(a) No water service lateral shall be laid through any trench having cinders, rubbish, rock or gravel fill, or any other material which may cause injury to or disintegration of the service lateral, unless adequate means of protection are provided by sand filling or such other insulation as may be approved by the Water Utility. Service laterals passing through curb or retaining walls shall be adequately safeguarded by provision of a channel space or pipe casing, not less than twice the diameter of the service connection. The space between the service lateral and channel or pipe casing shall be filled and lightly caulked with an oakum, mastic cement, or other resilient material, and made impervious to moisture.
(b) In backfilling the pipe trench, the service lateral must be protected against injury by carefully hand tamping the ground filling around the pipe. There should be at least six (6) inches of ground filling over the pipe, and it should be free from hard lumps, rocks, stones, or other injurious material.
(c) All water service laterals shall be of undiminished size from the street main in to the point of meter placement. Beyond the meter outlet valve, the piping shall be sized and proportioned to provide, on all floors, at all times, an equitable distribution of water supply for the greatest probable number of fixtures or appliances operating simultaneously.