Prior to March 1 of each year, the Director of Finance shall prepare and certify to the Mayor and Council an annual audit of the receipts and expenditures of the Sanitary Sewer Fund covering the prior fiscal year. The audit shall also provide all the information necessary for the members of Council to determine if the revenues are generating sufficient income to operate the system in a sound financial manner and also verify if the Class D industries are paying their proportionate share of the operating costs in proportion to the actual use of the sanitary sewer system.