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Tap water quality report

Wilmington, DE

EPA monitoring detected 38 contaminants across the 2 water suppliers serving Wilmington. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

2
water suppliers
208,471
people served
38
contaminants found
Delaware rankings Lead in Delaware PFAS in Delaware

What was found in Wilmington's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
3415.8 µg/L 34%
of the EPA limit 10000 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
Highest in the city: 3600 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2019
2/2 SYR4
Nitrate-Nitrite
3270.27 µg/L 33%
of the EPA limit 10000 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
Highest in the city: 3600 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2019
2/2 SYR4
Fluoride
1145 µg/L 29%
of the EPA limit 4000 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
Highest in the city: 1200 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2019
2/2 SYR4
Copper
337.25 µg/L 26%
of the EPA limit 1300 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2017
2/2 SYR4
TTHM
85.5 µg/L 107%
of the EPA limit, at the 95th percentile of samples — 80 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Chloroform
64.755 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Total Haloacetic Acids (HAA5)
64.3 µg/L 107%
of the EPA limit, at the 95th percentile of samples — 60 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Barium
40.08 µg/L 2%
of the EPA limit 2000 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2015
Highest in the city: 48.56 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2015
2/2 SYR4
Dichloroacetic Acid
33.89 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Lead
25.705 µg/L 171%
of the EPA limit, at the 95th percentile of samples — 15 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2017
2/2 SYR4
Trichloroacetic Acid
24.98 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Bromodichloromethane
17.4 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
Highest in the city: 18 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2019
2/2 SYR4
Gross Beta Particle Activity
12.1 pCi/L
No EPA limit set
Highest in the city: VEOLIA WATER DELAWARE, INC · 100,495 people · 2013
1/2 SYR4
Monochloroacetic Acid
8.455 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Dibromochloromethane
5 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
Highest in the city: 5.48 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2019
2/2 SYR4
Chromium
2.52 µg/L 2.5%
of the EPA limit 100 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2015
Highest in the city: 2.92 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2015
2/2 SYR4
Monobromoacetic Acid
2.135 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Dibromoacetic Acid
2.095 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Dalapon
2.035 µg/L 1%
of the EPA limit 200 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Bromoform
1.36 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Di(2-ethylhexyl) Phthalate
0.2795 µg/L 4.7%
of the EPA limit 6 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
Highest in the city: 0.6100 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2017
2/2 SYR4
Arsenic
0.5000 µg/L 5%
of the EPA limit 10 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2015
Highest in the city: 0.5950 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2015
2/2 SYR4
Combined Radium (-226 And -228)
0.4900 pCi/L 9.8%
of the EPA limit 5 pCi/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2016
2/2 SYR4
2,4-D
0.2850 µg/L 0.4%
of the EPA limit 70 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
2/2 SYR4
Atrazine
0.0310 µg/L 1%
of the EPA limit 3 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
Highest in the city: 0.1000 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2017
2/2 SYR4
Simazine
0.0720 µg/L 1.8%
of the EPA limit 4 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
Highest in the city: 0.0900 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2017
2/2 SYR4
Di(2-ethylhexyl) Adipate
0.0880 µg/L 0%
of the EPA limit 400 µg/L
Highest in the city: VEOLIA WATER DELAWARE, INC · 100,495 people · 2017
1/2 SYR4
Hexachlorocyclopentadiene
0.0770 µg/L 0.2%
of the EPA limit 50 µg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2019
1/2 SYR4
Pfba
0.0141 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2024
Highest in the city: 0.0406 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2023
2/2 UCMR-5
Pfpea
0.0322 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2024
2/2 UCMR-5
Pfhxa
0.0211 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2024
Highest in the city: 0.0317 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2023
2/2 UCMR-5
Pfhpa
0.0084 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2024
Highest in the city: 0.0277 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2023
2/2 UCMR-5
PFOA
0.0099 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2024
Highest in the city: 0.0244 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2023
2/2 UCMR-5
PFNA
0.0116 µg/L
No EPA limit set
Highest in the city: VEOLIA WATER DELAWARE, INC · 100,495 people · 2023
1/2 UCMR-5
Pfda
0.0047 µg/L
No EPA limit set
Highest in the city: VEOLIA WATER DELAWARE, INC · 100,495 people · 2023
1/2 UCMR-5
Pfuna
0.0038 µg/L
No EPA limit set
Highest in the city: VEOLIA WATER DELAWARE, INC · 100,495 people · 2023
1/2 UCMR-5
PFBS
0.0036 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2024
Highest in the city: 0.0037 µg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2023
2/2 UCMR-5
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
Main supplier: WILMINGTON WATER DEPARTMENT · 107,976 people · 2023
Highest in the city: 0.0020 mg/L — VEOLIA WATER DELAWARE, INC · 100,495 people · 2023
2/2 LCR
Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Wilmington

SupplierPopulation served
WILMINGTON WATER DEPARTMENT 107,976
VEOLIA WATER DELAWARE, INC 100,495

Frequently asked questions about Wilmington tap water

Is Wilmington tap water safe to drink?

EPA testing detected 38 contaminants in the water serving Wilmington. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Wilmington?

2 public water suppliers report drinking-water monitoring for Wilmington, Delaware to the EPA. Each is listed above with its population served.

What contaminants are in Wilmington's water?

The contaminants EPA monitoring detected in Wilmington include Nitrate, Nitrate-Nitrite, Fluoride, Copper, TTHM. The full list, with the level at the main supplier and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.