Radionuclides · 2024
Gross Alpha in Ontario, CA tap water
Ontario, CA's 2024 Gross Alpha measurement is below the federal limit of 15 pCi/L (MCL).
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Reported level Purchased Groundwater JCSD (870 Zone) | 2.3 pCi/L | 15 pCi/L MCL |
Reported level Purchased Groundwater CDA 1 (870 Zone) | 0.32 pCi/L | 15 pCi/L MCL |
Reported level Local Groundwater | 1.6 pCi/L | 15 pCi/L MCL |
Reported level Imported Water (WFA w/ SAWCO) | 1.3 pCi/L | 15 pCi/L MCL |
Verbatim from Ontario, CA's 2024 Consumer Confidence Report — source document ↗
About Gross Alpha
Gross alpha particle activity — a combined measure of alpha-emitting radioactive substances.
Long-term exposure above the federal limit increases cancer risk.
How Ontario, CA compares
4 of the 186 systems measuring Gross Alpha on The Water Map have it at or above the federal limit:
Nearby systems also reporting Gross Alpha:
People also ask
+Is there Gross Alpha in Ontario, CA tap water?
Yes — Ontario, CA's 2024 Consumer Confidence Report lists Gross Alpha at 2.3 pCi/L. Ontario, CA's 2024 Gross Alpha measurement is below the federal limit of 15 pCi/L (MCL).
+What's the federal limit for Gross Alpha in drinking water?
The federal MCL for Gross Alpha is 15 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 Alpha?
Gross alpha particle activity — a combined measure of alpha-emitting radioactive substances. Long-term exposure above the federal limit increases cancer risk.
+Which other U.S. cities have Gross Alpha over the federal limit?
4 of the 186 systems on The Water Map measuring Gross Alpha report it at or above the federal limit. Examples include Pomona, CA, Birmingham, AL, Burbank, CA.
+Where does this Gross Alpha measurement come from?
This page reproduces the Gross Alpha 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.