(a) The annual adjustment is based on sewer revenue fund expenses from the previous year and the lesser of the rated load capacity or actual load received at the wastewater treatment plant (works) for the last twelve (12) months, for each pollutant parameter as defined in Chapter 921. In addition to the base user charges applicable pursuant to Section 921.07 users discharging pollutants to the wastewater treatment works of the City, whose average concentration, as defined in Section 921.03 in one or more parameters exceeds in any month that concentration defined as normal in Section 921.03 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;
B. Previous years’ total pound of CBOD received at the plant (Bt);
C. Previous years’ total pounds of suspended solids received at the plant (St);
D. Previous years’ total pounds of phosphorus received at the plant (Pt);
E. Previous years’ total pounds of ammonia received at the plant (At); and
F. Previous years’ total pounds of oil and grease received at the Plant (Ot)
G. Data not available shall be estimated in the most practical manner possible
H. If the above parameter value exceeds the plants’ design capacity, then design capacity will be used.
(2) Surcharge on user charges per pound of CBOD in excess of normal equals:
Cto x 0.24 Bt |
(3) Surcharge on user charges per pound of suspended solids in excess of normal equals:
Cto x 0.17 St |
(4) Surcharge on user charges per pound of phosphorus in excess of normal equals:
Cto x 0.05 Pt |
(5) Surcharge on user charges per pound of ammonia in excess of normal equals:
Cto x 0.03 At |
(6) Surcharge on user charges per pound of oil and grease in excess of normal equals:
Cto x 0.03 Ot |
(7) Pounds of CBOD per billing period subject to surcharge equals: the average concentration of CBOD, calculated pursuant to Section 921.03, milligrams per liter minus 200 milligrams per liter, times the volume of wastewater discharged from the user to the wastewater treatment works per billing period, in 100 cubic feet times 0.006238.
(8) Pounds of suspended solids per billing period subject to surcharge equals: the average concentration of suspended solids, calculated pursuant to Section 921.03, milligrams per liter minus 240 milligrams per liter, times the volume of wastewater discharged from the user to the wastewater treatment works per billing period, in 100 cubic feet times 0.006238. If the average concentration of suspended solids is 240 milligrams per liter or less, no surcharge for suspended solids shall apply.
(9) Pounds of phosphorus per billing period subject to surcharge equals: the average concentration of phosphorus, calculated pursuant to Section 921.03, milligrams per liter minus 10 milligrams per liter, times the volumes of wastewater discharged from the user to the wastewater treatment works per billing period, in 100 cubic feet times 0.006238. If the average concentration of phosphorus is 10 milligrams per liter or less, no surcharge for phosphorus shall apply.
(10) Pounds of ammonia per billing period subject to surcharge equals: the average concentration of ammonia, calculated pursuant to Section 921.03, milligrams per liter minus 25 milligrams per liter, times the volume of wastewater discharged from the user to the wastewater treatment works per billing period, in 100 cubic feet times 0.006238. If the average concentration of ammonia is 25 milligrams per liter or less, no surcharge for ammonia shall apply.
(11) Pounds of oil and grease per billing period subject to surcharge equals: the average concentration of oil and grease, calculated pursuant to Section 921.03, milligrams per liter minus 150 milligrams per liter, times the volume of wastewater discharged from the user to the wastewater treatment works per billing period, in 100 cubic feet times 0.006238. If the average concentration of oil and grease is 150 milligrams per liter or less, no surcharge for oil and grease shall apply.
(12) Surcharge on user charges equals pounds of CBOD calculated pursuant to subsection (a)(7) hereof times surcharge per pound calculated pursuant to subsection (a)(2) hereof; plus pounds of suspended solids calculated pursuant to subsection (a)(8) hereof; times surcharge per pound calculated pursuant to subsection (a)(3) hereof; plus pounds of phosphorus calculated pursuant to subsection (a)(9) hereof times surcharge per pound calculated pursuant to subsection (a)(4) hereof; plus pounds of ammonia calculated pursuant to subsection (a)(10) hereof times surcharge per pound calculated pursuant to subsection (a)(5) hereof; plus pounds of oil and grease calculated pursuant to subsection (a)(11) hereof times surcharge per pound calculated pursuant to subsection (a)(6).
(13) Formulas as contained in subsections (a)(2), (3), (4), (5) and (6) hereof, shall be subject to adjustment as necessary based upon an annual audit of sewer revenue fund expenses.
(b) Surcharges may also be established for pollutants other than those provided for in this section which are permitted to be discharged to the wastewater treatment works by the Director, after pretreatment, or without pretreatment.
(c) Surcharges levied pursuant to this section shall be billed quarterly or as otherwise established by the Director or his designated representative. Rates shall be as established by the Director or his designated representative.
(Ord. 2004-23. Passed 4-13-04.)