Charges for industrial wastes treatment, sanitary sewage charges and normal concentrations shall be as follows:
(a) Base sanitary sewage charges for wastes discharged to the wastewater treatment works of the City from industries shall be determined upon the basis of the volume of wastewater discharged from the industry to the wastewater treatment works. This volume shall be the same as that recorded on the meter or meters used to measure water from the water system of the City, unless the industry is supplied with water from a source other than the water system of the City or unless a substantial volume of water supplied to the industry is not discharged to the wastewater treatment works, in which cases the volume of water discharged to the wastewater treatment works shall be determined by one or more meters installed to measure water flow and/or wastewater discharged, or by other means approved by the City. Meters installed other than the meter or meters used to record consumption from the water system of the City shall be approved by the City and installed at the expense of the industry.
(b) The volume of wastewater discharged from the industry to the wastewater treatment works shall be subject to a base charge of 1,000 cubic feet, as follows:
(1) Charges for each billing quarter during a calendar year shall be based upon the following data applicable for the previous calendar year:
A. Total sewer revenue fund expenses, excluding those expenses attributable to debt service costs and any expenses classified as reimbursable expenses (net sewer revenue fund expenses);
B. Total debt service payments to the Ohio Water Development Authority; and
C. Total metered consumption subject to sanitary sewage charges (expressed in 1,000 cubic feet). Data not available shall be estimated in the most practical manner possible.
(2) The base charge per 1,000 cubic feet shall equal the net sewer revenue fund expenses pursuant to subparagraph (b)(1)A. hereof, plus the total debt service payments to the Ohio Water Development Authority plus the total metered consumption subject to sanitary sewage charges, in 1,000 cubic feet.