Tap WaterIndex

← Colorado

Tap water quality report

Niwot, CO

EPA monitoring detected 21 contaminants across the 1 water supplier serving Niwot. 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
20,280
people served
21
contaminants found
Colorado rankings Lead in Colorado PFAS in Colorado

What was found in Niwot'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
934.5 µg/L 23%
of the EPA limit 4000 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Nitrate
240 µg/L 2.4%
of the EPA limit 10000 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
TTHM
87.53 µg/L 109%
of the EPA limit, at the 95th percentile of samples — 80 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Chloroform
71.11 µg/L
No EPA limit set
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Barium
50.25 µg/L 2.5%
of the EPA limit 2000 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
48.28 µg/L 80%
of the EPA limit 60 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Nitrate-Nitrite
21.175 µg/L 0.2%
of the EPA limit 10000 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2012
1/1 SYR4
Trichloroacetic Acid
19.929 µg/L
No EPA limit set
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Dichloroacetic Acid
18.8 µg/L
No EPA limit set
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Bromodichloromethane
12.51 µg/L
No EPA limit set
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Nitrite
8.11 µg/L 0.8%
of the EPA limit 1000 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2013
1/1 SYR4
Xylenes, Total
4.965 µg/L 0%
of the EPA limit 10000 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Monochloroacetic Acid
2.74 µg/L
No EPA limit set
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Dibromochloromethane
2.61 µg/L
No EPA limit set
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Gross Alpha, Excl. Radon And U
1.285 pCi/L 8.6%
of the EPA limit 15 pCi/L
Main supplier: LEFT HAND WD · 20,280 people · 2012
1/1 SYR4
Selenium
1.1 µg/L 2.2%
of the EPA limit 50 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Ethylbenzene
0.6100 µg/L 0.1%
of the EPA limit 700 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Combined Radium (-226 And -228)
0.2000 pCi/L 4%
of the EPA limit 5 pCi/L
Main supplier: LEFT HAND WD · 20,280 people · 2012
1/1 SYR4
Hexachlorocyclopentadiene
0.1064 µg/L 0.2%
of the EPA limit 50 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2017
1/1 SYR4
Hexachlorobenzene
0.0150 µg/L 1.5%
of the EPA limit 1 µg/L
Main supplier: LEFT HAND WD · 20,280 people · 2019
1/1 SYR4
Lead
0.0010 mg/L 6.7%
of the EPA limit 0.0150 mg/L
Main supplier: LEFT HAND WD · 20,280 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 Niwot

SupplierPopulation served
LEFT HAND WD 20,280

Frequently asked questions about Niwot tap water

Is Niwot tap water safe to drink?

EPA testing detected 21 contaminants in the water serving Niwot. 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 Niwot?

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

What contaminants are in Niwot's water?

The contaminants EPA monitoring detected in Niwot include Fluoride, Nitrate, TTHM, Chloroform, Barium. 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.