The side sewer shall be laid at uniform grade and in straight alignment so far as is possible. Changes in direction shall be made only with curved pipe with no greater than forty-five (45) degree bends. The connection to the building drain and combination bends of ninety (90) degrees shall include a clean out. All pipe shall be laid on a firm earth bedding containing no material larger than one inch. If the trench bottom contains mud or water, the pipe shall be laid on a four-inch granular base of 3/4-inch minus rock, pea gravel, sand, or combination thereof. Backfill around the pipe and to a point four inches above shall be selected trench side material hand-placed and hand-tamped, with no material larger than one inch.