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1 <br /> Vapor Extraction System Sample Calculations <br /> Moore Petroleum,Inc, 1399 E Yosemite Ave,Manteca,CA <br /> ' VAPOR EXTRACTION SAMPLE CALCULATIONS <br /> ' Calculating Daily-Extraction R� <br /> Once given the vapor analytical results in ug/l and the corresponding system flow rate for that <br /> sampling event in cubic feet per minute (CFM), a daily extraction rate may be calculated in <br /> ' pounds per day(lb/day) <br /> The sample calculations will be focused on the sampling event which occurred on February 24, <br /> ' 1995 This sampling event yielded concentrations of total petroleum hydrocarbons(TPI , as <br /> gasoline, at 160 ug/l, and a benzene concentration below laboratory detection limits The system <br /> flow rate on this day was 16 CFM <br /> The method for calculating daily extraction rates is to take the analytical concentrations which are <br /> reported in ug/l and, using standard conversions, convert tins value to units of pounds per cubic <br /> ' foot Tins value may then be multiplied by the system flow rate on the day the sample was <br /> collected, in CFM, and then converted to units of days The result will be the daily extraction rate <br /> in lb/day An example of this method is as follows <br /> 3 <br /> concentration (Lg)x 2 3177X 4 54x lb <br /> s�gxflow rate ( )x 1440 mini=extraction rate(') <br /> MITI day <br /> If this method is applied to the TPK as gasoline, concentrations, the following daily extraction <br /> rate results <br /> ' 160-M--x28 3171 x 1 lb x 16 ft 3 x 1440 mm= 023 lb TPH,as gasoline <br /> 1 ft 3 4 54x1 D$ Lg min daY day <br /> 1 <br /> This method can also be applied to the analytical results for benzene on this date Due to the <br /> ' benzene concentration being below laboratory detection limits, no benzene will be extracted on a <br /> daily rate <br /> Once the daily extraction rates are known, the cumulative quantities of TPK as gasoline, and <br /> benzene need to be calculated It will be assumed that the average daily extraction rate for a <br /> particular period will he somewhere between the most recent daily extraction rate and the <br /> previously calculated daily extraction rate It will be assumed that a good approximation of the <br /> average daily extraction rate for a particular period of time will be the most recent daily extraction <br /> rate averaged with the previously calculated daily extraction rate <br /> I , <br />