Radionuclides · 2025
Gross Beta Particle Activity in Contra Costa Water District, CA tap water
Contra Costa Water District, CA's 2025 Gross Beta Particle Activity measurement is below the federal limit of 50 PCI/L (MCL).
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Highest single sample Entry point | 7.01 PCI/L | 50 PCI/L MCL |
Average Entry point | 7.01 PCI/L | 50 PCI/L MCL |
Highest single sample Source water | 9.46 PCI/L | 50 PCI/L MCL |
Average Source water | 7.328 PCI/L | 50 PCI/L MCL |
Verbatim from Contra Costa Water District, CA's 2025 Consumer Confidence Report — source document ↗
About Gross Beta Particle Activity
Gross beta particle activity — a combined measure of beta-emitting radioactive substances.
Long-term exposure above the federal screening level increases cancer risk.
How Contra Costa Water District, CA compares
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People also ask
+Is there Gross Beta Particle Activity in Contra Costa Water District, CA tap water?
Yes — Contra Costa Water District, CA's 2025 Consumer Confidence Report lists Gross Beta Particle Activity at 7.328 PCI/L. Contra Costa Water District, CA's 2025 Gross Beta Particle Activity measurement is below the federal limit of 50 PCI/L (MCL).
+What's the federal limit for Gross Beta Particle Activity in drinking water?
The federal MCL for Gross Beta Particle Activity is 50 PCI/L. The EPA enforces this against the regulated reporting statistic (running annual average or 90th percentile), not a single-sample spike.
+What is Gross Beta Particle Activity?
Gross beta particle activity — a combined measure of beta-emitting radioactive substances. Long-term exposure above the federal screening level increases cancer risk.
+Where does this Gross Beta Particle Activity measurement come from?
This page reproduces the Gross Beta Particle Activity entry from the 2025 Consumer Confidence Report published by the Contra Costa Water District, 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/contra-costa-water-district/2025/source.