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Tap water quality report

Mamaroneck, NY

EPA monitoring detected 16 contaminants across the 1 water supplier serving Mamaroneck. 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
59,629
people served
16
contaminants found
New York rankings Lead in New York PFAS in New York

What was found in Mamaroneck'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
Fluoride
806 µg/L 20%
of the EPA limit 4000 µg/L
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Nitrate
231 µg/L 2.3%
of the EPA limit 10000 µg/L
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
58.415 µg/L 97%
of the EPA limit 60 µg/L
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
TTHM
52.22 µg/L 65%
of the EPA limit 80 µg/L
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Chloroform
46.885 µg/L
No EPA limit set
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Trichloroacetic Acid
42.355 µg/L
No EPA limit set
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Barium
19.8 µg/L 1%
of the EPA limit 2000 µg/L
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Dichloroacetic Acid
18.8 µg/L
No EPA limit set
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Lead
11.465 µg/L 76%
of the EPA limit 15 µg/L
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2017
1/1 SYR4
Bromodichloromethane
5.161 µg/L
No EPA limit set
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Monochloroacetic Acid
4.71 µg/L
No EPA limit set
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Cyanide
1.5 µg/L 0.8%
of the EPA limit 200 µg/L
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Dibromoacetic Acid
1.26 µg/L
No EPA limit set
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Dibromochloromethane
0.4770 µg/L
No EPA limit set
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Benzo(A)Pyrene
0.0200 µg/L 10%
of the EPA limit 0.2000 µg/L
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2019
1/1 SYR4
Lead
0.0030 mg/L 20%
of the EPA limit 0.0150 mg/L
Main supplier: WESTCHESTER JOINT WATER WORKS · 59,629 people · 2027
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 Mamaroneck

SupplierPopulation served
WESTCHESTER JOINT WATER WORKS 59,629

Frequently asked questions about Mamaroneck tap water

Is Mamaroneck tap water safe to drink?

EPA testing detected 16 contaminants in the water serving Mamaroneck. 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 Mamaroneck?

1 public water supplier report drinking-water monitoring for Mamaroneck, New York to the EPA. Each is listed above with its population served.

What contaminants are in Mamaroneck's water?

The contaminants EPA monitoring detected in Mamaroneck include Fluoride, Nitrate, Total Haloacetic Acids (HAA5), TTHM, Chloroform. 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.