On February 2, 2021 the California State Water Resources Control Board (SWRCB) voted to adopt the Revised Total Coliform Rule (RTCR). On May 28, 2021 the California Office of Administrative Law (OAL) approved the RTCR and it will go into effect on July 1, 2021.
Additional details are provided here:
RTCR Rulemaking Documentation can be found here:
Here is a copy of the RTCR language that has been adopted into Title 22 drinking water regulations ( RTCR Final Regulatory Language).