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Tap water quality report

Rancho Cucuamonga, CA

EPA monitoring detected 21 contaminants across the 1 water supplier serving Rancho Cucuamonga. 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
211,069
people served
21
contaminants found
California rankings Lead in California PFAS in California

What was found in Rancho Cucuamonga'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
Nitrate-Nitrite
710000 µg/L 7100%
of the EPA limit, at the 95th percentile of samples — 10000 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Nitrate
15000 µg/L 150%
of the EPA limit, at the 95th percentile of samples — 10000 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Fluoride
587 µg/L 15%
of the EPA limit 4000 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Barium
116.5 µg/L 5.8%
of the EPA limit 2000 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
TTHM
97.3 µg/L 122%
of the EPA limit, at the 95th percentile of samples — 80 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Copper
70 µg/L 5.4%
of the EPA limit 1300 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Dibromochloromethane
41.15 µg/L
No EPA limit set
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Bromoform
37.93 µg/L
No EPA limit set
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Bromodichloromethane
25 µg/L
No EPA limit set
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Chloroform
22.05 µg/L
No EPA limit set
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
18.91 µg/L 32%
of the EPA limit 60 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Combined Uranium
13.4398 µg/L 45%
of the EPA limit 30 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2017
1/1 SYR4
Dibromoacetic Acid
11 µg/L
No EPA limit set
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Trichloroacetic Acid
8 µg/L
No EPA limit set
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Dichloroacetic Acid
6.68 µg/L
No EPA limit set
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Arsenic
5.325 µg/L 53%
of the EPA limit 10 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Monobromoacetic Acid
1.8 µg/L
No EPA limit set
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Picloram
1.4 µg/L 0.3%
of the EPA limit 500 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Dichloromethane
0.9800 µg/L 20%
of the EPA limit 5 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
1,2-DIBROMO-3-CHLOROPROPANE
0.2900 µg/L 145%
of the EPA limit, at the 95th percentile of samples — 0.2000 µg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2019
1/1 SYR4
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
Main supplier: CUCAMONGA VALLEY WATER DISTRICT · 211,069 people · 2024
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 Rancho Cucuamonga

SupplierPopulation served
CUCAMONGA VALLEY WATER DISTRICT 211,069

Frequently asked questions about Rancho Cucuamonga tap water

Is Rancho Cucuamonga tap water safe to drink?

EPA testing detected 21 contaminants in the water serving Rancho Cucuamonga. 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 Rancho Cucuamonga?

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

What contaminants are in Rancho Cucuamonga's water?

The contaminants EPA monitoring detected in Rancho Cucuamonga include Nitrate-Nitrite, Nitrate, Fluoride, Barium, TTHM. 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.