No new water, sewer, steam or gas main or electric, telephone or other utility line shall hereafter be laid or constructed, and no such existing main or line shall be extended, in any of the streets of the Borough until the plan therefor shall have been first filed with the designated official and such plan, and the exact location of such main or line, approved by him or her. The designated official shall not approve the locating of any such main or line at a depth of less than 30 inches from the surface of the street unless he or she shall be convinced that locating the same at a depth of more than 30 inches from the surface is impossible or impractical.
(A.O.)