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Tap water quality report

Cottage Grove, WI

EPA monitoring detected 14 contaminants across the 1 water supplier serving Cottage Grove. 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
9,345
people served
14
contaminants found
Wisconsin rankings Lead in Wisconsin PFAS in Wisconsin

What was found in Cottage Grove'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
Fluoride
1260 µg/L 32%
of the EPA limit 4000 µg/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2019
1/1 SYR4
Copper
194.65 µg/L 15%
of the EPA limit 1300 µg/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2017
1/1 SYR4
Lead
13.913 µg/L 93%
of the EPA limit 15 µg/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2017
1/1 SYR4
Barium
12.575 µg/L 0.6%
of the EPA limit 2000 µg/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2017
1/1 SYR4
Gross Alpha, Excl. Radon And U
7.75 pCi/L 52%
of the EPA limit 15 pCi/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2014
1/1 SYR4
TTHM
6.922 µg/L 8.7%
of the EPA limit 80 µg/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2019
1/1 SYR4
Gross Beta Particle Activity
4.735 pCi/L
No EPA limit set
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2014
1/1 SYR4
Chloroform
4.44 µg/L
No EPA limit set
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2019
1/1 SYR4
Xylenes, Total
2.258 µg/L 0%
of the EPA limit 10000 µg/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2019
1/1 SYR4
Bromodichloromethane
2.04 µg/L
No EPA limit set
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2019
1/1 SYR4
Combined Radium (-226 And -228)
1.755 pCi/L 35%
of the EPA limit 5 pCi/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2014
1/1 SYR4
Dibromochloromethane
1.21 µg/L
No EPA limit set
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2019
1/1 SYR4
Styrene
0.5200 µg/L 0.5%
of the EPA limit 100 µg/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2019
1/1 SYR4
Lead
0.0023 mg/L 16%
of the EPA limit 0.0150 mg/L
Main supplier: COTTAGE GROVE WATERWORKS · 9,345 people · 2023
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 Cottage Grove

SupplierPopulation served
COTTAGE GROVE WATERWORKS 9,345

Frequently asked questions about Cottage Grove tap water

Is Cottage Grove tap water safe to drink?

EPA testing detected 14 contaminants in the water serving Cottage Grove. 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 Cottage Grove?

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

What contaminants are in Cottage Grove's water?

The contaminants EPA monitoring detected in Cottage Grove include Fluoride, Copper, Lead, Barium, Gross Alpha, Excl. Radon And U. 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.