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Tap water quality report

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 single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Bromodichloromethane
20.3 µg/L
No EPA limit set
 268/268 SYR4 2012–2019
Chloroform
110 µg/L
No EPA limit set
 268/268 SYR4 2012–2019
Dibromochloromethane
7.3 µg/L
No EPA limit set
 265/268 SYR4 2012–2019
Dichloroacetic Acid
49.6 µg/L
No EPA limit set
 262/263 SYR4 2012–2019
Trichloroacetic Acid
32.8 µg/L
No EPA limit set
 262/263 SYR4 2012–2019
TTHM
132 µg/L 165%
of the EPA limit, in the worst sample — 80 µg/L
 257/257 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
90.4 µg/L 151%
of the EPA limit, in the worst sample — 60 µg/L
 241/242 SYR4 2012–2019
Fluoride
1400 µg/L 35%
of the EPA limit 4000 µg/L
 152/153 SYR4 2012–2019
Monochloroacetic Acid
10.9 µg/L
No EPA limit set
 108/263 SYR4 2012–2019
Copper
417 µg/L 32%
of the EPA limit 1300 µg/L
 106/107 SYR4 2014–2017
Dibromoacetic Acid
3.3 µg/L
No EPA limit set
 68/263 SYR4 2012–2019
Nitrate
3600 µg/L 36%
of the EPA limit 10000 µg/L
 56/56 SYR4 2012–2019
Lead
28.5 µg/L 190%
of the EPA limit, in the worst sample — 15 µg/L
 30/109 SYR4 2013–2017
Nitrate-Nitrite
3600 µg/L 36%
of the EPA limit 10000 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
41.4 µg/L 2.1%
of the EPA limit 2000 µg/L
 5/5 SYR4 2013–2015
Bromoform
1.4 µg/L
No EPA limit set
 5/268 SYR4 2012–2019
Chromium
2.6 µg/L 2.6%
of the EPA limit 100 µg/L
 5/5 SYR4 2013–2015
2,4-D
0.3000 µg/L 0.4%
of the EPA limit 70 µg/L
 4/17 SYR4 2013–2019
Dalapon
2.2 µg/L 1.1%
of the EPA limit 200 µg/L
 4/17 SYR4 2013–2019
Monobromoacetic Acid
2.3 µg/L
No EPA limit set
 4/263 SYR4 2012–2019
Di(2-ethylhexyl) Phthalate
0.2800 µg/L 4.7%
of the EPA limit 6 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
coh@wilmingtonde.gov

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.