Mercer PWS
EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the Missouri Department of Natural Resources - Public Drinking Water Program, 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
- Mercer, Missouri
- Serves: 318
- Data available: 2014-2019
- Source: Purchased groundwater
Contaminants Detected
14
EXCEED
EWG HEALTH
GUIDELINES
21 Total Contaminants
- Legal does not necessarily equal safe. Getting a passing grade from the federal government does not mean the water meets the latest health guidelines.
- Legal limits for contaminants in tap water have not been updated in almost 20 years.
- The best way to ensure clean tap water is to keep pollution out of source water in the first place.
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See the guideContaminants Detected
Bromochloroacetic acid
Potential Effect: 323x EWG'S HEALTH GUIDELINEBromochloroacetic acid
more aboutthis 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 323 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.02 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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Bromodichloroacetic acid
Potential Effect: 69x EWG'S HEALTH GUIDELINEBromodichloroacetic acid
more aboutthis contaminant
Bromodichloroacetic acid is formed when chlorine or other disinfectants are used to treat drinking water. Bromodichloroacetic acid and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.
Bromodichloroacetic acid was found at 69 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.04 ppb for bromodichloroacetic 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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Bromodichloromethane
Potential Effect: cancer327x EWG'S HEALTH GUIDELINEBromodichloromethane
more aboutthis contaminant
Bromodichloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromodichloromethane and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Bromodichloromethane was found at 327 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.06 ppb for bromodichloromethane was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Bromoform
Potential Effect: cancer3.3x EWG'S HEALTH GUIDELINEBromoform
more aboutthis contaminant
Bromoform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromoform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Bromoform was found at 3.3 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.5 ppb for bromoform 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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Chlorodibromoacetic acid
Potential Effect: Cancer; Harm to reproduction and child development83x EWG'S HEALTH GUIDELINEChlorodibromoacetic acid
more aboutthis contaminant
Chlorodibromoacetic acid is formed when chlorine or other disinfectants are used to treat drinking water. Disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.
Chlorodibromoacetic acid was found at 83 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.02 ppb for chlorodibromoacetic 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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Chloroform
Potential Effect: cancer99x EWG'S HEALTH GUIDELINEChloroform
more aboutthis contaminant
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 99 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.4 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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Dibromoacetic acid
Potential Effect: 66x EWG'S HEALTH GUIDELINEDibromoacetic acid
more aboutthis contaminant
Dibromoacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Dibromoacetic acid was found at 66 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.04 ppb for dibromoacetic acid was defined in a peer-reviewed scientific study by EWG and represents a on-in-a-million lifetime cancer risk level. This health guideline protects against cancer.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Dibromochloromethane
Potential Effect: cancer104x EWG'S HEALTH GUIDELINEDibromochloromethane
more aboutthis contaminant
Dibromochloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Dibromochloromethane and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Dibromochloromethane was found at 104 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for dibromochloromethane was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Dichloroacetic acid
Potential Effect: cancer55x EWG'S HEALTH GUIDELINEDichloroacetic acid
more aboutthis 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 55 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.2 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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Haloacetic acids (HAA5)†
Potential Effect: cancer179x EWG'S HEALTH GUIDELINEHaloacetic acids (HAA5)
more aboutthis contaminant
Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of five haloacetic acids regulated by federal standards includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid.
Haloacetic acids (HAA5) was found at 179 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for the group of five haloacetic acids, or HAA5, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level. This health guideline protects against cancer.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Nitrate and nitrite*
Potential Effect: cancer2.3x EWG'S HEALTH GUIDELINENitrate and nitrite
more aboutthis 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
This Utility
Legal Limit
National Average
State Average
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
Runoff & Sprawl
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Total trihalomethanes (TTHMs)†
Potential Effect: cancer474x EWG'S HEALTH GUIDELINETotal trihalomethanes (TTHMs)
more aboutthis contaminant
Trihalomethanes are cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform.
Total trihalomethanes (TTHMs) was found at 474 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Tribromoacetic acid
Potential Effect: 5.3x EWG'S HEALTH GUIDELINETribromoacetic acid
more aboutthis contaminant
Tribromoacetic acid is formed when chlorine or other disinfectants are used to treat drinking water. Disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.
Tribromoacetic acid was found at 5.3 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.04 ppb for tribromoacetic 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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Trichloroacetic acid
Potential Effect: cancer44x EWG'S HEALTH GUIDELINETrichloroacetic acid
more aboutthis 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 44 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for 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
Treatment Byproducts
Filtering Options
Activated Carbon
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.
*This water utility buys or otherwise receives some or all of its finished water from Princeton PWS. 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.
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
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
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.
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Chromium (total)
more aboutthis contaminant
Chromium is a naturally occurring metal, but industrial uses can elevate its levels in water. One form, hexavalent chromium, causes cancer. Total chromium is not a good indicator of the amount of hexavalent chromium in drinking water.
How your levels compare
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Fluoride
more aboutthis contaminant
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems.
How your levels compare
This Utility
Legal Limit
National Average
State Average
ppm = parts per million
Pollution Sources
Treatment Byproducts
Filtering Options
Reverse Osmosis
Manganese
more aboutthis contaminant
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
This Utility
National Average
State Average
ppb = parts per billion
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.
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Ion Exchange
Monobromoacetic acid
more aboutthis contaminant
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
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 25 ppb for monobromoacetic 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.. This health guideline protects against muscular degeneration.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Monochloroacetic acid
more aboutthis contaminant
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
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 53 ppb for monochloroacetic 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.. This health guideline protects against system toxicity.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Selenium
more aboutthis contaminant
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
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
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.
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Includes chemicals detected in 2017-2019 for which annual utility averages were lower than an EWG-selected health guideline established by a federal or state public health authori.
Mercer PWS compliance with legally mandated federal standards:
- From April 2019 to March 2021, Mercer PWS complied with health-based drinking water standards.
- 6 QUARTERSin violation of any federal drinking water standard from April 2019 to March 2021
- Over the last 3 years this water utility has spent 2 QUARTERSin significant violation of federal drinking water standards
Information in this section on Mercer PWS comes from the U.S. EPA Enforcement and Compliance History Online database (ECHO).
LEARN MORE ABOUT THIS UTILITYWater Filters That Can Reduce Contaminant Levels
| Contaminant | Activated Carbon | Reverse Osmosis | Ion Exchange |
| CONTAMINANTS ABOVE HEALTH GUIDELINES | |||
| Bromochloroacetic acid | ✔ | ✔ | |
| Bromodichloroacetic acid | ✔ | ✔ | |
| Bromodichloromethane | ✔ | ✔ | |
| Bromoform | ✔ | ✔ | |
| Chlorodibromoacetic acid | ✔ | ✔ | |
| Chloroform | ✔ | ✔ | |
| Dibromoacetic acid | ✔ | ✔ | |
| Dibromochloromethane | ✔ | ✔ | |
| Dichloroacetic acid | ✔ | ✔ | |
| Haloacetic acids (HAA5) | ✔ | ✔ | |
| Nitrate & nitrite | ✔ | ✔ | |
| Total trihalomethanes (TTHMs) | ✔ | ✔ | |
| Tribromoacetic acid | ✔ | ✔ | |
| Trichloroacetic acid | ✔ | ✔ | |
| OTHER CONTAMINANTS DETECTED | |||
| Barium | ✔ | ✔ | |
| Chromium (total) | ✔ | ✔ | |
| Fluoride | ✔ | ||
| Manganese | ✔ | ||
| Monobromoacetic acid | ✔ | ✔ | |
| Monochloroacetic acid | ✔ | ✔ | |
| Selenium | ✔ | ||
Take Action
Contact Your Local Official
One of the best ways to push for cleaner water is to hold accountable the elected officials who have a say in water quality – from city hall and the state legislature to Congress all the way to the Oval Office – by asking questions and demanding answers.
LEARN MOREFilter Out Contaminants
Check out our recommendations for filters to protect your water against the detected contaminants.
EWG’S WATER FILTER GUIDE
