(A) The user charge shall be based on water usage as recorded by water meters and/or sewage meters for wastes having the following normal domestic concentrations:
(1) A five-day, 20°C biochemical oxygen demand (BOD) of 174 mg/l; and
(2) A suspended solids (SS) content of 204 mg/l.
(B) User charges shall consist of a basic user charge for operation and maintenance costs, plus replacement, and a capital cost charge for depreciation and shall be computed as follows:
(1) Estimate the projected annual revenue required to operate and maintain the wastewater facilities including a replacement/depreciation fund for the year for all works categories;
(2) Divide cost into fixed costs and treatment variable costs;
(3) Develop a fixed-cost flat monthly charge per user;
(4) Proportion the variable costs to wastewater facility categories by volume, suspended solids and BOD, if possible;
(5) Estimate wastewater volume, pounds of SS and pounds of BOD to be treated;
(6) Proportion the variable costs to nonindustrial and industrial users by volume, suspended solids and BOD;
(7) Compute costs per 1,000 gallons for normal sewage strength; and
(8) Compute surcharge costs per mg/l in excess of normal sewage strength for BOD and SS.
(1986 Code, § 7.42.020) (Ord. 1240, passed - -1984)