Laserfiche WebLink
UPDATE 30 11-11-94 <br /> SUMMARY <br /> Vapor extraction has removed the lighter fractions of gasoline <br /> range hydrocarbons found in the soil as well as all of the BTEX' s <br /> dissolved in the ground water and the capillary fringe . An <br /> estimated 531 pounds remained in the soil after the February 2, <br /> 1994 confirmation sampling. The system was turned on again <br /> February 16 and last sampled November 7, 1994 and has removed an <br /> additional 248 pounds of hydrocarbons for an estimated reduction <br /> of 92`s <br /> Monitoring of the ground water indicates that contaminated ground <br /> water has been remediated and meets the Title 22 and DHS <br /> standards Primary MCL' s have been met for two years, since <br /> September 11, 1992 and Secondary MCL' s have been met for over one <br /> Year, since June 18 , 1993 <br /> The WEGE laboratory, along with the confirmation analysis of <br /> MATRIX and AEN indicate that all of the more volatile and mobile <br /> compounds of gasoline including all of the BTEX' s have been <br /> removed Modeling has shown that these remaining, less mobile, <br /> non-carcinogenic compounds have concentrations low enough to <br /> warrant being left in place Results of the most recent modeling <br /> (November 7, 1994) indicate that during the next 100 years <br /> biodegradation is faster than contaminant delivery, therefore the <br /> TPHg in ground water would never reach 1 ug/L <br /> RECOMMENDATIONS <br /> 1 Continue to obtain site closure from RWQCB <br /> 2 Continue vapor extraction until closure has been <br /> granted <br /> HEALTH AND SAFETY <br /> This site has been classified as Class D personal protection <br /> Hard hats, gloves, steel toed boots and ear protection are <br /> to be worn In the event that field screening indicates that <br /> volatile organic compounds (VOC' s) exists at the site, all <br /> personnel shall wear appropriate half face cartridge respirator <br /> with the black organic compound cartridges and particle filters <br /> All personnel must carry their identification card showing that <br /> they are current with OSHA/SARA training <br /> METHODS AND QA/QC <br /> WELL SAMPLING AND ANALYTICAL TECHNIQUES <br /> Depth to ground water and ground water samples were obtained from <br /> all of the ground water monitoring wells on October 10 , 1994 <br /> Vacuum and depth to water measurements were obtained from all of <br /> pagel0 <br />