Air Quality
Moderate
Water Violations
193
Active Contamination
36
Active Permits
10
Air quality in Arapahoe County is rated moderate with a median AQI of 51 (273 days measured in 2025). 20 community water systems serve the area, with 193 recent violations in the last 5 years. 26 industrial facilities report toxic chemical releases totaling 157.5K lbs. 38 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
20Active Systemsi
25Recent Violationsi
193Recent Violations (Last 5 Years)
GALAMBS MOBILE HOME AND RV PARK
EAST CHERRY CREEK VALLEY WSD
STAGE RUN HOA
TRAVOIS HOA
EMERALD ACRES MOBILE HOME PARK
KEETON RANCH WATER
KEN CARYL WEST RANCH WD
MOUNTAIN VIEW VILLAGE
ASPEN RIDGE MHC
COLLINS AIRE MHC
LAGO VISTA MOBILE HOME PARK
POUDRE VALLEY MHC
SUNSET PARK MHC
Historical Violations (Over 5 Years Ago)
AURORA CITY OF
Industrial Monitoringi
Toxic Release Inventory (TRI)i
TRIContamination 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.