Phase I ESAs are essential for CERCLA liability protection but expensive for screening 15 potential sites ($45K-$150K).
Screen with publicly available data: FEMA flood zones, EPA brownfields, USFWS wetlands, USFS wildfire risk, EPA air quality.
Automated screening (seconds per parcel) → flag and rank → Phase I ESA only for parcels that pass screening. Cuts ESA spending by 60-80%.