Water Quality Report · Updated May 12, 2026
LOUISVILLE WATER COMPANY
LOUISVILLE WATER COMPANY delivers tap water graded D (62/100) by TapWaterSafety.org. The utility serves approximately 764,769 residents in LOUISVILLE, Kentucky using surface water. The most significant water quality concerns are: PFAS contamination; Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline. For questions, the utility can be reached at 502-271-8873.
Is LOUISVILLE tap water safe to drink?
LOUISVILLE WATER COMPANY delivers tap water that earns a grade of D (62/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including pfas contamination.
The utility serves 764,769 residents in LOUISVILLE, drawing from surface water.
Public testing data identifies 9 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Haloacetic acids (HAA5), Perfluorooctanoic acid (PFOA), Nitrate, Nitrate and nitrite, Chromium (hexavalent), Chlorite, Perfluorooctane sulfonate (PFOS). For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for LOUISVILLE residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for LOUISVILLE WATER COMPANY.
PFAS contamination
Severe concernPerfluorooctanoic acid (PFOA), Perfluorooctane sulfonate (PFOS) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 27.5 ppb, 459x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 23.8 ppb, 159x above the EWG health guideline of 0.15 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 15.8 ppb, 158x above the EWG health guideline of 0.1 ppb.
Contact LOUISVILLE WATER COMPANY
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for LOUISVILLE
Filters matched to the specific contaminants in this water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 62/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
27.5 ppb | 0.06 | — | — | — | — | — | 459× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
23.8 ppb | 0.15 | 80.0 | 100 | — | — | — | 159× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
15.8 ppb | 0.1 | 60.0 | 60 | — | — | — | 158× over |
| Perfluorooctanoic acid (PFOA) PFAS |
1.82 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 20× over |
| Nitrate Inorganic |
0.577 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 4.1× over |
| Nitrate and nitrite Inorganic |
0.578 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 4.1× over |
| Chromium (hexavalent) Heavy metal |
0.0806 ppb | 0.02 | — | — | — | — | — | 4.0× over |
| Chlorite Disinfection byproduct |
141.7 ppb | 50.0 | 1000.0 | — | — | — | — | 2.8× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.361 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 1.2× over |
| 1,4-Dioxane Semi-volatile organic compound |
0.22 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Chlorate Disinfection byproduct |
72.5 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) Other |
1.22 ppt | 9.0 | 10.0 | — | — | — | — | Below guideline |
| Molybdenum Other |
2.31 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Atrazine Pesticide/Herbicide |
0.004 ppb | 0.1 | 3.0 | 0.1 | 100 | 0.15 | — | Below guideline |
| Aluminum Heavy metal |
22.8 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Barium Heavy metal |
12.8 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Manganese Heavy metal |
1.11 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Vanadium Other |
0.125 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
1.33 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| 2,4-D Pesticide/Herbicide |
0.0242 ppb | 20.0 | 70.0 | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
1.17 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.375 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.162 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Ethinyl estradiol Other |
0.138 ppt | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.661 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Nitrite Inorganic |
0.0015 ppm | — | 1.0 | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
LOUISVILLE WATER COMPANY service area
This water system serves 1 community in Jefferson County, Kentucky. Click any city for its dedicated tap water quality page.
Find the right filter for LOUISVILLE water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.