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Tap water quality report

Louisville, KY

EPA monitoring detected 17 contaminants across the 1 water supplier serving Louisville. A detection doesn't automatically mean the water is unsafe — see the highest level found for each below, with its EPA source and period.

1
water supplier
806,997
people served
17
contaminants found
Kentucky rankings Lead in Kentucky PFAS in Kentucky

What was found in Louisville's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
1600 µg/L 16%
of the EPA limit 10000 µg/L
 1/1 SYR4
Nitrate-Nitrite
1600 µg/L 16%
of the EPA limit 10000 µg/L
 1/1 SYR4
Fluoride
1000 µg/L 25%
of the EPA limit 4000 µg/L
 1/1 SYR4
Chlorite
570 µg/L 57%
of the EPA limit 1000 µg/L
 1/1 SYR4
Copper
132 µg/L 10%
of the EPA limit 1300 µg/L
 1/1 SYR4
Total Haloacetic Acids (HAA5)
68 µg/L 113%
of the EPA limit, in the worst sample — 60 µg/L
 1/1 SYR4
TTHM
46.2 µg/L 58%
of the EPA limit 80 µg/L
 1/1 SYR4
Lead
13.5 µg/L 90%
of the EPA limit 15 µg/L
 1/1 SYR4
Gross Alpha, Excl. Radon And U
3.4 pCi/L 23%
of the EPA limit 15 pCi/L
 1/1 SYR4
Combined Radium (-226 And -228)
1.7 pCi/L 34%
of the EPA limit 5 pCi/L
 1/1 SYR4
2,4-D
0.3000 µg/L 0.4%
of the EPA limit 70 µg/L
 1/1 SYR4
Atrazine
0.2400 µg/L 8%
of the EPA limit 3 µg/L
 1/1 SYR4
PFOA
0.0075 µg/L
No EPA limit set
 1/1 UCMR-5
Pfpea
0.0041 µg/L
No EPA limit set
 1/1 UCMR-5
Pfhxa
0.0036 µg/L
No EPA limit set
 1/1 UCMR-5
PFBS
0.0030 µg/L
No EPA limit set
 1/1 UCMR-5
Lead
0.0011 mg/L 7.3%
of the EPA limit 0.0150 mg/L
 1/1 LCR
Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Louisville

SupplierPopulation served
LOUISVILLE WATER COMPANY 806,997

Frequently asked questions about Louisville tap water

Is Louisville tap water safe to drink?

EPA testing detected 17 contaminants in the water serving Louisville. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Louisville?

1 public water supplier report drinking-water monitoring for Louisville, Kentucky to the EPA. Each is listed above with its population served.

What contaminants are in Louisville's water?

The contaminants EPA monitoring detected in Louisville include Nitrate, Nitrate-Nitrite, Fluoride, Chlorite, Copper. The full list, with the highest level found and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.