The responsibility to keep excavated dirt, rocks, and other materials back two feet from the excavation's edge lies with the employer. Employers must ensure that spoil piles and heavy equipment are kept at least two feet away from trench edges to prevent collapse or cave-ins and to maintain a safe working environment for workers. This is a safety regulation emphasized by OSHA and other regulatory bodies to reduce risks of trench wall collapses or materials falling into the excavation, which could endanger workers or cause accidents. Workers are responsible for following safety guidelines, but the primary accountability for this safety measure is on the employer.