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ry. 1� FINDINGS ` Water Supply Well Survey A water supply well survey was conducted through the California Department of Water Resources (DWR) to identify documented supply wells within a 1/2-mile radius of the site. Nine documented domestic and agricultural welts were identified wi 5ia the area examined (Table 4, Figure 1). The closest well is approximately 400 feet southeast of the site and is used for don,:,stic purposes. Three additional domestic wells were documented without precise location by DWR;and it is not known whether any of these are within 1/2-mile of the site. During the course of this investigation, an undocumented supply well was identified on site. This well has been designated WSW-1 by PACIFIC. Sste personnel.identified the t use of water from WSW-1 as being primarily for sanitation, and stated that the water is never used for human consumption. Well construction derails were not available for WSW-1. Subsurface Conditions The soils underlying the site are predominantly fine grained. These fines vary from silt to clay and range in color from blue green to yellow brown. Sands were observed in each of the borings for Wells U-1 through U-3. The sands occurred at depths ranging from approximately 17 to 25-1/2 feet below ground surface and the thicknesses of the sands ranged from 1-1/2 to S feet. Further 6,-,tails of ti:�lithologies underlying the site way be found in the boring logs(Appendix A). A geologic cross section is presented as Figure 3. Groundwater was first encountered at depths ranging from approximately 11-1/2 to 13 feet he!O V surface during drilling, and stabilized at depths varying from 9.51 to 9.84 feet during the November 11, 1490, groundwater sampling event (Table 1). The direction of groundwater flow was calculated to be north-•northwesterly at a gradient of approximately 0.006. A groundwater contour reap is presented as Figure 4. i 3100101/PF-PORT 4 February 13,1991 i ty Er�nni :►