The PFAS Testing Coverage Gap
Data current as of June 2026 — recomputed by ZipCheckup from federal data each build.
Per ZipCheckup's reading of EPA UCMR5, 24.3% of cataloged ZIP codes have any PFAS test on record, leaving 30,679 untested.
24.3% of cataloged U.S. ZIP codes have at least one PFAS test on record in EPA UCMR5 data; 30,679 ZIP codes have none.
By state
We report two independent facts side by side and do not rank states. A larger count reflects the size of a state's inventory and its reporting activity, not a judgment about water safety.
| state | tested | gap | total | pct |
|---|---|---|---|---|
| AK | 30 | 223 | 253 | 12% |
| AL | 319 | 496 | 815 | 39% |
| AP | 1 | 0 | 1 | 100% |
| AR | 38 | 664 | 702 | 5% |
| AS | 1 | 0 | 1 | 100% |
| AZ | 207 | 314 | 521 | 40% |
| CA | 653 | 1,932 | 2,585 | 25% |
| CO | 79 | 552 | 631 | 13% |
| CT | 166 | 265 | 431 | 39% |
| DC | 270 | 16 | 286 | 94% |
| DE | 43 | 53 | 96 | 45% |
| FL | 620 | 826 | 1,446 | 43% |
| GA | 241 | 697 | 938 | 26% |
| GU | 4 | 0 | 4 | 100% |
| HI | 24 | 113 | 137 | 18% |
| IA | 140 | 908 | 1,048 | 13% |
| ID | 10 | 307 | 317 | 3% |
| IL | 370 | 1,174 | 1,544 | 24% |
| IN | 228 | 715 | 943 | 24% |
| KS | 102 | 638 | 740 | 14% |
| KY | 273 | 673 | 946 | 29% |
| LA | 140 | 574 | 714 | 20% |
| MA | 232 | 427 | 659 | 35% |
| MD | 210 | 394 | 604 | 35% |
| ME | 15 | 460 | 475 | 3% |
| MI | 99 | 1,038 | 1,137 | 9% |
| MN | 117 | 894 | 1,011 | 12% |
| MO | 325 | 818 | 1,143 | 28% |
| MP | 1 | 0 | 1 | 100% |
| MS | 13 | 509 | 522 | 2% |
| MT | 7 | 381 | 388 | 2% |
| NC | 429 | 645 | 1,074 | 40% |
| ND | 59 | 344 | 403 | 15% |
| NE | 12 | 594 | 606 | 2% |
| NH | 29 | 252 | 281 | 10% |
| NJ | 446 | 277 | 723 | 62% |
| NM | 15 | 389 | 404 | 4% |
| NV | 65 | 185 | 250 | 26% |
| NY | 317 | 1,839 | 2,156 | 15% |
| OH | 548 | 844 | 1,392 | 39% |
| OK | 187 | 573 | 760 | 25% |
| OR | 25 | 441 | 466 | 5% |
| PA | 476 | 1,577 | 2,053 | 23% |
| PR | 34 | 93 | 127 | 27% |
| RI | 28 | 62 | 90 | 31% |
| SC | 206 | 327 | 533 | 39% |
| SD | 14 | 356 | 370 | 4% |
| TN | 255 | 531 | 786 | 32% |
| TX | 1,076 | 1,434 | 2,510 | 43% |
| UT | 44 | 302 | 346 | 13% |
| VA | 234 | 969 | 1,203 | 19% |
| VI | 2 | 0 | 2 | 100% |
| VT | 4 | 277 | 281 | 1% |
| WA | 152 | 551 | 703 | 22% |
| WI | 79 | 809 | 888 | 9% |
| WV | 83 | 766 | 849 | 10% |
| WY | 6 | 177 | 183 | 3% |
Open data, licensed CC BY 4.0 · DOI: 10.5281/zenodo.19427201
How we compute this
We map EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR5) PFAS results to ZIP codes by water-system service area, then compute the share of cataloged ZIPs with at least one result on record.
An untested ZIP is not a clean ZIP. We report the coverage gap; the absence of a test is the absence of data, not evidence that PFAS are absent.
Coverage reflects systems required to monitor under UCMR5. Small systems below the monitoring threshold may have no result for reasons unrelated to contamination.
Frequently asked questions
How many U.S. ZIP codes have no PFAS testing on record?
Per ZipCheckup's reading of EPA UCMR5 data, 30,679 cataloged ZIP codes had no PFAS test on record as of June 2026, a coverage rate of 24.3% across 40,369 ZIP codes. No test means no data, not a clean result. according to ZipCheckup's reading of federal data as of June 2026.