(a) In addition to the base user charges applicable pursuant to Section 924.07, users discharging pollutants to the wastewater treatment works of the City, whose average concentration, as defined in Section 924.03, in one or more classifications exceeds in any month that concentration defined as normal in Section 924.03 in the corresponding classification, shall be subject to surcharges calculated as follows:
(1) Surcharges for each billing period during a calendar year shall be based upon the following values for that calendar year; estimated total operation, maintenance and replacement expenses excluding those expenses attributable to debt service costs and excluding any expenses classified as reimbursable general governmental expenses (Cto); estimated total pounds of BOD received at the plant (Bt); and estimated total pounds of suspended solids received at the plant (St). Data not available shall be estimated in the most practical manner possible.
(2) Surcharge on user charges per pound of BOD in excess of normal equals:
Cto x 0.28 Bt |
(3) Surcharge on user charges per pound of suspended solids in excess of normal equals:
Cto x 0.21 St |
(4) Pounds of BOD per billing period subject to surcharge equals: average concentration of BOD, calculated pursuant to Section 924.03 in milligrams per liter minus 200 milligrams per liter times volume of wastewater discharged from the user to the wastewater treatment works per billing period, in 100 cubic feet, times 0.00624. If average concentration of BOD is 200 milligrams per liter, or less, no surcharge for BOD shall apply.
(5) Pounds of suspended solids per billing period subject to surcharge equals: average concentration of suspended solids, calculated pursuant to Section 924.03 in milligrams per liter minus 240 milligrams per liter times volume of wastewater discharged from the user to the wastewater treatment works per billing period, in 100 cubic feet times 0.00624. If average concentration of suspended solids is 240 milligrams per liter, or less, no surcharge shall apply.
(6) Surcharge on user charge equals: Pounds of BOD calculated pursuant to subsection (a)(4) hereof times surcharge per pound calculated pursuant to subsection (a)(2) hereof; plus pounds of suspended solids calculated pursuant to subsection (a)(5) hereof times surcharge per pound calculated pursuant to subsection (a)(3) hereof.
(7) Formulas as contained in subsections (a)(2) and (3) shall be subject to adjustment as necessary based upon a bi-annual audit of wastewater revenue fund expenses.
(b) Surcharges may also be established for pollutants other than those provided for in this paragraph which are permitted to be discharged to the wastewater treatment works by the City, after pretreatment, or without pretreatment.
(Ord. 103 (84-85). Passed 9-20-84.)