoneham	11.7 µg/L	No	15	A-
121	Watertown	11.6 µg/L	No	5	A-
122	Dalton	11.2 µg/L	No	6	A
123	Quincy	11.1 µg/L	No	6	A-
124	Boston	10.9 µg/L	No	5	B
125	Newton	10.9 µg/L	No	8	B
126	Brookline	10.7 µg/L	No	6	A-
127	Tewksbury	10.3 µg/L	No	3	B
128	Fall River	10.0 µg/L	No	11	B-
129	Needham	10.0 µg/L	No	4	A-
130	Lincoln	9.9 µg/L	No	8	B+
131	Everett	9.6 µg/L	No	8	B+
132	Norwood	9.5 µg/L	No	8	A-
133	Longmeadow	9.1 µg/L	No	18	B
134	Nantucket	8.3 µg/L	No	12	D
135	Lexington	8.3 µg/L	No	7	B+
136	Amesbury	8.2 µg/L	No	0	A
137	Arlington	8.1 µg/L	No	4	A-
138	Reading	8.0 µg/L	No	1	A-
139	Waltham	7.9 µg/L	No	11	A-
140	Medford	7.9 µg/L	No	9	C
141	Wellesley	7.8 µg/L	No	20	B
142	Weston	7.7 µg/L	No	16	A-
143	Marblehead	7.7 µg/L	No	7	A-
144	Somerville	7.7 µg/L	No	12	B+
145	Framingham	7.5 µg/L	No	4	A-
146	Winthrop	7.5 µg/L	No	8	B+
147	Belmont	7.4 µg/L	No	5	B+
148	Revere	7.3 µg/L	No	13	B+
149	Canton	7.2 µg/L	No	11	A-
150	Malden	7.1 µg/L	No	20	B-
151	Agawam	7.1 µg/L	No	8	A-
152	North Andover	6.9 µg/L	No	5	A
153	Melrose	6.8 µg/L	No	16	B
154	Swampscott	6.4 µg/L	No	9	A-
155	South Hadley	4.4 µg/L	No	16	A-
156	Lynn	4.1 µg/L	No	5	A-
157	Northampton	3.8 µg/L	No	5	A-
158	Dedham	3.7 µg/L	No	1	B+
159	Chicopee	3.7 µg/L	No	0	A-
160	Falmouth	3.5 µg/L	No	23	B
161	North Attleborough	1.5 µg/L	No	15	F

FAQ

Frequently asked questions about manganese in Massachusetts

Is manganese in Massachusetts tap water harmful?

The EPA secondary MCL for manganese is 50 µg/L, set primarily for aesthetic reasons (taste, color, staining). 63 cities in Massachusetts exceed the secondary MCL. However, emerging research links chronic manganese exposure above 50–100 µg/L to neurodevelopmental effects in children, including reduced IQ.

How can I remove manganese from my drinking water?

Oxidation filtration (such as greensand or birm filters) is the most common and effective method for removing manganese from well water. Water softeners using ion exchange also work well. Standard carbon filters provide limited manganese removal. If your water has a metallic taste or brown/black discoloration, manganese may be the cause.

What causes high manganese in Massachusetts water?

Manganese occurs naturally in groundwater and surface water, particularly in areas with iron-rich geology. Low dissolved oxygen conditions (common in deep wells and reservoir bottom waters) increase manganese solubility. Industrial sources include mining, steel production, and battery manufacturing. Seasonal changes in reservoir water chemistry can cause manganese spikes.

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