Tap WaterIndex

← Wisconsin

Tap water quality report

Jefferson, WI

EPA monitoring detected 22 contaminants across the 1 water supplier serving Jefferson. 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
7,926
people served
22
contaminants found
Wisconsin rankings Lead in Wisconsin PFAS in Wisconsin

What was found in Jefferson'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
1070 µg/L 11%
of the EPA limit 10000 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Fluoride
1058 µg/L 26%
of the EPA limit 4000 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Nitrate-Nitrite
1045 µg/L 10%
of the EPA limit 10000 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2017
1/1 SYR4
Copper
327.8 µg/L 25%
of the EPA limit 1300 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2017
1/1 SYR4
Barium
151.95 µg/L 7.6%
of the EPA limit 2000 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2017
1/1 SYR4
Gross Alpha, Excl. Radon And U
21.51 pCi/L 143%
of the EPA limit, at the 95th percentile of samples — 15 pCi/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2017
1/1 SYR4
Lead
17.992 µg/L 120%
of the EPA limit, at the 95th percentile of samples — 15 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2017
1/1 SYR4
TTHM
17.726 µg/L 22%
of the EPA limit 80 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Gross Beta Particle Activity
10.844 pCi/L
No EPA limit set
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2014
1/1 SYR4
Bromoform
6.265 µg/L
No EPA limit set
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Combined Radium (-226 And -228)
5.94 pCi/L 119%
of the EPA limit, at the 95th percentile of samples — 5 pCi/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Dibromochloromethane
5.655 µg/L
No EPA limit set
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Bromodichloromethane
3.11 µg/L
No EPA limit set
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
2.925 µg/L 4.9%
of the EPA limit 60 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Di(2-ethylhexyl) Phthalate
2.2 µg/L 37%
of the EPA limit 6 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2017
1/1 SYR4
Chloroform
1.82 µg/L
No EPA limit set
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Dibromoacetic Acid
1.675 µg/L
No EPA limit set
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Combined Uranium
1.66983 µg/L 5.6%
of the EPA limit 30 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2017
1/1 SYR4
Xylenes, Total
1.02 µg/L 0%
of the EPA limit 10000 µg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Dichloroacetic Acid
0.7910 µg/L
No EPA limit set
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Monobromoacetic Acid
0.6005 µg/L
No EPA limit set
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2019
1/1 SYR4
Lead
0.0035 mg/L 23%
of the EPA limit 0.0150 mg/L
Main supplier: JEFFERSON WATERWORKS · 7,926 people · 2024
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 Jefferson

SupplierPopulation served
JEFFERSON WATERWORKS 7,926

Frequently asked questions about Jefferson tap water

Is Jefferson tap water safe to drink?

EPA testing detected 22 contaminants in the water serving Jefferson. 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 Jefferson?

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

What contaminants are in Jefferson's water?

The contaminants EPA monitoring detected in Jefferson include Nitrate, Fluoride, Nitrate-Nitrite, Copper, 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.