PFAS in US drinking water, state by state
11.4% of the 9235 US public water systems that reported a full set of results in the EPA’s UCMR5 monitoring (1056 of 9235) averaged PFOA or PFOS above the EPA’s 4 ppt limit (2023-2025), using EPA’s own sampling-location average method. Pick your state for its systems, the most-affected utilities, and how to check your own ZIP.
Check what your specific utility reported for YOUR ZIP code, and the exact filter that handles it: Check your water by ZIP →
All 50 states + DC
| State | Systems with full results | Averaged PFOA/PFOS over 4 ppt |
|---|---|---|
| New Jersey | 247 | 44.1% |
| Connecticut | 62 | 43.5% |
| Delaware | 36 | 33.3% |
| Florida | 380 | 32.4% |
| South Carolina | 134 | 31.3% |
| Massachusetts | 251 | 26.7% |
| Pennsylvania | 358 | 24.9% |
| North Carolina | 258 | 24.4% |
| Alabama | 275 | 19.3% |
| California | 638 | 18.7% |
| Maryland | 77 | 18.2% |
| New Hampshire | 48 | 16.7% |
| Arizona | 139 | 15.8% |
| West Virginia | 92 | 12.0% |
| Georgia | 241 | 11.2% |
| Ohio | 311 | 10.0% |
| New York | 304 | 9.9% |
| Wisconsin | 182 | 9.9% |
| Oregon | 117 | 8.5% |
| Washington | 227 | 8.4% |
| Virginia | 153 | 7.8% |
| Nevada | 47 | 6.4% |
| Tennessee | 240 | 6.2% |
| Nebraska | 48 | 6.2% |
| Minnesota | 177 | 5.6% |
| Maine | 36 | 5.6% |
| Oklahoma | 134 | 5.2% |
| Kentucky | 206 | 4.4% |
| Idaho | 55 | 3.6% |
| Illinois | 443 | 2.9% |
| Indiana | 218 | 2.8% |
| Colorado | 142 | 2.8% |
| Texas | 972 | 2.5% |
| Missouri | 208 | 2.4% |
| Kansas | 90 | 2.2% |
| South Dakota | 46 | 2.2% |
| Mississippi | 212 | 1.9% |
| Michigan | 300 | 1.7% |
| Utah | 121 | 1.7% |
| New Mexico | 64 | 1.6% |
| Arkansas | 148 | 0.0% |
| Hawaii | 41 | 0.0% |
| Iowa | 133 | 0.0% |
| Louisiana | 241 | 0.0% |
| Montana | 39 | 0.0% |
| North Dakota | 35 | 0.0% |
| Vermont | 32 | 0.0% |
| Alaska | 23 | limited data |
| District of Columbia | 3 | limited data |
| Rhode Island | 27 | limited data |
| Wyoming | 29 | limited data |
Rates are over the water systems that reported a FULL set of UCMR5 results in this state (the only ones EPA’s method can average) — not all systems, and not population. A state that tested more systems can show more detections simply because it looked harder. These are the systems’ own EPA UCMR5 monitoring results — “reported above the limit,” not “in violation.” The EPA limit (4 ppt for PFOA and for PFOS) is a running annual average, so a system counts here when the AVERAGE of a full set of results at one of its sampling locations is above the limit — EPA’s own method. That is an occurrence flag, not a compliance finding: real compliance is determined from quarterly samples reported to the state. Enforcement phases in through 2029-2031.
Sources: EPA UCMR5 occurrence data, Feb 2026 release (~95% complete; final reporting 2026) (2026-06), public domain; beyond-PFAS: EPA Six-Year Review (SYR4, compliance monitoring 2012-2019) + current state Drinking Water Watch (CA, FL). Computed by scripts/build_state_water_data.py. Built 2026-07-25. Every figure is traceable to the committed EPA data.