ARCHIVED REPORTS_MONITORING WELL (P-M6) ABANDONMENT REPORT

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M KLEINFELDER ' The original construction of the well is detailed in the following table. ' Well Total Depth Screened Bentonite Grout. Designation (ft bgs.) Casing Diameter Interval (ft (ft bgs) (ft bgs) b s ' P-M6 23.5 2 inches 23.5 to 8.5 8.5 to 6.5 6.5 to 0 ft bgs =feet below ground surface ' Kleinfelder visited the site on July 18, 2006 to locate and assess the well. The aboveground casing and monument were found separated from the well. Several feet of PVC pipe located in the vicinity were also apparently broken off from the well casing. ' The remaining well casing was measured to be approximately 16 feet bgs. No water was present in the well. WELL DESTRUCTION ' Prior to the monitoring well abandonment, Kleinfelder submitted a workplan titled, "Workplan, Monitoring Well Abandonment, Mossdale Landing, Lathrop, California (File No. 65078.T03/ST06R831, dated July 28, 2006) to Mr. Mike Inferna of EHD. Prior to ' conducting field activities, a well permit application was also submitted to, and approved by, EHD (Attachment A). EHD was also notified at least 48 hours prior to the start of well destruction activities. On August 3, 2006 Kleinfelder Staff Geologist, Mr. Fran Bean supervised the destruction of the monitoring well by Spectrum Exploration (Spectrum) of Stockton ' California. Mr. Mike Inferna from EHD observed the well destruction activities. Spectrum attempted to pull the monitoring well casing out of the ground with a winch line, during which approximately five feet of the casing broke off. The well was subsequently over drilled with 8-inch diameter hollow stem augers (with a stinger used as a guide) to an approximate depth of 25.5 feet bgs. A cement grout slurry was mixed using Type II-V Neat Cement and then pumped into the borehole through the auger. Upon removing the auger, additional grout was pumped into the borehole up to a depth of approximately 8 feet bgs. Approximately 35 gallons of grout were pumped into the ' borehole. The remainder of the hole was backfilled with bentonite chips (8 to 3 feet bgs) and native soil (3 feet bgs to the ground surface) to allow for construction activities without damaging the filled borehole. Water was added to the bentonite, which was ' allowed to hydrate prior to backfilling the top three feet of the borehole with native soil. LIMITATIONS ' Kleinfelder has prepared this report in accordance with the generally accepted standards of care, which exist in San Joaquin County at the time of writing. Kleinfelder ' should be notified for additional consultation if the client wishes to reduce the uncertainties beyond the level associated with this report. No warranty, expressed or implied, is made. 65078.T03/ST06R1001/FB:Iv Page 2 of 4 ©2006 Kleinfelder, Inc September 11,2006