← California

Tap water quality report

Hollister, CA

EPA monitoring detected 31 contaminants across the 20 water suppliers serving Hollister. A detection doesn't automatically mean the water is unsafe — see the highest level found for each below, with its EPA source and period.

20
water suppliers
53,545
people served
31
contaminants found

What was found in Hollister's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate-Nitrite
700000 µg/L 7000%
of the EPA limit, in the worst sample — 10000 µg/L
18/20 SYR4
Nitrate
17800 µg/L 178%
of the EPA limit, in the worst sample — 10000 µg/L
19/20 SYR4
Copper
1100 µg/L 85%
of the EPA limit 1300 µg/L
7/20 SYR4
Fluoride
520 µg/L 13%
of the EPA limit 4000 µg/L
19/20 SYR4
Barium
420 µg/L 21%
of the EPA limit 2000 µg/L
12/20 SYR4
Nitrite
400 µg/L 40%
of the EPA limit 1000 µg/L
5/20 SYR4
Arsenic
200 µg/L 2000%
of the EPA limit, in the worst sample — 10 µg/L
16/20 SYR4
TTHM
161.8 µg/L 202%
of the EPA limit, in the worst sample — 80 µg/L
18/20 SYR4
Bromoform
105.05 µg/L
No EPA limit set
17/20 SYR4
Dibromochloromethane
77.57 µg/L
No EPA limit set
13/20 SYR4
Combined Uranium
46.19 µg/L 154%
of the EPA limit, in the worst sample — 30 µg/L
10/20 SYR4
Chromium
41 µg/L 41%
of the EPA limit 100 µg/L
11/20 SYR4
Total Haloacetic Acids (HAA5)
35.4 µg/L 59%
of the EPA limit 60 µg/L
13/20 SYR4
Lead
35 µg/L 233%
of the EPA limit, in the worst sample — 15 µg/L
2/20 SYR4
Bromodichloromethane
34.37 µg/L
No EPA limit set
13/20 SYR4
Lithium
29 µg/L
No EPA limit set
2/20 UCMR-5
Asbestos
27 MFL 386%
of the EPA limit, in the worst sample — 7 MFL
1/20 SYR4
Dibromoacetic Acid
21.1 µg/L
No EPA limit set
17/20 SYR4
Dichloroacetic Acid
12.2 µg/L
No EPA limit set
9/20 SYR4
Chloroform
10 µg/L
No EPA limit set
9/20 SYR4
Selenium
9.1 µg/L 18%
of the EPA limit 50 µg/L
9/20 SYR4
Gross Beta Particle Activity
8.3 pCi/L
No EPA limit set
1/20 SYR4
Trichloroacetic Acid
7.1 µg/L
No EPA limit set
7/20 SYR4
Monochloroacetic Acid
4.5 µg/L
No EPA limit set
2/20 SYR4
Combined Radium (-226 And -228)
3.88 pCi/L 78%
of the EPA limit 5 pCi/L
3/20 SYR4
Monobromoacetic Acid
3 µg/L
No EPA limit set
5/20 SYR4
Toluene
2.3 µg/L 0.2%
of the EPA limit 1000 µg/L
2/20 SYR4
Antimony, Total
2 µg/L 33%
of the EPA limit 6 µg/L
1/20 SYR4
Cadmium
0.5000 µg/L 10%
of the EPA limit 5 µg/L
1/20 SYR4
Lead
0.0453 mg/L 302%
above the EPA limit of 0.0150 mg/L
19/20 LCR
PFOA
0.0046 µg/L
No EPA limit set
1/20 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. 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 Hollister

Frequently asked questions about Hollister tap water

Is Hollister tap water safe to drink?

EPA testing detected 31 contaminants in the water serving Hollister. 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 Hollister?

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

What contaminants are in Hollister's water?

The contaminants EPA monitoring detected in Hollister include Nitrate-Nitrite, Nitrate, Copper, Fluoride, Barium. The full list, with the highest level found 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.