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State-Specific RegulationsBeginner 12 min read

California Water Treatment Operator Certification: T1-T5 Program Overview

How California's T1-T5 water treatment operator certification works, who administers it, and the state-specific source water and treatment challenges operators need to know.

California Water Treatment Operator Certification: T1-T5 Program Overview
Who Certifies Water Treatment Operators in California
Since July 1, 2014, the State Water Resources Control Board (State Water Board), Division of Drinking Water has administered California's operator certification program, having taken over the role from the California Department of Public Health under Assembly Bill 15 (2012). Every operator responsible for a community or non-transient non-community public water system in California must hold a certificate at or above the grade required for that system's classification.
The T1-T5 Grade Ladder
California uses a five-level treatment certification ladder, T1 through T5:
  • T1 – entry level; typically small groundwater systems with minimal treatment (e.g., disinfection only)
  • T2 – slightly larger or more complex systems
  • T3 – requires spe

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