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t • • Mr. James Barton September 3, 2008 Page 2 of 4 2.0 FIELD WORK 2.1 Free Product Monitoring Background On April 20, 2005, Ground Zero Analysis, Inc. (Ground Zero) installed a Mini Maxi automated belt skimmer into well MW3. The skimmer was designed to automatically extract the product/water mixture from well MW3 and transfer the mixture to a product/water separator. The skimmer was in operation until May 12`h 2006. Prior to the installation of the belt skimmer, free product was removed manually by bailing. Since regular monitoring of MW3 began in July 2001, approximately 90 gallons of product/water was removed from the well by hand bailing,through the use of a passive oil skimmer, and by the automated belt skimmer. The product thickness was reduced from a high of 1.47 feet in September 2001 to not measurable by the end of June 2006. Current Measurement On August 12, 2008, prior to monitoring water levels in site wells, an electronic interface probe was used the check for measurable product thickness in well MW3. None was detected. A clear bailer was then used to retrieve a sample from the top of the water column in the well and the sample was visually inspected. A slight sheen was noted by the technician. 2.2 Groundwater Monitoring Water level elevations were monitored in wells MWl through MW7 on August 12, 2008 using an electronic water level indicator. The water probe and tape was decontaminated between wells by washing with a solution of laboratory-grade detergent, and then double rinsing with clean rinse water. The depth to groundwater in the wells ranged from 22.38 feet below the top of the well casing (btoc) in well MW3 to 23.40 feet btoc in well MW5. Groundwater elevations were calculated by subtracting the measured depth to groundwater in each well from the respective wellhead elevation. Groundwater flowed in a northeasterly direction with a average gradient of approximately 0.003 feet per foot. A potentiometric surface map for August 12, 2008 is shown on Figure 2. Groundwater monitoring data are summarized in Table 1. Monitoring data sheets are included in Attachment A. 2.3 Well Purging An experienced Ground Zero technician purged wells MWl through MW4 on August 12, 2008 using clean, disposable bailers. During the purging process, the technician measured the physical parameters of temperature, pH and electrical conductivity. Purging was terminated at each well after the measured parameters stabilized and a minimum of three well casing volumes had been evacuated. 2.4 Groundwater Sampling Groundwater samples were collected from each well using a disposable bailer after the water level in the well had recovered to pre-purged levels. Field purge logs are included in Attachment A. G:\GROUNDZE\GABBARD\reports\QMR\2008\3QM2008.doo