Disinfection byproducts · 2025

Perchlorate in Riverside, City of, CA tap water

Approaching the federal limit· 0.8× the limit

Riverside, City of, CA's 2025 Perchlorate level is between 80% and 100% of the federal limit (6 UG/L MCL) — measured but not in violation.

The measurement

StatisticValue
Highest single sample
Entry point
3.2 UG/L
Average
Source water
4.9619926199262 UG/L
Highest single sample
Source water
36 UG/L
Average
Entry point
1.398974358974359 UG/L
Average
Distribution
3.2973684210526315 UG/L
Highest single sample
Distribution
25 UG/L

Verbatim from Riverside, City of, CA's 2025 Consumer Confidence Report — source document ↗

About Perchlorate

A chemical used in rocket fuel and fireworks that can also form during disinfection.

Can interfere with thyroid hormone production; has no national enforceable limit but is regulated in some states.

How Riverside, City of, CA compares

5 of the 193 systems measuring Perchlorate on The Water Map have it at or above the federal limit:

Nearby systems also reporting Perchlorate:

People also ask

+Is there Perchlorate in Riverside, City of, CA tap water?

Yes — Riverside, City of, CA's 2025 Consumer Confidence Report lists Perchlorate at 4.9619926199262 UG/L. Riverside, City of, CA's 2025 Perchlorate level is between 80% and 100% of the federal limit (6 UG/L MCL) — measured but not in violation.

+What's the federal limit for Perchlorate in drinking water?

The federal MCL for Perchlorate is 6 UG/L. The EPA enforces this against the regulated reporting statistic (running annual average or 90th percentile), not a single-sample spike.

+What is Perchlorate?

A chemical used in rocket fuel and fireworks that can also form during disinfection. Can interfere with thyroid hormone production; has no national enforceable limit but is regulated in some states.

+Which other U.S. cities have Perchlorate over the federal limit?

5 of the 193 systems on The Water Map measuring Perchlorate report it at or above the federal limit. Examples include Rialto, CA, Rialto, City of, CA, Rialto, City of, CA.

+Where does this Perchlorate measurement come from?

This page reproduces the Perchlorate entry from the 2025 Consumer Confidence Report published by the Riverside, City of, CA water utility — the annual drinking-water report every U.S. utility is required by federal law to publish. The original source document is archived at /water/ca/riverside/2025/source.

Full report
All Riverside, City of, CA water-quality data →
Every contaminant measured in the 2025 report.
Contaminant pillar
Perchlorate across the U.S. →
Every public water system measuring Perchlorate, ranked.