Louisville, Kentucky Tap Water Quality Report
Serving utility: Louisville Water Company
Updated March 2026 • Data from EWG Tap Water Database & EPA SDWIS
Notable Concerns
Louisville tap water has 9 contaminants exceeding EWG health guidelines, including Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Haloacetic acids (HAA5). Additionally, 10 known or suspected carcinogens were detected, including Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Haloacetic acids (HAA5).
Water Provider Information
Contaminants Detected
| Contaminant | Detected Level | EWG Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Haloacetic acids (HAA9) carcinogen | 27.50 ppb | 0.06 ppb | No legal limit | Above guideline |
| Total trihalomethanes (TTHMs) carcinogen | 23.80 ppb | 0.15 ppb | 80 ppb | Above guideline |
| Haloacetic acids (HAA5) carcinogen | 15.80 ppb | 0.10 ppb | 60 ppb | Above guideline |
| Perfluorooctanoic acid (PFOA) carcinogen | 1.82 ppt | 0.09 ppt | 4 ppt | Above guideline |
| Nitrate carcinogen | 0.58 ppm | 0.14 ppm | 10 ppm | Above guideline |
| Nitrate and nitrite carcinogen | 0.58 ppm | 0.14 ppm | 10 ppm | Above guideline |
| Chromium (hexavalent) carcinogen | 0.08 ppb | 0.02 ppb | No legal limit | Above guideline |
| Chlorite | 141.70 ppb | 50 ppb | 1,000 ppb | Above guideline |
| Perfluorooctane sulfonate (PFOS) carcinogen | 0.36 ppt | 0.30 ppt | 4 ppt | Above guideline |
| 1,4-Dioxane carcinogen | 0.22 ppb | 0.35 ppb | No legal limit | Below guideline |
| 2,4-D | 0.02 ppb | 20 ppb | 70 ppb | Below guideline |
| Aluminum | 22.80 ppb | 600 ppb | No legal limit | Below guideline |
| Atrazine | 0.00 ppb | 0.10 ppb | 3 ppb | Below guideline |
| Barium | 12.80 ppb | 700 ppb | 2,000 ppb | Below guideline |
| Chlorate | 72.50 ppb | 210 ppb | No legal limit | Below guideline |
| Ethinyl estradiol | 0.14 ppt | N/A | No legal limit | Below guideline |
| Fluoride | 0.66 ppm | N/A | 4 ppm | Below guideline |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) | 1.22 ppt | 9 ppt | 10 ppt | Below guideline |
| Manganese | 1.11 ppb | 100 ppb | No legal limit | Below guideline |
| Molybdenum | 2.31 ppb | 40 ppb | No legal limit | Below guideline |
| Nitrite carcinogen | 0.00 ppm | N/A | 1 ppm | Below guideline |
| Perfluorobutane sulfonate (PFBS) | 0.38 ppt | 2,000 ppt | No legal limit | Below guideline |
| Perfluorohexanoic Acid (PFHxA) | 1.17 ppt | 1,000 ppt | No legal limit | Below guideline |
| Perfluoropentanoic Acid (PFPeA) | 1.33 ppt | 1,000 ppt | No legal limit | Below guideline |
| Strontium | 0.16 ppb | 1,500 ppb | No legal limit | Below guideline |
| Vanadium | 0.12 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.
Total trihalomethanes (TTHMs) 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.
Perfluorooctanoic acid (PFOA) carcinogen
Exposure to elevated levels of this contaminant may pose health risks. See EWG and EPA guidelines for more information.
Nitrate carcinogen
Nitrate is converted to nitrite in the body, which can interfere with oxygen transport in blood. Chronic exposure is linked to increased cancer risk.
Recommended Filtration for This Water
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Shop Hydrogen FlaskFrequently Asked Questions
Is Louisville tap water safe to drink?
Louisville tap water meets EPA legal standards for drinking water. However, 9 contaminants exceed stricter EWG health guidelines, and 10 known carcinogens were detected. While legally compliant, additional filtration is recommended for optimal safety.
What contaminants are in Louisville water?
A total of 26 contaminants were detected in Louisville tap water, including Haloacetic acids (HAA9), Total trihalomethanes (TTHMs). Of these, 9 exceed EWG health guidelines.
What's the best water filter for Louisville?
For Louisville 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 Louisville get its water?
Louisville tap water is provided by Louisville Water Company, serving approximately 764,769 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.
