Know Your Environment. Protect Your Health.

UTILITY

Wilsonville

location

Wilsonville, Illinois

serves

586

source

Purchased surface water

data

2018-2023

Overview

EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the Illinois Environmental Protection Agency, 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 (April 2024 - June 2024), tap water provided by this water utility was in compliance with federal health-based drinking water standards.

Contaminants Detected

Arsenic*

Potential Effect: cancer

This Utility: 0.367 ppb

92x

EWG's Health Guideline: 0.004 ppb

Arsenic

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 92 times above EWG's Health Guideline.

EWG Health Guideline

0.004 ppb or less

This Utility

0.367 ppb

Legal Limit

10 ppb

National Average

0.624 ppb

State Average

0.395 ppb

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.

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Agriculture

Industry

Naturally Occurring

Filtering Options

Reverse Osmosis

Ion Exchange

Atrazine*

Potential Effect: harm to the developing fetus

This Utility: 0.498 ppb

5x

EWG's Health Guideline: 0.1 ppb

Atrazine

Atrazine is a herbicide commonly detected in drinking water that comes from cornfield and other agricultural runoff. It is a hormone disrupter that harms the male and female reproductive systems of people and wildlife.

Atrazine was found at 5 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

0.498 ppb

Legal Limit

3 ppb

National Average

0.0145 ppb

State Average

0.0195 ppb

Health Risks

The EWG Health Guideline of 0.1 ppb for atrazine was defined by EWG based on epidemiological studies of human exposure to atrazine in drinking water.. This health guideline protects against harm to the developing fetus, harm to the reproductive system and hormone disruption.

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Agriculture

Filtering Options

Activated Carbon

Reverse Osmosis

Bromodichloromethane

Potential Effect: cancer

This Utility: 7.42 ppb

124x

EWG's Health Guideline: 0.06 ppb

Bromodichloromethane

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 124 times above EWG's Health Guideline.

EWG Health Guideline

0.06 ppb or less

This Utility

7.42 ppb

National Average

5.89 ppb

State Average

7.74 ppb

Health Risks

The EWG Health Guideline of 0.06 ppb for bromodichloromethane was based on the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer and harm to fetal growth and development.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Chloroform

Potential Effect: cancer

This Utility: 28.2 ppb

71x

EWG's Health Guideline: 0.4 ppb

Chloroform

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 71 times above EWG's Health Guideline.

EWG Health Guideline

0.4 ppb or less

This Utility

28.2 ppb

National Average

16.2 ppb

State Average

16.2 ppb

Health Risks

The EWG Health Guideline of 0.4 ppb for chloroform was based on the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer and harm to fetal growth and development.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Dibromochloromethane

Potential Effect: cancer

This Utility: 0.967 ppb

9.7x

EWG's Health Guideline: 0.1 ppb

Dibromochloromethane

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 9.7 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

0.967 ppb

National Average

3.55 ppb

State Average

4.25 ppb

Health Risks

The EWG Health Guideline of 0.1 ppb for dibromochloromethane was based on the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer and harm to fetal growth and development.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Dichloroacetic acid

Potential Effect: cancer

This Utility: 11.9 ppb

59x

EWG's Health Guideline: 0.2 ppb

Dichloroacetic acid

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 59 times above EWG's Health Guideline.

EWG Health Guideline

0.2 ppb or less

This Utility

11.9 ppb

National Average

8 ppb

State Average

7.18 ppb

Health Risks

The EWG Health Guideline of 0.2 ppb for dichloroacetic acid was defined by the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer and harm to reproduction and child development.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Haloacetic acids (HAA5)

Potential Effect: cancer

This Utility: 22.5 ppb

225x

EWG's Health Guideline: 0.1 ppb

Haloacetic acids (HAA5)

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 225 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

22.5 ppb

Legal Limit

60 ppb

National Average

19.8 ppb

State Average

13.6 ppb

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.

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Nitrate*

Potential Effect: cancer

This Utility: 0.467 ppm

3.3x

EWG's Health Guideline: 0.14 ppm

Nitrate

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 3.3 times above EWG's Health Guideline.

EWG Health Guideline

0.14 ppm or less

This Utility

0.467 ppm

Legal Limit

10 ppm

National Average

0.824 ppm

State Average

0.734 ppm

Health Risks

The EWG 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.

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppm = parts per million

Pollution Sources

Agriculture

Runoff & Sprawl

Naturally Occurring

Filtering Options

Reverse Osmosis

Ion Exchange

Nitrate and nitrite*

Potential Effect: cancer

This Utility: 0.830 ppm

5.9x

EWG's Health Guideline: 0.14 ppm

Nitrate and nitrite

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 5.9 times above EWG's Health Guideline.

EWG Health Guideline

0.14 ppm or less

This Utility

0.83 ppm

Legal Limit

10 ppm

National Average

0.78 ppm

State Average

0.805 ppm

Health Risks

The EWG 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.

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppm = parts per million

Pollution Sources

Agriculture

Runoff & Sprawl

Naturally Occurring

Filtering Options

Reverse Osmosis

Ion Exchange

Total trihalomethanes (TTHMs)

Potential Effect: cancer

This Utility: 36.6 ppb

244x

EWG's Health Guideline: 0.15 ppb

Total trihalomethanes (TTHMs)

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 244 times above EWG's Health Guideline.

EWG Health Guideline

0.15 ppb or less

This Utility

36.6 ppb

Legal Limit

80 ppb

National Average

29.1 ppb

State Average

28.7 ppb

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.

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Trichloroacetic acid

Potential Effect: cancer

This Utility: 10.4 ppb

104x

EWG's Health Guideline: 0.1 ppb

Trichloroacetic acid

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 104 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

10.4 ppb

National Average

6.57 ppb

State Average

4.92 ppb

Health Risks

The EWG Health Guideline of 0.1 ppb for trichloroacetic acid was defined by the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer and harm to reproduction and child development.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Includes chemicals detected in 2021-2023 for which annual utility averages exceeded an EWG-selected health guideline established by a federal or state public health authority.


*This water utility buys or otherwise receives some or all of its finished water from Gillespie. Tap water results marked with an * are from the supplying utility.


† 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.

Aluminum*

This Utility: 17.7 ppb

EWG's Health Guideline: 600 ppb

Aluminum

Aluminum is a metal released from metal refineries and mining operations. Too much aluminum exposure can impair children's brain development.

How your levels compare

EWG Health Guideline

600 ppb or less

This Utility

17.7 ppb

National Average

26.4 ppb

State Average

20.3 ppb

Health Risks

The EWG Health Guideline of 600 ppb for aluminum was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to the brain and nervous system.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Industry

Naturally Occurring

Filtering Options

Reverse Osmosis

Barium*

This Utility: 41.0 ppb

EWG's Health Guideline: 700 ppb

Barium

Barium is a mineral present in rocks, soil and water. High concentrations of barium in drinking water increase the risk of cardiovascular disease and hypertension.

How your levels compare

EWG Health Guideline

700 ppb or less

This Utility

41 ppb

Legal Limit

2,000 ppb

National Average

39.5 ppb

State Average

61.2 ppb

Health Risks

The EWG Health Guideline of 700 ppb for barium was defined by EWG as benchmark that protects against harm to the kidneys and the cardiovascular system.

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Industry

Naturally Occurring

Filtering Options

Reverse Osmosis

Ion Exchange

Dibromoacetic acid*

This Utility: 0.0425 ppb

EWG's Health Guideline: 0.03 ppb

Dibromoacetic acid

Dibromoacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.

How your levels compare

EWG Health Guideline

0.03 ppb or less

This Utility

0.0425 ppb

National Average

1.13 ppb

State Average

0.836 ppb

Health Risks

The EWG Health Guideline of 0.03 ppb for dibromoacetic acid was defined by the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer and harm to fetal growth and development.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Estriol*

This Utility: 0.230 ppt

No EWG Health Guideline

Estriol

Estriol is one of the 3 types of estrogen made by the human body. Sex hormones get into water downstream from livestock and pharmaceutical production, or incomplete removal in waste water treatment. There are no standards to gauge how risky additional hormones are for human health.

How your levels compare

This Utility

0.23 ppt

National Average

ppt

State Average

ppt

EWG Health Guideline

Not yet determined

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2016.

ppt = parts per trillion

Pollution Sources

Runoff & Sprawl

Filtering Options

Activated Carbon

Reverse Osmosis

Fluoride*

This Utility: 0.599 ppm

No EWG Health Guideline

Fluoride

Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems to prevent cavities and support oral health in people.

In 2015, the Department of Health and Human Services updated its recommendation of an optimal level of 0.7 parts per million, or ppm, added to drinking water based on the health benefits of tooth decay prevention. Studies have shown that fluoride added to community water systems at this level reduces dental cavities, especially in children.

And studies have conclusively shown that fluoride in toothpaste and mouthwash can also provide these benefits.

How your levels compare

This Utility

0.599 ppm

Legal Limit

4 ppm

National Average

0.49 ppm

State Average

0.681 ppm

EWG Health Guideline

Not yet determined

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppm = parts per million

Pollution Sources

Industry

Treatment Byproducts

Naturally Occurring

Filtering Options

Reverse Osmosis

Manganese*

This Utility: 26.1 ppb

EWG's Health Guideline: 100 ppb

Manganese

Manganese is a naturally occurring element that is common in food and drinking water. Excessive manganese exposures may impair children's attention, memory and intellectual capacity. Click here to read more about manganese.

How your levels compare

EWG Health Guideline

100 ppb or less

This Utility

26.1 ppb

National Average

8.66 ppb

State Average

4.87 ppb

Health Risks

The EWG Health Guideline of 100 ppb for manganese was defined by the state of Minnesota as a health risk limit, the concentration of a contaminant that can be consumed with little or no risk to health. This health guideline protects against harm to the brain and nervous system.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2023.

ppb = parts per billion

Pollution Sources

Industry

Naturally Occurring

Filtering Options

Ion Exchange

Monobromoacetic acid*

This Utility: 3.26 ppb

EWG's Health Guideline: 25 ppb

Monobromoacetic acid

Monobromoacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.

How your levels compare

EWG Health Guideline

25 ppb or less

This Utility

3.26 ppb

National Average

0.18 ppb

State Average

0.458 ppb

Health Risks

The EWG Health Guideline of 25 ppb for monobromoacetic acid was defined by the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against change to fetal growth and development.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Monochloroacetic acid

This Utility: 0.192 ppb

EWG's Health Guideline: 53 ppb

Monochloroacetic acid

Monochloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.

How your levels compare

EWG Health Guideline

53 ppb or less

This Utility

0.192 ppb

National Average

0.497 ppb

State Average

0.208 ppb

Health Risks

The EWG Health Guideline of 53 ppb for monochloroacetic acid was defined by the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk.a public health goal. This health guideline protects against change to fetal growth and development.

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Treatment Byproducts

Filtering Options

Activated Carbon

Reverse Osmosis

Selenium*

This Utility: 1.17 ppb

EWG's Health Guideline: 30 ppb

Selenium

Selenium is an essential element in diets. But too much selenium can decrease thyroid hormone production and cause hair loss, skin lesions and brittle fingernails.

How your levels compare

EWG Health Guideline

30 ppb or less

This Utility

1.17 ppb

Legal Limit

50 ppb

National Average

0.29 ppb

State Average

0.291 ppb

Health Risks

The EWG Health Guideline of 30 ppb for selenium 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 hair loss and nail damage.

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.

ppb = parts per billion

Pollution Sources

Industry

Naturally Occurring

Filtering Options

Reverse Osmosis

Testosterone*

This Utility: 0.0250 ppt

No EWG Health Guideline

Testosterone

Human sex hormones are sometimes detected at low concentrations in drinking water. There are no current health guidelines to determine whether these exposures are safe, or if they could pose a risk to human health.

How your levels compare

This Utility

0.025 ppt

National Average

0.003 ppt

State Average

0.019 ppt

EWG Health Guideline

Not yet determined

Legal Limit

None

Understanding the Data

The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2016.

ppt = parts per trillion

Pollution Sources

Runoff & Sprawl

Filtering Options

Activated Carbon

Reverse Osmosis

Includes chemicals detected in 2021-2023 for which annual utility averages were lower than an EWG-selected health guideline established by a federal or state public health authority.

Other Contaminants Tested

Chemicals tested for but not detected:

Bromoform, Monobromoacetic acid

Find A Filter

Utility: 

Wilsonville
view utility

Carbon Filters

FILTERS 8 contaminants exceeding guidelines (+5 others)

Can reduce the levels of many common contaminants.

pros

  • Lower upfront cost
  • Reduced maintenance

cons

  • Does not remove all contaminants

Reverse Osmosis

FILTERS 11 contaminants exceeding guidelines (+9 others)

Can reduce the levels of many common contaminants.

pros

  • Most effective

cons

  • Higher upfront cost
  • Requires more maintenance
  • Wastes water

Other Considerations

Ion Exchange

Pros: Softens hard water, Reduces some contaminants

Cons: Doesn’t remove all contaminants

Whole-House Filters

Pros: Useful for reducing radiologicals and TCE

Cons: Expensive to install and maintain, Risk of bacterial contamination

Distillation

Pros: Removes heavy metals and harmful microbes

Cons: Does not reduce most contaminants

Explore filter options for each contaminant. See which technologies are effective at reducing specific contaminants to help you make an informed decision on the best water treatment solution for your needs.

CONTAMINANTS ABOVE HEALTH GUIDELINES activated carbon reverse osmosis ion exchange
Arsenic
Atrazine
Bromodichloromethane
Chloroform
Dibromochloromethane
Dichloroacetic acid
Haloacetic acids (HAA5)
Nitrate
Nitrate & nitrite
Total trihalomethanes (TTHMs)
Trichloroacetic acid
OTHER CONTAMINANTS DETECTED activated carbon reverse osmosis ion exchange
Aluminum
Barium
Dibromoacetic acid
Estriol
Fluoride
Manganese
Monobromoacetic acid
Monochloroacetic acid
Selenium
Testosterone