In the case of public works contracts, such as installation of sewers and other utilities involving construction in the public streets on easements and rights-of-way, all water used in connection therewith from such work as water-settling backfill or earthwork, hydraulic testing of pipe or structures, flushing of pipes or street surface for cleanup, mixing or curing concrete and similar water uses, shall be obtained from the water system only at the locations and in the manner specified by the superintendent in accordance with procedures established by the utilities superintendent. All water so used shall be paid for by the contractor at the applicable metered rate. In the absence of a metered record of the water use, the utilities superintendent shall estimate the amount of water used and the charge for same shall be rendered to the contractor accordingly. The charges for water shall be considered to operate as a materials lien against the contractor if unpaid. A reasonable meter rental charge for use of any meter furnished by the utilities division to measure water used in connection with the contracts may be added to the billing for water consumed including repair of any damage done to the meter. (Ord. 1237-86 § 58, 1986.)