Water Quality Report · Updated May 12, 2026
CWS - BAKERSFIELD
CWS - BAKERSFIELD delivers tap water graded F (47/100) by TapWaterSafety.org. The utility serves approximately 267,881 residents in SAN JOSE, California using surface water. The most significant water quality concerns are: PFAS contamination; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Arsenic significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline. For questions, the utility can be reached at 408-367-8593.
Is SAN JOSE tap water safe to drink?
CWS - BAKERSFIELD delivers tap water that earns a grade of F (47/100) from TapWaterSafety.org — a poor rating, with significant contamination concerns and/or recent violations.
The utility serves 267,881 residents in SAN JOSE, drawing from surface water.
Public testing data identifies 18 contaminants in this water above EWG's health-based guidelines, including: Perfluorohexane sulfonate (PFHXS), Arsenic, Haloacetic acids (HAA9), Haloacetic acids (HAA5), Total trihalomethanes (TTHMs), Trichloroacetic acid, Bromodichloromethane, Chloroform, Dichloroacetic acid, Chromium (hexavalent), Dibromochloromethane, Nitrate, Nitrate and nitrite, Perfluorooctane sulfonate (PFOS), Dibromoacetic acid, Perfluorooctanoic acid (PFOA), Uranium, Chlorate. 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 CWS - BAKERSFIELD.
PFAS contamination
Severe concernPerfluorooctane sulfonate (PFOS), Perfluorooctanoic acid (PFOA) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Perfluorohexane sulfonate (PFHXS) significantly above health guideline
Moderate concernPerfluorohexane sulfonate (PFHXS) detected at 1.47 ppt, 1468x above the EWG health guideline of 0.001 ppt.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 3.13 ppb, 781x above the EWG health guideline of 0.004 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 39.6 ppb, 660x above the EWG health guideline of 0.06 ppb.
Contact CWS - BAKERSFIELD
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for SAN JOSE
Filters matched to the specific contaminants in this water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
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 47/100 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 |
|---|---|---|---|---|---|---|---|---|
| Perfluorohexane sulfonate (PFHXS) PFAS |
1.47 ppt | 0.001 | 10.0 | — | — | — | — | 1468× over |
| Arsenic Heavy metal |
3.13 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 781× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
39.6 ppb | 0.06 | — | — | — | — | — | 660× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
36.3 ppb | 0.1 | 60.0 | 60 | — | — | — | 363× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
35.6 ppb | 0.15 | 80.0 | 100 | — | — | — | 237× over |
| Trichloroacetic acid Disinfection byproduct |
13.1 ppb | 0.1 | — | — | — | — | — | 131× over |
| Bromodichloromethane Disinfection byproduct |
5.9 ppb | 0.06 | — | — | — | — | — | 98× over |
| Chloroform Disinfection byproduct |
27.1 ppb | 0.4 | — | — | — | — | — | 68× over |
| Dichloroacetic acid Disinfection byproduct |
11.9 ppb | 0.2 | — | — | — | — | — | 60× over |
| Chromium (hexavalent) Heavy metal |
0.661 ppb | 0.02 | — | — | — | — | — | 33× over |
| Dibromochloromethane Disinfection byproduct |
1.84 ppb | 0.1 | — | — | — | — | — | 18× over |
| Nitrate Inorganic |
1.87 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 13× over |
| Nitrate and nitrite Inorganic |
1.59 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 11× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
3.17 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 11× over |
| Dibromoacetic acid Disinfection byproduct |
0.3 ppb | 0.03 | — | — | — | — | — | 10× over |
| Perfluorooctanoic acid (PFOA) PFAS |
0.899 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 10× over |
| Uranium Radiological |
1.2 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 2.8× over |
| Chlorate Disinfection byproduct |
262.3 ppb | 210.0 | — | — | — | — | — | 1.2× over |
| 1,2,3-Trichloropropane Other |
0.000527 ppb | 0.0007 | — | — | — | — | — | Below guideline |
| Tetrachloroethylene (perchloroethylene) Volatile organic compound |
0.0425 ppb | 0.06 | 5.0 | — | — | — | — | Below guideline |
| Bromoform Disinfection byproduct |
0.224 ppb | 0.5 | — | — | — | — | — | Below guideline |
| Vanadium Other |
5.04 ppb | 21.0 | — | — | — | — | — | Below guideline |
| 1,2-Dibromo-3-chloropropane (DBCP) Other |
0.00033 ppb | 0.0017 | 0.2 | — | — | — | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.038 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Molybdenum Other |
2.49 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Trichloroethylene Volatile organic compound |
0.00736 ppb | 0.4 | 5.0 | 10 | 20 | 1.7 | — | Below guideline |
| 6:2 Fluorotelomer Sulfonic Acid (6:2 FTSA) Other |
0.014 ppt | 1.0 | — | — | — | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.569 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
7.33 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Manganese Heavy metal |
0.546 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
0.528 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
0.381 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
0.202 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Strontium Radiological |
0.345 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
0.174 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.279 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
0.068 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| 1,1-Dichloroethane Volatile organic compound |
0.000127 ppb | 3.0 | — | — | — | — | — | Below guideline |
| Chlorodifluoromethane Other |
0.0372 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.0942 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Germanium Other |
0.0143 ppb | — | — | — | — | — | — | Below guideline |
| Lithium Other |
2.12 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.
CWS - BAKERSFIELD service area
This water system serves 1 community in Kern 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.