Washington Enacts Stricter Protective Rules for Trench Excavation Workers
New regulation requires contractors to submit a detailed written safety plan before digging begins to prevent fatal cave-ins.
- By Jesse Jacobs
- Jun 01, 2026
Labor authorities in Washington have implemented enhanced safety measures for construction crews engaged in trenching operations. Under the newly enacted regulation, employers must formally evaluate site conditions and implement rigid protective systems well before any earth is broken.
The core of the updated rule mandates that contractors finalize and submit a comprehensive, written trench excavation work plan prior to the start of digging. This document must explicitly detail site-specific health and safety procedures, identify potential underground or atmospheric hazards and outline the exact engineering controls—such as sloping, benching or structural shoring—chosen to stabilize the trench walls.
According to state safety guidelines, these work plans must be developed by an employer-appointed "competent person" who possesses the specialized training to classify soil types and recognize early structural failures. The finished safety blueprints are required to remain directly on the active job site, ensuring they are immediately available for review during field inspections by the state Department of Labor and Industries.
Beyond procedural paperwork, the state guidelines underscore several critical field requirements to mitigate the inherent dangers of excavation. For any trench measuring 4 feet or deeper, crews must be provided with an immediate means of exit, such as a ladder or ramp, positioned so that workers do not have to travel more than 25 feet laterally to escape. Additionally, excavated soil piles and heavy machinery must be kept a minimum of 2 feet back from the trench edge to prevent accidental collapses.
Contractors seeking compliance assistance can download educational resources through the department's digital publication portal or obtain copies of the official work plan template via the agency's dedicated forms index.
About the Author
Jesse Jacobs is assistant editor of OHSOnline.com.