WaterVerge

Connecticut Water Quality Rankings

158 cities ranked · Data from EPA SDWIS

58.8
State avg score
158
Cities ranked
28%
A or B grade
47%
D or F grade
134
Health violations
102
PFAS detected

Connecticut water quality overview

Connecticut's drinking water quality is below average overall, with a state average score of 58.8 out of 100 — 15.4 points below the national average of 74.2. The median city score is 56.6, reflecting how water quality is distributed across the state's 158 ranked cities. 47% of cities scored a D or F, pointing to significant water quality challenges across much of the state. 44 cities did earn an A or B grade, showing that strong systems do exist. PFAS "forever chemicals" were detected in 102 of 158 cities (65%). Of those, 94 cities exceed the 2024 EPA maximum contaminant levels — a health concern requiring action. 3 cities have lead levels exceeding the EPA action level of 15 ppb, typically a sign of aging lead service lines or lead solder in older plumbing. Residents in these areas should use an NSF 53-certified filter. 134 cities have recorded health-based violations with the EPA — meaning contaminant levels exceeded safe limits or required testing was missed. Use the table below to find your city's specific record.

How Connecticut cities scored

21%
25%
21%
27%
A
11
7%
Excellent
B
33
21%
Good
C
39
25%
Fair
D
33
21%
Poor
F
42
27%
Failing

Score distribution by range

46 23 0
21
46
21
26
15
25
4
0–9
10–19
20–29
30–39
40–49
50–59
60–69
70–79
80–89
90–100

State vs national average

C-
Connecticut
58.8/100
B-
National avg
74.2/100
▼ 15.4 pts below national average

Water quality across Connecticut

Each dot is a city, colored by grade. Size reflects population served. Click any city to view its full report.

Connecticut city water quality map

All 158 cities in Connecticut

# City Grade Score Score Population Violations Issues
1 Plymouth
A+
95.6
4K 43 Unresolved
2 Uncasville
A
92.2
32K 3 Health Unresolved
3 Beacon Falls
A
92.1
23K 10 Health Unresolved
4 Sheffield
A
91.2
987 5 Health Unresolved
5 Barkhamsted
A-
89.7
8K 61 Health Unresolved
6 Sheffield
A-
89.3
1K 13 Health Unresolved
7 Berlin
A-
87
391K 3 Unresolved
8 Berlin
A-
87
391K 3 Unresolved
9 Berlin
A-
87
391K 3 Unresolved
10 Berlin
A-
87
391K 3 Unresolved
11 Norfolk
A-
86.3
913 10 Health Unresolved
12 Harwinton
B+
84.7
41K 51 Health Unresolved
13 Ansonia
B+
84.4
419K 32 PFAS Unresolved
14 Ansonia
B+
84.4
419K 32 PFAS Unresolved
15 Ansonia
B+
84.4
419K 32 PFAS Unresolved
16 Ansonia
B+
84.4
419K 32 PFAS Unresolved
17 Ansonia
B+
84.4
419K 32 PFAS Unresolved
18 Ansonia
B+
84.4
419K 32 PFAS Unresolved
19 Salisbury
B+
84.2
3K 43 Health Unresolved
20 North Canaan
B+
83.9
1K 7 Unresolved
21 Berlin
B+
83.6
464K 21 Unresolved
22 Lewisboro (T)
B+
83.6
656 104 Health Unresolved
23 Sprague
B+
83.4
1K 60 Unresolved
24 Ansonia
B+
82.4
432K 41 PFAS Unresolved
25 Ansonia
B+
82.4
432K 41 PFAS Unresolved
26 Windham
B+
80.8
22K 50 Health Unresolved
27 Berlin
B+
80.2
442K 18 Health PFAS Unresolved
28 Ansonia
B+
80.2
420K 45 PFAS Unresolved
29 Ansonia
B+
80.2
420K 45 PFAS Unresolved
30 Hampton
B
78.9
34K 11 Health PFAS Unresolved
31 Franklin
B
78.8
36K 29 Health PFAS Unresolved
32 Franklin
B
78.8
36K 29 Health PFAS Unresolved
33 Mashantucket
B
78
26K 47 Health PFAS Unresolved
34 Berlin
B
77
391K 11 Health Unresolved
35 East Granby
B
75.4
101K 203 PFAS Unresolved
36 Ansonia
B-
74.8
21K 35 Health PFAS Unresolved
37 Berlin
B-
74.6
446K 97 Health PFAS Unresolved
38 Groton
B-
74.5
12K 88 Health Unresolved
39 Clinton
B-
74.3
34K 288 PFAS Unresolved
40 Chester
B-
73.9
5K 115 Health Unresolved
41 Berlin
B-
73.8
492K 206 PFAS Unresolved
42 Berlin
B-
73.2
81K 55 Unresolved
43 Franklin
B-
70.5
37K 72 Health PFAS Unresolved
44 Hampton
B-
70.3
35K 43 Health PFAS Unresolved
45 Plainville
C+
69.6
33K 214 Health PFAS Unresolved
46 East Granby
C+
69.4
102K 258 Health PFAS Unresolved
47 Ansonia
C+
68.8
477K 85 Health PFAS Unresolved
48 Clinton
C+
68.5
35K 337 Health PFAS Unresolved
49 New London
C+
68.2
44K 158 Unresolved
50 Ansonia
C+
68.1
549K 126 Health PFAS Unresolved
51 Bristol
C+
67.9
85K 158 Health PFAS Unresolved
52 East Windsor
C+
67
21K 212 Health PFAS Unresolved
53 Clinton
C+
66.2
34K 347 Health PFAS Unresolved
54 East Granby
C+
66
17K 106 Health PFAS Unresolved
55 Middlebury
C
64.8
143K 124 Health Unresolved
56 Barkhamsted
C
64.7
8K 218 Health Unresolved
57 Carroll
C
64.5
1K 62 Health Lead Unresolved
58 Chester
C
64.1
5K 276 Health Unresolved
59 Carroll
C
64
2K 64 Health Lead Unresolved
60 Berlin
C
63.4
159K 176 Health PFAS Unresolved
61 North Stonington
C
63.2
2K 267 Health Unresolved
62 Bristol
C
63.1
62K 363 Health PFAS Unresolved
63 Berlin
C
62.5
396K 262 Health Unresolved
64 Goshen
C
62.3
4K 72 Health Unresolved
65 Bristol
C
62.1
59K 245 Health PFAS Unresolved
66 Berlin
C
60.9
544K 228 Health PFAS Unresolved
67 Berlin
C
60.5
544K 236 Health PFAS Unresolved
68 East Lyme
C
60.2
15K 219 Health PFAS Unresolved
69 Avon
C
60.1
6K 122 Health PFAS Unresolved
70 Ansonia
C-
60
456K 127 PFAS Unresolved
71 East Granby
C-
59.6
102K 265 Health PFAS Unresolved
72 Beacon Falls
C-
59
352K 155 Health PFAS Unresolved
73 Beacon Falls
C-
59
352K 155 Health PFAS Unresolved
74 Beacon Falls
C-
59
352K 155 Health PFAS Unresolved
75 Beacon Falls
C-
59
352K 155 Health PFAS Unresolved
76 Beacon Falls
C-
59
352K 155 Health PFAS Unresolved
77 Beacon Falls
C-
57.9
392K 158 Health PFAS Unresolved
78 Beacon Falls
C-
57.8
388K 172 Health PFAS Unresolved
79 East Granby
C-
57.8
153K 315 Health PFAS Unresolved
80 Killingly
C-
56.6
8K 172 Health PFAS Unresolved
81 Killingworth
C-
55.8
837 162 Health Unresolved
82 Middlebury
C-
55.4
125K 154 Health PFAS Unresolved
83 New London
C-
55
46K 307 Health Unresolved
84 Ansonia
D+
54.8
432K 92 Health PFAS Unresolved
85 Berlin
D+
54.4
509K 243 Health PFAS Unresolved
86 Clinton
D+
52.5
34K 567 Health PFAS Unresolved
87 Groton
D+
52.2
50K 123 Health Unresolved
88 Franklin
D+
52
37K 132 Health PFAS Unresolved
89 Middlebury
D+
50
125K 173 Health Unresolved
90 Brookfield
D+
50
5K 791 Health Unresolved
91 Woodbury
D+
50
3K 600 Health Unresolved
92 Ansonia
D
49.4
784K 200 Health PFAS Unresolved
93 Durham
D
49
3K 664 Health Unresolved
94 East Granby
D
48.8
122K 428 Health PFAS Unresolved
95 Beacon Falls
D
48.2
434K 234 Health PFAS Unresolved
96 Ansonia
D
48
515K 180 Health PFAS Unresolved
97 Harwinton
D
48
38K 784 Health Unresolved
98 Lower Sipaulovi, Lower Mishongnovi
D
48
609 293 Health Unresolved
99 Lower Sipaulovi, Lower Mishongnovi
D
48
609 293 Health Unresolved
100 Berlin
D
47.9
477K 259 Health Unresolved
101 Chester
D
47.7
5K 231 Health Unresolved
102 Beacon Falls
D
47.5
453K 237 Health PFAS Unresolved
103 Putnam
D
47.4
8K 179 Health PFAS Unresolved
104 Bow
D
47.4
808 112 Health Lead Unresolved
105 Ashford
D
47
1K 588 Health Unresolved
106 Pomfret
D
47
850 443 Health Unresolved
107 East Haddam
D
47
673 306 Health Unresolved
108 Cromwell
D
46.8
54K 302 Health Unresolved
109 Clinton
D
46.8
35K 482 Health PFAS Unresolved
110 Kent
D
46.7
2K 242 Health Unresolved
111 Old Lyme
D
46
5K 778 Health Unresolved
112 Plainfield
D
46
5K 448 Health Unresolved
113 East Hampton
D
46
3K 889 Health Unresolved
114 Marlborough
D
46
2K 312 Health Unresolved
115 Beacon Falls
D
45.4
463K 245 Health PFAS Unresolved
116 Colchester
D
45
6K 663 Health PFAS Unresolved
117 Cromwell
F
44.8
41K 257 Health Unresolved
118 Berlin
F
44.4
391K 262 Health Unresolved
119 Middlebury
F
44
9K 436 Health PFAS Unresolved
120 Bethel
F
43
72K 313 Health PFAS Unresolved
121 Hebron
F
43
3K 376 Health Unresolved
122 Willington
F
43
2K 370 Health Unresolved
123 Beacon Falls
F
42.6
352K 229 Health PFAS Unresolved
124 Beacon Falls
F
42.5
532K 269 Health PFAS Unresolved
125 Griswold
F
42.4
8K 361 Health Unresolved
126 Bethel
F
42
79K 1590 Health PFAS Unresolved
127 Sharon
F
42
865 154 Health Unresolved
128 Franklin
F
41.9
38K 457 Health PFAS Unresolved
129 Beacon Falls
F
41.6
352K 1850 Health PFAS Unresolved
130 Beacon Falls
F
41.6
352K 429 Health PFAS Unresolved
131 Beacon Falls
F
41.5
553K 232 Health PFAS Unresolved
132 Groton
F
41.5
48K 305 Health Unresolved
133 Berlin
F
41
553K 419 Health PFAS Unresolved
134 Washington
F
41
1K 335 Health Unresolved
135 Hopkinton
F
41
769 266 Health Unresolved
136 Harwinton
F
40.4
41K 340 Health Unresolved
137 Putnam
F
40
9K 735 Health PFAS Unresolved
138 Berlin
F
39.9
508K 524 Health PFAS Unresolved
139 Beacon Falls
F
39.8
423K 500 Health PFAS Unresolved
140 East Granby
F
39.6
120K 573 Health PFAS Unresolved
141 Harwinton
F
39.4
46K 212 Health PFAS Unresolved
142 Coventry
F
39
3K 235 Health Unresolved
143 Ansonia
F
38.7
419K 234 Health PFAS Unresolved
144 Brookfield
F
38.5
17K 998 Health PFAS Unresolved
145 East Granby
F
38.4
28K 436 Health PFAS Unresolved
146 Killingly
F
37.5
8K 407 Health PFAS Unresolved
147 Beacon Falls
F
36.6
525K 257 Health PFAS Unresolved
148 East Granby
F
36.4
103K 324 Health PFAS Unresolved
149 Franklin
F
35.9
62K 1243 Health PFAS Unresolved
150 Beacon Falls
F
35.6
361K 484 Health PFAS Unresolved
151 Beacon Falls
F
35.6
352K 285 Health PFAS Unresolved
152 Bethel
F
35
74K 860 Health PFAS Unresolved
153 Putnam
F
35
8K 748 Health PFAS Unresolved
154 Ansonia
F
34.5
573K 663 Health PFAS Unresolved
155 Ansonia
F
34.5
520K 577 Health PFAS Unresolved
156 Franklin
F
33.8
43K 278 Health PFAS Unresolved
157 Ansonia
F
33.5
591K 555 Health PFAS Unresolved
158 East Granby
F
33.4
153K 811 Health PFAS Unresolved