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. Monitoring Well Installation Report Quik Stop No 121 Page 5 Before groundwater sampling, CCI measured the depth to groundwater using an electronic sounding tape and field-checked the wells for the presence of free-floating product by collecting a sample in a clear acrylic bailer Free-floating product was not observed Each well was purged of stagnant water prior to collection of a sample Normal field measurements, including pH, conductivity, and water temperature were periodically recorded during the purging process A sample was collected when these parameters stabilized to within 10% of each other At least three well casing volumes of groundwater were purged from each well before sampling Samples were (a) collected with a clean Teflon bailer, (b)transferred to appropriate laboratory-supplied bottles, (c) labeled, (d) logged on a chain-of-custody form, and(e) placed in a chilled ice chest for transportation to a state-certified laboratory Appendix B contains CCI's Groundwater Sampling Protocol Subsurface Conditions CCI explored subsurface soils to depths of 25 feet at the three well locations In general, the upper 6 to 9 feet of soil encountered at the subject site consisted of brown to orange-brown, silty sand Below 9 feet, the subsurface soils became more granular, consisting of a orange-brown, fine-to- medium grain sand This sand horizon extended to depths of 18 to 20 feet on the north side of the site, at well locations MW-1 and MW-2 The one exception was at MW-3, located on the south side of the site, which was found to have light grey to grey-brown, silty clay at depths of 14 to 17 feet Below 22 feet and extending to a depth of 25 feet at all three monitoring well locations, a stiff grey- brown silty clay was encountered Each boring was terminated in this clay lense During the collection of samples, no unusual odors were noted at any of the three well locations Organic vapor readings taken on soil samples collected from the three wells registered no detectable vapor readings As previously mentioned, groundwater was generally encountered at a depth of approximately 14 to 15 feet at well locations MW-1 and MW-2 Groundwater at MW-3 was encountered at approximately 18 feet under confined conditions and immediately rose to approximately 15 feet Static water levels in the three wells were measured on April 30, 1999 at approximately 14 feet below the groundsurface Copies of the boring logs are attached in Appendix A SURVEYING A licensed land surveyor was retained to survey the monitoring wells accurately and to determine the elevation of each well casing The survey ensures accuracy so that the plot plans will portray the data in a manner useful for determining groundwater flow direction The survey included both horizontal and vertical measurements The survey was conducted using modern surveying equipment and methods so that accuracy is maintained Elevation readings were measured to the •