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GeorogxatT'echnics inc Page 2 Geo Corp-WP Addendum Project 507 2 March 31, 1997 2.2 Location of Additional Monitoring Well Monitoring well JM-3 is proposed to be installed approximately 40 feet south of the former USTs It will be constructed as outlined in the previous work plan 2.3 Additional Soil Borings Five additional soil bonngs are also proposed to be placed around the former UST area SB- F will be placed in the area we believe was the approximate center of the former UST pit SB-2 will be located approximately midway between the existing monitoring well, MW-9, and the proposed monitoring well, JM-2 SB-3 will be sited approximately 25 feet southeast of MW-9 SB-4 will be located approximately 15 feet south of the southwest corner of the former UST's SB-5 will be placed approximately 15 feet north of the northwest corner of the former UST's The soil borings will be drilled with a truck mounted, 8 inch diameter, hollow stem auger rig They will be advanced to the capillary fringe, groundwater expected to be approximately 20 feet below ground surface Soil samples will be collected for geological and analytical evaluation at five foot intervals Upon reaching total depth of the soil borings a capillary fringe sample will be collected then the borehole will be closed with a neat cement grout containing less then 4% bentonite The two soil borings under the covered storage area, SB-1 and SB-5, may not be accessible to a drill rig If this is the case arrangements will be made to complete the borings with hand auger equipment Monitoring well permits will be secured as necessary and the local regulatory agency will be notified 48 hours prior to commencing work The subsurface will be cleared of underground utilities by notifying Underground Service Alert Note In the event that soil conditions (1 e , course grained geology and high concentrations of gasoline) warrant, soil vapor extraction wells will be installed in the boreholes around the tank area These would be used for mitigating soil and groundwater contaminated by gasoline The wells would be constructed as follows 2 inch casing, 10 foot of screen, 0 04 inch screen slot size, pea gravel filter pack from 8 to 20 feet, bentonite/cement grout from 8 to 2 feet, dirt from 2 feet to ground surface, the casing will be snubbed off and a water tight cap secured on it, the surface will have a 2 inch concrete plug for security until the vapor extraction system is installed 3.0 SCHEDULE & REPORTING Geological Technics Inc anticipates beginning field work no later than 30 days after work plait approval and upon issuance of the drilling permit The information gathered during this phase of work will be presented in a report which will include a summary of the geology as well as the results of sample analyses The project will be supervised by Dr Ray Kablanow, a registered professional geologist Copies of the report will be forwarded to both the appropriate County and State regulatory agencies (SCEHD and CRWQCB-CVR) The three new monitoring wells and the existing MW-9 will be placed on a quarterly monitoring