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EWG's Tap Water Database — 2019 UPDATE

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Issaquah Water System

EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the Washington State Department of Health, 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 2019 - March 2019), tap water provided by this water utility was in compliance with federal health-based drinking water standards.

Utility Details

  • Issaquah, Washington
  • Serves: 22,926
  • Data available: 2012—2017
  • Source: Groundwater

Contaminants Detected

18

EXCEED
EWG HEALTH
GUIDELINES

25 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EWG Health Guidelines fill the gap in outdated government standards.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: cancer1,417x EWG'S HEALTH GUIDELINE
THIS UTILITY5.67 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 1,417 times above EWG's Health Guideline.

EWG Health Guideline

0.004 ppb or less

This Utility

5.67 ppb

Legal Limit

10 ppb

National Average

0.682 ppb

State Average

1.84 ppb
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
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

Bromochloroacetic acid

Potential Effect: 8.2x EWG'S HEALTH GUIDELINE
THIS UTILITY0.164 ppb
EWG HEALTH GUIDELINE0.02 ppb
NO LEGAL LIMIT
DETAILS
X

Bromochloroacetic acid

more about
this contaminant

Bromochloroacetic acid is formed when chlorine or other disinfectants are used to treat drinking water. Bromochloroacetic acid and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.

Bromochloroacetic acid was found at 8.2 times above EWG's Health Guideline.

EWG Health Guideline

0.02 ppb or less

This Utility

0.164 ppb

National Average

2.92 ppb

State Average

0.257 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
ppb = parts per billion

Health Risks

The EWG Health Guideline of 0.02 ppb for bromochloroacetic 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

Bromodichloromethane

Potential Effect: cancer40x EWG'S HEALTH GUIDELINE
THIS UTILITY2.43 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 40 times above EWG's Health Guideline.

EWG Health Guideline

0.06 ppb or less

This Utility

2.43 ppb

National Average

5.8 ppb

State Average

1.8 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
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

Chloroform

Potential Effect: cancer94x EWG'S HEALTH GUIDELINE
THIS UTILITY37.5 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 94 times above EWG's Health Guideline.

EWG Health Guideline

0.4 ppb or less

This Utility

37.5 ppb

National Average

15.1 ppb

State Average

15.9 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
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

Chromium (hexavalent)

Potential Effect: cancer4.1x EWG'S HEALTH GUIDELINE
THIS UTILITY0.0825 ppb
EWG HEALTH GUIDELINE0.02 ppb
NO LEGAL LIMIT
DETAILS
X

Chromium (hexavalent)

more about
this contaminant

Chromium (hexavalent) is a carcinogen that commonly contaminates American drinking water. Chromium (hexavalent) in drinking water may be due to industrial pollution or natural occurrences in mineral deposits and groundwater. Read more about chromium (hexavalent).

Chromium (hexavalent) was found at 4.1 times above EWG's Health Guideline.

EWG Health Guideline

0.02 ppb or less

This Utility

0.0825 ppb

National Average

0.492 ppb

State Average

0.227 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2012-2017.
ppb = parts per billion

Health Risks

The EWG Health Guideline of 0.02 ppb for chromium (hexavalent) 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 icon

Industry

naturally occuring icon

Naturally Occurring

Filtering Options

reverse osmosis icon

Reverse Osmosis

ion exchange icon

Ion Exchange

Dichloroacetic acid

Potential Effect: cancer45x EWG'S HEALTH GUIDELINE
THIS UTILITY8.93 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 45 times above EWG's Health Guideline.

EWG Health Guideline

0.2 ppb or less

This Utility

8.93 ppb

National Average

7.82 ppb

State Average

6.11 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
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: cancer283x EWG'S HEALTH GUIDELINE
THIS UTILITY28.3 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 283 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

28.3 ppb

Legal Limit

60 ppb

National Average

17.2 ppb

State Average

15.4 ppb
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
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 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

Nitrate

Potential Effect: cancer2.4x EWG'S HEALTH GUIDELINE
THIS UTILITY0.340 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 2.4 times above EWG's Health Guideline.

EWG Health Guideline

0.14 ppm or less

This Utility

0.34 ppm

Legal Limit

10 ppm

National Average

0.937 ppm

State Average

0.889 ppm
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
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

Nitrate and nitrite

Potential Effect: cancer2.3x EWG'S HEALTH GUIDELINE
THIS UTILITY0.315 ppm
EWG HEALTH GUIDELINE0.14 ppm
LEGAL LIMIT10 ppm
DETAILS
X

Nitrate and nitrite

more about
this 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 2.3 times above EWG's Health Guideline.

EWG Health Guideline

0.14 ppm or less

This Utility

0.315 ppm

Legal Limit

10 ppm

National Average

0.891 ppm

State Average

0.779 ppm
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
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 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: 4.2x EWG'S HEALTH GUIDELINE
THIS UTILITY4.16 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 4.2 times above EWG's Health Guideline.

EWG Health Guideline

1 ppt or less

This Utility

4.16 ppt

National Average

0.502 ppt

State Average

0.019 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2012-2017.
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

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Perfluoroheptanoic acid (PFHPA)

Potential Effect: 6.9x EWG'S HEALTH GUIDELINE
THIS UTILITY6.87 ppt
EWG HEALTH GUIDELINE1 ppt
NO LEGAL LIMIT
DETAILS
X

Perfluoroheptanoic acid (PFHPA)

more about
this contaminant

Perfluoroheptanoic acid 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.

Perfluoroheptanoic acid (PFHPA) was found at 6.9 times above EWG's Health Guideline.

EWG Health Guideline

1 ppt or less

This Utility

6.87 ppt

National Average

1.18 ppt

State Average

0.036 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2012-2017.
ppt = parts per trillion

Health Risks

The EWG Health Guideline of 1 ppt for perfluoroheptanoic acid 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: 64x EWG'S HEALTH GUIDELINE
THIS UTILITY64.4 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 64 times above EWG's Health Guideline.

EWG Health Guideline

1 ppt or less

This Utility

64.4 ppt

National Average

4.18 ppt

State Average

0.293 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2012-2017.
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

Perfluorononanoic acid (PFNA)

Potential Effect: 7.3x EWG'S HEALTH GUIDELINE
THIS UTILITY7.28 ppt
EWG HEALTH GUIDELINE1 ppt
NO LEGAL LIMIT
DETAILS
X

Perfluorononanoic acid (PFNA)

more about
this contaminant

Perfluorononanoic acid, otherwise known as PFNA or C9, is a PFC similar in function and use to PFOA. These chemicals were used in the production of non-stick, stain repellent and chemically inert coatings. Click here to read more about perfluorinated chemicals.

Perfluorononanoic acid (PFNA) was found at 7.3 times above EWG's Health Guideline.

EWG Health Guideline

1 ppt or less

This Utility

7.28 ppt

National Average

0.186 ppt

State Average

0.033 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2012-2017.
ppt = parts per trillion

Health Risks

The EWG Health Guideline of 1 ppt for perfluorononanoic acid 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

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Perfluorooctane sulfonate (PFOS)

Potential Effect: 159x EWG'S HEALTH GUIDELINE
THIS UTILITY158.8 ppt
EWG HEALTH GUIDELINE1 ppt
NO LEGAL LIMIT
DETAILS
X

Perfluorooctane sulfonate (PFOS)

more about
this contaminant

Perfluorooctane sulfonate (PFOS) 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.

Perfluorooctane sulfonate (PFOS) was found at 159 times above EWG's Health Guideline.

EWG Health Guideline

1 ppt or less

This Utility

158.8 ppt

National Average

3.6 ppt

State Average

0.722 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2012-2017.
ppt = parts per trillion

Health Risks

The EWG Health Guideline of 1 ppt for PFOS 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: cancer806x EWG'S HEALTH GUIDELINE
THIS UTILITY5.64 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 806 times above EWG's Health Guideline.

EWG Health Guideline

0.007 ppt or less

This Utility

5.64 ppt

National Average

2.41 ppt

State Average

0.067 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2012-2017.
ppt = parts per trillion

Health Risks

The EWG Health Guideline of 0.007 ppt for PFOA was defined 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: cancer2.8x EWG'S HEALTH GUIDELINE
THIS UTILITY0.14 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 2.8 times above EWG's Health Guideline.

EWG Health Guideline

0.05 pCi/L or less

This Utility

0.14 pCi/L

Legal Limit

5 pCi/L

National Average

0.47 pCi/L

State Average

0.11 pCi/L
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2012-2017.
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: cancer266x EWG'S HEALTH GUIDELINE
THIS UTILITY39.9 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 266 times above EWG's Health Guideline.

EWG Health Guideline

0.15 ppb or less

This Utility

39.9 ppb

Legal Limit

80 ppb

National Average

30.1 ppb

State Average

19.2 ppb
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
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: cancer189x EWG'S HEALTH GUIDELINE
THIS UTILITY18.9 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 189 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

18.9 ppb

National Average

6.42 ppb

State Average

8.94 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2015-2017.
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 2015-2017 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 3) program in 2013 to 2015 (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 2012 and 2017.

† HAA5 is a contaminant group that includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. TTHM is a contaminant group that includes bromodichloromethane, bromoform, chloroform and dibromochloromethane.


Other Contaminants Tested


Contaminants detected between 2012 and 2014 and were not part of EPA's UCMR-3 testing program or radiologicals:

Chromium (total), Bromoform, Dibromochloromethane

 

Chemicals tested for but not detected from 2012 to 2017:

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, 1,4-Dioxane, 2,2-Dichloropropane, 2,4,5-T, 2,4-D, 2,4-DB, Acifluorfen (Blazer), Antimony, Benzene, Benzoic acid, Beryllium, Bromobenzene, Bromochloromethane, Bromomethane, Cadmium, Carbon tetrachloride, Chlorodifluoromethane, Chloroethane, Chloromethane, cis-1,2-Dichloroethylene, cis-1,3-Dichloropropene, Cobalt, Cyanide, Dalapon, DCPA di-acid degradate, Dibromoacetic acid, Dibromomethane, Dicamba, Dichlorodifluoromethane, Dichloromethane (methylene chloride), Dinoseb, Ethylbenzene, Ethylene dibromide, Fluoride, Hexachlorobutadiene, Isopropylbenzene, m-Dichlorobenzene, Mercury (inorganic), Monobromoacetic acid, Monochlorobenzene (chlorobenzene), n-Butylbenzene, n-Propylbenzene, Naphthalene, Nitrite, o-Chlorotoluene, o-Dichlorobenzene, p-Chlorotoluene, p-Dichlorobenzene, p-Isopropyltoluene, Pentachlorophenol, Picloram, sec-Butylbenzene, Selenium, Silver, Styrene, tert-Butylbenzene, Tetrachloroethylene (perchloroethylene), Thallium, Toluene, trans-1,2-Dichloroethylene, trans-1,3-Dichloropropene, Trichloroethylene, Trichlorofluoromethane, Vinyl chloride, Xylenes (total)

Issaquah Water System compliance with legally mandated federal standards:

  • From April 2016 to March 2019, Issaquah Water System complied with health-based drinking water standards.

Information in this section on Issaquah Water System comes from the U.S. EPA Enforcement and Compliance History Online database (ECHO).

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Water Filters That Can Reduce Contaminant Levels

ContaminantActivated Carbonactivated carbonReverse Osmosisreverse osmosisIon Exchangeion exchange
CONTAMINANTS ABOVE
HEALTH GUIDELINES
Arsenic
Bromochloroacetic acid
Bromodichloromethane
Chloroform
Chromium (hexavalent)
Dichloroacetic acid
Haloacetic acids (HAA5)
Nitrate
Nitrate & nitrite
Perfluorobutane sulfonate (PFBS)
Perfluoroheptanoic acid (PFHPA)
Perfluorohexane sulfonate (PFHXS)
Perfluorononanoic acid (PFNA)
Perfluorooctane sulfonate (PFOS)
Perfluorooctanoic acid (PFOA)
Radium, combined (-226 & -228)
Total trihalomethanes (TTHMs)
Trichloroacetic acid
OTHER CONTAMINANTS
DETECTED
Barium
Chlorate
Manganese
Molybdenum
Monochloroacetic acid
Strontium
Vanadium

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.

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Filter Out Contaminants

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

EWG’S WATER FILTER GUIDE