A81/100
Rialto Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 158,951 residents · California
What's In Rialto's Tap Water?
69
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2013.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
WEST VALLEY WATER DISTRICT
Population Served
104,498
Water Source
Surface Water
System ID
CA3610004
RIALTO, CITY OF
Population Served
54,453
Water Source
Purchased Surface Water
System ID
CA3610038
Frequently Asked Questions About Rialto Water
Is Rialto tap water safe to drink?
Rialto, California tap water receives a grade of A (81/100), which is considered excellent. Out of 69 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 1 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Rialto's water?
Of the 69 contaminants tested in Rialto's water supply, the most notable include chlorate. No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Rialto have any water quality violations?
Yes, Rialto has 10 EPA violation(s) on record, with the most recent in 2013. Violation types include MR, MCL. 6 of these are health-based violations, which are the most serious category.
Do I need a water filter in Rialto?
Rialto water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does Rialto's tap water come from?
Rialto's drinking water is sourced from surface water and supplied by WEST VALLEY WATER DISTRICT and 1 other water system(s). The system serves approximately 158,951 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Rialto's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Rialto's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Rialto's water compare to other cities in California?
Rialto's water quality score of 81/100 earns a grade of A, which is considered excellent. This places Rialto among the better-performing water systems in California. Visit our California state page to see how all cities in the state compare.
What should I do if I'm concerned about Rialto's water quality?
If you have concerns about Rialto's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (WEST VALLEY WATER DISTRICT) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.