Contaminant 0300
Unresolved Long Term 1 Enhanced SWTR violation cited in 2025 (contaminant 0300).
PWSID MO1010508 · Surface waterMunicipal
10,775 people served. 10 health-based SDWIS violations recorded in the past 5 years. 8 remain unresolved. Last cited 1 year ago.
Unresolved Long Term 1 Enhanced SWTR violation cited in 2025 (contaminant 0300).
Unresolved Disinfectants and Disinfection Byproducts (Stage 2) violation cited in 2024 (contaminant 1009).
Unresolved Disinfectants and Disinfection Byproducts (Stage 2) violation cited in 2024 (contaminant 1009).
Unresolved Disinfectants and Disinfection Byproducts (Stage 2) violation cited in 2024 (contaminant 1008).
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
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded
Maximum contaminant level exceeded; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled
Failure to monitor as scheduled; returned to compliance
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded
Maximum contaminant level exceeded; returned to compliance
OTHER; returned to compliance
OTHER; returned to compliance
OTHER; returned to compliance
OTHER; returned to compliance
OTHER; returned to compliance
OTHER; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled
Failure to monitor as scheduled
OTHER; returned to compliance
OTHER; returned to compliance
Treatment technique violation; returned to compliance
Treatment technique violation; returned to compliance
Treatment technique violation; returned to compliance
Maryville, Missouri (Census place; block-group disparity scores aggregated by centroid containment): a service population of 10,691. Local disparity score for pm2.5 (fine particulate) sits well below the reference (42). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 42 | well below the reference |
| Ozone | 68 | below the reference |
| Nitrogen dioxide (NO₂) | 78 | below the reference |
| Diesel particulate | 34 | well below the reference |
| Toxic releases (RSEI) | 23 | well below the reference |
| Traffic proximity | 34 | well below the reference |
| Lead-paint risk (pre-1960 housing) | 89 | below the reference |
| Superfund site proximity | 0 | well below the reference |
| RMP-facility proximity | 145 | moderately above the reference |
| Hazardous-waste site proximity | 0 | well below the reference |
| Underground storage tanks | 115 | moderately above the reference |
| NPDES wastewater proximity | 22 | well below the reference |
| Drinking-water non-compliance | 0 | 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 2022-01-01 → 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.