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Tap water quality report

Pomona, CA

EPA monitoring detected 33 contaminants across the 2 water suppliers serving Pomona. 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.

2
water suppliers
181,567
people served
33
contaminants found
California rankings Lead in California PFAS in California

What was found in Pomona'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
17000 µg/L 170%
of the EPA limit, at the 95th percentile of samples — 10000 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
1/2 SYR4
Nitrate
16272 µg/L 163%
of the EPA limit, at the 95th percentile of samples — 10000 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
2/2 SYR4
Fluoride
504 µg/L 13%
of the EPA limit 4000 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
2/2 SYR4
Barium
100 µg/L 5%
of the EPA limit 2000 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 126.5 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
TTHM
39 µg/L 49%
of the EPA limit 80 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 89.75 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Chromium
88 µg/L 88%
of the EPA limit 100 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
2/2 SYR4
Tetrachloroethylene
7.6 µg/L 152%
of the EPA limit, at the 95th percentile of samples — 5 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 70 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Trichloroethylene
10 µg/L 200%
of the EPA limit, at the 95th percentile of samples — 5 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 42 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Total Haloacetic Acids (HAA5)
16.05 µg/L 27%
of the EPA limit 60 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 31.4 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Bromodichloromethane
12 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 29.65 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Dibromochloromethane
13 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 29.65 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
1,1-Dichloroethylene
28 µg/L 400%
of the EPA limit, at the 95th percentile of samples — 7 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
2/2 SYR4
Chloroform
13 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 19.65 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Bromoform
9.425 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 16 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Monochloroacetic Acid
12.9 µg/L
No EPA limit set
Highest in the city: CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
1/2 SYR4
Dichloroacetic Acid
8.365 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 12 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Combined Uranium
6.8724 µg/L 23%
of the EPA limit 30 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 11.397 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Lithium
9.3 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2024
1/2 UCMR-5
Arsenic
8.365 µg/L 84%
of the EPA limit 10 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
1/2 SYR4
Bromate
8.07 µg/L 81%
of the EPA limit 10 µg/L
Highest in the city: CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
1/2 SYR4
Dibromoacetic Acid
3.47 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 7.6 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Selenium
7.02 µg/L 14%
of the EPA limit 50 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
1/2 SYR4
Trichloroacetic Acid
6.8 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
2/2 SYR4
Monobromoacetic Acid
2.175 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
Highest in the city: 5.15 µg/L — CALIF STATE POLYTECHNICAL UNIV - POMONA · 29,854 people · 2019
2/2 SYR4
Thallium, Total
1.2 µg/L 60%
of the EPA limit 2 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
1/2 SYR4
1,2-DIBROMO-3-CHLOROPROPANE
0.0882 µg/L 44%
of the EPA limit 0.2000 µg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2019
1/2 SYR4
PFOS
0.0180 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2024
1/2 UCMR-5
PFHXS
0.0079 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2024
1/2 UCMR-5
PFOA
0.0071 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2024
1/2 UCMR-5
Pfpea
0.0044 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2024
1/2 UCMR-5
Pfhxa
0.0041 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2024
1/2 UCMR-5
PFBS
0.0032 µg/L
No EPA limit set
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2024
1/2 UCMR-5
Lead
0.0021 mg/L 14%
of the EPA limit 0.0150 mg/L
Main supplier: POMONA - CITY, WATER DEPT. · 151,713 people · 2025
2/2 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 Pomona

SupplierPopulation served
POMONA - CITY, WATER DEPT. 151,713
CALIF STATE POLYTECHNICAL UNIV - POMONA 29,854

Frequently asked questions about Pomona tap water

Is Pomona tap water safe to drink?

EPA testing detected 33 contaminants in the water serving Pomona. 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 Pomona?

2 public water suppliers report drinking-water monitoring for Pomona, California to the EPA. Each is listed above with its population served.

What contaminants are in Pomona's water?

The contaminants EPA monitoring detected in Pomona 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.