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Water Quality Report

Rio, WI

Columbia County · 1,095 residents · 1 water system

11

Contaminants detected

0

PFAS compounds

267

Hardness (mg/L)

0

Above legal limits

1

Above health guidelines

Rio drinking water comes from groundwater wells. Based on the most recent monitoring data, 11 contaminants have been detected in the water supply, including Lead, Nitrate, Copper, Radium, and 7 others. Water hardness is 267 mg/L (very hard), which can cause scale buildup in appliances and reduce soap effectiveness.

Contaminants detected in Rio water

Detection does not necessarily mean unsafe levels. See individual reports for concentrations and EPA limits.

Lead0.0014 / 0.015 mg/L
9% of EPA limit
Nitrate5.2 / 10 mg/L
52% of EPA limit
Copper174 / 1300 ug/L
13% of EPA limit
Radium1.4 / 5 pCi/L
28% of EPA limit
Gross Alpha Radiation1.5 / 15 pCi/L
10% of EPA limit
Total Trihalomethanes6.5 / 80 ug/L
8% of EPA limit
Atrazine0.018 / 3 ug/L
1% of EPA limit
Fluoride0.735 / 4 mg/L
18% of EPA limit
Chromium (total)0.0015 / 0.1 mg/L
2% of EPA limit
Barium0.0146 / 2 mg/L
1% of EPA limit
Gross Beta0.94 / 50 pCi/L
2% of EPA limit
Microplastics (not routinely tested)

Water systems serving Rio

RIO WATERWORKS

1,095 servedGroundwater11 contaminants1 above guideline
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Other cities in Columbia County

Water quality reports for nearby Wisconsin communities.

ArlingtonCambriaColumbusFall RiverFrieslandLodiPardeevillePortagePoynetteRandolphWisconsin DellsWyocena

Frequently asked questions

Is Rio, WI tap water safe to drink?
Rio tap water meets EPA legal standards (Maximum Contaminant Levels). However, 1 contaminant is present above independent health guidelines, which are often stricter than legal limits. 11 contaminants have been detected in the water supply, including Lead, Nitrate, Copper, Radium, Gross Alpha Radiation. View the detailed report for each water system to see specific levels and how they compare to both legal limits and health guidelines.
What contaminants are in Rio water?
Monitoring has detected 11 contaminants in Rio's water supply: Lead, Nitrate, Copper, Radium, Gross Alpha Radiation, Total Trihalomethanes, Atrazine, Fluoride, Chromium (total), Barium, Gross Beta. 1 exceed health guidelines. See individual system reports for concentrations relative to EPA limits.
Is Rio water hard?
Yes. Rio water has a hardness of 267 mg/L (very hard). Hard water is not a health concern but can cause scale buildup in water heaters and appliances, reduce soap effectiveness, and leave mineral deposits. Water softeners or conditioning systems can address hardness.
Where does Rio get its drinking water?
Rio's drinking water comes from groundwater wells that draw from underground aquifers. The water is treated and tested according to Wisconsin DNR and EPA requirements before distribution. Rio is served by one water system: RIO WATERWORKS.

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