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EWG's Tap Water Database — 2021 UPDATE

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Creston Water Supply

EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the Iowa 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

  • Creston, Iowa
  • Serves: 7,834
  • Data available: 2014-2019
  • Source: Surface water

Contaminants Detected

11

EXCEED
EWG HEALTH
GUIDELINES

19 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.

Looking for a countertop water filter?

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See the guide

Contaminants Detected

Arsenic

Potential Effect: cancer500x EWG'S HEALTH GUIDELINE
THIS UTILITY2.00 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 500 times above EWG's Health Guideline.

EWG Health Guideline

0.004 ppb or less

This Utility

2 ppb

Legal Limit

10 ppb

National Average

0.647 ppb

State Average

0.597 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: cancer167x EWG'S HEALTH GUIDELINE
THIS UTILITY10.0 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 167 times above EWG's Health Guideline.

EWG Health Guideline

0.06 ppb or less

This Utility

10 ppb

National Average

5.79 ppb

State Average

6.44 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

Chlorite

Potential Effect: change in blood chemistry3.2x EWG'S HEALTH GUIDELINE
THIS UTILITY160.8 ppb
EWG HEALTH GUIDELINE50 ppb
LEGAL LIMIT1,000 ppb
DETAILS
X

Chlorite is a disinfection byproduct resulting from water treatment with chlorine dioxide. Chlorite decreases hemoglobin levels and causes other hematologic effects.

Chlorite was found at 3.2 times above EWG's Health Guideline.

EWG Health Guideline

50 ppb or less

This Utility

160.8 ppb

Legal Limit

1,000 ppb

National Average

209.1 ppb

State Average

264.7 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 50 ppb for chlorite 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 change in blood chemistry.

Pollution Sources

industry icon

Industry

water treatment icon

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Chloroform

Potential Effect: cancer62x EWG'S HEALTH GUIDELINE
THIS UTILITY24.8 ppb
EWG HEALTH GUIDELINE0.4 ppb
NO LEGAL LIMIT
DETAILS
X

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.

Chloroform was found at 62 times above EWG's Health Guideline.

EWG Health Guideline

0.4 ppb or less

This Utility

24.8 ppb

National Average

15.5 ppb

State Average

15.3 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 0.4 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

water treatment icon

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Dibromoacetic acid

Potential Effect: 5.8x EWG'S HEALTH GUIDELINE
THIS UTILITY0.231 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 5.8 times above EWG's Health Guideline.

EWG Health Guideline

0.04 ppb or less

This Utility

0.231 ppb

National Average

1.1 ppb

State Average

1 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: cancer26x EWG'S HEALTH GUIDELINE
THIS UTILITY2.57 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 26 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

2.57 ppb

National Average

3.29 ppb

State Average

3.71 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

Dichloroacetic acid

Potential Effect: cancer64x EWG'S HEALTH GUIDELINE
THIS UTILITY12.8 ppb
EWG HEALTH GUIDELINE0.2 ppb
NO LEGAL LIMIT
DETAILS
X

Dichloroacetic acid

more about
this contaminant

Dichloroacetic 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.

Dichloroacetic acid was found at 64 times above EWG's Health Guideline.

EWG Health Guideline

0.2 ppb or less

This Utility

12.8 ppb

National Average

7.97 ppb

State Average

5.52 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 0.2 ppb for dichloroacetic acid was proposed in 2020 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.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: cancer226x EWG'S HEALTH GUIDELINE
THIS UTILITY22.6 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 226 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

22.6 ppb

Legal Limit

60 ppb

National Average

17.1 ppb

State Average

9.87 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

Nitrate

Potential Effect: cancer6.5x EWG'S HEALTH GUIDELINE
THIS UTILITY0.907 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 6.5 times above EWG's Health Guideline.

EWG Health Guideline

0.14 ppm or less

This Utility

0.907 ppm

Legal Limit

10 ppm

National Average

0.935 ppm

State Average

2.28 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

Total trihalomethanes (TTHMs)†

Potential Effect: cancer250x EWG'S HEALTH GUIDELINE
THIS UTILITY37.4 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 250 times above EWG's Health Guideline.

EWG Health Guideline

0.15 ppb or less

This Utility

37.4 ppb

Legal Limit

80 ppb

National Average

29.7 ppb

State Average

27 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

Trichloroacetic acid

Potential Effect: cancer94x EWG'S HEALTH GUIDELINE
THIS UTILITY9.38 ppb
EWG HEALTH GUIDELINE0.1 ppb
NO LEGAL LIMIT
DETAILS
X

Trichloroacetic acid

more about
this contaminant

Trichloroacetic 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.

Trichloroacetic acid was found at 94 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

9.38 ppb

National Average

6.62 ppb

State Average

2.67 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 trichloroacetic acid was proposed in 2020 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.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

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.



† 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


Creston Water Supply compliance with legally mandated federal standards:

  • From April 2019 to March 2021, Creston Water Supply complied with health-based drinking water standards.
  • 4 QUARTERS
    in violation of any federal drinking water standard from April 2019 to March 2021

Information in this section on Creston Water Supply 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
Chlorite
Chloroform
Dibromoacetic acid
Dibromochloromethane
Dichloroacetic acid
Haloacetic acids (HAA5)
Nitrate
Total trihalomethanes (TTHMs)
Trichloroacetic acid
OTHER CONTAMINANTS
DETECTED
Atrazine
Barium
Bromoform
Dalapon
Fluoride
Monochloroacetic acid
p-Dichlorobenzene
Picloram

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