Air Qualityi
Water Systemsi
Water Compliancei
CleanActive NPDESi
Air Quality — DuPage 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
168Ozone Daysi
105Drinking 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
1Active Systemsi
1Recent Violationsi
0Historical Violations (Over 5 Years Ago)
CLARENDON HILLS
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
2Expired / Terminatedi
1Nearest 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. There are only about 15 such facilities in all of Illinois.
Leaking Underground Storage Tanksi
IL EPAUnderground storage tanks (commonly at gas stations) can leak fuel and chemicals into soil and groundwater. "Open" means the leak is still being investigated or cleaned up. "Closed" means the site received a No Further Remediation (NFR) letter — cleanup is done.
Open Incidents (6)