Disinfection byproducts · 2025
TTHM in City of Thousand Oaks Water Department, CA tap water
City of Thousand Oaks Water Department, CA's 2025 TTHM measurement is below the federal limit of 80 UG/L (MCL).
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Average Distribution | 16.375 UG/L | 80 UG/L MCL |
Highest single sample Distribution | 22 UG/L | 80 UG/L MCL |
Verbatim from City of Thousand Oaks Water Department, CA's 2025 Consumer Confidence Report — source document ↗
About TTHM
Total trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter.
Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and increased cancer risk.
How City of Thousand Oaks Water Department, CA compares
5 of the 458 systems measuring TTHM on The Water Map have it at or above the federal limit:
Nearby systems also reporting TTHM:
People also ask
+Is there TTHM in City of Thousand Oaks Water Department, CA tap water?
Yes — City of Thousand Oaks Water Department, CA's 2025 Consumer Confidence Report lists TTHM at 16.375 UG/L. City of Thousand Oaks Water Department, CA's 2025 TTHM measurement is below the federal limit of 80 UG/L (MCL).
+What's the federal limit for TTHM in drinking water?
The federal MCL for TTHM is 80 UG/L. The EPA enforces this against the regulated reporting statistic (running annual average or 90th percentile), not a single-sample spike.
+What is TTHM?
Total trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and increased cancer risk.
+Which other U.S. cities have TTHM over the federal limit?
5 of the 458 systems on The Water Map measuring TTHM report it at or above the federal limit. Examples include Albuquerque, NM, Columbus, OH, Hollywood, FL.
+Where does this TTHM measurement come from?
This page reproduces the TTHM entry from the 2025 Consumer Confidence Report published by the City of Thousand Oaks Water Department, 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/thousand-oaks-water-department/2025/source.