Water Quality Report · Updated May 12, 2026
CWS - VISALIA
CWS - VISALIA delivers tap water graded F (53/100) by TapWaterSafety.org. The utility serves approximately 148,496 residents in SAN JOSE, California using groundwater. The most significant water quality concerns are: PFAS contamination; Haloacetic acids (HAA5) significantly above health guideline; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Arsenic significantly above health guideline. For questions, the utility can be reached at 408-367-8593.
Is SAN JOSE tap water safe to drink?
CWS - VISALIA delivers tap water that earns a grade of F (53/100) from TapWaterSafety.org — a poor rating, with significant contamination concerns and/or recent violations.
The utility serves 148,496 residents in SAN JOSE, drawing from groundwater.
Public testing data identifies 12 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA5), Perfluorohexane sulfonate (PFHXS), Arsenic, Chromium (hexavalent), Nitrate, Nitrate and nitrite, Uranium, Perfluorooctanoic acid (PFOA), Perfluorooctane sulfonate (PFOS), Bromodichloromethane, Dibromochloromethane, Total trihalomethanes (TTHMs). 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 - VISALIA.
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.
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.
Perfluorohexane sulfonate (PFHXS) significantly above health guideline
Moderate concernPerfluorohexane sulfonate (PFHXS) detected at 0.121 ppt, 121x above the EWG health guideline of 0.001 ppt.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 0.394 ppb, 98x above the EWG health guideline of 0.004 ppb.
Contact CWS - VISALIA
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.
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 53/100 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 |
| Perfluorohexane sulfonate (PFHXS) PFAS |
0.121 ppt | 0.001 | 10.0 | — | — | — | — | 121× over |
| Arsenic Heavy metal |
0.394 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 98× over |
| Chromium (hexavalent) Heavy metal |
0.775 ppb | 0.02 | — | — | — | — | — | 39× over |
| Nitrate Inorganic |
3.07 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 22× over |
| Nitrate and nitrite Inorganic |
2.49 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 18× over |
| Uranium Radiological |
2.11 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 4.9× over |
| Perfluorooctanoic acid (PFOA) PFAS |
0.338 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 3.8× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.789 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 2.6× over |
| Bromodichloromethane Disinfection byproduct |
0.135 ppb | 0.06 | — | — | — | — | — | 2.2× over |
| Dibromochloromethane Disinfection byproduct |
0.143 ppb | 0.1 | — | — | — | — | — | 1.4× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
0.187 ppb | 0.15 | 80.0 | 100 | — | — | — | 1.2× over |
| Radium, combined (-226 and -228) Radiological |
0.05 pCi/L | 0.05 | 5.0 | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
138.2 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
10.3 ppb | 21.0 | — | — | — | — | — | Below guideline |
| 1,2,3-Trichloropropane Other |
0.000277 ppb | 0.0007 | — | — | — | — | — | Below guideline |
| Chloroform Disinfection byproduct |
0.113 ppb | 0.4 | — | — | — | — | — | Below guideline |
| Bromoform Disinfection byproduct |
0.0478 ppb | 0.5 | — | — | — | — | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.00899 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Molybdenum Other |
0.76 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
3.4 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
1.18 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
0.659 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
0.204 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.254 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.118 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
0.00332 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
0.014 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Chlorodifluoromethane Other |
0.186 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.01 ppm | — | 4.0 | 1.5 | 1.5 | — | — | 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 - VISALIA service area
This water system serves 1 community in Tulare 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.