Laserfiche WebLink
1 <br /> C7016gua[TeelWINC Page 16 <br /> Dual Phase Extraction Pilot Test Report <br /> Project No 662 2 <br /> February 22,2005 <br /> 4 The current well configuration should be adequate to support a remedial design plan <br /> to address the residual contamination in soils and shallow groundwater at the site <br /> ' Our recommendations are based on our knowledge of site conditions, and on the state and <br /> limitations of subsurface investigative technology <br /> The following recommendations are made <br /> 1 Perform interim remedial action by installing a high vacuum dual phase extraction <br /> ' unit to address the on site contamination Dual phased extraction should be <br /> performed on well EW-2 with a separate dedicated groundwater pump on EW-l The <br /> treatment system should include carbon filtration of extracted groundwater to be <br /> ' discharged to City of Manteca public treatment works <br /> 2 A full scale Corrective Action Plan (CAP) should be deferred until after off site wells <br /> ' MW-5 and MW-6 have been monitored for several quarters to determine contaminant <br /> trends and after the interim remedial action has been in operation for a year to <br /> determine it's effectiveness at mitigating this plume Once these tasks Piave been <br /> ' accomplished a full scale CAP can be developed if needed, in accordance with <br /> County mandates and USTCFP requirements for three remedial alternatives <br /> 8.0 LMTATIONS <br /> t This report was prepared in accordance with the generally accepted standard of care and <br /> practice in effect at the time Services were rendered It should be recognized that definition <br /> and evaluation of environmental conditions is an inexact science and that the state or practice <br /> ' of environmental geology/hydrology is changing and evolving and that standards existing at <br /> the present time may change as knowledge increases and the state of the practice continues to <br /> improve Further, that differing subsurface soil characteristics can be experienced within a <br /> ' small distance and therefore cannot be known in an absolute sense All conclusions and <br /> recommendations are based on the available data and information. <br /> ' The tasks proposed and completed during this project were reviewed and approved by the <br /> local regulatory agency for compliance with the law No warranty, expressed or implied, is <br /> ' made <br /> r <br /> 71 I <br />