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Eckert Cold Storage Company 757 Moffat Boulevard January 3, 2000 • Manteca, California Page: 2 monitoring wells provided data for determining gradients and analyses of the underlying groundwater. During the initial development of the wells, it was discovered that the well casing in MW- 2 had been damaged during the installation of the well. Bailers and pumps would not go down the well and only water level readings could be taken with an electronic sounder. Rather than overdrilling this well and setting a replacement well, it was decided to keep this well for gradient information. Because all three borings had contamination, it was decided to place the replacement well in the down-gradient direction. On March 22, ' 1995, a replacement well, MW-4 was installed. On September 18'` and 19a', 1997, WHF, Inc., in conjunction with Frontier Drilling ' Company, a licensed C57 Contractor, did drill three soil borings and converted same to groundwater monitoring wells with two-inch W. PVC casings. Samples from the borings were analyzed to determine the extent of the soil contamination plume. Continued quarterly groundwater monitoring events have taken place since the installation of the initial monitoring wells. The quarterly monitoring report dated May 12, 1998, shows the results of groundwater analysis for oxygenates by EPA method 8260. Only MTBE was shown to be present in the samples. Future groundwater sampling events will I etest for MTBE by EPA method 8020. On November 23rd, 1998, a Receptor Survey was completed for this site. This survey ' identified any and all receptors within a 2,000 foot radius of the contaminated area of the subject site. ' 3.0 Scope of Work ' On November 2nd and 3rd, 1999, WBF, Inc., in conjunction with Frontier Drilling, a state licensed drilling contractor, completed four (4) shallow soil borings, one of which was converted to a monitoring well, to depths between 38.0' to 41.5' bgl. (groundwater depth —23'). One (1) deep boring (at the former location of the UST's) to a depth of 56.5' was also completed to confirm the presence or absence of petroleum hydrocarbons and the vertical extent of the soil contamination in the unauthorized release area. The event provided data to evaluate the vertical and lateral extent of soil contamination, and the extent of groundwater contamination underlying the site. Soil boring/monitoring well locations are identified in Figure 3 of this report. 1 1