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Tap water quality report

Louisville, CO

EPA monitoring detected 23 contaminants across the 1 water supplier serving Louisville. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

1
water supplier
20,975
people served
23
contaminants found
Colorado rankings Lead in Colorado PFAS in Colorado

What was found in Louisville's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Fluoride
790 µg/L 20%
of the EPA limit 4000 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Chlorite
445.5 µg/L 45%
of the EPA limit 1000 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Nitrate
116 µg/L 1.2%
of the EPA limit 10000 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
TTHM
60.4 µg/L 76%
of the EPA limit 80 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Chloroform
58.665 µg/L
No EPA limit set
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Barium
43.25 µg/L 2.2%
of the EPA limit 2000 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
29.46 µg/L 49%
of the EPA limit 60 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Dichloroacetic Acid
15.965 µg/L
No EPA limit set
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Trichloroacetic Acid
9.13 µg/L
No EPA limit set
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Bromodichloromethane
7.63 µg/L
No EPA limit set
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Monochloroacetic Acid
2.49 µg/L
No EPA limit set
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Monobromoacetic Acid
2.2 µg/L
No EPA limit set
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Dibromochloromethane
1.84 µg/L
No EPA limit set
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Dibromoacetic Acid
1.1 µg/L
No EPA limit set
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Combined Radium (-226 And -228)
0.9800 pCi/L 20%
of the EPA limit 5 pCi/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2017
1/1 SYR4
Selenium
0.8180 µg/L 1.6%
of the EPA limit 50 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Arsenic
0.7660 µg/L 7.7%
of the EPA limit 10 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Chromium
0.4495 µg/L 0.4%
of the EPA limit 100 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Gross Alpha, Excl. Radon And U
0.3950 pCi/L 2.6%
of the EPA limit 15 pCi/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2017
1/1 SYR4
Dichloromethane
0.3200 µg/L 6.4%
of the EPA limit 5 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Xylenes, Total
0.2800 µg/L 0%
of the EPA limit 10000 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Antimony, Total
0.0695 µg/L 1.2%
of the EPA limit 6 µg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2019
1/1 SYR4
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
Main supplier: LOUISVILLE CITY OF · 20,975 people · 2025
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 95th percentile of the system's samples — 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 CITY OF 20,975

Frequently asked questions about Louisville tap water

Is Louisville tap water safe to drink?

EPA testing detected 23 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, Colorado 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 Fluoride, Chlorite, Nitrate, TTHM, Chloroform. The full list, with the level at the main supplier 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.