The maintenance of the public improvements may be performed by city forces and/or by one or more contractors retained by the city. The letting of contracts for maintenance shall be conducted in the manner authorized for letting of general city contracts of the same nature. If maintenance is to be performed by city forces, the account of the district shall be charged for direct and indirect costs, supervision and administration in accordance with normal and reasonable accounting standards and procedures. (Ord. 98-017 § 2; prior code § 81.05.501)