Disinfection byproducts · 2025
Perchlorate in City of Antioch, CA tap water
City of Antioch, CA's 2025 Consumer Confidence Report tested for Perchlorate and reported no detectable amount.
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Highest single sample Entry point | Not detected UG/L | 6 UG/L MCL |
Highest single sample Source water | Not detected UG/L | 6 UG/L MCL |
Verbatim from City of Antioch, 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 City of Antioch, 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 City of Antioch, CA tap water?
City of Antioch, CA's 2025 Consumer Confidence Report tested for Perchlorate and found no detectable amount.
+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 City of Antioch, 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/antioch/2025/source.