This account shall include the cost of all transmission and distribution mains used for conveying water from the pumping station, impounding reservoir or other source of supply to the consumer; this includes the cost of all trenching for pipes, placing main pipes, special castings, materials for joints, shut offs, manholes, valves and the cost of filling trenches, and restoring the surface of the street to its former condition as required by municipal authorities.
220 CMR, 52.108