Additional industrial unit charges.

The formula for sewer surcharge shall be computed by the Chief Plant Operator and/or Superintendent of Sewers. The additional units for industrial/commercial establishments to be added to the established Town flow rate shall be the product of the sewer surcharge factor and the established district flow rate charge as shown in the schedule of units of use for industrial plants in § 257-165. The general form for the determination of the surcharge factor (SF) shall be as follows:SF=a(BOD-300)300+b(SS-300)300+c(CLD-25)25+d(P-10)10Where:SF=Surcharge factorBOD=Milligrams per liter of biochemical oxygen demand as defined in § 257-7SS =Milligrams per liter of suspended solids as defined in § 257-7CLD =Milligrams per liter of chlorine demand as defined in § 257-7P =Milligrams per liter of phosphorus as defined in § 257-7a =Proportion of operation and maintenance cost to treat a pound of biochemical oxygen demand (BOD)b=Proportion of operation and maintenance cost to treat a pound of suspended solids (SS)c=Proportion of operation and maintenance cost to treat a pound of chlorine demand (CLD)d=Proportion of operation and maintenance cost to treat a pound of phosphorus (P)NOTES:a, b, c, and d are decimal portions of the total operation and maintenance costs for the sewerage system.

The values shall be determined by the Chief Plant Operator/Superintendent of Sewers on a yearly basis from data accumulated each preceding year from the actual operations and maintenance costs.If any of the values for BOD, SS, CLD or P as determined by laboratory analysis are less than the respective normal values stated in the definition of "normal sewage" in § 257-7 , the factor for that pollutant shall be eliminated from the formula.More than one identifiable pollutant may be present in the sewage, and each such pollutant therefore shall appear as an additional term in the formula for determination of the sewer surcharge factor.