SITE INFORMATION AND CORRESPONDENCE FILE 2

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q Darpetro, Inc. Page 3 of 3 749 E. Charter Way 05 December 2008 Stockton , CA office for installation of monitoring well MW- 15 no later than 25 January 2009 and to install the well no later than 16 March 2009 . A work plan to install the monitoring well between BM-6 and the source area , or a technical justification for not installing it, should be submitted to the EHD immediately for review if you desire to minimize drilling costs and install it at the same time as MW- 15, otherwise submit the document to the EHD by 16 March 2009 . The EHD has reviewed the data derived from the groundwater monitoring program and has determined that a reduced sampling frequency will still permit adequate characterization of the plume behavior: • Semi-annual sampling for MW-1 , MW-2 , MW4 through MW-6 , MW-8 , MW- 17B and MW- 18C; and • Annual sampling for MW-3 , MW- 10 through MW- 14 and MW- 16 . You may discontinue sampling of MW-7 and MW-9 as it appears very likely that the contaminants monitored by these wells are related to the 701 E . Charter Way site. Depth to water in all wells should be measured during each monitoring event to determine the groundwater gradient. The contaminant concentration in MW-18C continues to decline , leading the EHD to believe that the vertical extent of impacted groundwater has been adequately delineated , but the well should be monitored at the semi-annual frequency to confirm the conclusion . Questions or comments may be directed to Nuel Henderson , Professional Geologist, at (209) 468-3436. Sincerely, Nuel C . Henderson , Jr. , PG Marga�o, REHS Engineering Geologist Program Coordinator C : J . Barton — CVRWQCB ; 11020 Sun Center Dr. #200, Rancho Cordova , CA 95670 D . Lafontaine — AEI ; 11244 Pyrites Way, Gold River, CA 95670 D . Van Allen — AEI ; 3446 N . Golden State Blvd . , Ste. C; Turlock, CA 95382 i Directive Letter 1208. doc j