Inorganic chemicals · 2025
Cyanide in Contra Costa Water District, CA tap water
Contra Costa Water District, CA's 2025 Cyanide measurement is below the federal limit of 150 UG/L (MCL).
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Highest single sample Source water | 1.2 UG/L | 150 UG/L MCL |
Average Entry point | 0.6799999999999999 UG/L | 150 UG/L MCL |
Average Source water | 0.64 UG/L | 150 UG/L MCL |
Highest single sample Entry point | 1.4 UG/L | 150 UG/L MCL |
Verbatim from Contra Costa Water District, CA's 2025 Consumer Confidence Report — source document ↗
How Contra Costa Water District, CA compares
2 of the 189 systems measuring Cyanide on The Water Map have it at or above the federal limit:
Nearby systems also reporting Cyanide:
People also ask
+Is there Cyanide in Contra Costa Water District, CA tap water?
Yes — Contra Costa Water District, CA's 2025 Consumer Confidence Report lists Cyanide at 0.6799999999999999 UG/L. Contra Costa Water District, CA's 2025 Cyanide measurement is below the federal limit of 150 UG/L (MCL).
+What's the federal limit for Cyanide in drinking water?
The federal MCL for Cyanide is 150 UG/L. The EPA enforces this against the regulated reporting statistic (running annual average or 90th percentile), not a single-sample spike.
+Which other U.S. cities have Cyanide over the federal limit?
2 of the 189 systems on The Water Map measuring Cyanide report it at or above the federal limit. Examples include Mcallen, TX, Odessa, TX.
+Where does this Cyanide measurement come from?
This page reproduces the Cyanide 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.