Water Main Trench Excavation

Service Description

Trenches for water main pipes are typically relatively shallow in comparison to that of sanitary sewer pipes. The typical depth range for water main pipe trenching from proposed pipe to proposed grades between 5 and 7 feet in cold weather climates. Sometimes the trench will be deeper if required for clearance around other underground utilities. The primary concern with the depth of water piping is assuring that the ‘cover’ (distance between top of pipe and finish grade above) is below the frost line for that area, that is the maximum depth the frost will creep below the surface grade during cold months. 5’ depth of cover is relatively standard in terms of watermain installations. The width of the trench depends primarily on the size of the pipe being placed. For water main pipe trenches housing pipe 6 or 8” in diameter at a depth of 5′, and a trench box wall thickness of 6-8″,the typical total trench width will be approximately 42-48″. Some contractors will try to tighten up their trenches even further, but adequate room to work around the pipe and pipe bell (69″ on either side) is needed. According to current OSHA regulation, trenches 5’ or deeper will require proper benching to establish a safe working environment, however many contractors typically have their own standards in terms of what is safe and reasonable for trench benching. OSHA also required that trench excavations deeper than 20’ have a shoring system designed by a professional.

Contact Details