(a) The standard strengths for biochemical oxygen demand and suspended solids, as shown in § 1044.04, shall be subtracted from the average strengths, as determined in the manner described in division (b) hereof, to determine the extra strengths of each industrial class user for each strength surcharge billing period. The extra strengths and the volume of wastewater charged for the billing period shall then be used to determine the weight in pounds of biochemical oxygen demand (BOD) and suspended solids (SS) to be charged for the strength surcharge. The BOD surcharge shall be based on pounds of BOD or 0.5 times the pounds of chemical oxygen demand (COD), whichever is greater.
(b) To determine the BOD, COD and SS concentrations, an average shall be used which will be established from a minimum of two tests per month taken on composite samples.
(c) The charges for handling those wastes exceeding the limits set forth in divisions (a) and (b) hereof shall be based on the following formula:
Surcharge = C x B x V x 8.345
C | = | unit cost per pound |
B | = | concentration exceeding base 220 mg/l |
V | = | total volume of flow in millions of gallons |
8.345 | = | constant of proportionality |
(d) The charges calculated from the rate structure for any billing period, plus the surcharge as calculated in division (c) hereof, shall be the charge made to the customer for the billing period.
(e) Industrial waste testing shall be performed as described in § 1042.31.
(Ord. 86-32, passed 6-23-1986)