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realoguaCTecknicsJnc Page 17 L�J Site Conceptual Model Report }v� Project No 724 2 & � lU 7 May 2,2006 l W 3 ' to separate the aquifer into shallow, inte�} ediate and deep levels The intermediate aquifer has been defined by wells BIW-1,'MW-2, MW-3, MW-106, MW-107, MW-108;� ,/MW-109,qVIW-110 and MW-111 (see Figure 7) The deep aquifer level has been defined 1 by wells MW-202, MW-208, MW-209 and MW-210 The groundwater gradients calculated for the intermediate and deep aquifer levels for the monitoring events conducted since the new wells' installation (December 2003) are depicted in the ' following illustration adapted from the rose diagrams in Figure 6B and 6C 1 1 Intermediate Deep (45-65' bgs) (70-80' bgs) The above diagram shows that the gradient in the intermediate aquifer has a primarily ' northeast to easterly trend while the deeper aquifer has a southeast to easterly trend This supports the Morita site intermediate plume as depicted in Figure 15 that shows limited extension off site to the east and northeast location of MW-108 The southeast trend in the ' deeper aquifer shown above supports the depiction in Figure 16 which places deep well MW- 208 down gradient of the GASCO site plume ' In their February 3, 1995 letter correspondence (see Appendix A) the SJC PHS/EHD stated "At the present time PHS/EHD feels that since the Morita site is slightly up gradient from the , Darpetro site that it is unlikely that the contamination in MW-2 and MW-3 is due to the ' Darpetro sate" The historical gradients for the GASCO (Darpetro) site included in the CCG report in Appendix G show only one instance in which northwesterly direction was recorded- January 26, 1990 @ N28°W All of the gradients in 1995 were northeasterly and one to the ' north The rose diagrams for the Morita site, Figures 6A, 6B & 6C, do not show any northwesterly gradients from 1992 to the present The source for the SJC PHS/EHD declaration that would put the Morita site in an up gradient position to the Darpetro t (GASCO) site is unknown to GTI but may be from one of the release sites to the west of the GASCO site But regardless of its source, this conclusion is anomalous to the Monta project data 1