The national picture
Water data.
With the context.
Explore what EPA’s drinking-water survey found across the United States. Every share has a denominator. Every snapshot has a date.
A dated monitoring snapshot
The numbers behind the records
These totals cover the full imported UCMR 5 release, including systems without a published detail page.
- Systems with PFAS results
- 10,312
- At least one result for any of the 29 PFAS measured.
- Systems where PFAS was found
- 3,595
- At least one PFAS detection at a reporting level or above.
- Share with PFAS found
- 34.9%
- 3,595 of 10,312 systems with PFAS results.
- Laboratory result records
- 1,992,002
- 30 substances: 29 PFAS and lithium. One sample can produce many result records.
A detection is not the same as exceeding an EPA limit. These are counts of systems and laboratory records, not a percentage of people, households, or taps.
Explore by place
PFAS findings by state & territory
The bar shows systems with a PFAS detection divided by systems with any PFAS result in that location. Small denominators can produce large percentages.
57 locations shown
| State or territory | Any UCMR 5 results | PFAS results | PFAS found | Share with PFAS found |
|---|---|---|---|---|
| Alabama | 308 | 308 | 116 | 37.7% |
| Alaska | 31 | 31 | 9 | 29.0% |
| American Samoa | 1 | 1 | 1 | 100.0% |
| Arizona | 182 | 182 | 61 | 33.5% |
| Arkansas | 172 | 172 | 10 | 5.8% |
| California | 735 | 735 | 248 | 33.7% |
| Colorado | 165 | 165 | 39 | 23.6% |
| Connecticut | 66 | 66 | 42 | 63.6% |
| Delaware | 35 | 35 | 17 | 48.6% |
| District of Columbia | 4 | 4 | 4 | 100.0% |
| Florida | 404 | 404 | 192 | 47.5% |
| Georgia | 254 | 254 | 81 | 31.9% |
| Guam | 4 | 4 | 2 | 50.0% |
| Hawaii | 45 | 45 | 2 | 4.4% |
| Idaho | 64 | 64 | 9 | 14.1% |
| Illinois | 487 | 487 | 128 | 26.3% |
| Indiana | 230 | 230 | 55 | 23.9% |
| Iowa | 153 | 153 | 32 | 20.9% |
| Kansas | 103 | 103 | 35 | 34.0% |
| Kentucky | 232 | 232 | 88 | 37.9% |
| Louisiana | 262 | 262 | 47 | 17.9% |
| Maine | 39 | 39 | 10 | 25.6% |
| Maryland | 85 | 85 | 30 | 35.3% |
| Massachusetts | 266 | 266 | 144 | 54.1% |
| Michigan | 325 | 325 | 45 | 13.8% |
| Minnesota | 201 | 201 | 88 | 43.8% |
| Mississippi | 237 | 237 | 9 | 3.8% |
| Missouri | 246 | 246 | 77 | 31.3% |
| Montana | 46 | 46 | 5 | 10.9% |
| Nebraska | 53 | 53 | 7 | 13.2% |
| Nevada | 59 | 59 | 10 | 16.9% |
| New Hampshire | 48 | 48 | 17 | 35.4% |
| New Jersey | 266 | 265 | 174 | 65.7% |
| New Mexico | 82 | 82 | 11 | 13.4% |
| New York | 336 | 336 | 100 | 29.8% |
| North Carolina | 290 | 290 | 144 | 49.7% |
| North Dakota | 41 | 41 | 7 | 17.1% |
| Northern Mariana Islands | 2 | 2 | 1 | 50.0% |
| Ohio | 348 | 348 | 142 | 40.8% |
| Oklahoma | 168 | 168 | 68 | 40.5% |
| Oregon | 129 | 129 | 18 | 14.0% |
| Pennsylvania | 390 | 390 | 177 | 45.4% |
| Puerto Rico | 99 | 99 | 39 | 39.4% |
| Rhode Island | 29 | 29 | 15 | 51.7% |
| South Carolina | 166 | 166 | 92 | 55.4% |
| South Dakota | 56 | 56 | 7 | 12.5% |
| Tennessee | 277 | 277 | 87 | 31.4% |
| Texas | 1,147 | 1,147 | 619 | 54.0% |
| U.S. Virgin Islands | 3 | 3 | 1 | 33.3% |
| Utah | 131 | 131 | 17 | 13.0% |
| Vermont | 38 | 38 | 3 | 7.9% |
| Virginia | 168 | 168 | 52 | 31.0% |
| Washington | 254 | 254 | 68 | 26.8% |
| West Virginia | 103 | 103 | 34 | 33.0% |
| Wisconsin | 206 | 206 | 53 | 25.7% |
| Wyoming | 34 | 34 | 4 | 11.8% |
| Other EPA location codesCodes: 05, 06, AP | 8 | 8 | 2 | 25.0% |
No matching location. Try a full state name or a two-letter abbreviation.
This table includes all system types with survey results. State overviews count active community water systems, so their totals may differ. Filtering this table does not change the national totals above.
Look inside the survey
Which PFAS were found most often?
The six PFAS reported at the most systems in this release. Detection frequency does not measure toxicity or establish current conditions at a tap.
- PFPeA2,066 of 10,307 systems20.0%
- PFBA1,935 of 10,307 systems18.8%
- PFHxA1,807 of 10,307 systems17.5%
- PFBS1,707 of 10,307 systems16.6%
- PFOS1,352 of 10,307 systems13.1%
- PFOA1,305 of 10,307 systems12.7%
Lithium was measured separately from PFAS: it was detected at 3,773 of 10,313 systems (36.6%). It is included in the full table below.
See all 30 substances and their denominators
| Substance | Systems with results | Systems with a detection | Share with a detection |
|---|---|---|---|
| lithium | 10,313 | 3,773 | 36.6% |
| PFPeA | 10,307 | 2,066 | 20.0% |
| PFBA | 10,307 | 1,935 | 18.8% |
| PFHxA | 10,307 | 1,807 | 17.5% |
| PFBS | 10,307 | 1,707 | 16.6% |
| PFOS | 10,307 | 1,352 | 13.1% |
| PFOA | 10,307 | 1,305 | 12.7% |
| PFHxS | 10,307 | 1,037 | 10.1% |
| PFHpA | 10,307 | 555 | 5.4% |
| 6:2 FTS | 10,307 | 183 | 1.8% |
| PFNA | 10,307 | 83 | 0.8% |
| PFPeS | 10,307 | 50 | 0.5% |
| HFPO-DA | 10,307 | 48 | 0.5% |
| PFDA | 10,307 | 17 | 0.2% |
| 8:2 FTS | 10,307 | 10 | <0.1% |
| PFUnA | 10,307 | 6 | <0.1% |
| PFHpS | 10,307 | 5 | <0.1% |
| NFDHA | 10,307 | 4 | <0.1% |
| PFDoA | 10,307 | 4 | <0.1% |
| 4:2 FTS | 10,307 | 3 | <0.1% |
| ADONA | 10,307 | 3 | <0.1% |
| PFMPA | 10,307 | 2 | <0.1% |
| 9Cl-PF3ONS | 10,307 | 1 | <0.1% |
| NEtFOSAA | 10,309 | 1 | <0.1% |
| NMeFOSAA | 10,309 | 1 | <0.1% |
| PFMBA | 10,307 | 1 | <0.1% |
| 11Cl-PF3OUdS | 10,307 | 0 | 0.0% |
| PFEESA | 10,307 | 0 | 0.0% |
| PFTA | 10,309 | 0 | 0.0% |
| PFTrDA | 10,309 | 0 | 0.0% |
Scope & sources
Read the denominator first.
- What counts as a system?
- One distinct EPA public water system ID with at least one UCMR 5 result in the imported release. The 10,313 total covers the survey records, regardless of which pages this site has published.
- What counts as a PFAS detection?
- At least one reported detection for any monitored PFAS. The denominator includes systems with at least one PFAS result; it does not require results for all 29 PFAS. 1 system has lithium results only and is excluded from that denominator.
- What does “not detected” mean?
- No reported detection at the laboratory’s reporting level. It does not establish a concentration of zero, and the reporting level is not a health threshold. Read the glossary.
- Which dates and locations are used?
- The loaded records span Jan 3, 2023–Jun 17, 2026. The source labels this the final release, August 2026. State assignments come from the EPA registry, 2026Q2 extract; other location codes are retained separately, not reassigned to a state. This database snapshot was prepared Sep 3, 2026.
These unweighted system counts summarize monitoring records. They are not a safety score, a population exposure estimate, a compliance determination, or a live water advisory.