Laserfiche WebLink
ere <br /> Organic concentrations in the extraction well air stream w <br /> x° monitored continuously using a photoionization detector (PID) <br /> calibrated to the isobutylene standard. <br /> The extraction well effluent was piped to a 270 lb canister of <br /> 1 vapor phase carbon for control of VOC emissions during the test. <br /> This flowline was fitted with a sampling port and sample pump for <br /> the collection of vapor samples. Samples were collected in <br /> tedlar bags. A schematic drawing of the test instrumentation is <br /> shown on Figure 3. <br /> 4.0 TEST FORMAT <br /> Each of the three vadose wells was developed prior to beginning <br /> the extraction tests. This consisted of operating the extraction <br /> pump at progressively greater vacuum rates for approximately 20 <br /> minutes. <br /> During the testing, the vapor extraction system was c•perated at a ' <br /> p' minimum of two air flow rates in order to provide verification o.f <br /> the calculated permeability and flow regime parameters. <br /> The first constant rate test was conducted on April 25 utilizing <br /> well VP2 for extraction. The flow rate was gradually increased <br /> over the first 10 minutes of the test until the system stabilized <br /> at a vacuum of approximately 63 inches of water and a flowrate of <br /> approximately 85 cubic feet per minute (cfm) . The test was <br /> r� continued for a total of 350 minutes while monitoring the pres- <br /> sure response periodically in the observation wells. Air samples <br /> were collected from the flowline in tedlar bags after 12, 127 and <br /> 252 minutes. <br /> r The second constant rate test was conducted on April 26 utilizing <br /> ly <br /> well VPl for extraction, A stabilized fl ro imately fib inchesw rate of of <br /> 36 cfm was maintained at a vacuum o£ app <br /> water. This test ran a total of 212 minutes. Air samples were <br /> collected after 39 and 189 minutes of extraction. <br /> i <br /> At the conclusion of the VP1 test the blowe_' was connected to <br /> ,wry well VP3 for.the purpose of sampling. A single sample was col <br /> lected after a 20 minute production period. <br /> Samples were labeled and placed in a refrigerated container for <br /> transport to a state certified laboratory. Samples were trans- <br /> ported to Sequoia Analytical Laboratory under chain-of -custody , <br /> protocol and analyzed for benzene, toluene, ethylbenzene, xylenes <br /> (STEX) and total .low-medium boiling point hydrocarbons (TPFiG) by / <br /> EPA methods 5030/8020/8015. <br /> -- — ---5.0 --TEST-RESULTS-- <br /> The pressure response data for each of the observation wells has <br /> been plotted versus the log of time for both of the constant rate <br /> 2 <br />