South Dakota tap water
0 of 48 South Dakota water systems with full PFAS testing (0%) averaged above a 2024 federal PFAS level at one or more sampling points.
- 461 active community water systems in the EPA file; 41 serve 3,300+ people and have a full PFAS set.
- 57 systems had at least one health-based violation since 2021-10-26.
- 0 systems report a lead 90th percentile above 15 ppb (some results are old; check each system page).
Largest systems
| System | People served | PFAS above a 2024 level? | Health-based violations since 2021-10-26 |
|---|---|---|---|
| Sioux Falls | 216,462 | No | 0 |
| Rapid City | 72,009 | No | 0 |
| Aberdeen | 27,989 | No | 7 |
| Brookings Municipal Utilities | 23,377 | No | 0 |
| Watertown Municipal Utilities | 23,230 | No | 0 |
| Web Water Development Association | 20,750 | No | 0 |
| Mitchell | 15,651 | No | 0 |
| Yankton | 15,411 | No | 0 |
All 2 utilities with a page in South Dakota
- Rapid City 72,009
- Sioux Falls 216,462
Why not "the state's water quality"? You drink from one utility, not a state. Rollups count systems, not people, so one large utility counts the same as a small one. Use the system pages for your actual water.
Not medical or legal advice. UCMR 5 results are screening data, not compliance determinations.
Sources and freshness
Public-water-system facts, violations and lead/copper results: EPA ECHO SDWA download (SDWIS snapshot 2026-10-13). PFAS and lithium results: EPA UCMR 5 final data (sampling 2023–2025). Both are U.S. government works, downloaded 2026-10-26. Numbers are computed by the published method; the same fields are in the open data files.