Within the limitations specified in Section 32-151 and elsewhere, slopes of site grading, drainage and other improvements and facilities shall be determined by the preparer of the plan to suit the specific site and in accordance with accepted engineering practice. No fill or cut shall be made which creates an exposed surface steeper in slope than two (2) horizontal to one (1) vertical unless specifically waived by the Director after receipt of a report by a soil engineer certifying that the engineer has investigated the property, and that, in the engineer's opinion, such steeper slope will be structurally stable and that the ground cover to be used is of a low maintenance type and will effectively control erosion. The Director may require that slopes be constructed with exposed surface flatter than those shown in Section 32-151, or may require such other measures as the Director deems necessary for stability and safety. Sides of temporary excavations made for foundations, buildings, and utility installations shall be protected, shored, or sloped as required by regulations of the Maryland State Department of Labor and Industry.