Air Quality
Moderate
Water Violations
48
Active Contamination
2
Active Permits
10
Air quality in Arapahoe County is rated moderate with a median AQI of 51 (273 days measured in 2025). 28 community water systems serve the area, with 48 recent violations in the last 5 years. 19 industrial facilities report toxic chemical releases totaling 43.0K lbs. 5 contamination sites are tracked, all with completed or ongoing remediation.
Air Quality — Arapahoe 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
33Ozone Daysi
240Drinking Wateri
SDWISPublic water systems registered to serve this area. Community systems (CWS) provide water to residents year-round. Violations indicate a system failed to meet federal drinking water standards.
Community Systemsi
28Active Systemsi
25Recent Violationsi
48Recent Violations (Last 5 Years)
FRANKLIN MOBILE HOME PARK
FOXRIDGE FARMS MHP
COLUMBINE LAKES HOA
STERLING RANCH CAB
EAGLE RIVER VILLAGE MHP
EL MORRO MOBILE ESTATES
VALLEY AT WINTER PARK WD
LAKE FORK MHP
Historical Violations (Over 5 Years Ago)
Industrial Monitoringi
Toxic Release Inventory (TRI)i
TRIWastewater & Stormwater Permits (NPDES)i
NPDESContamination Sitesi
Contaminated sites tracked by the EPA and state agencies. Superfund sites are the most seriously contaminated locations. Brownfields are former industrial properties being cleaned up for reuse. LUST sites have confirmed leaks from underground storage tanks.