Chesterfield, Missouri Tap Water Quality Report
Serving utility: Missouri American St. Louis County & St. Charles County
Updated March 2026 • Data from EWG Tap Water Database & EPA SDWIS
High Priority Concerns
Chesterfield tap water has 14 contaminants exceeding EWG health guidelines, including Haloacetic acids (HAA9), Haloacetic acids (HAA5), Total trihalomethanes (TTHMs). Additionally, 15 known or suspected carcinogens were detected, including Haloacetic acids (HAA9), Haloacetic acids (HAA5), Total trihalomethanes (TTHMs).
Water Provider Information
Contaminants Detected
| Contaminant | Detected Level | EWG Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Haloacetic acids (HAA9) carcinogen | 22.80 ppb | 0.06 ppb | No legal limit | Above guideline |
| Haloacetic acids (HAA5) carcinogen | 20.70 ppb | 0.10 ppb | 60 ppb | Above guideline |
| Total trihalomethanes (TTHMs) carcinogen | 30.90 ppb | 0.15 ppb | 80 ppb | Above guideline |
| Arsenic carcinogen | 0.40 ppb | 0.00 ppb | 10 ppb | Above guideline |
| Dichloroacetic acid carcinogen | 17.70 ppb | 0.20 ppb | No legal limit | Above guideline |
| Chloroform carcinogen | 26.20 ppb | 0.40 ppb | No legal limit | Above guideline |
| Chromium (hexavalent) carcinogen | 1.26 ppb | 0.02 ppb | No legal limit | Above guideline |
| Bromodichloromethane carcinogen | 3.63 ppb | 0.06 ppb | No legal limit | Above guideline |
| Trichloroacetic acid carcinogen | 1.88 ppb | 0.10 ppb | No legal limit | Above guideline |
| Dibromochloromethane carcinogen | 0.99 ppb | 0.10 ppb | No legal limit | Above guideline |
| Dibromoacetic acid | 0.28 ppb | 0.03 ppb | No legal limit | Above guideline |
| Nitrate carcinogen | 0.46 ppm | 0.14 ppm | 10 ppm | Above guideline |
| Nitrate and nitrite carcinogen | 0.47 ppm | 0.14 ppm | 10 ppm | Above guideline |
| Atrazine | 0.13 ppb | 0.10 ppb | 3 ppb | Above guideline |
| 1,4-Dioxane carcinogen | 0.02 ppb | 0.35 ppb | No legal limit | Below guideline |
| 2,4-D | 0.03 ppb | 20 ppb | 70 ppb | Below guideline |
| 2-Methoxyethanol | 0.38 ppb | N/A | No legal limit | Below guideline |
| Aluminum | 0.67 ppb | 600 ppb | No legal limit | Below guideline |
| Bromoform carcinogen | 0.04 ppb | 0.50 ppb | No legal limit | Below guideline |
| Chlorate | 163.40 ppb | 210 ppb | No legal limit | Near guideline |
| Fluoride | 0.64 ppm | N/A | 4 ppm | Below guideline |
| Lithium | 23.10 ppb | N/A | No legal limit | Below guideline |
| Manganese | 0.18 ppb | 100 ppb | No legal limit | Below guideline |
| Molybdenum | 1.94 ppb | 40 ppb | No legal limit | Below guideline |
| Monochloroacetic acid | 0.82 ppb | 53 ppb | No legal limit | Below guideline |
| Nitrite carcinogen | 0.01 ppm | N/A | 1 ppm | Below guideline |
| Perfluorobutanoic Acid (PFBA) | 0.84 ppt | 1,000 ppt | No legal limit | Below guideline |
| Selenium | 0.27 ppb | 30 ppb | 50 ppb | Below guideline |
| Strontium | 0.11 ppb | 1,500 ppb | No legal limit | Below guideline |
| Testosterone | 0.01 ppt | N/A | No legal limit | Below guideline |
| Vanadium | 2.09 ppb | 21 ppb | No legal limit | Below guideline |
Health Context
Haloacetic acids (HAA9) carcinogen
Exposure to elevated levels of this contaminant may pose health risks. See EWG and EPA guidelines for more information.
Haloacetic acids (HAA5) carcinogen
Exposure to elevated levels of this contaminant may pose health risks. See EWG and EPA guidelines for more information.
Total trihalomethanes (TTHMs) carcinogen
Exposure to elevated levels of this contaminant may pose health risks. See EWG and EPA guidelines for more information.
Arsenic carcinogen
Long-term exposure increases risk of skin cancer, bladder cancer, and lung cancer; chronic exposure causes neurological effects and cardiovascular disease.
Dichloroacetic acid carcinogen
Exposure to elevated levels of this contaminant may pose health risks. See EWG and EPA guidelines for more information.
Recommended Filtration for This Water
Echo RO System
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Filters water at every tap in your home. Reduces chlorine, VOCs, and disinfection byproducts from your shower, bath, and kitchen water.
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Shop Hydrogen FlaskFrequently Asked Questions
Is Chesterfield tap water safe to drink?
Chesterfield tap water meets EPA legal standards for drinking water. However, 14 contaminants exceed stricter EWG health guidelines, and 15 known carcinogens were detected. While legally compliant, additional filtration is recommended for optimal safety.
What contaminants are in Chesterfield water?
A total of 31 contaminants were detected in Chesterfield tap water, including Haloacetic acids (HAA9), Haloacetic acids (HAA5). Of these, 14 exceed EWG health guidelines.
What's the best water filter for Chesterfield?
For Chesterfield tap water, we recommend a reverse osmosis (RO) system for drinking water — it removes up to 99.9% of contaminants including heavy metals, PFAS, and disinfection byproducts. For shower and bath water, a whole-home filtration system reduces chlorine and volatile organics.
Where does Chesterfield get its water?
Chesterfield tap water is provided by Missouri American St. Louis County & St. Charles County, serving approximately 1,100,000 people. For detailed source water information, contact your local utility or visit the EPA's SDWIS database.
Nearby City Water Reports
Data sources: Environmental Working Group (EWG) Tap Water Database, U.S. EPA Safe Drinking Water Information System (SDWIS)
Last updated: March 2026
Methodology: Contaminant levels are compared against both EPA legal limits (Maximum Contaminant Levels) and EWG health guidelines, which are often stricter and based on the latest scientific research.
