(A) Work shall, in every case, proceed from the sewer toward the structure involved. Any variation in this procedure shall be at the sole responsibility of the contractor unless prior approval of the Engineer has been secured.
(B) Trenching shall proceed in accordance with latest manual on Safety in Construction as published by the Occupational Safety and Health Act. The trench shall be ample width at the bottom to accommodate the structure to be placed and any work on the structure that conditions necessitate. Tunneling under existing structures may be permitted when practical, but in no case shall any one tunnel exceed ten feet in length.
(C) Sheeting requirements for excavation to insure the safety of personnel, the public, property, or proper installation, shall be furnished and placed by the contractor in accordance with good practice and at his own expense. Requirements and specifications for sheeting shall satisfy the intent of the Occupational Safety and Health Act.
(D) Where water is encountered in a trench, sufficient sump shall be constructed and adequate pumping equipment made available so that the installation of any drain or appurtenances shall be done in the dry. Under no conditions shall water be allowed to enter the sewer from the trench.
(E) If at any time during the excavation, in the Engineer's opinion, the material being excavated is not suitable for backfill, such material shall immediately be removed from the site by the contractor at his own expense. Unsatisfactory materials shall include, but not be limited to, boulders, clay, muck, frozen ground, and the like. Where unsatisfactory material is removed, it shall be replaced by sand or gravel not containing pieces larger than three inches in diameter. Furnishing and placing this material shall be at the contractor's expense.
(F) Any unsuitable foundation material shall be removed and replaced with crushed stone or selected sand. If excavation is deeper than desired depth, the trench shall be filled with crushed stone or selected sand. In no case may loose fill from excavation be used to bring the trench up to grade. Blocks or rigid objects should never be used to support the pipe. Selected sand bedding and tamped cover to twelve inches above the pipe will be required.
(Ord. 235, adopted 9-4-84) Penalty, see § 51.99