SITE INFORMATION AND CORRESPONDENCE

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} T Mr. Benjamin Hall - 2 - 15 October 2004 Musco Family Olive Company Your expectation appeared to be that the analysis would prove the return system unnecessary. The 10 June 2004 Kennedy/Jenks technical letter report (hereafter report) completed the analysis. Reservoir Construction The memorandum makes no claim that Project Manual for the New Retention Pond prepared by FoodPro International was used by Musco for the final reservoir design/construction as implied in your letter. The memorandum refers to the manual's description of a liner because, had it been installed by Musco, it would likely have been adequate to comply with the requirements of Task 16. You letter identifies the 2001 Process Water Storage Reservoir Contract Documents and Specifications and the August 2001 construction drawings by HDR Engineering, Inc. as the correct references for the 84-million gallon reservoir design/construction. Our files contain two sets of drawings prepared by HDR, one dated November 2001 and one dated September 2001,but none dated August 2001. Unless otherwise noted, the drawings referenced below are in the November 2001 set. Drawing C-1 (SITE PLAN) depicts a small area straddling the drainage on the upstream toe as "SCARIFIED AND RECOMPACTED SUBGRADE." It also shows a borrow area of about 1.7 acres within the reservoir area. Our files do not contain documentation showing the final elevation contours of the borrow area. Your letter and the report both state Musco directed the contractor responsible for reservoir and dam construction to scarify and compact the native clay soil over as much of the reservoir bottom ground surface as possible. Musco has not provided the Regional Board with documentation that it directed the contractor to perform this work, or with documentation that the work was performed as Musco directed. Further,Musco has not provided the Regional Board with a delineation of the area the contractor found possible to rework and actually reworked. Reservoir Soils Although the report states that there is insufficient information available to determine the thickness of the native clay soil underlying the reservoir over its entire surface, it nevertheless estimates the bottom of the reservoir has"up to" 17 feet of natural clay soil. The report bases this estimate on information obtained from boring logs and "information from construction" (presumably notes and records generated during the construction process) documented in a 8 June 2001 Hydrogeologic Investigation prepared by Kleinfelder. We could not validate the estimate with information we reviewed in the Kleinfelder report, and have to be more concerned with areas where natural clay soil is the least thick anyway. Your letter refers to the results of permeability tests performed on soil samples collected from the reservoir area and documented in the same Kleinfelder report. This Kleinfelder report documents the results of laboratory permeability tests of two samples collected from one boring(TW-2) on a slope near the reservoir's upstream end. While this 26.5-ft boring penetrated clay layers that yielded permeabilities of 9.0 x 10'6 and 4.14 x 10-7 cm/sec in the laboratory, it also penetrated sandy gravel layers containing up to %2-inch diameter gravel. Additional evidence that soils underlying the reservoir area contain occasional and unpredictable sand and gravel lenses is contained in Drawing G-4 (LOG OF TEST BORING PROFILE) dated September 2001. Your letter and the report are not enough to justify the laboratory permeability test results of two samples taken from one boring as conservatively representative of the permeabilities of all soils forming the invert of the entire 42-acre reservoir area. hi addition to the probable variability in permeability of soils now inundated with wastewater, Musco provided no documentation that would enable an independent party to conclude that excavation in the borrow area did not compromise the integrity of clayey deposits and create conduits for impounded wastewater to enter groundwater.