Sec. 24-21. User fees.
   (a)   A monthly fee shall be levied and collected from all users for the service of sewage collection, treatment and disposal provided through the joint wastewater system. User fees shall be calculated according to the following formula:
Monthly User Fee (A × Volume) + (B × COD) (C × SS)
Where:
Volume =
Monthly sewage discharge or the best engineering estimate thereof.
COD =
Monthly discharge of chemical oxygen demand or the best engineering estimate thereof.
SS =
Monthly discharge of suspended solids or the best engineering estimate thereof.
A =
Unit cost of flow volume based upon the adopted annual wastewater budget and the total volume discharge by all users.
B =
Unit cost of COD based upon the adopted annual wastewater budget and the total annual quantity of COD contributed by all users.
C =
Unit cost of suspended solids based upon the adopted annual wastewater budget and the total annual quantity of suspended solids contributed by all users.
 
   (b)   The monthly volume of discharge for residential users shall be presumed to be ninety (90) percent of the average water use as reflected by the billings for the months of December, January and February. If metered water use data is not available for a residential user, the discharge shall be estimated from the average residential class. The volume of discharge for all commercial and industrial users shall be presumed to be ninety-five (95) percent of the average water use as reflected by the billings for the months of December, January and February.
   (c)   The quantities of COD and suspended solids used in the user fee formula may be established by engineering estimation, by short-term sampling and analysis extrapolated to a yearly total, or by extensive sampling and analysis by the user or the city. The director shall set the standards for sampling and analysis.
   (d)   Where data of flow volume, quantities or COD or suspended solids are reported to the city by the user and form the basis for the user's fee, such data shall be subject to city verification. If subsequent measurements or other investigations reveal that such user is discharging a volume of flow, COD or suspended solids significantly in excess of that reported to the city, the director may assess such user according to the data obtained by the city retroactive to the time of the user's latest report together with any applicable delinquent charges, penalties and interest as provided in section 24-32. Prior to revising a user fee pursuant to this subsection, the city shall obtain at least two (2) twenty-four-hour samples and flow measurements.
   (e)   The per-unit cost factors A, B and C in the user fee formula shall be established each fiscal year prior to the beginning of the fiscal year for the joint wastewater system according to the following method:
   (1)   After adoption of an annual wastewater budget, a finding shall be made apportioning the budgeted amount among the three (3) user fee factors. Budgeted expenditures shall be apportioned to the factor to which they are attributable or primarily related.
   (2)   The per-unit cost of each factor shall be computed by dividing the amount of the adopted annual wastewater budget apportioned to such factor by the number of units of such factor discharged into the joint wastewater system in the preceding fiscal year.
   (f)   The discharge volumes for all users shall be estimated annually but may be changed at any time to reflect the actual measured volume. The director, upon a finding that the methods enumerated in subsection (b) do not reasonably reflect the average volume discharge of a user or user class, may establish a more accurate method and notify the affected users. Such revised methods for user classes shall be subject to the approval of the mayor and council.
(Ord. No. 4376, § 1, 9-2-75; Ord. No. 4527, §§ 4--8, 6-28-76; Ord. No. 4594, § 8, 11-22-76; Ord. No. 4672, § 2, 6-20-77; Ord. No. 4854, § 2, 7-3-78)