Washington Water Treatment Operator Certification
Washington's Department of Health (DOH), Office of Drinking Water, certifies Water Treatment Plant Operators (WTPO) statewide across four grades — WTPO 1 (entry) through WTPO 4 (highest) — governed by WAC 246-292, on a 3-year renewal cycle.
Diverse Source Water Across the State
Washington draws drinking water from a genuinely diverse mix of sources, and operators should understand the picture beyond their own facility:
- Cascade Range snowmelt reservoirs: Seattle Public Utilities' Cedar and Tolt watersheds are a well-known example of protected, forested surface-water supply feeding a major metro system.
- Puget Sound-area groundwater aquifers: Serve many smaller communities and suburban systems around the Sound.
- Columbia River basin: East of the Cascades, both surface water and groundwater from the Colu