Metals · 2025
Magnesium in City of Cupertino, CA tap water
City of Cupertino, CA's 2025 report shows Magnesium detected, but the EPA has not set an enforceable federal limit for it.
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Average Source water | 25 MG/L | None set |
Highest single sample Source water | 27 MG/L | None set |
Verbatim from City of Cupertino, CA's 2025 Consumer Confidence Report — source document ↗
About Magnesium
A naturally occurring mineral that contributes to water hardness.
Not federally regulated for health; affects scaling and taste.
How City of Cupertino, CA compares
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People also ask
+Is there Magnesium in City of Cupertino, CA tap water?
Yes — City of Cupertino, CA's 2025 Consumer Confidence Report lists Magnesium at 25 MG/L. City of Cupertino, CA's 2025 report shows Magnesium detected, but the EPA has not set an enforceable federal limit for it.
+What's the federal limit for Magnesium in drinking water?
The EPA has not set an enforceable federal limit for Magnesium. Utilities still report any measured levels in their annual Consumer Confidence Report.
+What is Magnesium?
A naturally occurring mineral that contributes to water hardness. Not federally regulated for health; affects scaling and taste.
+Where does this Magnesium measurement come from?
This page reproduces the Magnesium entry from the 2025 Consumer Confidence Report published by the City of Cupertino, 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/cupertino/2025/source.