Contaminant 0400
Disinfectants and Disinfection Byproducts (Stage 2) health-based violation cited in 2021 (contaminant 0400).
PWSID SD4600364 · Purchased / wholesaleMunicipal
499 people served. 3 health-based SDWIS violations recorded in the past 5 years. Last cited 5 years ago.
Disinfectants and Disinfection Byproducts (Stage 2) health-based violation cited in 2021 (contaminant 0400).
Disinfectants and Disinfection Byproducts (Stage 2) health-based violation cited in 2021 (contaminant 0400).
Disinfectants and Disinfection Byproducts (Stage 2) health-based violation cited in 2021 (contaminant 0400).
Health-based violations exceed an MCL or treatment-technique standard. Monitoring violations are reporting failures with no measured exceedance — they tell you the system isn't fully transparent, not that the water is unsafe today.
Treatment technique violation; returned to compliance
Treatment technique violation; returned to compliance
Treatment technique violation; returned to compliance
Brookings County, South Dakota (utility's served county per SDWIS GEOGRAPHIC_AREA — city-level not yet matched): a service population of 34,631. Local disparity score for pm2.5 (fine particulate) sits well below the reference (1). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 1 | well below the reference |
| Ozone | 69 | below the reference |
| Nitrogen dioxide (NO₂) | 82 | below the reference |
| Diesel particulate | 27 | well below the reference |
| Toxic releases (RSEI) | 39 | well below the reference |
| Traffic proximity | 35 | well below the reference |
| Lead-paint risk (pre-1960 housing) | 54 | below the reference |
| Superfund site proximity | 0 | well below the reference |
| RMP-facility proximity | 0 | well below the reference |
| Hazardous-waste site proximity | 36 | well below the reference |
| Underground storage tanks | 63 | below the reference |
| NPDES wastewater proximity | 51 | below the reference |
| Drinking-water non-compliance | 1 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).
Source. EPA Safe Drinking Water Information System · retrieved 2026-05-07. Reporting period 2021-01-01 → 2026-05-07.
What this is not. SDWIS records compliance against federal MCLs — not a direct readout of tap-water concentrations. Active health-based violations are not the same as a current crisis; we link to the EPA record so you can verify return-to-compliance status before forming a conclusion.