Rio Waterworks
EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the Wisconsin Department of Natural Resources, as well as information from the U.S. EPA Enforcement and Compliance History database (ECHO). For the latest quarter assessed by the U.S. EPA (January 2021 - March 2021), tap water provided by this water utility was in compliance with federal health-based drinking water standards.
Utility Details
- Rio, Wisconsin
- Serves: 1,058
- Data available: 2014-2019
- Source: Groundwater
Contaminants Detected
6
EXCEED
EWG HEALTH
GUIDELINES
21 Total Contaminants
- Legal does not necessarily equal safe. Getting a passing grade from the federal government does not mean the water meets the latest health guidelines.
- Legal limits for contaminants in tap water have not been updated in almost 20 years.
- The best way to ensure clean tap water is to keep pollution out of source water in the first place.
Legal ≠ Safe
EWG Health Guidelines fill the gap in outdated government standards.
The federal government’s legal limits are not health-protective. The EPA has not set a new tap water standard in almost 20 years, and some standards are more than 40 years old.
Contaminants Detected
Bromodichloromethane
Potential Effect: cancer4.6x EWG'S HEALTH GUIDELINEBromodichloromethane
more aboutthis contaminant
Bromodichloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromodichloromethane and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Bromodichloromethane was found at 4.6 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.06 ppb for bromodichloromethane was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Dibromochloromethane
Potential Effect: cancer4.7x EWG'S HEALTH GUIDELINEDibromochloromethane
more aboutthis contaminant
Dibromochloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Dibromochloromethane and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Dibromochloromethane was found at 4.7 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for dibromochloromethane was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Nitrate
Potential Effect: cancer23x EWG'S HEALTH GUIDELINENitrate
more aboutthis contaminant
Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.
Nitrate was found at 23 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppm = parts per million
Health Risks
The EWG Health Guideline of 0.14 ppm for nitrate was defined by EWG . This health guideline protects against cancer and harm to fetal growth and development.
Pollution Sources
Agriculture
Runoff & Sprawl
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Nitrate and nitrite
Potential Effect: cancer26x EWG'S HEALTH GUIDELINENitrate and nitrite
more aboutthis contaminant
Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.
Nitrate and nitrite was found at 26 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppm = parts per million
Health Risks
The health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.Pollution Sources
Agriculture
Runoff & Sprawl
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Radium, combined (-226 & -228)
Potential Effect: cancer14x EWG'S HEALTH GUIDELINERadium, combined (-226 & -228)
more aboutthis contaminant
Radium is a radioactive element that causes bone cancer and other cancers. It can occur naturally in groundwater, and oil and gas extraction activities such as hydraulic fracturing can elevate concentrations.
Radium, combined (-226 & -228) was found at 14 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
pCi/L = picocuries per liter
Health Risks
EWG applied the health guideline of 0.05 pCi/L, defined by the California Office of Environmental Health Hazard Assessment as a public health goal for radium-226, to radium-226 and radium-228 combined. This health guideline protects against cancer.Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Total trihalomethanes (TTHMs)†
Potential Effect: cancer16x EWG'S HEALTH GUIDELINETotal trihalomethanes (TTHMs)
more aboutthis contaminant
Trihalomethanes are cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform.
Total trihalomethanes (TTHMs) was found at 16 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Includes chemicals detected in 2017-2019 for which annual utility averages exceeded an EWG-selected health guideline established by a federal or state public health authority; radiological contaminants detected between 2014 and 2019.
† HAA5 is a contaminant group that includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. HAA9 is a contaminant group that includes the chemicals in HAA5 and bromochloroacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid and tribromoacetic acid. TTHM is a contaminant group that includes bromodichloromethane, bromoform, chloroform and dibromochloromethane.
Acetone
more aboutthis contaminant
Acetone is a solvent used for many industrial purposes.
How your levels compare
This Utility
National Average
State Average
ppb = parts per billion
Pollution Sources
Industry
Runoff & Sprawl
Naturally Occurring
Barium is a mineral present in rocks, soil and water. High concentrations of barium in drinking water increase the risk of cardiovascular disease and hypertension.
How your levels compare
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 700 ppb for barium was defined by EWG as benchmark that protects against harm to the kidneys and the cardiovascular system.
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Beryllium
more aboutthis contaminant
Beryllium is a toxic metal that is both naturally occurring and released into the environment from industrial pollution and incineration. Beryllium can damage lungs, bones and the digestive system.
How your levels compare
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 1 ppb for beryllium was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to the stomach and intestines.
Pollution Sources
Industry
Filtering Options
Reverse Osmosis
Ion Exchange
Bromoform
more aboutthis contaminant
Bromoform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromoform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.5 ppb for bromoform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Chloroform
more aboutthis contaminant
Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.4 ppb for chloroform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Chromium (total)
more aboutthis contaminant
Chromium is a naturally occurring metal, but industrial uses can elevate its levels in water. One form, hexavalent chromium, causes cancer. Total chromium is not a good indicator of the amount of hexavalent chromium in drinking water.
How your levels compare
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Dibromoacetic acid
more aboutthis contaminant
Dibromoacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.04 ppb for dibromoacetic acid was defined in a peer-reviewed scientific study by EWG and represents a on-in-a-million lifetime cancer risk level. This health guideline protects against cancer.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Dichloromethane (methylene chloride)
Dichloromethane (methylene chloride)
more aboutthis contaminant
Methylene chloride is a common industrial solvent used for paint stripping, vapor degreasing, printing, electronics manufacturing and cleaning. It causes cancer and liver damage in animal studies.
How your levels compare
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 4 ppb for dichloromethane (methylene chloride) was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.
Pollution Sources
Industry
Runoff & Sprawl
Filtering Options
Activated Carbon
Reverse Osmosis
Fluoride
more aboutthis contaminant
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems.
How your levels compare
This Utility
Legal Limit
National Average
State Average
ppm = parts per million
Pollution Sources
Treatment Byproducts
Filtering Options
Reverse Osmosis
Haloacetic acids (HAA5)
more aboutthis contaminant
Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of five haloacetic acids regulated by federal standards includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid.
How your levels compare
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for the group of five haloacetic acids, or HAA5, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level. This health guideline protects against cancer.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Mercury (inorganic)
more aboutthis contaminant
Mercury is a potent neurotoxin that also damages the kidneys and other internal organs. Mercury enters drinking water from industrial pollution, mining wastes and coal-fired power plants.
How your levels compare
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 1.2 ppb for mercury (inorganic) was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to internal organs.
Pollution Sources
Industry
Runoff & Sprawl
Naturally Occurring
Filtering Options
Activated Carbon
Reverse Osmosis
n-Butylbenzene
more aboutthis contaminant
n-Butylbenzene is an industrial chemical.
How your levels compare
This Utility
National Average
State Average
ppb = parts per billion
Pollution Sources
Industry
Runoff & Sprawl
Filtering Options
Activated Carbon
Reverse Osmosis
Silver occurs naturally in surface and groundwater and can be added to water as a biocide that inhibits growth of bacteria and algae. Increasingly, the use of antimicrobial nano-sized silver particles in consumer products contributes to silver in water sources used for drinking water.
How your levels compare
This Utility
National Average
State Average
ppb = parts per billion
Pollution Sources
Industry
Runoff & Sprawl
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Styrene
more aboutthis contaminant
Styrene is a volatile cancer-causing chemical used for manufacturing Styrofoam (polystyrene) and other plastics. Releases from industrial production sites and hazardous waste landfills cause styrene contamination in drinking water.
How your levels compare
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.5 ppb for styrene was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.
Pollution Sources
Industry
Filtering Options
Activated Carbon
Reverse Osmosis
Thallium
more aboutthis contaminant
Thalium is a naturally occurring metal released into the environment from metal smelting and coal burning. Exposure to too much thalium can cause hair loss, liver damage, reduced sperm motility and nervous system impairment.
How your levels compare
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for thallium was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to internal organs.
Pollution Sources
Industry
Filtering Options
Reverse Osmosis
Ion Exchange
Includes chemicals detected in 2017-2019 for which annual utility averages were lower than an EWG-selected health guideline established by a federal or state public health authori.
Other Contaminants Tested
✕Rio Waterworks compliance with legally mandated federal standards:
- From April 2019 to March 2021, Rio Waterworks complied with health-based drinking water standards.
- 1 QUARTERin violation of any federal drinking water standard from April 2019 to March 2021
Information in this section on Rio Waterworks comes from the U.S. EPA Enforcement and Compliance History Online database (ECHO).
LEARN MORE ABOUT THIS UTILITYWater Filters That Can Reduce Contaminant Levels
| Contaminant | Activated Carbon | Reverse Osmosis | Ion Exchange |
| CONTAMINANTS ABOVE HEALTH GUIDELINES | |||
| Bromodichloromethane | ✔ | ✔ | |
| Dibromochloromethane | ✔ | ✔ | |
| Nitrate | ✔ | ✔ | |
| Nitrate & nitrite | ✔ | ✔ | |
| Radium, combined (-226 & -228) | ✔ | ✔ | |
| Total trihalomethanes (TTHMs) | ✔ | ✔ | |
| OTHER CONTAMINANTS DETECTED | |||
| Acetone | |||
| Barium | ✔ | ✔ | |
| Beryllium | ✔ | ✔ | |
| Bromoform | ✔ | ✔ | |
| Chloroform | ✔ | ✔ | |
| Chromium (total) | ✔ | ✔ | |
| Dibromoacetic acid | ✔ | ✔ | |
| Dichloromethane (methylene chloride) | ✔ | ✔ | |
| Fluoride | ✔ | ||
| Haloacetic acids (HAA5) | ✔ | ✔ | |
| Mercury (inorganic) | ✔ | ✔ | |
| n-Butylbenzene | ✔ | ✔ | |
| Silver | ✔ | ✔ | |
| Styrene | ✔ | ✔ | |
| Thallium | ✔ | ✔ | |
Take Action
Contact Your Local Official
One of the best ways to push for cleaner water is to hold accountable the elected officials who have a say in water quality – from city hall and the state legislature to Congress all the way to the Oval Office – by asking questions and demanding answers.
LEARN MOREFilter Out Contaminants
Check out our recommendations for filters to protect your water against the detected contaminants.
EWG’S WATER FILTER GUIDE
