Laserfiche WebLink
Manuel Sanchez page 2 <br /> 1876 Country Club Blvd, Stockton <br /> If over-excavation is not planned for this site, then the following investigation should be <br /> completed. <br /> In order to verify the impact to the groundwater from the ongoing interaction between <br /> the elevated groundwater levels and the residual soil contamination remaining above <br /> the monitoring well screened interval, PHS-EHD will require an additional monitoring <br /> well to be placed in the area of highest soil contamination (soil probe "SP-E" area). <br /> This well should be constructed in such a manner that will allow the current DTW to be- <br /> within the new screened interval and also have the lower limit of the new screen overlap <br /> the top of the screened interval of MW-1 by at least two (2') feet. In addition, air sparge <br /> and vapor extraction wells should be installed to investigate these remedial alternatives. <br /> Please continue to sample all of the groundwater wells for this site for MTBE on a <br /> quarterly basis. The sample with the highest concentration should be analyzed by EPA <br /> method 82408 or 8260A (GC/MS) to confirm that there are no false positives being <br /> recorded by the EPA method 8020 as submitted in your QMR's. <br /> Soil samples from the new well installation should also be sampled and confirmed for <br /> MTBE. The findings from this new well installation and sampling should provide the <br /> most accurate and relevant data for the highest area of concern at this site. <br /> A workplan that proposes the additional monitoring, vapor extraction, and air <br /> sparge wells or one that proposes over-excavation of the residual contaminated <br /> soils should be submitted within sixty (60) days of the date of this letter. <br /> Please continue to direct your reports or any questions you may have to Michael <br /> lnfurna at (209) 468-3454. <br /> Donna Heran, REHS, Director <br /> Environmental Health Division <br /> Michael Infurna Jr., Senior REHS Margaret Lagorio, REHS <br /> LOP/Site Mitigation Unit IV Supervisor <br /> MI/ <br /> c: Martin Clark - SWRCB Cleanup Fund, 2014 "T" St. Ste 130, Sacramento, 94212. <br /> c: Wm. Hunter - 2220 Loma Vista Dr., Sacramento, 95825 <br />