SITE INFORMATION AND CORRESPONDENCE

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,W.0 3. Destruction of MW-3. Because of the proximity of the proposed monitoring well to MW-1, MW-3 will be left in place, for the time being, so that it can be used in determining groundwater gradient. 4. Disposition of Contaminated Soils and Backfilled Material. According to records at the WHF Environmental Consultants offices, approximately 80 cubic yards of contaminated soil were excavated at the site. This material was from the narrow plume of contamination from the surface down to a depth of 22 feet in the vicinity of the abandoned fuel island in the northwestern corner of the property as well as from the waste oil tank excavation in the southeastern corner of the property. Using the diagrams which were drawn at the time of the excavations, calculations were made regarding the reasonable quantity of contaminated soil which was removed from the two excavations. This calculated volume checks with the volume in the stockpiles on the property (see Attachment A) . The contaminated soils were stockpiled on site. A grab sample of the pile center, taken on 2/26/91, indicated that the average contamination was 44 mg/kg of kerosene. However, a composite resample of the stockpiles on 3.0/2/91 returned 29 mg/kg for motor oil and none detected for BTXE, kerosene, diesel, and oil and grease. The chain of custody and analytical sheets for both of these samples are included as Attachment B. In order to replace the soil removed from the excavations, clean fill material was hauled to the site by Don Lambert & Sons of Waterford, California. An examination of the files of this contractor on August 4, 1992, revealed the following: • On February 8, 1991, approximately 20 yards of fill dirt was hauled to the site from the Western Stone Products facility in Hickman, California. The truck hauled a load of crushed granite for another client and then picked up 24.94 tons of 3/4 inch aggregate base from the Western Stone Products Hughson facility and hauled it to the Yellow Submarine site to be placed in the excavation. • On February 9, 1991, 41,800 pounds of road base material was hauled from 7/11 materials, Inc. , of Modesto and placed as backfill. • On February 11, 1991, 25.94 tons of 3/4 inch aggregate base was hauled to the site from Western Stone Products at Hughson.