Tap Water Quality Report
Tap water quality in Riverside, California
Tap water in Riverside, California receives a grade of F (56/100) from TapWaterSafety.org. It's served by Riverside Water Authority. The most significant water quality concerns are: Arsenic significantly above health guideline; Chromium-6 detected; Radium-228 detected. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database, and Riverside's published Consumer Confidence Report.
What's in Riverside's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving Riverside.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 3.87 ppb, 968x above the EWG health guideline of 0.004 ppb.
Chromium-6 detected
Moderate concernChromium-6 detected at 0.07 ppb.
Radium-228 detected
Moderate concernRadium-228 detected at 0.38 pCi/L.
Recommended filters for Riverside
Filters matched to the specific contaminants in Riverside's water supply.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
Reverse Osmosis or water softener
$249-$750RO removes radium effectively; ion-exchange water softeners also reduce radium concentration.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in Riverside's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. 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 |
|---|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
3.87 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2023 | 968× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
8.3 ppb | 0.1 | 60 | 60 | — | — | 2024 | 83× over |
| Nitrate Inorganic |
3.3 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2024 | 24× over |
| Radium-228 Radiological |
0.38 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 2024 | 20× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
8.6 ppb | 0.6 | 80 | 100 | — | — | 2024 | 14× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.085 ppb | 0.02 | — | — | — | 0.02 | 2023 | 4.2× over |
| Lead Heavy metal |
0.91 ppb | 0 | 15 | 5 | 10 | 0.2 | 2023 | — |
| Contaminant | Detected (2024) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) Disinfection byproduct |
8.3 ppb | 0.1 | 60 | 60 | — | — | 83× over |
| Nitrate Inorganic |
3.3 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 24× over |
| Radium-228 Radiological |
0.38 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 20× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
8.6 ppb | 0.6 | 80 | 100 | — | — | 14× over |
| Contaminant | Detected (2023) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
3.87 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 968× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.085 ppb | 0.02 | — | — | — | 0.02 | 4.2× over |
| Lead Heavy metal |
0.91 ppb | 0 | 15 | 5 | 10 | 0.2 | — |
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, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from Riverside Water Authority.
General Contact
Water Quality Contact
For questions about contaminants or test results.