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PFAS in Drinking Water by State

Data from the EPA's UCMR5 monitoring program. 1,687 of 3,490 tested water systems have at least one PFAS compound above the EPA's Maximum Contaminant Levels.

1,687
Systems over EPA limits
3,490
Systems tested (UCMR5)
48%
Over limit rate
5
Regulated PFAS compounds

What this data shows

In 2023, the EPA finalized Maximum Contaminant Levels for five PFAS compounds: PFOA (4 ppt), PFOS (4 ppt), PFHxS (10 ppt), PFNA (10 ppt), and GenX/HFPO-DA (10 ppt). The data below comes from the EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR5), which required large water systems to test for PFAS between 2023 and 2025.

A system is counted as "over limit" if any of these five compounds exceeds its MCL. States are ranked by the total number of affected systems. Note that UCMR5 primarily tested larger systems (serving 3,300+ people), so smaller community systems may have undetected PFAS contamination.

PFAS rankings by state

# State Tested Over Limit Rate
1 California 236 165
70%
2 Florida 191 157
82%
3 New Jersey 174 156
90%
4 Pennsylvania 174 119
68%
5 North Carolina 145 115
79%
6 Massachusetts 143 106
74%
7 Texas 611 103
17%
8 Alabama 118 80
68%
9 South Carolina 90 68
76%
10 Ohio 141 59
42%
11 New York 98 52
53%
12 Georgia 77 42
55%
13 Connecticut 48 38
79%
14 Tennessee 87 37
43%
15 Washington 66 34
52%
16 Kentucky 87 32
37%
17 Illinois 123 27
22%
18 Arizona 57 25
44%
19 Wisconsin 51 23
45%
20 West Virginia 34 21
62%
21 Virginia 54 20
37%
22 Indiana 55 19
35%
23 Minnesota 87 17
20%
24 Maryland 30 16
53%
25 New Hampshire 18 16
89%
26 Colorado 39 14
36%
27 Delaware 17 14
82%
28 Oklahoma 61 13
21%
29 Oregon 18 11
61%
30 Rhode Island 15 10
67%
31 Missouri 71 9
13%
32 Iowa 32 8
25%
33 Louisiana 47 7
15%
34 Michigan 44 7
16%
35 Mississippi 9 7
78%
36 Kansas 34 5
15%
37 Maine 10 5
50%
38 New Mexico 10 5
50%
39 Alaska 9 4
44%
40 Nebraska 7 4
57%
41 Utah 16 4
25%
42 Idaho 8 3
38%
43 Nevada 10 3
30%
44 Montana 5 2
40%
45 South Dakota 7 2
29%
46 Arkansas 11 1
9%
47 Vermont 3 1
33%
48 Wyoming 3 1
33%
49 Hawaii 2 0
0%
50 North Dakota 7 0
0%

About the EPA's PFAS limits

PFAS (per- and polyfluoroalkyl substances) are synthetic chemicals used in nonstick coatings, firefighting foam, and many industrial processes. They are often called "forever chemicals" because they do not break down in the environment. Long-term exposure has been linked to cancer, immune system effects, thyroid disruption, and developmental issues.

The EPA's 2023 MCLs are the first enforceable federal limits for PFAS in drinking water. Water systems have until 2029 to comply. In the meantime, the UCMR5 monitoring data provides the best available picture of which systems are affected.

If your water system has PFAS above the EPA limits, an activated carbon or reverse osmosis filter certified for PFAS removal (NSF/ANSI 53 or 58) can reduce exposure. See our water filter guide for specific recommendations, or compare PFAS-specific filters.

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