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Tap water quality report

Wilmington, MA

EPA monitoring detected 23 contaminants across the 1 water supplier 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.

1
water supplier
21,654
people served
23
contaminants found
Massachusetts rankings Lead in Massachusetts PFAS in Massachusetts

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
1192.5 µg/L 12%
of the EPA limit 10000 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Nitrite
330.5 µg/L 33%
of the EPA limit 1000 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
TTHM
86.385 µg/L 108%
of the EPA limit, at the 95th percentile of samples — 80 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Chloroform
59.7 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
46.6 µg/L 78%
of the EPA limit 60 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Arsenic
44.455 µg/L 445%
of the EPA limit, at the 95th percentile of samples — 10 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Barium
36 µg/L 1.8%
of the EPA limit 2000 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Trichloroacetic Acid
32.5 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Bromodichloromethane
24.7 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Dichloroacetic Acid
21.4 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Dibromochloromethane
10.89 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Monochloroacetic Acid
4.25 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Dibromoacetic Acid
3.52 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Bromoform
1.731 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Chromium
1.54 µg/L 1.5%
of the EPA limit 100 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Monobromoacetic Acid
1.1275 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Di(2-ethylhexyl) Phthalate
0.9130 µg/L 15%
of the EPA limit 6 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
cis-1,2-Dichloroethylene
0.6400 µg/L 0.9%
of the EPA limit 70 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Vinyl Chloride
0.6140 µg/L 31%
of the EPA limit 2 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Styrene
0.5600 µg/L 0.6%
of the EPA limit 100 µg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2019
1/1 SYR4
Pfba
0.0088 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2025
1/1 UCMR-5
Pfpea
0.0030 µg/L
No EPA limit set
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2025
1/1 UCMR-5
Lead
0.0018 mg/L 12%
of the EPA limit 0.0150 mg/L
Main supplier: WILMINGTON WATER DEPT · 21,654 people · 2025
1/1 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 DEPT 21,654

Frequently asked questions about Wilmington tap water

Is Wilmington tap water safe to drink?

EPA testing detected 23 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?

1 public water supplier report drinking-water monitoring for Wilmington, Massachusetts 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, Nitrite, TTHM, Chloroform, Total Haloacetic Acids (HAA5). 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.