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L � <br /> CONDOR EARTH TECHNOLOGIES INC <br /> } 188 Frank West Circle Suite <br /> Stockton CA 95206 <br /> Phone 209.234.0518 <br /> FAX 209.234.0538 <br /> CONDOR O C T 14 2004 www.condorearth.com <br /> ISN <br /> October 12, 2004 <br /> Victoria L. McCartney <br /> San Joaquin County Environmental Health Department <br /> 304 E. Weber Avenue, Third Floor <br /> Stockton, CA 95202-2708 <br /> Subject: Monitoring Well Installation Preliminary Report and Monitoring Well Destruction <br /> Work Plan, 730 E. Channel Street, Stockton <br /> Condor Project No. 3849E <br /> Dear Ms. McCartney: <br /> Condor Earth Technologies, Inc. (Condor) observed the installation of three groundwater monitoring <br /> wells (MW-1, MW-2, and MW-3) at 730 E. Channel Street (Site) in Stockton, California, on September <br /> 23 and 24, 2004 (Figures 1 and 2, attached). The wells were installed by V & W Drilling (C57 #720904) <br /> of Isleton, California. All three wells were installed to a total depth of 47 feet below ground surface (bgs) <br /> with 15 feet of screen in each well. <br /> On October 7, 2004, a Condor technician measured the depth to water and the total depth in all three <br /> monitoring wells in preparation for developing the wells. The technician measured the total depth in <br /> MW-3 at 38.44 feet. This measurement was approximately 8.6 feet less than the expected total depth, so <br /> the technician secured the wells and returned to the office without developing the wells. On October 8, <br /> 2004, a Condor geologist measured the depth to water and the total depth in MW-3. The depth to water <br /> was 36.97 feet below the top of the well casing, and the total depth of the well was 38.26 feet below the <br /> top of the well casing. The total depth measurement indicated that the lower portion of the well screen <br /> was plugged with a foreign material. The geologist used a hand auger to extract some of the material <br /> plugging the well. Inspection of the material removed from the well indicated that it is cement grout. The <br /> lower 8.6 feet of well screen appears to be filled with grout, therefore. The mechanism by which the <br /> grout entered the well screen is not known. Details of the well construction are noted on the geologic log, <br /> attached. Condor recommends that monitoring well MW-3 be properly destroyed and.a replacement well <br /> (MW-3R) be installed approximately 10 feet south of MW-3, as shown on Figure 2, attached. The <br /> replacement well will be installed using the methods described in the Monitoring Well Installation Work <br /> Plan, dated August 11, 2004. <br /> Monitoring Well Destruction <br /> Condor will submit a well destruction permit application to the San Joaquin County Environmental <br /> Health Department (SJCEHD) and will receive the permit prior to initiating fieldwork. The boring for <br /> monitoring well MW-3 was drilled using eight-inch outside diameter, continuous-flight hollow-stem <br />