Lead Contamination

Lead in Connecticut Drinking Water

Ranked by 90th percentile lead level (ppb) · Data from EPA SDWIS & UCMR

158

Cities Tested

Exceeds Limit

% Exceeds Limit

1.5 ppb

State Avg

▼ 0% vs national

vs National

134

Health Violations

Analysis

Lead in Connecticut: what the data shows

Connecticut has 158 cities with lead monitoring data, with very few cities exceeding the EPA action level of 15 ppb. The state average 90th percentile lead level is 1.5 ppb, compared to 3.3 ppb nationally — better than the national average. 3 cities exceed the 15 ppb action level. High lead levels in tap water typically indicate aging infrastructure — lead service lines, lead solder in older plumbing, or lead-containing brass fixtures. There is no safe level of lead exposure for children. The 90th percentile measurement means that 90% of tap samples in a city are at or below the reported level. This is the standard EPA uses under the Lead and Copper Rule to determine if a water system needs to take corrective action. An NSF 53-certified pitcher or under-sink filter can effectively remove lead at the tap.

Comparison

Cities exceeding 15 ppb EPA Action Level

Connecticut

3 of 158 cities

← = Exactly at national rate

National avg

378 of 15681 cities

City Map

Lead data across Connecticut

Each dot is a city, colored by overall water quality grade. Cities with lead levels above the 15 ppb EPA action level are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by lead level in Connecticut

Highest Lead levels (ppb)

All Cities

All Connecticut cities ranked by lead level

#	City	Level	Exceeds?	Violations	Grade
1	Carroll	48.0 ppb	Yes	10	C
2	Carroll	48.0 ppb	Yes	9	C
3	Bow	44.0 ppb	Yes	53	D
4	Coventry	8.5 ppb	No	34	F
5	Lower Sipaulovi, Lower Mishongnovi	5.0 ppb	No	63	D
6	Lower Sipaulovi, Lower Mishongnovi	5.0 ppb	No	63	D
7	Windham	4.3 ppb	No	11	B+
8	Hopkinton	4.0 ppb	No	37	F
9	Lewisboro (T)	4.0 ppb	No	3	B+
10	Washington	3.7 ppb	No	31	F
11	Groton	3.0 ppb	No	6	B-
12	Beacon Falls	2.8 ppb	No	27	F
13	Clinton	2.8 ppb	No	20	D
14	Putnam	2.8 ppb	No	72	F
15	Putnam	2.8 ppb	No	120	F
16	Putnam	2.8 ppb	No	19	D
17	Brookfield	2.8 ppb	No	56	D+
18	Plymouth	2.8 ppb	No	0	A+
19	Killingworth	2.7 ppb	No	35	C-
20	Uncasville	2.6 ppb	No	1	A
21	Franklin	2.5 ppb	No	143	F
22	Bethel	2.4 ppb	No	59	F
23	Bethel	2.4 ppb	No	25	F
24	Berlin	2.2 ppb	No	6	F
25	Berlin	2.2 ppb	No	1	D
26	Middlebury	2.2 ppb	No	11	D+
27	Berlin	2.2 ppb	No	0	B-
28	Marlborough	2.2 ppb	No	19	D
29	Middlebury	2.0 ppb	No	18	C-
30	Brookfield	2.0 ppb	No	85	F
31	Plainfield	2.0 ppb	No	37	D
32	Middlebury	1.8 ppb	No	15	F
33	East Haddam	1.8 ppb	No	26	D
34	Kent	1.6 ppb	No	30	D
35	Ashford	1.6 ppb	No	32	D
36	Franklin	1.5 ppb	No	32	F
37	Cromwell	1.4 ppb	No	25	F
38	North Canaan	1.3 ppb	No	0	B+
39	Hebron	1.1 ppb	No	21	F
40	Sheffield	1.1 ppb	No	7	A-
41	Sheffield	1.1 ppb	No	3	A
42	Mashantucket	1.0 ppb	No	7	B
43	Sharon	0.8 ppb	No	9	F
44	Willington	0.6 ppb	No	41	F
45	Killingly	0.5 ppb	No	32	F
46	Killingly	0.5 ppb	No	14	C-
47	Ansonia	0.0 ppb	No	2	D
48	Ansonia	0.0 ppb	No	12	F
49	Ansonia	0.0 ppb	No	18	F
50	Beacon Falls	0.0 ppb	No	4	F
51	Ansonia	0.0 ppb	No	1	C+
52	Berlin	0.0 ppb	No	5	C
53	Berlin	0.0 ppb	No	8	C
54	Beacon Falls	0.0 ppb	No	7	F
55	Beacon Falls	0.0 ppb	No	5	F
56	Ansonia	0.0 ppb	No	28	F
57	Ansonia	0.0 ppb	No	4	D
58	Berlin	0.0 ppb	No	3	D+
59	Berlin	0.0 ppb	No	40	F
60	Berlin	0.0 ppb	No	0	B-
61	Ansonia	0.0 ppb	No	4	C+
62	Berlin	0.0 ppb	No	0	B+
63	Beacon Falls	0.0 ppb	No	7	D
64	Ansonia	0.0 ppb	No	0	C-
65	Beacon Falls	0.0 ppb	No	7	D
66	Berlin	0.0 ppb	No	1	B-
67	Berlin	0.0 ppb	No	4	B+
68	Beacon Falls	0.0 ppb	No	7	D
69	Ansonia	0.0 ppb	No	4	D+
70	Ansonia	0.0 ppb	No	0	B+
71	Ansonia	0.0 ppb	No	0	B+
72	Ansonia	0.0 ppb	No	0	B+
73	Ansonia	0.0 ppb	No	0	B+
74	Ansonia	0.0 ppb	No	25	F
75	Ansonia	0.0 ppb	No	0	B+
76	Ansonia	0.0 ppb	No	0	B+
77	Ansonia	0.0 ppb	No	0	B+
78	Ansonia	0.0 ppb	No	0	B+
79	Ansonia	0.0 ppb	No	0	B+
80	Ansonia	0.0 ppb	No	0	B+
81	Berlin	0.0 ppb	No	9	C
82	Beacon Falls	0.0 ppb	No	2	C-
83	Berlin	0.0 ppb	No	33	F
84	Berlin	0.0 ppb	No	1	B
85	Berlin	0.0 ppb	No	0	A-
86	Berlin	0.0 ppb	No	0	A-
87	Berlin	0.0 ppb	No	0	A-
88	Berlin	0.0 ppb	No	0	A-
89	Beacon Falls	0.0 ppb	No	3	C-
90	Beacon Falls	0.0 ppb	No	46	F
91	Beacon Falls	0.0 ppb	No	7	F
92	Beacon Falls	0.0 ppb	No	2	F
93	Beacon Falls	0.0 ppb	No	2	F
94	Beacon Falls	0.0 ppb	No	2	F
95	Beacon Falls	0.0 ppb	No	2	C-
96	Beacon Falls	0.0 ppb	No	2	C-
97	Beacon Falls	0.0 ppb	No	2	C-
98	Beacon Falls	0.0 ppb	No	2	C-
99	Beacon Falls	0.0 ppb	No	2	C-
100	Berlin	0.0 ppb	No	4	C
101	East Granby	0.0 ppb	No	5	C-
102	East Granby	0.0 ppb	No	85	F
103	Middlebury	0.0 ppb	No	14	C
104	East Granby	0.0 ppb	No	9	D
105	East Granby	0.0 ppb	No	25	F
106	East Granby	0.0 ppb	No	24	F
107	East Granby	0.0 ppb	No	12	C-
108	East Granby	0.0 ppb	No	1	C+
109	East Granby	0.0 ppb	No	0	B
110	Bristol	0.0 ppb	No	4	C+
111	Bethel	0.0 ppb	No	135	F
112	Bristol	0.0 ppb	No	18	C
113	Bristol	0.0 ppb	No	9	C
114	Cromwell	0.0 ppb	No	11	D
115	Groton	0.0 ppb	No	23	D+
116	Groton	0.0 ppb	No	17	F
117	Harwinton	0.0 ppb	No	8	F
118	New London	0.0 ppb	No	16	C-
119	New London	0.0 ppb	No	0	C+
120	Franklin	0.0 ppb	No	27	F
121	Harwinton	0.0 ppb	No	19	F
122	Harwinton	0.0 ppb	No	3	B+
123	Harwinton	0.0 ppb	No	5	D
124	Franklin	0.0 ppb	No	19	B-
125	Franklin	0.0 ppb	No	23	D+
126	Franklin	0.0 ppb	No	13	B
127	Franklin	0.0 ppb	No	13	B
128	Clinton	0.0 ppb	No	18	C+
129	Hampton	0.0 ppb	No	12	B-
130	Clinton	0.0 ppb	No	4	D+
131	Hampton	0.0 ppb	No	1	B
132	Clinton	0.0 ppb	No	7	C+
133	Clinton	0.0 ppb	No	0	B-
134	Plainville	0.0 ppb	No	3	C+
135	East Granby	0.0 ppb	No	9	F
136	Beacon Falls	0.0 ppb	No	1	A
137	East Windsor	0.0 ppb	No	6	C+
138	Ansonia	0.0 ppb	No	6	B-
139	East Granby	0.0 ppb	No	3	C+
140	East Lyme	0.0 ppb	No	6	C
141	Griswold	0.0 ppb	No	53	F
142	Barkhamsted	0.0 ppb	No	12	C
143	Barkhamsted	0.0 ppb	No	7	A-
144	Avon	0.0 ppb	No	8	C
145	Colchester	0.0 ppb	No	34	D
146	Chester	0.0 ppb	No	10	D
147	Chester	0.0 ppb	No	12	B-
148	Chester	0.0 ppb	No	5	C
149	Old Lyme	0.0 ppb	No	42	D
150	Goshen	0.0 ppb	No	10	C
151	East Hampton	0.0 ppb	No	64	D
152	Woodbury	0.0 ppb	No	18	D+
153	Durham	0.0 ppb	No	46	D
154	Salisbury	0.0 ppb	No	4	B+
155	North Stonington	0.0 ppb	No	19	C
156	Sprague	0.0 ppb	No	0	B+
157	Norfolk	0.0 ppb	No	3	A-
158	Pomfret	0.0 ppb	No	66	D

FAQ

Frequently asked questions about lead in Connecticut

Is lead in Connecticut tap water a concern?

Yes — 3 of 158 cities with lead data exceed the EPA action level of 15 ppb. The state average is 1.5 ppb. Even below the action level, lead poses health risks especially for children and pregnant women. If your home was built before 1986, consider testing your tap water directly.

How can I reduce lead exposure from Connecticut tap water?

Use an NSF 53-certified water filter, which is specifically certified to reduce lead. Run your cold tap for 30 seconds before drinking or cooking, especially if water has been sitting in pipes for hours. Never use hot tap water for cooking or making baby formula, as heat increases lead leaching from pipes.

Which Connecticut cities have the highest lead levels?

The cities with the highest 90th percentile lead levels in Connecticut are: Carroll (48.0 ppb), Carroll (48.0 ppb), Bow (44.0 ppb), Coventry (8.5 ppb), Lower Sipaulovi, Lower Mishongnovi (5.0 ppb). See the full ranked table above.

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