The water mains shall be of adequate size and so designed in conjunction with related facilities to maintain a minimum operating pressure of twenty-five psi for each customer at the time of maximum demand in the system. The minimum size for use in the distribution system shall be six inch diameter on which fire hydrants are located, except where a smaller size will deliver the flow requirement of Section 13.12.040 when documented by calculations. Where fire hydrants do not occur, smaller sizes may be used with nominal two inch diameter being the smallest permissible main size. (Ord. 383 § 190, 1974).

All water mains shall be so designed to resist and withstand the maximum internal and external forces to which they may be subjected under normal operation conditions. Class 150 pipe shall be the minimum pressure class used. Where necessary, pipe of higher pressure rating shall be used to give the proper factor of safety. (Ord. 383 § 191, 1974).

All water mains shall be of the following types:
A. Asbestos-Cement Pipe. All asbestos-cement pipe shall conform to AWWA Standard Specifications C400-64T.
B. Cast Iron Pipe. All cast iron pipes shall conform to AWWA Standard Specifications C102-53, C106-62 and C108-62. The waterway surfaces of all cast iron pipe shall be cement lined in conformance with AWWA Standard Specifications C104-64.
C. Steel Pipe. Steel pipe of sizes up to but not including thirty inches (O.D.) shall conform to AWWA Standard Specifications C202-64 T. Steel pipe of sizes greater than thirty inches (O.D.) shall conform to AWWA Standard Specifications C201-60 T. Wall thickness of steel pipe shall be such that design working pressures can be adequately met. Steel protective coating shall be approved by the county engineer, but in no case shall such protective coatings be less than AWWA Standards C203-62. Where galvanizing is specified it shall conform to the requirements of ASTM Designation A120-63T. Where cement mortar lining is specified it shall conform to AWWA Standards C104-64 or C205-62, whichever is applicable.
D. Prestressed Reinforced Concrete Pipe--Steel Cylinder Type. Prestressed reinforced concrete pipe--steel cylinder type shall conform to AWWA Standard Specifications C301-64 and C303-70.
E. Ductile Iron Pipe. Ductile iron pipe shall comply with the requirements of AWWA Standards C151-65.
F. Polyvinyl Chloride (PVC) Plastic Pipe. Polyvinyl Chloride (PVC) plastic pipe may be used up to a size of six inches nominal diameter provided that it meets the Commercial Standard C3256-63. Larger sizes may be approved at the discretion of the county engineer. (Ord. 383 § 192, 1974).

All diameters shall be full nominal inside diameters. The actual diameters may not be less than the nominal diameter by more than five percent when measured approximately three inches from the ends of the pipe section. (Ord. 383 § 193, 1974).

The water mains shall be placed in the easement or road right-of-way. The minimum cover shall be thirty-six inches below the finished street grade. The mains shall be laid in the streets on which the property to be served fronts or on an approved easement, and in subdivisions, on all streets within and to the limits of the subdivision. (Ord. 383 § 194, 1974).

All water systems shall be designed to permit the circulation of water where practical, except where impractical because of cul-de-sacs and like conditions of incomplete grid system developments. (Ord. 383 § 195, 1974).