All breaks or openings shall be refilled by the applicant for the permit, to the approval of the Township Engineer, replacing all the excavated materials in the opening without raising the surface of the highway, road, street, avenue, lane, alley, sidewalk or footpath, due allowance being made for the structures being placed in the trench. All refilling must be done with suitable materials, thoroughly compacted, tamping in uniform layers, not exceeding six inches in depth, and all surplus dirt must be removed from the job. The work of replacing the surface of the highway shall be done by the Township, except that the Commissioners may waive such requirements when the work is to be undertaken by or under the direction of a municipality or public utility, and provided that a satisfactory guaranty is furnished, in writing, guaranteeing that the restoration of the highway is done in accordance with the requirements of the Township's proper official and will be maintained for a period of one year from the date of completion of permanent restoration. The restoration and maintenance shall be to the satisfaction of the Township Engineer.