3.15.4. Means of access and supervision: The employer shall ensure that ladders are placed in trenches at intervals of 15 linear metres or fractions thereof and in such manner as to follow the progress of the works.
Ladders shall rest on the bottom of the trench and extend at least 1 m above ground level.
When workers are in a trench, the employer shall post an experienced person at ground level so that he may detect faults, earth breaking away or any other source of danger.
R.R.Q., 1981, c. S-2.1, r. 6, s. 3.15.4; O.C. 807-92, s. 12.