A birds-eye look at PFAS exposure risk across Westchester. This page is useful for policymakers or planners who need the regional picture rather than a single property.
Towns Ranked by Land Contamination Proximity
Ranks distance to known PFAS sites and watersheds. A DEP WATER tag means municipal tap water there is filtered upstream and safer than this land-based rank implies; it doesn't mean the town has no nearby contamination, and some properties in these towns may still be on private wells.
Methodology
The town ranking and the DEP tag answer two different questions. The ranking measures proximity to known PFAS sites and watersheds only. This is a proxy for where contamination sources cluster, regardless of how any given property gets its water. The DEP tag flags towns where municipal tap water comes from the NYC DEP aqueduct (Catskill/Croton supply, which is filtered and monitored upstream), so a resident on that municipal line faces lower tap-water risk than the rank alone suggests. A town can carry both a high rank and the DEP tag: New Castle ranks high because of a known dry-cleaner PFAS cluster there, independent of its water supply. The DEP service radius is also an approximation, not a guarantee every property in it is off private wells.
The heatmap is a modeled surface clipped to the county's actual boundary: risk is estimated at every point across Westchester using the same distance-weighted exposure factors, the same inputs as an address score, evaluated continuously rather than at one point. Each town's index uses the same factors, scaled to 0–100, and excludes home-specific inputs like water source and property age since those vary address to address.
WaterWatch Westchester provides risk estimates based on publicly available geospatial data. This overview is intended to support planning and outreach, not to replace certified laboratory testing or town-specific investigation. Data sources: NYS DEC, USEPA ECHO, USGS NHD, Westchester County GIS.