WORK PLANS FILE 2 - Laserfiche WebLink

Home Browse Search

i I Additionally, Monitoring Wells # 1 ,2,3 ,4, 5 & 16 will also be monitored for vacuum influence. At the last groundwater monitoring event on 1 /16/2006 each of these wells had several feet of well screen out of the groundwater. See attached Vapor Extraction Well locations and cross section. The total purging and extraction period on each Extraction Well testing will not exceed 2 hours each. We propose to purge, monitor and sample three of the Extraction Wells on the first day and complete the testing and monitoring on the other two Extraction Wells on the second day. Applied vacuum, P . I.D . measurements, flow rates, down hole vapor temperatures and the induced vacuum in the perimeter extraction observation wells will be monitored and logged every thirty minutes. Extracted vapor concentrations for each well that is being actively purged will be measured periodically (every thirty minutes) with an Thermodine 580 B PID, additionally two influent vapor samples per well will be collected for laboratory analysis in Tedlar bags to analyze the extracted vapor concentrations. One tedlar bag will be collected at the start of the extraction process on each vapor well (baseline concentrations) and then another vapor sample will be collected at the end of the extraction cycle for that Extraction Well. The air samples will be submitted to Air Toxics in Folsom, Ca. a State=Certified Laboratory for analysis of TPHg, BTEX and Oxygenates by EPA Method TO 15 . Once the first two hours of purging on V W= 1 has been completed the system will be turned off and moved to the next vapor well VW. 3 . We are expecting that the teardown and move time from wel to well should allow for the subsurface to stabilize back to a fairly normal condition. While the system is moved, all perimeter vapor & groundwater monitoring well caps will be removed to allow the surface atmosphere to equilibrate with the subsurface. When the system is started up on VW- 3 , all perimeter observation wells will be closed and monitored in the same sequence as was done on V W- 1 . Now that V W= 3 is the extraction well, V W- 1 will now be monitored for vacuum influence. This cycle of moving and monitoring will continue until all five of the vapor wells have been purged, logged and sampled. See example of the vapor extraction data log that will be filled out on each vapor and monitoring well. The SVE testing will be conducted under permit exemption from the local Air Pollution Control District (APCD) . Off gas treatment will be via catalytic converter. One effluent sample will also be collected and analyzed for TPHg, BTEX and Oxygenates by EPA Method TO 15 in order to verify destruction efficiency. The collected data will be used to calculate vacuum radius of influence and potential hydrocarbon removal rates. We are also going to confirm that all of the piping runs from the treatment pad to the vapor wells is in serviceable condition. Any failures or deficiencies will be logged and reported with the most logical repairs suggested.