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GeologiralTeckaicslnc Page 3 <br /> Groundwater Monitonng Report <br /> Project No 723 2 <br /> December 17,2002 <br /> was positive or upward) in direction but additional monitoring is needed before drawing <br /> p ( p ) g <br /> conclusions <br /> 1.2 Groundwater Sampling Procedure <br /> ' On September 9, 2002, Del-Tech Geotechnical Support personnel arrived on-site, opened <br /> the wells and measured the depth to water with an electrically actuated sounding tape The <br /> water level readings were recorded to an accuracy of 0 01 feet In wells where free-floating <br /> product is suspected, a clear disposable bailer is used to gauge the interface During this <br /> monitoring no free product was noted <br /> ' Stagnant water in the well casing was purged using a Waterra pump as recorded in the field <br /> logs (Appendix C) The rate of well purging was monitored The wells were purged of <br /> approximately three casing volumes and until the groundwater parameters (temperature, <br /> conductivity and pH) had stabilized (Appendix C) indicating that water representative of <br /> actual aquifer conditions was entering the well Groundwater parameter stabilization was <br /> ' characterized by three successive readings within 10% <br /> M Before a sample was collected, the well's water level was allowed to recharge to at least <br /> 80% of the initial level The purge water was placed in a properly labeled 55-gallon DOT <br /> (Department of Transportation 17-H) approved container and temporarily stored on-site <br /> ' The dedicated Waterra pump was used to collect each monitoring well sample Extreme <br /> care was exercised while transferring the sample into 40-m1 VOA vials preserved with <br /> ' hydrochloric acid All samples were checked for headspace bubbles, labeled, inserted into <br /> foam holders and placed into an ice chest cooled to 4°C for transport to the laboratory <br /> The sampling technician wore disposable gloves while collecting all samples <br /> A chain of custody document, listing all samples collected and their intended analyses, <br /> ' accompanied the samples from the field to the laboratory, thereby providing a means to <br /> track the movement of the samples and ensure their integrity <br /> 1.3 Laboratory Analyses <br /> ' The groundwater samples collected on September 9, 2002, were delivered to Sherwood <br /> Labs of Hilmar, California(certification #1400) for analyses of <br /> ' • Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX), MTBE, by EPA method 8020 <br /> • Total Petroleum Hydrocarbons as Gasoline (TPH-G) by EPA method 5030/8015(M) <br />