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Tap water quality report

Chilmark, MA

EPA monitoring detected 6 contaminants across the 2 water suppliers serving Chilmark. 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
930
people served
6
contaminants found
Massachusetts rankings Lead in Massachusetts PFAS in Massachusetts

What was found in Chilmark'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
350 µg/L 3.5%
of the EPA limit 10000 µg/L
Main supplier: MENEMSHA WATER COMPANY · 841 people · 2019
Highest in the city: 550 µg/L — Aquinnah Wampanoag · 89 people · 2018
2/2 SYR4
Barium
10 µg/L 0.5%
of the EPA limit 2000 µg/L
Main supplier: MENEMSHA WATER COMPANY · 841 people · 2019
1/2 SYR4
Combined Uranium
1 µg/L 3.3%
of the EPA limit 30 µg/L
Highest in the city: Aquinnah Wampanoag · 89 people · 2012
1/2 SYR4
Gross Alpha, Excl. Radon And U
0.1100 pCi/L 0.7%
of the EPA limit 15 pCi/L
Highest in the city: Aquinnah Wampanoag · 89 people · 2012
1/2 SYR4
Combined Radium (-226 And -228)
0.1000 pCi/L 2%
of the EPA limit 5 pCi/L
Highest in the city: Aquinnah Wampanoag · 89 people · 2012
1/2 SYR4
Lead
0.0023 mg/L 16%
of the EPA limit 0.0150 mg/L
Main supplier: MENEMSHA WATER COMPANY · 841 people · 2026
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 Chilmark

SupplierPopulation served
MENEMSHA WATER COMPANY 841
Aquinnah Wampanoag 89

Frequently asked questions about Chilmark tap water

Is Chilmark tap water safe to drink?

EPA testing detected 6 contaminants in the water serving Chilmark. 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 Chilmark?

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

What contaminants are in Chilmark's water?

The contaminants EPA monitoring detected in Chilmark include Nitrate, Barium, Combined Uranium, Gross Alpha, Excl. Radon And U, Combined Radium (-226 And -228). 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.