Cottage Grove
EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the Minnesota Department of Health - Environmental Health Division, 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
- Cottage Grove, Minnesota
- Serves: 36,900
- Data available: 2013-2020*
- Source: Groundwater
* 2013 testing is for chemicals in EPA's Third Unregulated Contaminant Monitoring Rule (UCMR-3) only. 2020/2021 testing is for chemicals in EPA's Fourth Unregulated Contaminant Monitoring Rule (UCMR-4) only.
Contaminants Detected
12
EXCEED
EWG HEALTH
GUIDELINES
31 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.
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See the guideContaminants Detected
Arsenic
Potential Effect: cancer250x EWG'S HEALTH GUIDELINEArsenic
more aboutthis contaminant
Arsenic is a potent carcinogen and common contaminant in drinking water. Arsenic causes thousands of cases of cancer each year in the U.S. Click here to read more about arsenic.
Arsenic was found at 250 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.004 ppb for arsenic 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
![agriculture icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-agriculture.png)
Agriculture
![industry icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-industry.png)
Industry
![naturally occuring icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-naturally-occuring.png)
Naturally Occurring
Filtering Options
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
![ion exchange icon](https://static.ewg.org/reports/2017/tap-water/img/IonExchange_Icon.png)
Ion Exchange
Bromodichloromethane
Potential Effect: cancer8.2x 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 8.2 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
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Dibromoacetic acid
Potential Effect: 18x EWG'S HEALTH GUIDELINEDibromoacetic 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.
Dibromoacetic acid was found at 18 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 0.04 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
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Dibromochloromethane
Potential Effect: cancer6.7x 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 6.7 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
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Haloacetic acids (HAA5)†
Potential Effect: cancer7.5x EWG'S HEALTH GUIDELINEHaloacetic 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.
Haloacetic acids (HAA5) was found at 7.5 times above EWG's Health Guideline.
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
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Haloacetic acids (HAA9)†
Potential Effect: cancer20x EWG'S HEALTH GUIDELINEHaloacetic acids (HAA9)
more aboutthis contaminant
Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of nine haloacetic acids includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid, which are regulated as a group by the federal government (HAA5); and bromochloroacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid, and tribromoacetic acid.
Haloacetic acids (HAA9) was found at 20 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 the group of nine haloacetic acids, or HAA9, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level as . This health guideline protects against cancer.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Nitrate
Potential Effect: cancer3x 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 3 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 icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-agriculture.png)
Agriculture
![urban area icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-runoff-sprawl.png)
Runoff & Sprawl
![naturally occuring icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-naturally-occuring.png)
Naturally Occurring
Filtering Options
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
![ion exchange icon](https://static.ewg.org/reports/2017/tap-water/img/IonExchange_Icon.png)
Ion Exchange
Perfluorobutane sulfonate (PFBS)
Potential Effect: 26x EWG'S HEALTH GUIDELINEPerfluorobutane sulfonate (PFBS)
more aboutthis contaminant
Perfluorobutane sulfonate (PFBS) is a member of a group of perfluorinated chemicals used in many consumer products. PFOS and other perfluorinated chemicals can cause serious health effects, including cancer, endocrine disruption, accelerated puberty, liver and immune system damage, and thyroid changes. These chemicals are persistent in the environment and they accumulate in people. Click here to read more about perfluorinated chemicals.
Perfluorobutane sulfonate (PFBS) was found at 26 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppt = parts per trillion
Health Risks
The EWG Health Guideline of 1 ppt for perfluorobutane sulfonate was defined by EWG based on studies by Phillipe Grandjean of Harvard University and many other independent researchers who found reduced effectiveness of vaccines and adverse impacts on mammary gland development from exposure to PFOA and PFOS, the two PFAS most widely detected in drinking water. This health guideline applies to the entire class of PFAS detected in water.
Pollution Sources
![industry icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-industry.png)
Industry
![urban area icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-runoff-sprawl.png)
Runoff & Sprawl
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Perfluorohexane sulfonate (PFHXS)
Potential Effect: 17x EWG'S HEALTH GUIDELINEPerfluorohexane sulfonate (PFHXS)
more aboutthis contaminant
Perfluorohexane sulfonate is a member of a group of perfluorinated chemicals used in many consumer products. Perfluorinated chemicals can cause serious health effects, including cancer, endocrine disruption, accelerated puberty, liver and immune system damage, and thyroid changes. These chemicals are persistent in the environment and they accumulate in people. Click here to read more about perfluorinated chemicals.
Perfluorohexane sulfonate (PFHXS) was found at 17 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppt = parts per trillion
Health Risks
The EWG Health Guideline of 1 ppt for perfluorohexane sulfonate was defined by EWG based on studies by Phillipe Grandjean of Harvard University and many other independent researchers who found reduced effectiveness of vaccines and adverse impacts on mammary gland development from exposure to PFOA and PFOS, the two PFAS most widely detected in drinking water. This health guideline applies to the entire class of PFAS detected in water.
Pollution Sources
![industry icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-industry.png)
Industry
![urban area icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-runoff-sprawl.png)
Runoff & Sprawl
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Perfluorooctanoic acid (PFOA)
Potential Effect: cancer674x EWG'S HEALTH GUIDELINEPerfluorooctanoic acid (PFOA)
more aboutthis contaminant
Perfluorooctanoic acid (PFOA) is a member of a group of perfluorinated chemicals used in many consumer products. PFOA and other perfluorinated chemicals can cause serious health effects, including cancer, endocrine disruption, accelerated puberty, liver and immune system damage, and thyroid changes. These chemicals are persistent in the environment and they accumulate in people. Click here to read more about perfluorinated chemicals.
Perfluorooctanoic acid (PFOA) was found at 674 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppt = parts per trillion
Health Risks
The EWG Health Guideline of 0.007 ppt for PFOA was proposed by 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 icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-industry.png)
Industry
![urban area icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-runoff-sprawl.png)
Runoff & Sprawl
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Radium, combined (-226 & -228)
Potential Effect: cancer51x 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 51 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 icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-industry.png)
Industry
![naturally occuring icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-naturally-occuring.png)
Naturally Occurring
Filtering Options
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
![ion exchange icon](https://static.ewg.org/reports/2017/tap-water/img/IonExchange_Icon.png)
Ion Exchange
Total trihalomethanes (TTHMs)†
Potential Effect: cancer12x 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 12 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
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
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; chemicals detected under the EPA's Unregulated Contaminant Monitoring Rule (UCMR 4) program in 2017 to 2020 (and subsequent testing when available), for which annual utility averages exceeded a 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.
Other Contaminants Tested
✕Cottage Grove compliance with legally mandated federal standards:
- From April 2019 to March 2021, Cottage Grove complied with health-based drinking water standards.
Information in this section on Cottage Grove 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 | |||
Arsenic | ✔ | ✔ | |
Bromodichloromethane | ✔ | ✔ | |
Dibromoacetic acid | ✔ | ✔ | |
Dibromochloromethane | ✔ | ✔ | |
Haloacetic acids (HAA5) | ✔ | ✔ | |
Haloacetic acids (HAA9) | ✔ | ✔ | |
Nitrate | ✔ | ✔ | |
Perfluorobutane sulfonate (PFBS) | ✔ | ✔ | |
Perfluorohexane sulfonate (PFHXS) | ✔ | ✔ | |
Perfluorooctanoic acid (PFOA) | ✔ | ✔ | |
Radium, combined (-226 & -228) | ✔ | ✔ | |
Total trihalomethanes (TTHMs) | ✔ | ✔ | |
OTHER CONTAMINANTS DETECTED | |||
1,4-Dioxane | ✔ | ||
Bromide | ✔ | ✔ | |
Bromoform | ✔ | ✔ | |
Chloroform | ✔ | ✔ | |
Chromium (hexavalent) | ✔ | ✔ | |
Chromium (total) | ✔ | ✔ | |
cis-1,2-Dichloroethylene | ✔ | ✔ | |
Cobalt | ✔ | ✔ | |
Di(2-ethylhexyl) phthalate | ✔ | ✔ | |
Dichloroacetic acid | ✔ | ✔ | |
Fluoride | ✔ | ||
Manganese | ✔ | ||
Molybdenum | ✔ | ✔ | |
Perfluorobutanoic acid (PFBA) | ✔ | ✔ | |
Perfluorohexanoic Acid (PFHxA) | ✔ | ✔ | |
Perfluoropentanoic acid (PFPeA) | ✔ | ✔ | |
Strontium | ✔ | ✔ | |
Trichloroethylene | ✔ | ✔ | |
Xylenes (total) | ✔ | ✔ |
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