Air Qualityi
Water Systemsi
Water Violationsi
2Active NPDESi
Air Quality — Cook 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
145Ozone Daysi
97Drinking 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
2Recent Violations (Last 5 Years)
NORTHFIELD
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
5Leaking 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 (11)
EV Charging & Alternative Fuel Stationsi
AFDCPublicly listed alternative fuel and EV charging stations within the municipality. Data from the U.S. Department of Energy. "Open" stations are currently available for use; "Planned" stations are approved but not yet operational.
Total Stationsi
4EV Stationsi
4Level 2 Portsi
8