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• during the spring of 1997,the fall of 1998, and the spring of 1999 is indicated to be toward the northwest,toward the south, and toward east, respectively. The variable direction of groundwater flow and the configuration of the groundwater divide in the area may be influenced by the groundwater production wells at the facility. 3.0 Borehole Drilling and Well Installation A total of four monitoring wells(MW-1 through MW-4)have been installed at the site.Figure 2 is a scaled site map showing the location of the wells in relation to the wastewater pond and land application areas. The wells were installed at locations approximately the same as those described in the Workplan. A B-53 auger drilling rig,equipped with 8-inch nominal diameter augers, was mobilized to the site on November 22,2004. A total of four borings were installed to depths of between 125 to 135 feet BGL. Soil samples were collected every 10 feet during drilling. Descriptions of the sediments • encountered during drilling are included on the boring logs in Appendix A. Borehole cuttings were placed in containers supplied by the facility and disposed of on facility property. In general,the borings penetrated thorough clayey sands and silty clays with few exceptions. One notable exception occurred at approximately 60 feet deep in MW-3 where"a black flowing sand" was encountered. This was unusual in that saturated conditions at all other borings were encountered at significantly greater depths and the organic content of the zone was higher than was encountered at any other boring. The occurrence of the flowing sand proved problematic during well construction and well development(see below). A 2-inch diameter monitoring well was constructed in each of the 8-inch nominal diameter borings. Well construction material consisted of 2-inch diameter flush threaded PVC pipe with 20 feet of #10 slot screen and a threaded end cap at the base. The annular space between the well screen and boring was backfilled with#2 drillers sand as the auger flights were withdrawn. A bentonite seal was placed on top of the sandpack and the remainder of the boring annulus was backfilled with a neat grout. A summary of well construction information is included in Table 1,and a diagram of • 4