PFAS Contamination

PFAS in Connecticut Drinking Water

Ranked by number of PFAS compounds detected · Data from EPA SDWIS & UCMR

128

Cities Tested

Exceeds Limit

73%

% Exceeds Limit

4.5 compounds

State Avg

▲ 52% vs national

vs National

134

Health Violations

Analysis

PFAS in Connecticut: what the data shows

Connecticut has 128 cities with PFAS monitoring data from the EPA's UCMR 5 program. PFAS ("forever chemicals") were detected in 102 of those cities (80%), with many cities exceeding the EPA's 2024 maximum contaminant levels of 4 ppt. The state average is worse than the national average. 94 cities exceed the EPA MCL for at least one PFAS compound. PFAS are linked to cancer, immune system disruption, and developmental issues. The 2024 EPA rule requires water systems exceeding the MCL to notify customers and reduce levels by 2029. PFAS data comes from the EPA's Unregulated Contaminant Monitoring Rule 5 (UCMR 5), which required large water systems to test for 29 PFAS compounds between 2023–2025. Not all systems have completed testing — cities without data may still have PFAS present.

Comparison

Cities exceeding EPA MCL (4 ppt each)

Connecticut

73%

94 of 128 cities

→ ▲ 52% above national rate (worse)

National avg

21%

1662 of 7853 cities

City Map

PFAS data across Connecticut

Each dot is a city, colored by overall water quality grade. PFAS-tested cities are shown; those exceeding the 4 ppt EPA MCL appear in red. Size reflects population served.

Worst Offenders

Top 10 cities by pfas level in Connecticut

Highest PFAS levels (compounds)

All Cities

All Connecticut cities ranked by pfas level

#	City	Level	Exceeds?	Violations	Grade
1	Ansonia	9 compounds	Yes	12	F
2	Berlin	9 compounds	Yes	5	C
3	Berlin	9 compounds	Yes	8	C
4	Ansonia	9 compounds	Yes	28	F
5	Berlin	9 compounds	Yes	40	F
6	East Granby	9 compounds	Yes	5	C-
7	Ansonia	8 compounds	Yes	18	F
8	Berlin	8 compounds	Yes	3	D+
9	Berlin	8 compounds	Yes	0	B-
10	Beacon Falls	8 compounds	Yes	7	D
11	Beacon Falls	8 compounds	Yes	7	D
12	Beacon Falls	8 compounds	Yes	7	D
13	Beacon Falls	8 compounds	Yes	27	F
14	Beacon Falls	8 compounds	Yes	2	C-
15	Beacon Falls	8 compounds	Yes	46	F
16	East Granby	8 compounds	Yes	85	F
17	East Granby	8 compounds	Yes	9	D
18	East Granby	8 compounds	Yes	25	F
19	East Granby	8 compounds	Yes	24	F
20	East Granby	8 compounds	Yes	12	C-
21	East Granby	8 compounds	Yes	1	C+
22	East Granby	8 compounds	Yes	0	B
23	Ansonia	7 compounds	Yes	2	D
24	Beacon Falls	7 compounds	Yes	4	F
25	Berlin	7 compounds	Yes	6	F
26	Beacon Falls	7 compounds	Yes	7	F
27	Beacon Falls	7 compounds	Yes	5	F
28	Ansonia	7 compounds	Yes	4	D
29	Ansonia	7 compounds	Yes	4	C+
30	Berlin	7 compounds	Yes	4	B+
31	Beacon Falls	7 compounds	Yes	3	C-
32	Beacon Falls	7 compounds	Yes	7	F
33	Beacon Falls	7 compounds	Yes	2	F
34	Beacon Falls	7 compounds	Yes	2	F
35	Beacon Falls	7 compounds	Yes	2	F
36	Beacon Falls	7 compounds	Yes	2	C-
37	Beacon Falls	7 compounds	Yes	2	C-
38	Beacon Falls	7 compounds	Yes	2	C-
39	Beacon Falls	7 compounds	Yes	2	C-
40	Beacon Falls	7 compounds	Yes	2	C-
41	Berlin	7 compounds	Yes	4	C
42	Bristol	7 compounds	Yes	4	C+
43	Clinton	7 compounds	Yes	18	C+
44	Clinton	7 compounds	Yes	20	D
45	Clinton	7 compounds	Yes	4	D+
46	Clinton	7 compounds	Yes	7	C+
47	Clinton	7 compounds	Yes	0	B-
48	Plainville	7 compounds	Yes	3	C+
49	East Granby	7 compounds	Yes	9	F
50	Ansonia	6 compounds	Yes	4	D+
51	Ansonia	6 compounds	Yes	0	B+
52	Ansonia	6 compounds	Yes	0	B+
53	Franklin	6 compounds	Yes	27	F
54	Hampton	6 compounds	Yes	12	B-
55	Hampton	6 compounds	Yes	1	B
56	Mashantucket	6 compounds	Yes	7	B
57	East Windsor	6 compounds	Yes	6	C+
58	Ansonia	6 compounds	Yes	6	B-
59	East Lyme	6 compounds	Yes	6	C
60	Ansonia	5 compounds	Yes	0	C-
61	Bethel	5 compounds	Yes	135	F
62	Franklin	5 compounds	Yes	143	F
63	Franklin	5 compounds	Yes	32	F
64	Franklin	5 compounds	Yes	19	B-
65	Franklin	5 compounds	Yes	23	D+
66	Franklin	5 compounds	Yes	13	B
67	Franklin	5 compounds	Yes	13	B
68	Brookfield	5 compounds	Yes	85	F
69	East Granby	5 compounds	Yes	3	C+
70	Putnam	5 compounds	Yes	72	F
71	Putnam	5 compounds	Yes	120	F
72	Putnam	5 compounds	Yes	19	D
73	Ansonia	4 compounds	Yes	1	C+
74	Ansonia	4 compounds	Yes	0	B+
75	Ansonia	4 compounds	Yes	0	B+
76	Ansonia	4 compounds	Yes	25	F
77	Ansonia	4 compounds	Yes	0	B+
78	Ansonia	4 compounds	Yes	0	B+
79	Ansonia	4 compounds	Yes	0	B+
80	Ansonia	4 compounds	Yes	0	B+
81	Ansonia	4 compounds	Yes	0	B+
82	Ansonia	4 compounds	Yes	0	B+
83	Bethel	4 compounds	Yes	59	F
84	Bethel	4 compounds	Yes	25	F
85	Killingly	4 compounds	Yes	32	F
86	Killingly	4 compounds	Yes	14	C-
87	Bristol	3 compounds	Yes	9	C
88	Cromwell	3 compounds	No	11	D
89	Berlin	2 compounds	Yes	1	B-
90	Berlin	2 compounds	No	9	C
91	Middlebury	2 compounds	Yes	18	C-
92	Bristol	2 compounds	Yes	18	C
93	Harwinton	2 compounds	Yes	8	F
94	Middlebury	2 compounds	Yes	15	F
95	Avon	2 compounds	Yes	8	C
96	Colchester	2 compounds	Yes	34	D
97	Berlin	1 compounds	No	1	D
98	Groton	1 compounds	No	23	D+
99	Groton	1 compounds	No	17	F
100	Windham	1 compounds	No	11	B+
101	Groton	1 compounds	No	6	B-
102	Griswold	1 compounds	No	53	F
103	Berlin	0 compounds	No	0	B+
104	Berlin	0 compounds	No	33	F
105	Berlin	0 compounds	No	1	B
106	Berlin	0 compounds	No	0	A-
107	Berlin	0 compounds	No	0	A-
108	Berlin	0 compounds	No	0	A-
109	Berlin	0 compounds	No	0	A-
110	Middlebury	0 compounds	No	14	C
111	Middlebury	0 compounds	No	11	D+
112	Berlin	0 compounds	No	0	B-
113	New London	0 compounds	No	16	C-
114	New London	0 compounds	No	0	C+
115	Harwinton	0 compounds	No	19	F
116	Cromwell	0 compounds	No	25	F
117	Harwinton	0 compounds	No	3	B+
118	Harwinton	0 compounds	No	5	D
119	Uncasville	0 compounds	No	1	A
120	Beacon Falls	0 compounds	No	1	A
121	Barkhamsted	0 compounds	No	12	C
122	Barkhamsted	0 compounds	No	7	A-
123	Chester	0 compounds	No	10	D
124	Chester	0 compounds	No	12	B-
125	Chester	0 compounds	No	5	C
126	Plymouth	0 compounds	No	0	A+
127	Goshen	0 compounds	No	10	C
128	Coventry	0 compounds	No	34	F

FAQ

Frequently asked questions about pfas in Connecticut

Does Connecticut tap water contain PFAS?

PFAS were detected in 102 of 128 Connecticut cities tested under EPA's UCMR 5 program. 94 cities exceed the 2024 EPA MCL of 4 ppt for individual PFAS compounds.

How can I remove PFAS from my drinking water in Connecticut?

Reverse osmosis (RO) systems are the most effective at removing PFAS, typically removing 90%+ of compounds. High-quality activated carbon block filters (NSF 58-certified for RO, or NSF 53 for solid carbon) also provide significant reduction. Standard pitcher filters vary widely in PFAS removal.

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