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Tap water quality report

Waltham, MA

EPA monitoring detected 1 contaminant across the 1 water supplier serving Waltham. 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
65,218
people served
1
contaminants found
Massachusetts rankings Lead in Massachusetts PFAS in Massachusetts

What was found in Waltham'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
Lead
0.0019 mg/L 13%
of the EPA limit 0.0150 mg/L
Main supplier: WALTHAM WATER DEPARTMENT · 65,218 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 Waltham

SupplierPopulation served
WALTHAM WATER DEPARTMENT 65,218

Frequently asked questions about Waltham tap water

Is Waltham tap water safe to drink?

EPA testing detected 1 contaminant in the water serving Waltham. 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 Waltham?

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

What contaminants are in Waltham's water?

The contaminants EPA monitoring detected in Waltham include Lead. 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.