Water Quality Report · Updated May 12, 2026
WEST VALLEY WATER DISTRICT
WEST VALLEY WATER DISTRICT delivers tap water graded F (53/100) by TapWaterSafety.org. The utility serves approximately 104,498 residents in RIALTO, 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 (HAA5) significantly above health guideline. For questions, the utility can be reached at 909-875-3706.
Is RIALTO tap water safe to drink?
WEST VALLEY WATER DISTRICT 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 104,498 residents in RIALTO, drawing from surface water.
Public testing data identifies 19 contaminants in this water above EWG's health-based guidelines, including: Perfluorohexane sulfonate (PFHXS), Arsenic, Haloacetic acids (HAA5), Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Bromodichloromethane, Chromium (hexavalent), Dibromochloromethane, Dibromoacetic acid, Nitrate and nitrite, Radium, combined (-226 and -228), Chloroform, Trichloroacetic acid, Nitrate, Perfluorooctanoic acid (PFOA), Dichloroacetic acid, Uranium, Bromoform, Tetrachloroethylene (perchloroethylene). 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 RIALTO residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for WEST VALLEY WATER DISTRICT.
PFAS contamination
Severe concernPerfluorooctanoic 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 1.35 ppt, 1345x above the EWG health guideline of 0.001 ppt.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 2.64 ppb, 659x above the EWG health guideline of 0.004 ppb.
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.
Contact WEST VALLEY WATER DISTRICT
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 RIALTO
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 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 |
|---|---|---|---|---|---|---|---|---|
| Perfluorohexane sulfonate (PFHXS) PFAS |
1.35 ppt | 0.001 | 10.0 | — | — | — | — | 1345× over |
| Arsenic Heavy metal |
2.64 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 659× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
36.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 362× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
18.1 ppb | 0.06 | — | — | — | — | — | 301× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
16.0 ppb | 0.15 | 80.0 | 100 | — | — | — | 107× over |
| Bromodichloromethane Disinfection byproduct |
4.47 ppb | 0.06 | — | — | — | — | — | 75× over |
| Chromium (hexavalent) Heavy metal |
1.2 ppb | 0.02 | — | — | — | — | — | 60× over |
| Dibromochloromethane Disinfection byproduct |
4.24 ppb | 0.1 | — | — | — | — | — | 42× over |
| Dibromoacetic acid Disinfection byproduct |
1.02 ppb | 0.03 | — | — | — | — | — | 34× over |
| Nitrate and nitrite Inorganic |
2.94 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 21× over |
| Radium, combined (-226 and -228) Radiological |
0.84 pCi/L | 0.05 | 5.0 | — | — | — | — | 17× over |
| Chloroform Disinfection byproduct |
5.97 ppb | 0.4 | — | — | — | — | — | 15× over |
| Trichloroacetic acid Disinfection byproduct |
1.42 ppb | 0.1 | — | — | — | — | — | 14× over |
| Nitrate Inorganic |
1.49 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 11× over |
| Perfluorooctanoic acid (PFOA) PFAS |
0.894 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 9.9× over |
| Dichloroacetic acid Disinfection byproduct |
1.83 ppb | 0.2 | — | — | — | — | — | 9.1× over |
| Uranium Radiological |
2.66 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 6.2× over |
| Bromoform Disinfection byproduct |
1.37 ppb | 0.5 | — | — | — | — | — | 2.7× over |
| Tetrachloroethylene (perchloroethylene) Volatile organic compound |
0.101 ppb | 0.06 | 5.0 | — | — | — | — | 1.7× over |
| Chlorate Disinfection byproduct |
80.5 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Perchlorate Disinfection byproduct |
0.226 ppb | 1.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
4.23 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
2.85 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Bromochloromethane Other |
0.00263 ppb | 0.06 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
3.83 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.01 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| MTBE Volatile organic compound |
0.206 ppb | 13.0 | — | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
1.84 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
1.1 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
1.03 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.0191 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Cobalt Other |
0.0273 ppb | 70.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.661 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
0.276 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.332 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.289 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.
WEST VALLEY WATER DISTRICT service area
This water system serves 1 community in San Bernardino County, California. Click any city for its dedicated tap water quality page.
Find the right filter for RIALTO water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.