Metals · 2025

Calcium in City of Antioch, CA tap water

Detected — no federal limit

City of Antioch, CA's 2025 report shows Calcium detected, but the EPA has not set an enforceable federal limit for it.

The measurement

StatisticValue
Average
Entry point
8.25 MG/L
Average
Source water
5.666666666666667 MG/L
Highest single sample
Entry point
15 MG/L
Highest single sample
Source water
13 MG/L

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

About Calcium

A naturally occurring mineral that contributes to water hardness.

Not federally regulated for health; affects scaling and taste.

How City of Antioch, CA compares

Nearby systems also reporting Calcium:

People also ask

+Is there Calcium in City of Antioch, CA tap water?

Yes — City of Antioch, CA's 2025 Consumer Confidence Report lists Calcium at 8.25 MG/L. City of Antioch, CA's 2025 report shows Calcium detected, but the EPA has not set an enforceable federal limit for it.

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

The EPA has not set an enforceable federal limit for Calcium. Utilities still report any measured levels in their annual Consumer Confidence Report.

+What is Calcium?

A naturally occurring mineral that contributes to water hardness. Not federally regulated for health; affects scaling and taste.

+Where does this Calcium measurement come from?

This page reproduces the Calcium 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.

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