(a) Sewage Surcharge.
(1) Establishment. A sewage surcharge shall be fixed by the City and levied for any person whose premises are served by a sanitary sewer connection and who discharges wastes other than normal sewage into the sewerage system.
(2) Basis. Surcharges shall be based on the applicable constituents of the wastewater as follows:
A. Total suspended solids;
B. C.B.O.D., five days at twenty degrees Centigrade;
C. C.O.D.;
D. Phosphorus; and/or
E. Oil and grease.
(b) Calculations.
(1) Surcharge formulas. Whenever the wastes are ruled acceptable to wastewater treatment and the wastewater contains suspended solids, C.B.O.D. and/or C.O.D. and/or phosphorus and/or oil and grease in excess of normal sewage, the excess shall be subjected to a surcharge derived in accordance with the following formulas:
SC = ((SS-225) x F x 8.34 x CS) + ((CBOD-185) x F x 8.34 x CB)
= F x 8.34 x ((SS-225) x CS + (CBOD-185) x CB)
SC = Surcharge based on average daily flow.
SS = Total suspended solids in wastes as discharged in mg/l.
225 = Suspended solids concentrations in normal sewage in mg/l.
F = Flow in millions of gallons per day of wastes as discharged.
CS = Cost to treat one pound of suspended solids in cents per pound. Total operating cost attributable to total pounds of suspended solids/total pounds of suspended solids removed.
CBOD = Total C.B.O.D. in wastes as discharged in mg/l.
185 = C.B.O.D. concentration in normal sewage in mg/l.
CB = Cost to treat one pound of C.B.O.D. in cents per pound.
Total operating cost attributable to C.B.O.D./total pounds of C.B.O.D. removed.
or
SC = ((SS-225) x F x 8.34 x CS) + ((COD-250) x F x 8.34 x CC)
= F x 8.34 x ((SS-225) x CS + (COD-250) x CC)
COD = Total C.O.D. in wastes as discharged in mg/l.
250 = C.O.D. concentration in normal sewage in mg/l.
CC = Cost to treat one pound of C.O.D. in cents per pound.
Total operating cost attributable to C.O.D./total pounds of C.O.D. removed.
or
SC = (P-8) x F x 8.34 x CP
P = Total phosphorus in wastes as discharged in mg/l.
8 = Total phosphorus concentration in normal sewage in mg/l.
CP = Cost to treat one pound of phosphorus in cents per pound.
Total operating cost attributable to phosphorus/total pounds of phosphorus removed.
or
SC = (OG-80) x F x 8.34 x COG
OG = Total oil and grease in wastes as discharged in mg/l.
80 = Total oil and grease concentration in normal sewage in mg/l.
COG = Cost to remove one pound of oil and grease in cents per pound. Total operating cost attributable to oil and grease/ total pounds of oil and grease removed.
(2) Use of C.B.O.D. and C.O.D. analyses. Whenever a waste cannot be analyzed by a C.B.O.D. test, the C.O.D. result shall prevail in calculating a surcharge. Whenever both testing methods are possible, the POTW shall determine which analysis shall apply in computing the surcharge based on which will provide the higher surcharge.
(3) Annual review of strength surcharge. On or before March 1 of each year, the strength surcharge for the POTW for the previous year will be reviewed. The cost to treat the C.B.O.D., C.O.D., oil and grease, suspended solids and phosphorus shall be based on the total operating cost of the sewerage works. Increases or decreases in the cost of treating and disposing of excess amounts of C.B.O.D., C.O.D., oil and grease, suspended solids and phosphorus shall be reflected on a proportionate basis in the strength surcharge on the basis of cost per pound.
(c) Surcharge for Excess Concentration.
(1) When the total suspended solids, CBOD, COD, phosphorus and/or oil and grease of a water or waste accepted for admission to the system exceed the values of their constituents for normal sewage, the excess concentration in any or all, as the case may be, shall be subject to a surcharge as follows:
A. Pounds of excess suspended solids per day x $0.57 per lb. = suspended solids surcharge.
B. Pounds of excess CBOD per day x $0.56 per lb. = CBOD surcharge.
C. Pounds of excess COD per day x $0.25 per lb. = COD surcharge.
D. Pounds of excess phosphorus per day x $0.85 per lb. = phosphorus surcharge.
E. Pounds of excess oil and grease per day x $0.57 per lb. = oil and grease surcharge.
(2) In addition to the above surcharges, the City shall have the right to surcharge any user for the discharge of any other pollutant into the sewerage system.
(Ord. 91-65. Passed 1-21-91; Ord. 2010-46. Passed 11-16-10; Ord. 2014-19. Passed 4-1-14; Ord. 2015-15. Passed 4-7-15; Ord. 2016-20. Passed 4-5-16; Ord. 2017-22. Passed 8-15-17; Ord. 2018-13. Passed 4-3-18; Ord. 2019-12. Passed 4-2-19; Ord. 2020-22. Passed 4-21-20; Ord. 2021-15. Passed 3-16-21; Ord. 2022-22. Passed 4-19-22.)