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Project No 034-98081 <br /> Page No 3 <br /> 4 0 SCOPE OF THE AUGUST 1998 ASSESSMENT <br /> The original scope of work outlined in Krazan's June 9, 1998 Workplan called for the advancement of <br /> two 40-feet deep Geoprobe® borings (one northwest and one southeast of the former UST excavation) to <br /> define the lateral extent of possible soil and groundwater contamination, and four 50-feet deep additional <br /> Geoprobe® borings to determine the maximum lateral extent of possible groundwater contamination <br /> These depths of exploration were based on a water table depth of approximately 45 feet bgs determined <br /> 1 during Krazan's March 1998 field investigation at the subject site Based on the SJCEHD request to <br /> obtain soil samples from a depth of 60 feet bgs (which was anticipated to be as much as 20 feet below the <br /> groundwater surface), Krazan advanced the soil and groundwater borings using hollow stem auger rather <br /> than Geoprobe® methods The revised scope of work in Krazan's Workplan Addendum dated July 23, <br /> 1998 was approved by Ms Jan Thompson of Wilbur-Ellis Company and by Mr Michael Infiirna of the <br /> SJCEHD on August 4, 1998 A copy of the SJCEHD drilling permit, workplan addendum, and <br /> addendum approval is included in Appendix A <br /> The August 11, 1998 scope of work included two 60-feet deep borings to determine the maximum <br /> vertical extent of possible PHC soil and groundwater impact and four 34 to 40-feet deep borings to <br /> determine the maximum lateral extent of PHCs in groundwater Please refer to Appendix B for <br /> specific methods employed during the field investigation and to Figure 2 for borehole locations <br /> 5.0 FINDINGS OF THE AUGUST 1998 ASSESSMENT <br /> 5 1 Soil Profile and Field Observations <br /> A review of soil boring logs in Appendix C suggests the soil profile beneath the subject site may be <br /> generalized as follows <br /> 0 to 25 feet bgs Interbedded layers of sandy SILT (ML), clayey SILT <br /> and silty CLAY (CL/CH) <br /> 25 to 47 feet bgs Silty CLAY (CL) and clayey SILT(ML) <br /> 47 to 60 feet bgs Interbedded layers of silty CLAY (CL), silty SAND <br /> (SM), and sandy SILT (ML) <br /> Positive photoionization detector (PID) readings were noted within portions of the soil profile in boring <br /> B-2 (between depths of 10 and 40 feet) and B-3 (between 20 and 55 feet) No hydrocarbon odors or <br /> KRAZAN & ASSOCIATES, INC <br /> Offices Serving the Western United States <br /> 3498051 SGS <br />