§ 51.05 SEWER SERVICE CHARGES.
   The sewer service charge for the use of, and for the service supplied by, the sewage of the city shall consist of the sum of a user charge for operation, maintenance, and replacement; a debt retirement charge; and a surcharge, if applicable.
   (A)   The user charge shall be based on water usage as recorded by water meters and/or sewage meters for wastes having concentrations equal to, or less than, the following:
      (1)   A five-day, 20°C biochemical oxygen demand (BOD) of 245 mg/l; and
      (2)   A suspended solids (SS) content of 230 mg/l.
 
The charge shall be computed as follows: Unit costs for flow, BOD, and SS shall be calculated by allocating the total annual OM&R costs to the three parameters in proportion to that share of the cost attributable to each. The user charge shall be the sum of the products obtained by multiplying the unit costs by the flow, BOD, and SS constituents in 100 cubic feet of domestic waste, as follows.

UC =
FC + BC    (BA) + SC (SA)
   F B S

Where:
UC = User charge per 100 cubic feet of wastewater
FC = The portion of the annual OM&R cost attributable to flow
F = Total flow to be received at the treatment plant in a given year, in 100 C.F.
BC = The portion of the annual OM&R cost attributable to BOD
BA = The number of pounds of BOD in 100 C.F. of domestic flow (153 pounds/100 C.F.)
B = Total BOD to be received at the treatment plant in given year, in pounds
SC = The portion of the annual OM&R cost attributable to SS
SA = The number of pounds of BOD in 100 C.F. of domestic flow (144 pounds/100 C.F.)
S = Total SS to be received at the treatment plant in a given year, in pounds
 
   (B)   Debt retirement charges shall be based on water usage for wastes having concentrations equal to or less than those listed in division (A) above. Debt retirement unit costs for flow, BOD, and suspended solids shall be calculated by allocating the total annual debt retirement costs to the three parameters in proportion to that share of the cost attributable to each.
 
The debt retirement charge shall be the sum of the products obtained by multiplying the unit costs by the flow, BOD, and SS constituents in 100 C.F. of domestic waste, as follows:
DC = FD + BD (BA) + SD (SA)
   F B         S
Where:
DC   =   Debt retirement charge per 100 C.F. of wastewater
FD   =   The portion of the annual debt retirement costs attributable to flow
F   =   Total flow to be received at the treatment plant in a given year, in 100 C.F.
BD   =   The portion of the annual debt retirement costs attributable to BOD
BA   =   The number of pounds of BOD in 100 C.F. of domestic flow
Where:
B   =   Total BOD to be received at the treatment plant in a given year, in pounds
SD   =   The portion of the annual debt retirement costs attributable to SS
SA   =   The number of pounds of SS in 100 C.F. of domestic flow
S   =   Total SS to be received at the treatment plant in a given year, in pounds
 
   (C)   A surcharge shall be levied to all users whose waste discharges exceed the maximum wasteload contributions for BOD (1.53 pounds/100 C.F.) and SS (1.44 pounds/100 C.F.) listed in division (A) above. The surcharge shall be based on applying the user charge unit charges for BOD and SS to the amount of each of these constituents discharged by the user in excess of 1.53 pounds/100 C.F. and 1.44 pounds/100 C.F., respectively, as follows.
 
XC =BC (BX -1.53) + SC (SX -1.44)
B       S
Where:
XC   =   Amount of surcharge per 100 cubic feet of wastewater
BX   =   The BOD wasteload contribution in excess of 1.53 pounds/100 C.F.
SX   =   The suspended solids wasteload contribution in excess of 1.44 pounds/100 C.F.
All other notations as in divisions (A) and (B) above
 
   (D)   Sewer service charges shall be computed by summing the component charges and multiplying by the recorded wastewater discharge, as follows.
 
SSC = V (UC + DC + XC)
Where:
SSC   =   The sewer service charge per billing
V   =    Volume of wastewater recorded during the billing period
All other notations as in divisions (A) through (C) above
 
(2006 Code, § 3.30) (Ord. 88, 3rd Series, passed 11-28-1991)