Geo-Thermal Energy: Trenching and Excavations

Workers who install, operate, or maintain geothermal systems may be exposed to excavation and trenching hazards when they drill wells and install system piping below ground. Workers may need to work near or enter an excavation or trench to lay system piping during installation or replace piping during maintenance. Some of the best soils for heat transfer (essential for a geothermal system) may not be best for a stable trench.

Employers must meet OSHA's requirements while doing excavation and trenching operations. Trenches or excavations can collapse rapidly and, therefore, can be very dangerous, if they are not properly shored or otherwise protected. The excavated soil must not be placed at the very edge of a trench because it will add to the pressure on the trench walls. Vibrations from a backhoe operating at the perimeter of the excavation can also increase the likelihood of a cave-in.

OSHA's Construction eTool on Trenching and Excavations provides additional infomation on the excavation and trenching hazards. Safety and Health Topics Page on Trenching and Excavation is another source that should be consulted.