Air Qualityi
Water Systemsi
Water Violationsi
53Active NPDESi
Air Quality — St. Louis City County (2025)i
AQSThe Air Quality Index measures how clean or polluted the air is on a given day. AQI is reported at the county level. A score of 0–50 is considered good; 51–100 is moderate; above 100 may be unhealthy for sensitive groups.
Median AQI
PM2.5 Daysi
99Ozone Daysi
33Drinking Wateri
SDWISPublic water systems registered to serve this area. Community systems (CWS) provide water to residents year-round. Transient systems serve places like gas stations or restaurants. Violations indicate a system failed to meet federal drinking water standards.
Community Systemsi
6Active Systemsi
3Recent Violationsi
53Recent Violations (Last 5 Years)
Wastewater & Stormwater Permits (NPDES)i
NPDESUnder the Clean Water Act, any facility that discharges wastewater or stormwater into rivers, lakes, or streams must hold an NPDES permit. "Effective" means the permit is currently active and the facility is authorized to discharge under its permit conditions.
Active Permitsi
13Expired / Terminatedi
37Nearest Hazardous Waste Disposal Facilitiesi
RCRAThese are the closest licensed facilities where hazardous waste (chemicals, solvents, industrial byproducts) can be legally treated, stored, or disposed of.
Cleanup Sites (Brownfields)i
EPA BrownfieldsFormer industrial or commercial properties where contamination has been found. "Remedy Complete" means cleanup is finished. "Construction Complete" means cleanup infrastructure is built but monitoring continues. "In Progress" means the site is still being investigated or cleaned up.