← Rancho Cucuamonga, CA

Tap water quality report

ZIP 91784 — Rancho Cucuamonga, CA

EPA monitoring across the 4 water suppliers serving ZIP 91784 in Rancho Cucuamonga, CA detected 32 contaminants. A detection doesn't automatically mean the water is unsafe — see the highest level found below, with the EPA limit for each.

4
water suppliers
332,616
people served
32
contaminants found

What was found in ZIP 91784

The highest level seen across the suppliers serving this ZIP, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate-Nitrite
990000 µg/L 9900%
of the EPA limit, in the worst sample — 10000 µg/L
3/4 SYR4
Nitrate
22600 µg/L 226%
of the EPA limit, in the worst sample — 10000 µg/L
3/4 SYR4
Fluoride
990 µg/L 25%
of the EPA limit 4000 µg/L
3/4 SYR4
Copper
380 µg/L 29%
of the EPA limit 1300 µg/L
2/4 SYR4
TTHM
160 µg/L 200%
of the EPA limit, in the worst sample — 80 µg/L
4/4 SYR4
Barium
120 µg/L 6%
of the EPA limit 2000 µg/L
1/4 SYR4
Dibromochloromethane
60 µg/L
No EPA limit set
4/4 SYR4
Bromodichloromethane
50 µg/L
No EPA limit set
4/4 SYR4
Bromoform
46 µg/L
No EPA limit set
3/4 SYR4
Total Haloacetic Acids (HAA5)
38 µg/L 63%
of the EPA limit 60 µg/L
4/4 SYR4
Chloroform
37 µg/L
No EPA limit set
4/4 SYR4
Tetrachloroethylene
24 µg/L 480%
of the EPA limit, in the worst sample — 5 µg/L
1/4 SYR4
Dichloroacetic Acid
16 µg/L
No EPA limit set
4/4 SYR4
Trichloroacetic Acid
16 µg/L
No EPA limit set
3/4 SYR4
Combined Uranium
14.602 µg/L 49%
of the EPA limit 30 µg/L
3/4 SYR4
Dibromoacetic Acid
14.3 µg/L
No EPA limit set
3/4 SYR4
Gross Beta Particle Activity
9.8 pCi/L
No EPA limit set
1/4 SYR4
Monobromoacetic Acid
6.2 µg/L
No EPA limit set
3/4 SYR4
Monochloroacetic Acid
5.7 µg/L
No EPA limit set
1/4 SYR4
Arsenic
5.5 µg/L 55%
of the EPA limit 10 µg/L
3/4 SYR4
Trichloroethylene
3.1 µg/L 62%
of the EPA limit 5 µg/L
1/4 SYR4
1,2-DIBROMO-3-CHLOROPROPANE
1.8 µg/L 900%
of the EPA limit, in the worst sample — 0.2000 µg/L
3/4 SYR4
Picloram
1.4 µg/L 0.3%
of the EPA limit 500 µg/L
1/4 SYR4
Dichloromethane
0.9800 µg/L 20%
of the EPA limit 5 µg/L
1/4 SYR4
PFOA
0.0129 µg/L
No EPA limit set
1/4 UCMR-5
PFOS
0.0104 µg/L
No EPA limit set
1/4 UCMR-5
Pfhxa
0.0084 µg/L
No EPA limit set
2/4 UCMR-5
Pfpea
0.0064 µg/L
No EPA limit set
2/4 UCMR-5
Lead
0.0056 mg/L 37%
of the EPA limit 0.0150 mg/L
4/4 LCR
PFBS
0.0051 µg/L
No EPA limit set
2/4 UCMR-5
Pfhpa
0.0046 µg/L
No EPA limit set
1/4 UCMR-5
PFHXS
0.0037 µg/L
No EPA limit set
1/4 UCMR-5
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.

Water suppliers serving ZIP 91784

SupplierStatePopulation served
CUCAMONGA VALLEY WATER DISTRICT CA 211,069
UPLAND, CITY OF CA 78,376
GSWC - CLAREMONT CA 39,730
SAN ANTONIO WATER COMPANY CA 3,441

Frequently asked questions about ZIP 91784 tap water

Is the tap water in ZIP 91784 safe to drink?

EPA testing detected 32 contaminants across the water suppliers serving ZIP 91784. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and your utility's annual Consumer Confidence Report for the official status.

Which water suppliers serve ZIP 91784?

4 public water suppliers report EPA drinking-water monitoring for ZIP 91784. Each is listed above with its population served.

What contaminants are in ZIP 91784's water?

EPA monitoring detected Nitrate-Nitrite, Nitrate, Fluoride, Copper, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.