Tap Water Results

Is Wilmington, DE tap water safe?

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

Summary

Wilmington Water Department, the largest system here, had PFAS above the 2024 federal limits (PFOA) in EPA's 2023–2025 testing.

Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility issues a boil-water or do-not-drink notice, follow it.

2 public water systems serve parts of Wilmington. The largest, Wilmington Water Department, serves 107,976 people, and 2 systems here had PFAS above a federal limit. Your water bill names your system.

Largest system

Wilmington Water Department

107,976 people · Surface water · EPA ID DE0000663

Buys treated water from Artesian Water Company.

PFASHighest averageLimitStatus
PFOA
Above limit
7.73 ppt4 pptAbove limit
PFOS
Not detected
–4 pptNot detected
PFHxS
Not detected
–10 pptNot detected
PFNA
Not detected
–10 pptNot detected
HFPO-DA (GenX)
Not detected
–10 pptNot detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

For context: the PFOA average is higher than at 76% of the Delaware systems EPA tested.

Lead: 0 ppb at the 90th percentile (Dec 2023, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 1

Full Wilmington Water Department results

Across Delaware, 11 of 34 water systems EPA tested had PFAS above a 2024 federal limit, and 1 system were above the lead action level in results from the last five years. Delaware results.

Wilmington homes and lead pipes

79%
of homes built before 1980 (Delaware 42%, US 50%)
54%
built before 1950 (Delaware 12%)
52%
of households rent (Delaware 27%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Wilmington city (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Wilmington

How nearby cities compare

CityMain water systemPFASLead (90th pct.)
Newark 13 mi
Newark Water Department
Newark Water DepartmentAbove limit1 ppb
Middletown 22 mi
Middletown Water Department
Middletown Water DepartmentNone above limits0 ppb
Dover 40 mi
Dover Water Department
Dover Water DepartmentNone above limits2 ppb
Wilmington ZIP codes (5)
  • 19801
  • 19802
  • 19805
  • 19806
  • 19809

Questions

Is Wilmington tap water safe to drink?

Wilmington Water Department had 1 health-based violation since 2016, and EPA testing found PFAS above the 2024 federal limits, which it must meet by 2029. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Wilmington, DE?

2 public water systems serve parts of Wilmington. The largest is Wilmington Water Department (107,976 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Wilmington tap water have PFAS?

Yes. EPA's 2023–2025 testing found entry-point averages above the 2024 federal limits for PFOA at Wilmington Water Department. Systems have until 2029 to meet them.

Do Wilmington homes have lead pipes?

Census estimates put 79% of Wilmington homes as built before 1980 (Delaware: 42%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Wilmington Water Department's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

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