§ A182-5. Water main and sewer crossings and separation.

A. 

Wherever possible, separate water and sewer lines at least 10 feet horizontally. Where not possible, separate as much as possible; lay in a separate trench and, if in the same trench, keep water main as far as possible from sewer main and at least 18 inches above sewer.

B. 

At street intersection or at other locations where water and sewer lines must cross, place crown of sewers 18 inches below invert of water line, if possible. If less than 18 inches lower or if water line must pass under sewer, special care must be taken as follows:

(1) 

One full length of water main shall be centered on sewer crossing so joints are equidistant and as far as possible from the sewer. The sewer shall be constructed of materials and with joints that are equivalent to water main standards of construction and shall be pressure tested to assure watertightness prior to backfilling. The sewer so constructed shall be at least 44 feet or three full lengths of pipe, whichever is greater. The pressure test of this portion of sewer shall be done in accordance with AWWA Standard C-600, Section 13.7, at not less than 20 pounds per square inch and maximum leakage allowance at 20 pounds per square inch shall be 8 1/2 gallons per day per mile per inch nominal diameter of pipe.

(2) 

Water line passing under sewer shall, in addition, be protected by providing a vertical separation of at least 18 inches between the bottom of the sewer and the top of the water main. Provide adequate support for sewer to eliminate any possibility of settling of the sewer line.