Tap Water Results

Delaware tap water quality

204 community water systems serving 1 million people.

Data: U.S. EPA · How we read the data · How we check it

11
systems with PFAS above a federal limit
637,113
people served by them
34
systems EPA tested for PFAS
1
systems above the lead action level

PFAS: EPA's 2023–2025 testing. Lead: results from the last five years.

Water systems with PFAS above the federal limit

Based on EPA's UCMR 5 results (2023–2025) compared to the April 2024 limits, the way EPA compares them. Systems have until 2029 to comply. Largest first.

Delaware PFAS report: chart, rankings and data to download →

Delaware's own PFAS limits

Statutory public-notification threshold (not enforceable): PFOA 4 ppt, PFOS 4 ppt, PFHxS 10 ppt, PFNA 10 ppt, HFPO-DA 10 ppt.

Forever Chemicals Mandatory Reporting Act (16 Del. C. ch. 30R) requires mailed notice above these levels or Hazard Index 1. Lower EPA MCLs would override.

Source: Laws of Delaware Vol. 85, Ch. 220 (SB 72), Forever Chemicals Mandatory Reporting Act, checked 2026-11-14. Utility pages compare each system's EPA results with these limits. State compliance is judged on the state's own sampling.

Largest water systems in Delaware

Delaware cities and towns

Most health-based violations since 2016

All Delaware utilities on this site

Every Delaware system serving 50,000+ people or with PFAS above a federal limit, A to Z. Download all 204 systems as CSV.

Questions

Does Delaware tap water have PFAS?

EPA tested 34 community water systems in Delaware for 29 PFAS between 2023 and 2025. 13 had at least one regulated PFAS detected, and 11 had an entry-point average above a 2024 federal limit. Those 11 systems serve about 637,113 people (62% of people on community water in Delaware). Systems have until 2029 to meet the limits.

How many Delaware water systems have violations?

26 systems in Delaware had at least one health-based violation since 2016 (53 violations in total). 45 violations are currently listed as unaddressed.

Which Delaware water systems are over the lead action level?

1 system had a lead 90th percentile above the 15 ppb action level in their most recent results from the last five years. Lead depends on each home's pipes, so a test of your own tap is the only way to know your level.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.