Water Quality Report · Updated May 12, 2026
CALIFORNIA WATER SERVICE CO. - PALOS VER
CALIFORNIA WATER SERVICE CO. - PALOS VER delivers tap water graded D (64/100) by TapWaterSafety.org. The utility serves approximately 71,452 residents in SAN JOSE, California using surface water (purchased). The most significant water quality concerns are: Haloacetic acids (HAA5) significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Arsenic detected. For questions, the utility can be reached at 408-367-8593.
Is SAN JOSE tap water safe to drink?
CALIFORNIA WATER SERVICE CO. - PALOS VER delivers tap water that earns a grade of D (64/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including haloacetic acids (haa5) significantly above health guideline.
The utility serves 71,452 residents in SAN JOSE, drawing from surface water (purchased).
Public testing data identifies 17 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA5), Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Bromodichloromethane, Dibromochloromethane, Bromochloroacetic acid, Dibromoacetic acid, Arsenic*, Dichloroacetic acid, Trichloroacetic acid, Chloroform, Bromoform, Uranium*, Chromium (hexavalent), Nitrate*, Nitrate and nitrite*, Radium, combined (-226 and -228)*. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for SAN JOSE residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for CALIFORNIA WATER SERVICE CO. - PALOS VER.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 36.2 ppb, 362x above the EWG health guideline of 0.1 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 14.2 ppb, 236x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 32.7 ppb, 218x above the EWG health guideline of 0.15 ppb.
Arsenic detected
Moderate concernArsenic detected at 0.16 ppb.
Contact CALIFORNIA WATER SERVICE CO. - PALOS VER
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Recommended water filters for SAN JOSE
Filters matched to the specific contaminants in this water supply.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 64/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA5) Disinfection byproduct |
36.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 362× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
14.2 ppb | 0.06 | — | — | — | — | — | 236× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
32.7 ppb | 0.15 | 80.0 | 100 | — | — | — | 218× over |
| Bromodichloromethane Disinfection byproduct |
9.19 ppb | 0.06 | — | — | — | — | — | 153× over |
| Dibromochloromethane Disinfection byproduct |
10.0 ppb | 0.1 | — | — | — | — | — | 100× over |
| Bromochloroacetic acid Disinfection byproduct |
1.79 ppb | 0.02 | — | — | — | — | — | 89× over |
| Dibromoacetic acid Disinfection byproduct |
2.61 ppb | 0.03 | — | — | — | — | — | 87× over |
| Arsenic* Heavy metal |
0.16 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 40× over |
| Dichloroacetic acid Disinfection byproduct |
5.96 ppb | 0.2 | — | — | — | — | — | 30× over |
| Trichloroacetic acid Disinfection byproduct |
2.95 ppb | 0.1 | — | — | — | — | — | 30× over |
| Chloroform Disinfection byproduct |
9.7 ppb | 0.4 | — | — | — | — | — | 24× over |
| Bromoform Disinfection byproduct |
3.74 ppb | 0.5 | — | — | — | — | — | 7.5× over |
| Uranium* Radiological |
1.33 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 3.1× over |
| Chromium (hexavalent) Heavy metal |
0.0418 ppb | 0.02 | — | — | — | — | — | 2.1× over |
| Nitrate* Inorganic |
0.281 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 2.0× over |
| Nitrate and nitrite* Inorganic |
0.287 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 2.0× over |
| Radium, combined (-226 and -228)* Radiological |
0.07 pCi/L | 0.05 | 5.0 | — | — | — | — | 1.4× over |
| N-Nitrosodimethylamine (NDMA) Other |
2.01 ppt | 3.0 | — | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
75.8 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Aluminum* Heavy metal |
77.5 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Vanadium Other |
2.71 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
4.95 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Barium* Heavy metal |
36.7 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Manganese Heavy metal |
1.0 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.0465 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
1.15 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.663 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Lithium Other |
42.7 ppb | — | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
CALIFORNIA WATER SERVICE CO. - PALOS VER service area
This water system serves 1 community in Los Angeles County, California. Click any city for its dedicated tap water quality page.
Find the right filter for SAN JOSE water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.