- EPA's UCMR 5 testing looked for 30 contaminants here and found 6.
- PFPeA (a PFAS): found in 8 of 8 samples, average 11.7 ppt, highest 32.2 ppt (EPA UCMR 5 testing, Feb 2023–Jan 2024)
- PFHxA (a PFAS): found in 8 of 8 samples, average 9.5 ppt, highest 21.1 ppt (EPA UCMR 5 testing, Feb 2023–Jan 2024)
- PFBA (a PFAS): found in 7 of 8 samples, average 7.3 ppt, highest 14.1 ppt (EPA UCMR 5 testing, Feb 2023–Jan 2024)
- PFOA (a PFAS): found in 8 of 8 samples, average 7.1 ppt, highest 9.9 ppt (EPA UCMR 5 testing, Feb 2023–Jan 2024) PFOA or PFOS averaged above 4.0 ppt in UCMR 5 testing
- PFHpA (a PFAS): found in 5 of 8 samples, average 2.9 ppt, highest 8.4 ppt (EPA UCMR 5 testing, Feb 2023–Jan 2024)
- PFBS (a PFAS): found in 4 of 8 samples, average 1.7 ppt, highest 3.6 ppt (EPA UCMR 5 testing, Feb 2023–Jan 2024)
- Lead, 90th percentile: 0 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2021–Dec 31, 2023). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
Public EPA test results
Can you drink Wilmington tap water? What EPA records show
EPA DE0000663 · serves Wilmington, DE · about 107,976 people (EPA SDWIS)
This report shows EPA's federal records for this water system: UCMR 5 testing, lead testing and violations. It isn't a test of the water at your tap, and it has no Water Score.
Public EPA test results
Wilmington Water Department (EPA DE0000663)
EPA data as of October 14, 2026. For Wilmington's main utility, Wilmington Water Department: We found no health-based violations in EPA's records for this system (DE0000663) since July 1, 2021, as of October 14, 2026. This water system averaged above 4.0 ppt for PFOA or PFOS in EPA's UCMR 5 testing.
What EPA records show for Wilmington Water Department, as of October 14, 2026
We found no health-based violations in EPA's records for this system (DE0000663) since July 1, 2021, as of October 14, 2026.
Source: EPA ECHO record for Wilmington Water Department (SDWIS). Data as of October 14, 2026.
Lead, 90th percentile: 0 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2021–Dec 31, 2023). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
This water system averaged above 4.0 ppt for PFOA or PFOS in EPA's UCMR 5 testing.
EPA's UCMR 5 testing looked for 30 contaminants here and found 6.
Source: EPA records (SDWIS, UCMR 5). SDWIS: data as of Oct 14, 2026. EPA UCMR 5 data, samples through June 2026.
Your water bill names your utility.
Does Wilmington Water Department use chloramine?
We didn't find chloramine in Wilmington Water Department's EPA treatment records. That's not a complete list; your utility's annual water quality report says which disinfectant it uses.