Water Quality Report · Updated October 07, 2026
Riverside Water Authority
Riverside Water Authority delivers tap water graded C (70/100) by TapWaterSafety.org. The utility serves approximately 331,000 residents in Riverside, California using groundwater from the Bunker Hill Basin. The most significant water quality concerns are: Arsenic significantly above health guideline; Chromium-6 detected; Radium-228 detected. For questions, the utility can be reached at (213) 621-1650.
Is Riverside tap water safe to drink?
Riverside Water Authority delivers tap water that earns a grade of C (70/100) from TapWaterSafety.org — an average rating, with several contaminants above health guidelines but generally compliant with US legal limits.
The utility serves 331,000 residents in Riverside, drawing from groundwater (Bunker Hill Basin) and disinfecting with chloramine.
Public testing data identifies 21 contaminants in this water above EWG's health-based guidelines, including: Arsenic, Arsenic, Arsenic, Haloacetic Acids (HAA5), Haloacetic Acids (HAA5), Haloacetic Acids (HAA5), Nitrate, Nitrate, Radium-228, Nitrate, Radium-228, Radium-228, Total Trihalomethanes (TTHMs), Total Trihalomethanes (TTHMs), Total Trihalomethanes (TTHMs), Chromium-6 (Hexavalent), Chromium-6 (Hexavalent), Chromium-6 (Hexavalent), Lead, Lead, Lead. 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.
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for Riverside Water Authority.
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.
Contact Riverside Water Authority
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Water Quality Contact
For questions about contaminants, test results, or your Consumer Confidence Report.
Treatment Plant
Recommended water filters for Riverside
Filters matched to the specific contaminants in this water supply.
Reverse osmosis certified for arsenic (NSF/ANSI 58)
$429-$599Reverse osmosis certified under NSF/ANSI 58 for arsenic is the most reliable home option.
Reverse osmosis certified for chromium (NSF/ANSI 58)
$429-$599Chromium-6 needs reverse osmosis for reliable reduction. Standard carbon filters do not address it.
Reverse osmosis certified for radium (NSF/ANSI 58)
$429-$750RO certified for radium 226/228 reduces it; ion-exchange water softeners also reduce radium.
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 70/100 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 |
|---|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
3.87 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2023 | 968× over |
| Arsenic Heavy metal |
3.0 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2024 | 750× over |
| Arsenic Heavy metal |
2.28 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2022 | 570× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
8.3 ppb | 0.1 | 60 | 60 | — | — | 2024 | 83× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
8.14 ppb | 0.1 | 60 | 60 | — | — | 2022 | 81× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
7.92 ppb | 0.1 | 60 | 60 | — | — | 2023 | 79× over |
| Nitrate Inorganic |
3.3 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2024 | 24× over |
| Nitrate Inorganic |
3.2 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2022 | 23× over |
| Radium-228 Radiological |
0.38 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 2024 | 20× over |
| Nitrate Inorganic |
2.69 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2023 | 19× over |
| Radium-228 Radiological |
0.358 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 2023 | 19× over |
| Radium-228 Radiological |
0.343 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 2022 | 18× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
8.6 ppb | 0.6 | 80 | 100 | — | — | 2024 | 14× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
8.24 ppb | 0.6 | 80 | 100 | — | — | 2022 | 14× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
6.52 ppb | 0.6 | 80 | 100 | — | — | 2023 | 11× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.085 ppb | 0.02 | — | — | — | 0.02 | 2023 | 4.2× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.07 ppb | 0.02 | — | — | — | 0.02 | 2024 | 3.5× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.059 ppb | 0.02 | — | — | — | 0.02 | 2022 | 2.9× over |
| Lead Heavy metal |
0.8 ppb | 0 | 15 | 5 | 10 | 0.2 | 2024 | — |
| Lead Heavy metal |
0.91 ppb | 0 | 15 | 5 | 10 | 0.2 | 2023 | — |
| Lead Heavy metal |
0.883 ppb | 0 | 15 | 5 | 10 | 0.2 | 2022 | — |
| Contaminant | Detected (2024) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
8.6 ppb | 0.6 | 80 | 100 | — | — | 14× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
8.3 ppb | 0.1 | 60 | 60 | — | — | 83× over |
| Lead Heavy metal |
0.8 ppb | 0 | 15 | 5 | 10 | 0.2 | — |
| Arsenic Heavy metal |
3.0 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 750× over |
| Radium-228 Radiological |
0.38 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 20× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.07 ppb | 0.02 | — | — | — | 0.02 | 3.5× over |
| Nitrate Inorganic |
3.3 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 24× over |
| Contaminant | Detected (2023) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
6.52 ppb | 0.6 | 80 | 100 | — | — | 11× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
7.92 ppb | 0.1 | 60 | 60 | — | — | 79× over |
| Lead Heavy metal |
0.91 ppb | 0 | 15 | 5 | 10 | 0.2 | — |
| Arsenic Heavy metal |
3.87 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 968× over |
| Radium-228 Radiological |
0.358 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 19× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.085 ppb | 0.02 | — | — | — | 0.02 | 4.2× over |
| Nitrate Inorganic |
2.69 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 19× over |
| Contaminant | Detected (2022) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
8.24 ppb | 0.6 | 80 | 100 | — | — | 14× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
8.14 ppb | 0.1 | 60 | 60 | — | — | 81× over |
| Lead Heavy metal |
0.883 ppb | 0 | 15 | 5 | 10 | 0.2 | — |
| Arsenic Heavy metal |
2.28 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 570× over |
| Radium-228 Radiological |
0.343 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 18× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.059 ppb | 0.02 | — | — | — | 0.02 | 2.9× over |
| Nitrate Inorganic |
3.2 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 23× over |
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, and Riverside Water Authority's Consumer Confidence Report.
Riverside Water Authority service area
This water system serves 1 community in Riverside County, California. Click any city for its dedicated tap water quality page.
Find the right filter for Riverside water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.