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Tap water quality report

Whitethorn, CA

EPA monitoring detected 17 contaminants across the 2 water suppliers serving Whitethorn. 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
919
people served
17
contaminants found
California rankings Lead in California PFAS in California

What was found in Whitethorn'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
793500 µg/L 7935%
of the EPA limit, at the 95th percentile of samples — 10000 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Nitrate
1600 µg/L 16%
of the EPA limit 10000 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Fluoride
249 µg/L 6.2%
of the EPA limit 4000 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
2/2 SYR4
Barium
168 µg/L 8.4%
of the EPA limit 2000 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Copper
120 µg/L 9.2%
of the EPA limit 1300 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Total Haloacetic Acids (HAA5)
45 µg/L 75%
of the EPA limit 60 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
TTHM
35 µg/L 44%
of the EPA limit 80 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Dichloroacetic Acid
28 µg/L
No EPA limit set
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Chloroform
23 µg/L
No EPA limit set
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Trichloroacetic Acid
17 µg/L
No EPA limit set
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Antimony, Total
16 µg/L 267%
of the EPA limit, at the 95th percentile of samples — 6 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Bromodichloromethane
8.3 µg/L
No EPA limit set
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Arsenic
6.88 µg/L 69%
of the EPA limit 10 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Dibromochloromethane
3.6 µg/L
No EPA limit set
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Combined Uranium
1.29555 µg/L 4.3%
of the EPA limit 30 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Toluene
0.8600 µg/L 0.1%
of the EPA limit 1000 µg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2019
1/2 SYR4
Lead
0.0013 mg/L 8.4%
of the EPA limit 0.0150 mg/L
Main supplier: RESORT IMPROVEMENT DISTRICT #1 · 803 people · 2023
Highest in the city: 0.0032 mg/L — REDCREST WATER WORKS · 116 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 Whitethorn

SupplierPopulation served
RESORT IMPROVEMENT DISTRICT #1 803
REDCREST WATER WORKS 116

Frequently asked questions about Whitethorn tap water

Is Whitethorn tap water safe to drink?

EPA testing detected 17 contaminants in the water serving Whitethorn. 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 Whitethorn?

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

What contaminants are in Whitethorn's water?

The contaminants EPA monitoring detected in Whitethorn include Nitrate-Nitrite, Nitrate, Fluoride, Barium, Copper. 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.