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Mr. Ross Atkinson February 25,2010 Page 2 of 3 Monitoring Well Destruction On February 23, 2010, a Ground Zero Geologist, under the supervision of a California Professional Geologist, supervised V&W Drilling, Inc. ([V&W] C57 License #720904) during the destruction of groundwater monitoring wells MW4, MW5, MW7, MW8, MW15, MW16, MW17, MW19R and MW21. There are no other monitoring wells associated with the site. Ms. Lori Duncan of EHD was on site to inspect the grouting of the wells. A site plan showing the location of the destroyed monitoring wells is provided as Figure 2. Prior to well destruction activities the depth to bottom (DTB) in all site wells was monitored to insure no obstructions were present in any of the wells. The wells varied in depth from 20 feet below ground surface (bgs) in well MW21 to 36 feet bgs in well MW4. Well construction details are summarized in Table 1. The wells were destroyed by pressure grouting with neat cement grout. Neat cement grout was pumped into each well in one continuous operation through a tremie pipe system until each well was completely full. Pressure was then applied to the wellhead using a pressure cap at approximately 20-25 pounds per square inch (psi) for two to three minutes, which forced the grout through the well screens and into the filterpack. The wells were then checked for subsidence and more grout was added as necessary. After the wells were grouted, the well boxes were removed and wells MW4, MW8 and MW 16 were overdrilled to a depth of 3 feet bgs with a 2.5-foot diameter drill bit and wells MW5, MW7, MW15, MW17, MW19R and MW21 were over-drilled to a depth of 5 feet bgs using 8-inch diameter hollow stem augers. The resulting annulus was then backfilled with neat cement grout to approximately 1 foot bgs and followed by cuttings. The surface of each well was completed with native soil or concrete dyed black, depending on the existing surface. DISCUSSION All monitoring wells associated with the site have been destroyed. As per the January 28, 2010, RWQCB correspondence the investigation at the site is complete and the Waste Discharge Requirements(WDRs) should be rescinded. GAGROUNDWSWHIDEREPORTS\Well Destruction Rpt.doc