Laserfiche WebLink
1 <br /> Working To Restore Nature <br /> the petroleum hydrocarbon concentrations extracted from these wells The regenerative blower <br /> system was operated on each well for 30 minutes, and induced vacuum changes were monitored <br /> in the observation wells The extraction flowrate from well VW-1 ranged from 105 cfm to 109 <br /> ' cfm at an applied vacuum of 30 inches of water The extraction flowrate from well VW-3 <br /> ranged from 113 cfm to 118 cfm at an applied vacuum of 30 inches of water After 30 minutes <br /> ' of operation a vapor sample was collected from each well for laboratory analysis <br /> Vapor samples were collected through a 114-inch Teflon sample line connected to a stainless <br /> steel wellhead fitting, and collected in Tedlar sample bags Teflon tubing was used to minimize <br /> sample loss through adsorption and the possibility of distorted results from sample lines <br /> ' contaminated by previous test runs The samples were sent to Sequoia Analytical for analysis <br /> of TPHg and BTEX using EPA Methods 5030/8015/8020. A chain-of-custody record <br /> accompanied all samples delivered to the laboratory <br /> ' 7.2 Remedial Investigation Results <br /> 7.2.1 Long Term Soil Vapor Test <br /> ' During the long term extraction test from VW-2, well head flowrate and vacuum readings <br /> recorded were 100 to 105 cfm and 30 inches of water, respectively Induced vacuums in <br /> observation wells VW-1 and VW-3 were almost instantaneous due to the porous soil conditions <br /> of the site As the flowrate was increased to over 100 cfm, the observed induced vacuums <br /> ' increased to vacuums ranging from 0 72 to 1 2 inches of water These values were observed <br /> at a vacuum of 30 inches of water These induced vacuum responses are considered to be good <br /> response levels The achievable flow of 100 cfm is considered to be high but not unusual for <br /> such porous soil conditions VW-1 is located 24 5 feet from extraction well VW-2 and VW-3 <br /> 1 is located 31 5 feet from VW-2 Field monitoring data from the vapor extraction test are <br /> presented in Appendix F <br /> ' 1500471R-031594 FNL 10 <br />