(1) Except as otherwise provided by special ordinance, every contract for the construction of sewers shall be prepared by the Law Department and shall provide that:

(a) the assessment bills for constructing the sewer shall be collected by the contractor, or in the discretion of the Water Department by the City, from the owners of property abutting on the street according to their respective fronts, as provided in § 13-304;[38]

(b) any amount in excess of such assessments shall be paid by the City;[39]

(c) any claim by the contractor for the adjustment and amendment of an assessment bill, or for additional sums, shall be made within 6 months from the date of delivery of the assessment bill to the contractor or filing of a lien, whichever is later;[40]

(d) where the assessment bills on the contract are in excess of the amount due to the contractor, the excess shall be collected by the City;[41]

(e) the contractor shall accept the assessment bills as payment in full and shall collect them at his own expense without recourse to the City.

(.1) The contractor may use the name of the City and employ all remedies or proceedings, including lien, which would be available to the City, provided that the contract has been fulfilled and all work under it has been done in accordance with its terms.[42]

(2) Whenever an ordinance is enacted for the construction of sewers, the Procurement Department shall, except as provided in § 13-403(3), advertise for proposals and award contracts in accordance with plans and specifications prepared by the Water Department.[43]

(3) Whenever a contract for the construction of sewers is for new development, unless otherwise provided in such ordinance, no advertisement shall be made for the work required until evidence satisfactory to the Water Department is filed by the applicant evidencing that the development for which the sewer is requested will be undertaken and completed as part of the current program of work.[44]