What factor primarily impacts the excavation depth when dealing with sewer line installations?

The incline of the sewer line is a critical factor in determining the excavation depth during installations. The slope, or incline, is essential for ensuring proper drainage within the sewer line. A standard pitch of 1/4 inch per foot is often recommended to facilitate the flow of wastewater and prevent blockages.

When the incline is set properly, it helps maintain the needed gravitational force to move waste efficiently through the system. If the pitch is too shallow, it could lead to stagnation or backflow, while too steep an incline could lead to the solid waste moving faster than the liquid, causing blockages at lower points in the system. Thus, achieving the correct incline directly influences how deep the trench must be excavated for the pipe installation, ensuring that the line is appropriately positioned to function correctly according to engineering standards.