PFAS by ZIP Code: Free Water Quality Check (2026)
Check PFAS contamination in your drinking water by ZIP code. EPA UCMR5 test data for every US public water system. Free, instant, no signup.
Reviewed by Dr. Marcus Reilly, PhD – PFAS & Drinking Water Scientist
Quick Answer
Enter your 5-digit ZIP code to check PFAS contamination in your drinking water using EPA UCMR5 test data (2023-2025). The basic check – does your water have detected PFAS, which compounds, and how it compares to the EPA 4 ppt limit – is completely free with no signup. Most US ZIPs have data because UCMR5 covered every public water system serving 10,000+ people.
Key facts
- EPA UCMR5 testing period
- 2023-2025
- PFAS compounds tested by UCMR5
- 29
- EPA limit for PFOA and PFOS
- 4 parts per trillion each
- Cost of free ZIP check
- $0, no signup required
- Coverage
- Every US public water system serving 10,000+ people
Frequently asked questions
How do I check PFAS in my water by ZIP code?
Enter your 5-digit ZIP code in the search at knowyourexposure.com. We pull EPA UCMR5 data for every public water system serving that ZIP and show detection levels, compound breakdowns, and how your area compares to the EPA 4 ppt limit.
Is the ZIP code PFAS check actually free?
Yes. The basic check is completely free and requires no signup. The paid $9.99 report adds 10-year trends, compound-by-compound risk analysis, lawsuit eligibility, and personalized filter recommendations.
Where does the ZIP-level PFAS data come from?
EPA's Unregulated Contaminant Monitoring Rule 5 (UCMR5) program tested every large US public water system between 2023 and 2025 for 29 PFAS compounds. We pull the raw EPA data, link it to your water utility via PWSID, and show results for your specific ZIP.