The State Water Resources Control Board recently published a chart comparing key elements of the 3 certification programs they now oversee: Drinking Water (Treatment), Drinking Water (Distribution), and Wastewater Treatment Plant Operator. You can find this informative chart here:
The following information is pulled from The State Water Resources Control Board website:
As of July 1, 2014, the Drinking Water Operator Certification Program transitioned from the California Department of Public Health to the State Water Resources Control Board, Division of Financial Assistance. For additional information regarding this transition, please see the Frequently Asked Questions.
The site contains additional information on exam changes and important certification contacts in addition to the information about the reorganization.