Ordinance No. 20222 - Laserfiche WebLink

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fl fl fl n M Estimate ~ased on monitoring data or measurements for the substance. Nate.:. These are "estimates" because even the best measurements have some error associated with them. C Estimate based on mass balance calculations if directly used to calculate mass. E Estimate based on published emission factors. o Estimate based on engineering calculations (using published mathematical formu- las, e.g., evaporation rates) or best engineering judgment. n F. Examples of Each Estimation Method fl ~ ) 1. Method M: Averages of measurements of Volatile Organic Compounds (VOCs) in water sent to publicly owned treatment works (pOTW) multiplied by the total water discharge as recorded by the public utility may be used to estimate outputs to the POTW of those compounds. ~ 1 t k 2. Method C: To estimate releases of Chemical X to air from a process vent: ! 1 '" t Step 1. Draw a diagram, label all streams, and list input and output values. , .. .- J \ " J VENT TO ATMOSPHERE - CHEMICAL X OUTPUT 5 -- 500 lbs./yr. MATERIALS ACCOUNI1NG ........................: BOUNDARY PURCHASED CHEMICAL X - INPUT 4 8,000 lbs./yr. PROCESS PRODUCT SHIPMENT- OUTPUT 2 6,000 lbs./yr. SOLID WASTE- OUTPUT 3 1,5001bs./yr. RECYCLED CHEMICAL X 2000 Ibs/yr . . .. . . . . . . . .. . .. . . . . . . . . . . . .. . . . . . . . . ... . . . . . . . . . . . . . . ... . . ... .. . .. .. .. .. .. Consider a unit process that uses Chemical X to produce a product. In a year, 10,000 pounds of Chemical X are used to produce 24,000 pounds of a product containing 25% (6,000 pounds) of Chemical X by weight. The input consists of 8,000 pounds of purchased Chemical X and 2,000 pounds that are collected from recycling. This process generates 10,000 pounds of solid waste containing 15% (1,500 pounds) of Chemical X, and re-generates 2,000 pounds of Chemical X for recycling. The only other unit process stream is a process vent, which emits an unknown amount of Chemical X to the atmosphere. 16