Contaminant · PFAS
PFBA in drinking water
Perfluorobutanoic acid, one of the most mobile short-chain PFAS and among the most frequently detected in UCMR 5.
highest recorded single-sample basis; sampled 2023–2025. Source: EPA records; Saint Paul Park (MN1820018).
What the rules say
PFBA has no federal limit. The USGS health-based screening level of 6,000 ng/L (from EPA's IRIS reference dose) is shown for scale only.
What EPA's assessment says
EPA's 2022 IRIS assessment for PFBA cites thyroid, liver and developmental effects in animal studies.
Across the country
EPA tested 10,307 water systems for PFBA and found it in 1,935. Half of the systems that found it measured less than 7.2 ppt, and one in ten measured more than 16.0 ppt.
EPA's final UCMR 5 occurrence file contains 66,356 PFBA results from 10,307 systems. 5,463 results were at or above the minimum reporting level, across 1,935 systems. Among detections, the median was 7.2 ppt and the 90th percentile was 16.0 ppt.
0 systems had a result at or above the reference on the page's stated comparison basis. For contaminants with a limit, that basis is the yearly average at the highest sampling location, not the highest single sample.
Systems with the highest recorded PFBA results
| System | State | Population served | Recorded value | Records / periods |
|---|---|---|---|---|
| Saint Paul Park MN1820018 | Minnesota | 5,427 | 1,700 ppt | 2 |
| Oakdale MN1820016 | Minnesota | 30,144 | 1,270 ppt | 7 |
| Iowa-American Wtr Co-Clinton District IA2326048 | Iowa | 24,769 | 648 ppt | 2 |
| Newport MN1820014 | Minnesota | 4,000 | 550 ppt | 4 |
| Woodbury MN1820025 | Minnesota | 82,643 | 386 ppt | 24 |
| Prescott Waterworks WI6480243 | Wisconsin | 4,258 | 280 ppt | 4 |
| Hastings MN1190012 | Minnesota | 23,222 | 380 ppt | 10 |
| Cottage Grove MN1820004 | Minnesota | 42,760 | 220 ppt | 7 |
| South Saint Paul MN1190020 | Minnesota | 20,664 | 168 ppt | 8 |
| Lake Elmo MN1820009 | Minnesota | 10,978 | 140 ppt | 6 |
| Oak Park Heights MN1820020 | Minnesota | 4,776 | 130 ppt | 4 |
| Stillwater MN1820024 | Minnesota | 19,462 | 118 ppt | 15 |
| Il American-Lincoln IL1075030 | Illinois | 15,200 | 233 ppt | 5 |
| Brookhaven National Laboratory NY5111891 | New York | 3,500 | 123 ppt | 2 |
| Airway Heights City of WA5300650 | Washington | 9,489 | 79.2 ppt | 2 |
| Inver Grove Heights MN1190014 | Minnesota | 34,189 | 102 ppt | 2 |
| Ralls County Pwsd 1 MO2024499 | Missouri | 7,662 | 79.9 ppt | 2 |
| North Saint Paul MN1620011 | Minnesota | 13,134 | 85.1 ppt | 10 |
| Municipal Services Commission DE0000634 | Delaware | 5,549 | 147 ppt | 1 |
| Artesian Water Company DE0000552 | Delaware | 231,114 | 79.1 ppt | 21 |
| Galesburg IL0950200 | Illinois | 31,620 | 85.0 ppt | 2 |
| White Bear Township MN1620025 | Minnesota | 11,699 | 74.0 ppt | 10 |
| White Bear Lake MN1620024 | Minnesota | 25,634 | 68.5 ppt | 2 |
| Rosemount MN1190019 | Minnesota | 26,500 | 70.3 ppt | 15 |
| Jericho WD NY2902831 | New York | 58,000 | 67.0 ppt | 11 |
Filters and testing
NSF/ANSI 58 (reverse osmosis); carbon filters vary for short-chain PFAS
A standard number by itself is not a contaminant claim. Check the product's current certification listing and performance data sheet for PFBA or the specific contaminant you want to reduce. A utility-level record is not a test of your own faucet.