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EWG's Tap Water Database — 2021 UPDATE

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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.

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EWG Health Guidelines fill the gap in outdated government standards.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

Arsenic

Potential Effect: cancer250x EWG'S HEALTH GUIDELINE
THIS UTILITY1.000 ppb
EWG HEALTH GUIDELINE0.004 ppb
LEGAL LIMIT10 ppb
DETAILS
X

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

0.004 ppb or less

This Utility

1 ppb

Legal Limit

10 ppb

National Average

0.647 ppb

State Average

0.48 ppb
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
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

Agriculture

industry icon

Industry

naturally occuring icon

Naturally Occurring

Filtering Options

reverse osmosis icon

Reverse Osmosis

ion exchange icon

Ion Exchange

Bromodichloromethane

Potential Effect: cancer8.2x EWG'S HEALTH GUIDELINE
THIS UTILITY0.490 ppb
EWG HEALTH GUIDELINE0.06 ppb
NO LEGAL LIMIT
DETAILS
X

Bromodichloromethane

more about
this 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

0.06 ppb or less

This Utility

0.49 ppb

National Average

5.79 ppb

State Average

3.09 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
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

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Dibromoacetic acid

Potential Effect: 18x EWG'S HEALTH GUIDELINE
THIS UTILITY0.723 ppb
EWG HEALTH GUIDELINE0.04 ppb
NO LEGAL LIMIT
DETAILS
X

Dibromoacetic acid

more about
this 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

0.04 ppb or less

This Utility

0.723 ppb

National Average

1.1 ppb

State Average

0.433 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
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

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Dibromochloromethane

Potential Effect: cancer6.7x EWG'S HEALTH GUIDELINE
THIS UTILITY0.669 ppb
EWG HEALTH GUIDELINE0.1 ppb
NO LEGAL LIMIT
DETAILS
X

Dibromochloromethane

more about
this 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

0.1 ppb or less

This Utility

0.669 ppb

National Average

3.29 ppb

State Average

1.23 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
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

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Haloacetic acids (HAA5)†

Potential Effect: cancer7.5x EWG'S HEALTH GUIDELINE
THIS UTILITY0.750 ppb
EWG HEALTH GUIDELINE0.1 ppb
LEGAL LIMIT60 ppb
DETAILS
X

Haloacetic acids (HAA5)

more about
this 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

0.1 ppb or less

This Utility

0.75 ppb

Legal Limit

60 ppb

National Average

17.1 ppb

State Average

10.8 ppb
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
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

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Haloacetic acids (HAA9)†

Potential Effect: cancer20x EWG'S HEALTH GUIDELINE
THIS UTILITY1.21 ppb
EWG HEALTH GUIDELINE0.06 ppb
NO LEGAL LIMIT
DETAILS
X

Haloacetic acids (HAA9)

more about
this 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

0.06 ppb or less

This Utility

1.21 ppb

National Average

23.7 ppb

State Average

13.4 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2021.
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

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Nitrate

Potential Effect: cancer3x EWG'S HEALTH GUIDELINE
THIS UTILITY0.418 ppm
EWG HEALTH GUIDELINE0.14 ppm
LEGAL LIMIT10 ppm
DETAILS
X

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

0.14 ppm or less

This Utility

0.418 ppm

Legal Limit

10 ppm

National Average

0.935 ppm

State Average

0.455 ppm
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
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

Agriculture

urban area icon

Runoff & Sprawl

naturally occuring icon

Naturally Occurring

Filtering Options

reverse osmosis icon

Reverse Osmosis

ion exchange icon

Ion Exchange

Perfluorobutane sulfonate (PFBS)

Potential Effect: 26x EWG'S HEALTH GUIDELINE
THIS UTILITY25.8 ppt
EWG HEALTH GUIDELINE1 ppt
NO LEGAL LIMIT
DETAILS
X

Perfluorobutane sulfonate (PFBS)

more about
this 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

1 ppt or less

This Utility

25.8 ppt

National Average

156.3 ppt

State Average

0.271 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2019.
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

Industry

urban area icon

Runoff & Sprawl

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Perfluorohexane sulfonate (PFHXS)

Potential Effect: 17x EWG'S HEALTH GUIDELINE
THIS UTILITY16.7 ppt
EWG HEALTH GUIDELINE1 ppt
NO LEGAL LIMIT
DETAILS
X

Perfluorohexane sulfonate (PFHXS)

more about
this 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

1 ppt or less

This Utility

16.7 ppt

National Average

0.361 ppt

State Average

0.568 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2019.
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

Industry

urban area icon

Runoff & Sprawl

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Perfluorooctanoic acid (PFOA)

Potential Effect: cancer674x EWG'S HEALTH GUIDELINE
THIS UTILITY4.72 ppt
EWG HEALTH GUIDELINE0.007 ppt
NO LEGAL LIMIT
DETAILS
X

Perfluorooctanoic acid (PFOA)

more about
this 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

0.007 ppt or less

This Utility

4.72 ppt

National Average

1.15 ppt

State Average

1.22 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2019.
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

Industry

urban area icon

Runoff & Sprawl

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Radium, combined (-226 & -228)

Potential Effect: cancer51x EWG'S HEALTH GUIDELINE
THIS UTILITY2.55 pCi/L
EWG HEALTH GUIDELINE0.05 pCi/L
LEGAL LIMIT5 pCi/L
DETAILS
X

Radium, combined (-226 & -228)

more about
this 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

0.05 pCi/L or less

This Utility

2.55 pCi/L

Legal Limit

5 pCi/L

National Average

0.46 pCi/L

State Average

1.24 pCi/L
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2014-2019.
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

Industry

naturally occuring icon

Naturally Occurring

Filtering Options

reverse osmosis icon

Reverse Osmosis

ion exchange icon

Ion Exchange

Total trihalomethanes (TTHMs)†

Potential Effect: cancer12x EWG'S HEALTH GUIDELINE
THIS UTILITY1.77 ppb
EWG HEALTH GUIDELINE0.15 ppb
LEGAL LIMIT80 ppb
DETAILS
X

Total trihalomethanes (TTHMs)

more about
this 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

0.15 ppb or less

This Utility

1.77 ppb

Legal Limit

80 ppb

National Average

29.7 ppb

State Average

15 ppb
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
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

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

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


Chemicals tested for but not detected from 2014 to 2019:

1,1,1,2-Tetrachloroethane , 1,1,1-Trichloroethane , 1,1,2,2-Tetrachloroethane , 1,1,2-Trichloroethane , 1,1-Dichloroethane , 1,1-Dichloroethylene , 1,1-Dichloropropene , 1,2,3-Trichlorobenzene , 1,2,3-Trichloropropane , 1,2,4-Trichlorobenzene , 1,2,4-Trimethylbenzene , 1,2-Dibromo-3-chloropropane (DBCP) , 1,2-Dichloroethane , 1,2-Dichloropropane , 1,3,5-Trimethylbenzene , 1,3-Butadiene , 1,3-Dichloropropane , 1-butanol , 1-Naphthol , 2,2-Dichloropropane , 2,4,5-TP (Silvex) , 2,4-D , 2-methoxyethanol , 2-propen-1-ol , 3-Hydroxycarbofuran , Acetone , Alachlor (Lasso) , Aldicarb , Aldicarb sulfone , Aldicarb sulfoxide , Aldrin , Alpha-hexachlorocyclohexane , Altyl chloride , Antimony , Atrazine , Barium , Benzene , Benzo[a]pyrene , Beryllium , Bromobenzene , Bromochloromethane , Bromomethane , Butachlor , Butylated hydroxyanisole , Cadmium , Carbaryl , Carbofuran , Carbon tetrachloride , Chlorate , Chlordane , Chlorodifluoromethane , Chlorodifluoromethane , Chloroethane , Chloromethane , Chlorpyriphos , cis-1,3-Dichloropropene , Cyanide , Dalapon , Di(2-ethylhexyl) adipate , Dibromomethane , Dicamba , Dichlorodifluoromethane , Dichlorofluoromethane , Dichloromethane (methylene chloride) , Dieldrin , Dimethipin , Dinoseb , Endrin , Ethoprop , Ethyl ether , Ethylbenzene , Ethylene dibromide , Germanium , Glyphosate , Heptachlor , Heptachlor epoxide , Hexachlorobenzene (HCB) , Hexachlorobutadiene , Hexachlorocyclopentadiene , Isopropylbenzene , Lindane , m-Dichlorobenzene , Mercury (inorganic) , Methomyl , Methoxychlor , Methyl ethyl ketone , Methyl isobutyl ketone , Metolachlor , Metribuzin , Monobromoacetic acid , Monochloroacetic acid , Monochlorobenzene (chlorobenzene) , MTBE , n-Butylbenzene , n-Propylbenzene , Naphthalene , Nitrite , o-Chlorotoluene , o-Dichlorobenzene , o-toluidine , Oxamyl (Vydate) , Oxyflurofen , p-Chlorotoluene , p-Dichlorobenzene , p-Isopropyltoluene , Pentachlorophenol , Perfluoroheptanoic acid (PFHPA) , Perfluorononanoic acid (PFNA) , Perfluorooctane sulfonate (PFOS) , Permethrin , Picloram , Polychlorinated biphenyls (PCBs) , Profenofos , Propachlor , Quinoline , sec-Butylbenzene , Selenium , Simazine , Styrene , Tebuconazole , tert-Butylbenzene , Tetrachloroethylene (perchloroethylene) , Tetrahydrofuran , Thallium , Toluene , Toxaphene , trans-1,2-Dichloroethylene , trans-1,3-Dichloropropene , Tribufos , Trichloroacetic acid , Trichlorofluoromethane , Trichlorotrifluoroethane , Vanadium , Vinyl chloride

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 UTILITY

Water Filters That Can Reduce Contaminant Levels

ContaminantActivated Carbonactivated carbonReverse Osmosisreverse osmosisIon Exchangeion 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 MORE

Filter Out Contaminants

Check out our recommendations for filters to protect your water against the detected contaminants.

EWG’S WATER FILTER GUIDE