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Tap water quality report

Williamstown, MO

EPA monitoring detected 16 contaminants across the 1 water supplier serving Williamstown. A detection doesn't automatically mean the water is unsafe — see the highest level found for each below, with its EPA source and period.

1
water supplier
7,140
people served
16
contaminants found
Missouri rankings Lead in Missouri PFAS in Missouri

What was found in Williamstown's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate-Nitrite
7900 µg/L 79%
of the EPA limit 10000 µg/L
 1/1 SYR4
Copper
846 µg/L 65%
of the EPA limit 1300 µg/L
 1/1 SYR4
Fluoride
130 µg/L 3.3%
of the EPA limit 4000 µg/L
 1/1 SYR4
Barium
54.2 µg/L 2.7%
of the EPA limit 2000 µg/L
 1/1 SYR4
TTHM
10.4 µg/L 13%
of the EPA limit 80 µg/L
 1/1 SYR4
Lead
7.24 µg/L 48%
of the EPA limit 15 µg/L
 1/1 SYR4
Monobromoacetic Acid
4.79 µg/L
No EPA limit set
 1/1 SYR4
Dibromochloromethane
3.69 µg/L
No EPA limit set
 1/1 SYR4
Bromodichloromethane
3.5 µg/L
No EPA limit set
 1/1 SYR4
Chromium
3.01 µg/L 3%
of the EPA limit 100 µg/L
 1/1 SYR4
Trichloroacetic Acid
2.98 µg/L
No EPA limit set
 1/1 SYR4
Dichloroacetic Acid
2.94 µg/L
No EPA limit set
 1/1 SYR4
Chloroform
2.52 µg/L
No EPA limit set
 1/1 SYR4
Dibromoacetic Acid
1.37 µg/L
No EPA limit set
 1/1 SYR4
Bromoform
0.7800 µg/L
No EPA limit set
 1/1 SYR4
Lead
0.0022 mg/L 15%
of the EPA limit 0.0150 mg/L
 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 single worst sample on record — 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 Williamstown

SupplierPopulation served
CLARK COUNTY CONS PWSD 1 7,140

Frequently asked questions about Williamstown tap water

Is Williamstown tap water safe to drink?

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

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

What contaminants are in Williamstown's water?

The contaminants EPA monitoring detected in Williamstown include Nitrate-Nitrite, Copper, Fluoride, Barium, TTHM. The full list, with the highest level found 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.