Permittees not previously served by the city's system shall pay a monthly fee for the permit to operate a separate system equal to the amount of city utility tax which would have been assessed on the volume of wastewater if processed by the city wastewater utility. Such fees shall be calculated at least annually and shall be based on the permittee's reports as filed with the state. Permittees withdrawing from the city wastewater system shall pay an annual permit fee payable monthly based upon the amount of the city utility tax attributable to permittee's industrial wastewater assessment paid to the city during the previous twelve months of operations prior to withdrawal. Permit fees shall be adjusted annually according to the Consumer Price Index published by the Bureau of Labor Statistics of the U.S. Department of Labor for All Urban Consumer (CPT-U), U.S. City Average for All Items, with a reference base period of 1982-84 = 100. Permit fees shall be paid by the permittee during the term of the permit. (Ord. 1006, § 3, 1991.)