Item 4 - PH on MWMC Reg. SDCs - Laserfiche WebLink

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SYSTEM DEVELOPMENT CHARGE METHODOLOGY BMF. The majority of the infrastructure associated with this "General" component was constructed in the 1980s and early 1990s. The current loading or current required capacity is presented as annual average dry tons of digested biosolids. Current biosolids loading = 4,962 x 1.183 = 5,869 tons per year Where: - 4,962 dry tons per year (actual 2002 value) - 1.183 factor to convert actual value to a value that can be directly compared to the projected 2025 capacity value when a ~reater biosolids load will be generated by changes in the treatment process, and is calculated as follows: = {(60 x 1.23) + (40 x 1.11)}/100= 1.183 o '~fhere: 60 is the weighting given to BOlD for biosolids produc~on 1.23 is the BOD ppcd raQo (selected/actual) calculated as follows: - = 0.185/0.15 = 1.23 Where: 0.185 is the selected annual average BOD ppcd for proiected influent BOD values - 0.15 is the actual BOlD ppcd (annual average over 12-year period) - 40 is the weighffng given to TSS for biosolids producQon - 1.11 is the TSS ppcd raQo (selected/actual) calculated as follows: = 0.233/0.21 = 1.11 Where: 0.233 is the selected annual average TSS ppcd for projected influent TSS values (average of dry (0.205) and wet (0.26) seasonal values) 0.21 is the actual TSS ppcd (annua] average over 12-year period) Some existing biosolids facilities in the "general" subcomponent have more than 5,869 dry tons per year of processing capacity wh~le other existing facilities have less. However, in aggregate there is no available capacity and the existing capacity is assumed to be 5,869 dry tons per year as well. The proiected 2025 biosolids is 8,600 dry tons per year on an average annual basis. This value is esQmated based on a computer model of the WPCF that predicts bioso]ids $EA31003271388(DG). DOC/0410400~4