A87/100
RIO ALTO WATER DISTRICT — Water Quality Report 2026
Serving 3,329 people · California
Water Source
Groundwater
County
—
System ID
CA5210005
Violations
5
Contaminant Test Results
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2015.
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
Frequently Asked Questions About RIO ALTO WATER DISTRICT
Is RIO ALTO WATER DISTRICT water safe to drink?
RIO ALTO WATER DISTRICT water receives a grade of A (87/100), which is considered excellent. Out of 27 contaminants tested, none exceed EPA legal limits. The water meets federal safety standards.
What contaminants has RIO ALTO WATER DISTRICT detected?
27 contaminants were tested in RIO ALTO WATER DISTRICT's water. No contaminants exceed EPA legal limits or health goals, indicating good water quality management.
Does RIO ALTO WATER DISTRICT have any EPA violations?
Yes, RIO ALTO WATER DISTRICT has 5 EPA violation(s) on record, with the most recent in 2015. Violation types include MCL, MR. 2 are health-based violations.
How many people does RIO ALTO WATER DISTRICT serve?
RIO ALTO WATER DISTRICT serves approximately 3,329 people, California.
What type of water does RIO ALTO WATER DISTRICT provide?
RIO ALTO WATER DISTRICT sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is CA5210005.
How does RIO ALTO WATER DISTRICT compare to other utilities in California?
RIO ALTO WATER DISTRICT scores 87/100 with a grade of A (excellent). This places it among the higher-performing utilities in the state. Visit our California state page for a full comparison of water systems.