Our Data Sources

All data sourced directly from official government databases. Nothing is estimated, interpolated, or inferred. Every result links to its primary source.

Government APIs & Databases

PFASData.com aggregates data from five federal sources, each with different update frequencies and coverage.

Live API

EPA ECHO

Enforcement and Compliance History Online. Covers over 1 million regulated facilities — drinking water systems, industrial discharge sites, and Superfund locations. The backbone of our water system lookups.

echo.epa.gov ↗
Live API

EPA Envirofacts

Integrates data from the Toxics Release Inventory (TRI), Safe Drinking Water Information System (SDWIS), and Superfund records. Over 200 PFAS compounds now tracked in TRI.

epa.gov/enviro ↗
Quarterly Update

UCMR 5

The Fifth Unregulated Contaminant Monitoring Rule. Requires testing of 29 PFAS compounds across all public water systems serving 3,300+. The most comprehensive PFAS drinking water dataset ever collected.

UCMR 5 Data Finder ↗
Live API

Water Quality Portal

A multi-agency portal (EPA + USGS + state agencies) covering surface water and groundwater sampling. Supports geo-based queries by county and watershed. Useful for non-drinking-water exposure pathways.

waterqualitydata.us ↗
Periodic Update

PFAS National Datasets

EPA bulk downloads covering 12 data categories: discharge monitoring, spills, federal sites, greenhouse gas data, industry sectors, production data, and more. Used for historical analysis.

PFAS Metadata ↗
Coming Soon

State Databases

States like NJ, CA, and MI maintain PFAS databases with richer local data not captured in federal systems. Integration is ongoing. Minnesota's PRISM product reporting data will be a major addition.

Coverage Gaps

Understanding where data is missing is as important as the data itself.

Private Wells

An estimated 43 million Americans rely on private wells. Federal monitoring programs cover only public water systems — private wells are almost entirely absent from these datasets. If you're on a well, the only way to know is to test.

Data Age

Most results in federal databases are 1–3 years old. Many water providers have since taken action to reduce PFAS. This data shows past conditions, not necessarily today's treatment levels.

Small Water Systems

Systems serving fewer than 3,300 people were not required to test under UCMR 5. This creates a significant blind spot in rural and semi-rural communities where PFAS contamination from nearby sources may be present.

State Data Fragmentation

Several states maintain PFAS databases with richer local data not reflected in federal systems. Integration is ongoing and uneven. We flag this clearly for states where we know better local data exists.

Shifting Regulations

The EPA finalized MCLs for six PFAS in April 2024 but has since signaled revisions for four of them. Health thresholds on this site will update as regulations change — we track this in our Active PFAS Data dashboard.

Non-Water Pathways

Food, food packaging, consumer products, and indoor air are significant exposure sources not covered here. This site focuses on water and soil data where federal monitoring exists. See Water Data for household exposure information.

The most important thing to understand about these gaps A zip code or water system that does not appear in our results was likely never tested — not confirmed safe. We make this distinction explicit in every search result. "No data" is not a clean bill of health.