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Tap water quality report

Ayer, MA

EPA monitoring detected 20 contaminants across the 2 water suppliers serving Ayer. 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
14,979
people served
20
contaminants found
Massachusetts rankings Lead in Massachusetts PFAS in Massachusetts

What was found in Ayer'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
910 µg/L 9.1%
of the EPA limit 10000 µg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
2/2 SYR4
Copper
510.5 µg/L 39%
of the EPA limit 1300 µg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
Highest in the city: 511 µg/L — DEVENS MASSDEVELOPMENT · 6,500 people · 2019
2/2 SYR4
Fluoride
100 µg/L 2.5%
of the EPA limit 4000 µg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2018
Highest in the city: 120 µg/L — DEVENS MASSDEVELOPMENT · 6,500 people · 2019
2/2 SYR4
Arsenic
81.4 µg/L 814%
of the EPA limit, at the 95th percentile of samples — 10 µg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
2/2 SYR4
Barium
44.15 µg/L 2.2%
of the EPA limit 2000 µg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2018
2/2 SYR4
TTHM
27.3 µg/L 34%
of the EPA limit 80 µg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
2/2 SYR4
Lead
20.6 µg/L 137%
of the EPA limit, at the 95th percentile of samples — 15 µg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2016
2/2 SYR4
Chloroform
16.24 µg/L
No EPA limit set
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
2/2 SYR4
Dibromochloromethane
3.5975 µg/L
No EPA limit set
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
Highest in the city: 8.85 µg/L — DEVENS MASSDEVELOPMENT · 6,500 people · 2019
2/2 SYR4
Bromodichloromethane
8.546 µg/L
No EPA limit set
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
2/2 SYR4
Total Haloacetic Acids (HAA5)
8.384 µg/L 14%
of the EPA limit 60 µg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
2/2 SYR4
Trichloroacetic Acid
6.683 µg/L
No EPA limit set
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
1/2 SYR4
Bromoform
4.64 µg/L
No EPA limit set
Highest in the city: DEVENS MASSDEVELOPMENT · 6,500 people · 2019
1/2 SYR4
Dibromoacetic Acid
2.26 µg/L
No EPA limit set
Highest in the city: DEVENS MASSDEVELOPMENT · 6,500 people · 2019
1/2 SYR4
Dichloroacetic Acid
1.715 µg/L
No EPA limit set
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2019
Highest in the city: 1.765 µg/L — DEVENS MASSDEVELOPMENT · 6,500 people · 2019
2/2 SYR4
Chromium
1 µg/L 1%
of the EPA limit 100 µg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2018
1/2 SYR4
Pfba
0.0199 µg/L
No EPA limit set
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2024
2/2 UCMR-5
Pfpea
0.0131 µg/L
No EPA limit set
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2024
2/2 UCMR-5
Pfhxa
0.0052 µg/L
No EPA limit set
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2024
1/2 UCMR-5
Lead
0.0028 mg/L 19%
of the EPA limit 0.0150 mg/L
Main supplier: AYER DPW WATER DIVISION · 8,479 people · 2025
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 Ayer

SupplierPopulation served
AYER DPW WATER DIVISION 8,479
DEVENS MASSDEVELOPMENT 6,500

Frequently asked questions about Ayer tap water

Is Ayer tap water safe to drink?

EPA testing detected 20 contaminants in the water serving Ayer. 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 Ayer?

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

What contaminants are in Ayer's water?

The contaminants EPA monitoring detected in Ayer include Nitrate, Copper, Fluoride, Arsenic, Barium. 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.