A. Basis For Wastewater User Charges: The wastewater user charge for the use of and for service supplied by the wastewater facilities of the city shall consist of a basic user charge for operation and maintenance plus replacement, and a surcharge, if applicable. It shall apply to all users of the sanitary sewer system and the combined sewer system.
B. Charge Based On Waste Strength: The user charge shall be based on water usage as recorded by water meters for normal waste having the following strengths:
1. A five (5) day, twenty degree centigrade (20°C) biochemical oxygen demand (BOD) of two hundred milligrams per liter (200 mg/l).
2. A suspended solids (SS) content of two hundred fifty milligrams per liter (250 mg/l).
C. Meter Readings: Water meter readings shall be assumed to equal sewage flow except in cases where the user may show adequate proof that water passed through the meter is not returned to the sewer. An adjustment in meter readings will be made in such cases if the user furnishes the meter readings of water flow not discharged to the sewer.
D. Computation: The user charge shall consist of operation and maintenance costs plus replacement and shall be computed as follows:
1. Estimate the projected annual revenue required to operate and maintain the wastewater facilities including a replacement fund for the year, and the debt service requirements;
2. Estimate wastewater volume discharged to the sewer system based on total water meter readings after appropriate adjustment for water not returned to the sewer and/or water from unmetered private sources which is discharged to the sewer system;
3. Compute costs per one thousand (1,000) gallons for normal sewage strength wastes.
E. Excess Use: A surcharge will be levied to all users whose waters exceed the normal concentrations for BOD (200 mg/l) and SS (250 mg/l). The surcharge will be based on water usage as recorded by water meters and/or sewage meters for all wastes which exceed the two hundred milligrams per liter (200 mg/l) and two hundred fifty milligrams per liter (250 mg/l) concentration for BOD and SS, respectively.
F. Annual Review: The adequacy of the wastewater service charge shall be reviewed annually by certified public accountants for the city in their annual audit report. The wastewater meter charge shall be revised periodically to reflect a change in operation and maintenance costs including replacement costs and adjusted as required. One of the purposes of the annual review shall be to maintain service charges in relation to cost and assure that all use classes are being charged an equitable share. (Ord. 146, 1980)