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1 <br /> period of weeks. Laboratory analysis of the soil after treatment <br /> showed it to be clean, and the EHD authorized returning it to the <br />' excava tion. Refer to Exhibit G for a copy of that correspon- <br /> dence. <br />' October• 4 & Sr 1940 -- Five (5) auger holes were placed in an <br /> attempt to further define the plume. Four were located on Normac <br /> property, and one was located to the west of the tank site on <br />' property owned by Hammertown Partners. The locations of those 5 <br /> holes are shown on Plate VI. Details are given in Exhibit G. <br /> April S & 90 1992 - Because the previous work had not determined <br />' the vertical & lateral extent of the contamination, six (fir) <br /> additional auger holes were placed as shown on Plates VI & VIII. <br /> The limits were defined except in a southerly direction on the <br />' Hammertown property. Exhibit D gives more details of the work <br /> performed. <br />' August 130 1992 - Three additional sail borings were located on <br /> Hammertown Partners property as shown on Plate VI. Exhibit E <br /> discusses the results of that work, which revealed that Toluene <br /> was detected in all three hales at 40 ' bgl. , which is the approx- <br /> imate <br /> pprox-imate depth of the water- table in the Spring of 1966. <br /> As a result of the above work, the County EHD staff has ordered <br />' that monitoring wells be installed to determine if the ground- <br /> water has been impacted by the leaking UST which was located on <br /> Normac property. The proposed workplan which follows is designed <br />' to accomplish that purpose. <br /> WORKPLAN FOR PLACING THREE (3) GROUNDWATER MONITORING WELLS ON <br /> APN'S 094-054-411 & 094-450-021. <br />' 1. The approximate locations of the three (3) monitoring wells <br /> are shown on Plates VIZ & VIII; the actual locations may vary <br /> slightly from those indicated. The final locations and wellhead <br /> elevations will be surveyed in after completion of the work. <br /> :. Osterberg & Stewart drilling equipment will be used. It will <br />' be equipped with sufficient clean 5-foot lengths of 10 1/4" OD X <br /> b 1/4" ID auger flights to allow the advancing and completing of <br /> each well without stopping to clean flights. Flights will be <br />' thoroughly steam-cleaned between wells to eliminate the possibil- <br /> ity of cross-contamination. Drilling permit applications for the <br /> two properties are attached to this workplan, with the necessary <br /> f ees. <br /> 3. The rig will be equipped with both an 1B" California Modified <br /> i 3 <br /> f <br />