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R604 UPDATE 20 7-16-1993 creates and anomalously high concentration at this well With this in mind, the "Present California Water Quality Goals" have been met for over 6 months, see Table 1 . Fecal Coliform: From December, 1991 through February, 1992, monthly fecal coliform samples were collected from monitor wells MW3 , MW4, MWS and MW6 Samples were again collected in June, 1992, from monitoring wells MW3 , MW4 and MW6 During the September 11, 1992 sampling, MW3 and MW6 were dry; no fecal coliform samples were obtained Table 2 shows the results of these samples As of June, 1992 all these wells are below detection limits, <2 . 2 MPN, for fecal coliform VAPOR EXTRACTION Note: A correction to total operational hours of system has been introduced to Table 3 - Vapor Recovery Summary. The systems automatically cycles during the months of May through October. The cycling occurs as the blowers warm during the daylight hours (10 :00 AM - 8 : 00 PM) and shut off for a 20 minute cool down period, see section SAN JOAQUIN COUNTY REVIEW ANSWERS (COMMENTS) - Concerning pulsing the system, . This correction has reduced the total amount of gasoline range hydrocarbons that have been recovered at this site, which is reflected in the following text and denoted with * and on Table 3 . Vapor Recovery Results: The vapor extraction system was shut down on November 21, 1991 on completion of operation under Initial Variance #91-19 and 90 day Variance #91-20 A total of 13, 116 pounds of gasoline range hydrocarbons were removed from the soils and ground water beneath this site by that time The vadose zone vapor recovery wells (P1, P3-Swarm and EX) contributed little to the total recovered hydrocarbons during this time period P1 = 1 . 3 pounds, P3-Swarm = 561 4 pounds and EX = 127 pounds The system was restarted under the Authority to Construct Permit (AP 91-106) on March 31, 1992 * On July 21, 22, and 23 , 1992 , four new vadose zone vapor recovery wells were installed and manifolded to the recovery system As of July 22, 1992 the existing vapor extraction system (MW5, P1, P3--Swarm and EX) had produced 13902 8 and the newly installed well VSB3 produced 3 6 pounds of gasoline range hydrocarbons Since that time only the newly installed wells (VSB3, VSB5, VSB9 and VSB11) and MW5 have been used for vapor extraction. As of the latest sampling (June 18, 1993) the new wells and MW5 have removed 3713 pounds of gasoline range hydrocarbons, for a total recovery of 17619 pounds, see Table 3 and Charts, Figures 6A through 6E of vapor recovery page 5