Disinfection byproducts · 2024
Perchlorate in Ontario, CA tap water
Ontario, CA's 2024 Perchlorate measurement is below the federal limit of 6 ug/L (MCL).
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Reported level Local Groundwater | 1.5 ug/L | 6 ug/L MCL |
Reported level Purchased Groundwater CDA 2 (1110 Zone) | 0.56 ug/L | 6 ug/L MCL |
Reported level Purchased Groundwater JCSD (870 Zone) | 0.83 ug/L | 6 ug/L MCL |
Reported level Purchased Groundwater CDA 1 (870 Zone) | 0.17 ug/L | 6 ug/L MCL |
Verbatim from Ontario, CA's 2024 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 Ontario, CA compares
Nearby systems also reporting Perchlorate:
People also ask
+Is there Perchlorate in Ontario, CA tap water?
Yes — Ontario, CA's 2024 Consumer Confidence Report lists Perchlorate at 1.5 ug/L. Ontario, CA's 2024 Perchlorate measurement is below the federal limit of 6 ug/L (MCL).
+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.
+Where does this Perchlorate measurement come from?
This page reproduces the Perchlorate entry from the 2024 Consumer Confidence Report published by the Ontario, 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/ontario/2024/source.