(1) The minimum grade shall be one-fourth inch per foot (25 inches per 100 feet in length) unless a flatter grade is authorized by the city inspector.

(2) The pipeline shall be laid straight and on even uniform grade between bends.

(3) The pipe shall be bedded on three-fourths-inch to one-fourth-inch gravel, pea gravel or undisturbed soil free from rocks.

(4) Backfill to eight inches over the top of the pipe shall be three-fourths-inch to one-fourth-inch gravel, pea gravel or soil free from rocks, hand placed and well compacted. Backfill from eight inches above the top of the pipe to the ground surface shall not contain rocks in excess of 12 inches in any dimension.

(5) The minimum cover over the top of the pipe shall be 12 inches unless otherwise authorized by the city inspector; except that pipe across driveways, etc., shall have a minimum of 18 inches of cover.

(6) A cleanout shall be provided for each 90-degree bend and for every two 45-degree bends.

(7) The pipeline must be inspected by the city inspector after pipeline is laid and before backfilling. If backfilling is started prior to the inspection, the installation will not be approved.

(8) The tee must be installed immediately ahead of the plug in the building service connection line to the main sewer line. (Ord. 177, 1967; Ord. 171 § 2, 1967).