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- Mr Martin Harris Page 2 of 3 SITE ACTIVITIES Activities at the site included monitoring groundwater levels in site monitoring wells, purging and sampling groundwater from site monitoring wells, and analyzing samples for total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, ethylbenzene, total xylenes (BTEX), oxygenated gasoline additives, 1,2-dichloroethane (1,2-DCA), and ethylene dibromide (EDB) Measured Groundwater Elevations An experienced field technician measured the depth to groundwater in monitoring wells MW 1 through MW7 on March 12, 2004 Groundwater elevations were calculated by subtracting the measured depth to groundwater in each well from the respective wellhead elevation The depth to groundwater in the wells ranged from 5 81 to 6 71 feet below the tops of the well casings (btoc) The potentiometric surface in wells MW 1 through MW4 rose an average of 0 63 feet between December 16, 2003 and March 12, 2004 The potentiometric surface in all site wells rose and average of 0 30 feet between January 23, 2004 and March 12, 2004 The calculated groundwater elevation in well MW7 is somewhat anomalous as compared to the groundwater elevations in other site wells, it is generally higher than expected, based upon historical groundwater gradients When the datum from well MW7 is not used in contouring, the gradient is consistent with historical data A potentiometric surface map generated from the March 12, 2004 monitoring data is shown on Figure 2 Groundwater monitoring data are summarized in Table 1 Monitoring data sheets are included in Attachment A Groundwater Sampling Procedures Monitoring wells MW 1 through MW7 were sampled on March 12, 2004 The wells were purged of at least three well casing volumes prior to sampling The physical parameters of temperature, pH and electrical conductivity were measured during the purging process Groundwater samples were collected after the physical parameters stabilized and groundwater in the wells recovered to at least 80% of pre-purged levels The samples were placed into an ice chest refrigerated to approximately 4°C and transported to Argon Laboratories (FLAP #2359) under chain of custody protocol Well purge logs are included in Attachment A GROUNDWATER ANALYTICAL RESULTS Groundwater samples were analyzed for the presence of TPHg, BTEX, and oxygenated gasoline additives (including the lead scavengers 1,2-DCA and EDB) using EPA methods 801513, 802113, and 826013, respectively TPHg was detected in wells MW1 and MW7 at concentrations of 720 micrograms per liter (µg/L) and 190 µg/L, respectively No TPHg was detected in wells MW2 through MW6 G 1GROUNDZE\TufSBoyNReports\QMR\IQM2004 doc