Washington Distribution System Operator Certification
Washington's Water Distribution Manager (WDM) certification is administered by the Department of Health (DOH), separate from the Water Treatment Plant Operator (WTPO) track. WDM 1 through WDM 4 are graded by system size and complexity, on the same 3-year renewal cycle used for Treatment certification.
A Wide Range of Geography
Washington's distribution systems span very different operating environments:
- Seattle-Tacoma metro corridor: Dense, growing networks requiring extensive pressure-zone management across genuinely hilly terrain.
- Puget Sound islands and eastern Washington agricultural communities: Small rural and island systems relying on simpler groundwater-fed infrastructure, generally with less staffing than the metro utilities.
Seismic Design Considerations
As with treatment infrastructure, Washin