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` Extended Plume Definition:-7500 W I1 th St., Tracy CA. Page I1 *- 4.6 Disposal of Drill Cuttings Drill cuttings from the well borings were retained in 55-gal., close-topped, steel drums. When full, the drums were closed and staged on the 7500 West Eleventh Street property until the results of analyses of soil and water samples were available and the soil in the drums was classified. The clean soil was disposed as clean fill on the 7500 West Eleventh Street property. When a United States Environmental Protection Agency (EPA) permit is obtained and the material has been accepted for disposal, it will be loaded into a truck and shipped to Forward Landfill, a Class Il disposal facility in Manteca, California. tr Note: A 1,000-gallon polyethylene holding tank was previously located on the 7500 West Eleventh Street site for the purpose of retaining development and purge water. However, that tank was stolen from the property between April and July, 2003.The new 1,100-gallon tank was installed on the site in February 2001. 4.7 Survey of Well-bead Locations and Elevations The locations of the new wells at the Navarra Site were surveyed on June 16, 2004 by a California-licensed land surveyor. Their latitude and longitude were computed and the elevations of both the top of the casing and the wellhead box cover frame of each were determined relative to mean sea level (MSL) in compliance with California Bill AB 2886 .� (Water Code Sections 13195-13198). The surveyed latitudes and longitudes of both the new and pre-existing wells are recorded in Table 1, which also includes the surveyed elevations of the casing tops and the ground elevations of each well currently extant on the site. 4.8 Refined Interpretation of Hydrostratigraphy Figure 3 shows a longitudinal hydrostratigraphic section drawn along section line A-A', the location of which is shown on Figure 2. That section line is approximately aligned along the long axis of the primary plume of affected groundwater emanating from the 7500 West Eleventh Street site. Figures 4 through 8 show five hydrostratigraphic cross-sections drawn on the section lines B-B' through F-F' that are also shown on Figure 2. It is wcll-established that the complexity of the stratigraphy in alluvial fans of the type that underlies the subject site presents the engineer who wishes to interpret their detailed characteristics for application to contaminant transport analysis with a challenging problem (Salvany, J. M., et al. 2004; Taylor, M. P and J. Lewin, 1996). However, in many cases, it is possible to reduce the degree of complexity of the stratigraphic interpretation by presenting the well log data in the form of hydrostratigraphic sections. That technique involves dividing the sediments into general classes based on their hydraulic conductivity and cation exchange capacity, which are the soil characteristics of primary relevance to contaminant transport analysis. In the cross-sections shown on Figures 3 through 8, the permeable gravels, sands and silts have been segregated from the relatively less permeable clays and silty clays. sic