Lead Contamination

Lead in Connecticut Drinking Water

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

129

Cities Tested

Exceeds Limit

% Exceeds Limit

1.3 ppb

State Avg

▼ 0% vs national

vs National

105

Health Violations

Analysis

Lead in Connecticut: what the data shows

Connecticut has 129 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 1.3 ppb, compared to 3.3 ppb nationally — better than the national average. 2 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

2 of 129 cities

← = Exactly at national rate

National avg

352 of 15325 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	9	C
2	Carroll	48.0 ppb	Yes	10	C
3	Lower Sipaulovi, Lower Mishongnovi	5.0 ppb	No	63	D
4	Lower Sipaulovi, Lower Mishongnovi	5.0 ppb	No	63	D
5	Lewisboro (T)	4.0 ppb	No	3	B+
6	Washington	3.7 ppb	No	31	F
7	Stonington	3.0 ppb	No	6	B
8	Guilford	2.8 ppb	No	20	D
9	Putnam	2.8 ppb	No	19	D
10	Thomaston	2.8 ppb	No	0	A+
11	Woodstock	2.8 ppb	No	120	F
12	New Fairfield	2.8 ppb	No	56	D+
13	Killingworth	2.7 ppb	No	35	C-
14	Uncasville	2.6 ppb	No	1	A
15	Montville	2.5 ppb	No	143	F
16	Danbury	2.4 ppb	No	59	F
17	Bethel	2.4 ppb	No	25	F
18	Newington	2.2 ppb	No	1	D
19	New Britain	2.2 ppb	No	0	B-
20	Berlin	2.2 ppb	No	6	F
21	Watertown	2.2 ppb	No	11	D+
22	Plainfield	2.0 ppb	No	37	D
23	New Milford	2.0 ppb	No	85	F
24	Southbury	1.8 ppb	No	15	D
25	Kent	1.6 ppb	No	30	D
26	North Canaan	1.3 ppb	No	0	B+
27	Hebron	1.1 ppb	No	21	F
28	Sheffield	1.1 ppb	No	3	A
29	Mashantucket	1.0 ppb	No	7	B
30	Sharon	0.8 ppb	No	9	F
31	Willington	0.6 ppb	No	41	F
32	Brooklyn	0.5 ppb	No	14	C-
33	Killingly	0.5 ppb	No	32	F
34	Ansonia	0.0 ppb	No	0	B+
35	Bethany	0.0 ppb	No	4	C-
36	Branford	0.0 ppb	No	0	A-
37	Cheshire	0.0 ppb	No	28	F
38	Derby	0.0 ppb	No	0	B+
39	East Haven	0.0 ppb	No	0	A-
40	Hamden	0.0 ppb	No	0	A-
41	Milford	0.0 ppb	No	0	B+
42	New Haven	0.0 ppb	No	0	A-
43	North Branford	0.0 ppb	No	25	F
44	North Haven	0.0 ppb	No	0	C-
45	Orange	0.0 ppb	No	0	B+
46	Prospect	0.0 ppb	No	1	C+
47	Seymour	0.0 ppb	No	2	D+
48	West Haven	0.0 ppb	No	0	B+
49	Woodbridge	0.0 ppb	No	0	B+
50	East Hartford	0.0 ppb	No	0	A-
51	Farmington	0.0 ppb	No	3	D+
52	Glastonbury	0.0 ppb	No	4	B+
53	Hartford	0.0 ppb	No	0	A-
54	Rocky Hill	0.0 ppb	No	1	B
55	South Windsor	0.0 ppb	No	5	C
56	West Hartford	0.0 ppb	No	0	B+
57	Wethersfield	0.0 ppb	No	0	A-
58	Windsor	0.0 ppb	No	0	A-
59	Windsor Locks	0.0 ppb	No	0	B-
60	Beacon Falls	0.0 ppb	No	3	C-
61	Bridgeport	0.0 ppb	No	2	C-
62	Darien	0.0 ppb	No	7	F
63	Fairfield	0.0 ppb	No	2	C-
64	New Canaan	0.0 ppb	No	7	F
65	Redding	0.0 ppb	No	2	C-
66	Shelton	0.0 ppb	No	2	C-
67	Stamford	0.0 ppb	No	4	F
68	Stratford	0.0 ppb	No	2	C-
69	Westport	0.0 ppb	No	2	C-
70	Waterbury	0.0 ppb	No	14	C
71	East Windsor	0.0 ppb	No	25	F
72	Ellington	0.0 ppb	No	0	B
73	Suffield	0.0 ppb	No	1	C+
74	Plainville	0.0 ppb	No	4	C
75	Meriden	0.0 ppb	No	4	C+
76	Bristol	0.0 ppb	No	4	C+
77	Plymouth	0.0 ppb	No	18	C
78	Manchester	0.0 ppb	No	8	C
79	Waterford	0.0 ppb	No	16	C-
80	Middletown	0.0 ppb	No	11	D
81	Southington	0.0 ppb	No	12	F
82	Wilton	0.0 ppb	No	7	D
83	Norwalk	0.0 ppb	No	7	D
84	Harwinton	0.0 ppb	No	5	D
85	Torrington	0.0 ppb	No	3	B+
86	Wallingford	0.0 ppb	No	4	D
87	Bozrah	0.0 ppb	No	13	B
88	Franklin	0.0 ppb	No	13	B
89	Lisbon	0.0 ppb	No	27	F
90	Norwich	0.0 ppb	No	19	B-
91	Preston	0.0 ppb	No	23	D+
92	Hampton	0.0 ppb	No	1	B
93	Clinton	0.0 ppb	No	4	D+
94	Madison	0.0 ppb	No	18	C+
95	Old Saybrook	0.0 ppb	No	0	B-
96	Westbrook	0.0 ppb	No	7	C+
97	Groton	0.0 ppb	No	17	F
98	New London	0.0 ppb	No	0	C+
99	Naugatuck	0.0 ppb	No	1	A
100	Mansfield	0.0 ppb	No	85	F
101	Enfield	0.0 ppb	No	9	D
102	Somers	0.0 ppb	No	6	C+
103	East Lyme	0.0 ppb	No	6	C
104	Avon	0.0 ppb	No	3	C+
105	Cromwell	0.0 ppb	No	1	B
106	Oxford	0.0 ppb	No	6	B
107	Barkhamsted	0.0 ppb	No	12	C
108	Winchester	0.0 ppb	No	7	A-
109	Griswold	0.0 ppb	No	53	F
110	Ledyard	0.0 ppb	No	23	D+
111	Portland	0.0 ppb	No	9	C
112	Deep River	0.0 ppb	No	5	C
113	Colchester	0.0 ppb	No	34	D
114	Newtown	0.0 ppb	No	46	F
115	Wolcott	0.0 ppb	No	18	F
116	Granby	0.0 ppb	No	3	C+
117	Durham	0.0 ppb	No	46	D
118	Tolland	0.0 ppb	No	24	F
119	North Stonington	0.0 ppb	No	19	C
120	East Hampton	0.0 ppb	No	64	D
121	Brookfield	0.0 ppb	No	135	F
122	Sprague	0.0 ppb	No	0	B+
123	Woodbury	0.0 ppb	No	18	D+
124	Norfolk	0.0 ppb	No	3	A-
125	Pomfret	0.0 ppb	No	66	D
126	Stafford	0.0 ppb	No	12	C
127	Greenwich	0.0 ppb	No	5	F
128	Old Lyme	0.0 ppb	No	42	D
129	Salisbury	0.0 ppb	No	4	A-

FAQ

Frequently asked questions about lead in Connecticut

Is lead in Connecticut tap water a concern?

Yes — 2 of 129 cities with lead data exceed the EPA action level of 15 ppb. The state average is 1.3 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), Lower Sipaulovi, Lower Mishongnovi (5.0 ppb), Lower Sipaulovi, Lower Mishongnovi (5.0 ppb), Lewisboro (T) (4.0 ppb). See the full ranked table above.

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