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Wilmington Water Department

EPA monitoring tested this supplier for 105 contaminants and detected 33. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

105
contaminants tested
33
detected
107,976
people served
13
health-based violations
Delaware rankingsLead in DelawarePFAS in Delaware
Water source
Surface water
Ownership
Local government
Counties served
New Castle

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

13
health-based violations
29
violations on file
0
still open
ViolationTypeStatusPeriod
TT Health-based Resolved 2017-10-01
TT Health-based Resolved 2017-10-01
MCL Health-based Resolved 2013-07-01 → 2013-07-31
MCL Health-based Resolved 2013-07-01 → 2013-07-31
MCL Health-based Resolved 2013-07-01 → 2013-07-31
MCL Health-based Resolved 2013-07-01 → 2013-07-31
TT Health-based Resolved 2004-05-01 → 2004-05-31
TT Health-based Resolved 2004-05-01 → 2004-05-31
TT Health-based Resolved 2004-05-01 → 2004-05-31
TT Health-based Resolved 2004-05-01 → 2004-05-31

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
Pfhxa 0.0211 µg/L 8/8 2024
PFOA 0.0099 µg/L 8/8 2024
Pfpea 0.0322 µg/L 8/8 2024
Pfba 0.0141 µg/L 7/8 2024
Pfhpa 0.0084 µg/L 5/8 2024
PFBS 0.0036 µg/L 4/8 2024

Other contaminants detected

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 this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Bromodichloromethane
17.4 µg/L
No EPA limit set
worst single sample: 20.3 µg/L
268/268 SYR4 2012–2019
Chloroform
64.755 µg/L
No EPA limit set
worst single sample: 110 µg/L
268/268 SYR4 2012–2019
Dibromochloromethane
5 µg/L
No EPA limit set
worst single sample: 7.3 µg/L
265/268 SYR4 2012–2019
Dichloroacetic Acid
33.89 µg/L
No EPA limit set
worst single sample: 49.6 µg/L
262/263 SYR4 2012–2019
Trichloroacetic Acid
24.98 µg/L
No EPA limit set
worst single sample: 32.8 µg/L
262/263 SYR4 2012–2019
TTHM
85.5 µg/L 107%
of the EPA limit, at the 95th percentile of samples — 80 µg/L
worst single sample: 132 µg/L
257/257 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
64.3 µg/L 107%
of the EPA limit, at the 95th percentile of samples — 60 µg/L
worst single sample: 90.4 µg/L
241/242 SYR4 2012–2019
Fluoride
1145 µg/L 29%
of the EPA limit 4000 µg/L
worst single sample: 1400 µg/L
152/153 SYR4 2012–2019
Monochloroacetic Acid
8.455 µg/L
No EPA limit set
worst single sample: 10.9 µg/L
108/263 SYR4 2012–2019
Copper
337.25 µg/L 26%
of the EPA limit 1300 µg/L
worst single sample: 417 µg/L
106/107 SYR4 2014–2017
Dibromoacetic Acid
2.095 µg/L
No EPA limit set
worst single sample: 3.3 µg/L
68/263 SYR4 2012–2019
Nitrate
3415.8 µg/L 34%
of the EPA limit 10000 µg/L
worst single sample: 3600 µg/L
56/56 SYR4 2012–2019
Lead
25.705 µg/L 171%
of the EPA limit, at the 95th percentile of samples — 15 µg/L
worst single sample: 28.5 µg/L
30/109 SYR4 2013–2017
Nitrate-Nitrite
3270.27 µg/L 33%
of the EPA limit 10000 µg/L
worst single sample: 3600 µg/L
28/28 SYR4 2012–2019
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 11/11 LCR 2023
Barium
40.08 µg/L 2%
of the EPA limit 2000 µg/L
worst single sample: 41.4 µg/L
5/5 SYR4 2013–2015
Bromoform
1.36 µg/L
No EPA limit set
worst single sample: 1.4 µg/L
5/268 SYR4 2012–2019
Chromium
2.52 µg/L 2.5%
of the EPA limit 100 µg/L
worst single sample: 2.6 µg/L
5/5 SYR4 2013–2015
2,4-D
0.2850 µg/L 0.4%
of the EPA limit 70 µg/L
worst single sample: 0.3000 µg/L
4/17 SYR4 2013–2019
Dalapon
2.035 µg/L 1%
of the EPA limit 200 µg/L
worst single sample: 2.2 µg/L
4/17 SYR4 2013–2019
Monobromoacetic Acid
2.135 µg/L
No EPA limit set
worst single sample: 2.3 µg/L
4/263 SYR4 2012–2019
Di(2-ethylhexyl) Phthalate
0.2795 µg/L 4.7%
of the EPA limit 6 µg/L
worst single sample: 0.2800 µg/L
2/8 SYR4 2013–2019
Arsenic
0.5000 µg/L 5%
of the EPA limit 10 µg/L
 1/5 SYR4 2013–2015
Atrazine
0.0310 µg/L 1%
of the EPA limit 3 µg/L
 1/10 SYR4 2013–2019
Combined Radium (-226 And -228)
0.4900 pCi/L 9.8%
of the EPA limit 5 pCi/L
 1/1 SYR4 2016
Hexachlorocyclopentadiene
0.0770 µg/L 0.2%
of the EPA limit 50 µg/L
 1/12 SYR4 2013–2019
Simazine
0.0720 µg/L 1.8%
of the EPA limit 4 µg/L
 1/10 SYR4 2013–2019
72 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,4,5-TP4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCadmiumCarbofuranCarbon TetrachlorideChlordaneDichloromethaneDi(2-ethylhexyl) AdipateDinosebEthylene DibromideEndrinEthylbenzeneHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaNitriteOxamylPfdaPfdoaPfeesaPfhpsPFHXSPfmbaPfmpaPFNAPFOSPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
OH, CHRISTIANA
Phone
302-576-3017
Email
[email protected]

Frequently asked questions about Wilmington Water Department

Is Wilmington Water Department tap water safe to drink?

EPA monitoring detected 33 contaminants in Wilmington Water Department's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Wilmington Water Department's water?

EPA monitoring detected Bromodichloromethane, Chloroform, Dibromochloromethane, Dichloroacetic Acid, Trichloroacetic Acid, and others. The full list with the level and data source for each is above.

How many people does Wilmington Water Department serve?

Wilmington Water Department reports serving 107,976 people in Delaware, per its EPA record.

Has Wilmington Water Department had any water quality violations?

The EPA has 29 violations on file for Wilmington Water Department, of which 13 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

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.