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CAMBRBA <br /> From March through June 1999, weekly groundwater extraction (GWE) was performed on <br /> well RW-1A From July 1999 to June 2000, GWE occurred bi-monthly Beginning <br /> June 2000 the GWE occurred weekly During each GWE event, approximately 5,000 gallons <br /> of water is purged by a vacuum truck and transported to the Martinez Refining Company for <br /> recycling On August 22, 2000 a pump was installed in RW-lA and it currently pumps into a <br /> Baker tank A vacuum truck then empties this tank and recycles the water as described <br /> above As of February 23, 2001, approximately 445,443 gallons of water have been <br /> removed from RW-lA As shown on Table 2, based on the concentration data, groundwater <br /> extraction has effectively removed approximately 322 pounds of TPHg, 41 pounds of <br /> benzene, and 506 pounds of MTBE <br /> ANTICIPATED SECOND QUARTER 2001 ACTIVITIES <br /> Blaine will gauge and sample the site wells according to the existing sampling schedule and <br /> tabulate the data Cambria will prepare a groundwater monitoring report We anticipate <br /> completing construction of the permanent groundwater extraction system and starting it up <br /> in the second quarter <br /> • CONCLUSIONS AND RECOMMENDATIONS <br /> The petroleum hydrocarbon and MTBE concentrations in groundwater samples collected <br /> from the shallow wells this quarter are within the historical norm for this site Wells MW-5, <br /> MW-8, and RW-1A continue to contain the highest levels of hydrocarbons and MTBE <br /> However, analytical data from offsite wells suggests the hydrocarbons and MTBE detected <br /> onsite wells are remaining onsite <br /> Groundwater samples from the Caltrans well contained low levels of toluene and xylenes, <br /> which it has contained in the past MTBE (by EPA Method 8260) was reported in the <br /> Boardman well bailer sample this quarter at a concentration of 2 89 ppb The EPA <br /> Method 8020 analysis for MTBE on the same groundwater sample did not detect MTBE <br /> This suggests that the detection of MTBE may be anomalous The groundwater sample <br /> collected from the sample port on this well did not contain MTBE (by either EPA Method <br /> 8020 or 8260) Well MW-14, which is located between the Shell site and the Boardman, well <br /> did not contain MTBE These data further support the idea that the detection of MTBE in <br /> the bailer sample from the Boardman well is anomalous and/or not associated with the Shell <br /> site <br /> i <br /> 0783 2 <br />