Laserfiche WebLink
Mr.Thomas Bauhs .2- 16 March 2005 <br /> • Ms. Kitty Walker <br /> proposed soil vapor monitoring points with an identifier that has not already been used <br /> for sample identification. <br /> 4. We do not concur with the monitoring schedule provided on Page 8 of the Work Plan. <br /> The scheduled monitoring does not propose sampling until six months after the startup of <br /> the SVS system and proposes to eliminate a sampling point after one round of non- <br /> delectable results. This is not sufficient. Increased monitoring is needed for the first <br /> three months of operation. After the initial rounds of sampling from the soil vapor <br /> monitoring points,the L&M OU may propose performance based monitoring or a set <br /> time schedule. <br /> 5. The Work Plan needs to include monitoring for methane and polynuclear aromatic <br /> hydrocarbons. _ <br /> 6. The L&M OU needs to provide a discussion of the proposed teak test during sample <br /> collection,which is mentioned on page 8. <br /> 7. The locations of the five proposed soil vapor monitoring points are not sufficient to <br /> determine the radius of influence for the SVE system. At least one soil vapor monitoring <br /> point is needed to the west of the furthest SVE well to determine lateral radius of <br /> influence. A soil vapor monitoring point also is needed south of the screened portion of <br /> "ASVE-6." Furthermore,all of the monitoring points are proposed to a total depth of five <br /> feet below ground surface. Based on the depth of the SVE wells,about nine feet below <br /> ground surface, the L&M OU needs at least one location with multiple depth monitoring <br /> points to evaluate the effectiveness of the system at capturing vapors at and below the <br /> depth of the SVE well_ <br /> 8. Proposed SV-1 appears to be located to evaluate the influence from SVE-1,which is not <br /> consistent with the remaining four proposed soil vapor monitoring points,which are <br /> evaluating the"ASVE"wells. The L&M OU needs to include a discussion of each of the <br /> proposed soil vapor monitoring points with the rationale for their locations. <br /> 9. As shown on Figure 3 of the Work Plan,them is a large area between the dual phase <br /> extraction system west to the screwed areas ofASVB-3 and ASVE-q. The L&M OU <br /> needs to discuss how it will determine the eflects of the SVE system in this area. <br /> 10. Regional Board staff concuna with moving proposed soil vapor monitoring points under <br /> the apartment buildings,as requested in DTSC's attached memorandum,to accommodate <br /> data needs for the completion of a human health risk assessment. <br /> 11. Regional Board staff does not concur with drilling soil vapor monitoring point borings <br /> deeper than the proposed total depth of the proposed soil vapor monitoring point to <br /> collect additional data for the human health risk assessment, as commented on in the <br /> attached DTSC memorandum. For the data needed from deeper depths,the L&M OU <br /> • <br />