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• • <br /> Fax: (916) 464-4797 <br /> Email: kshelton@waterboards.ca.gov <br /> >>> <Mark.Wuttig@CH2M.com> 5/27/2008 4:42 PM »> <br /> Kristi, <br /> As we discussed, we are currently working with San Joaquin County <br /> Environmental Health Department (EHD) to obtain their required permits <br /> for destruction of the 10 soil vapor extraction wells (VEW-1 through <br /> VEW-10) and 3 deeper groundwater monitoring wells (N-21, N-22, N-23) at <br /> the Holt Release Site. The wells are being abandoned in accordance with <br /> CH2M HILL's work plan (dated November 1, 2007) as conditionally approved <br /> by the RWQCB. We are scheduled to perform the well destruction <br /> activities next week from June 4-6. Gregg Drilling and Testing is <br /> scheduled to perform the work under our oversight. <br /> We are requesting a change in well destruction methodology for the 3 <br /> deeper wells. Our work plan stated that we would over-drill the wells <br /> and grout the original boreholes to surface. This is feasible for the <br /> shallow SVE wells but not the deeper wells. The deeper wells are <br /> constructed with 8-5/8" steel conductor casings grouted inside 15" <br /> diameter boreholes to approximately 301 . The 2" PVC well casings are <br /> grouted inside the 8-5/8" conductor casing. Removal of the B-5/8" <br /> conductor casing and annular grout seal can not be feasibly over drilled <br /> short of a monumental effort which could actually drag contamination <br /> down from the shallow zone to the deeper water-bearing unit. The <br /> intermediate step of drilling-out the grout and 2" PVC casing inside of <br /> the 8-5/8" conductor casing (which would require an air rotary rig with <br /> ODEX casing) would not provide any benefit over leaving the conductor <br /> casing in place and would be extremely expensive. <br /> We are requesting that the 3 deeper wells be destroyed by pressure <br /> grouting them in place. The annular grout seal between the 8-5/8" <br /> conductor casing and 15" boring was specifically installed to protect <br /> the deeper water-bearing unit from the shallow contamination in the area <br /> of the 3 deeper wells. This seal will continue to provide this <br /> protection in the future. <br /> Roger Lucich with CUM HILL is currently working with Frank Girardi at <br /> EHD (fgirardi@sjcehd.com or 209.593.7868) to obtain the well destruction <br /> permits. Frank Girardi and EHD require a letter of concurrence from <br /> RWQCB that pressure grouting the 3 deep wells is acceptable before <br /> issuing the permits. If you are in agreement, please send a letter (or <br /> e-mail) to Frank Girardi stating your concurrence. As noted above, we <br /> are scheduled to perform the well destruction activities June 4-6 so we <br /> need this concurrence as soon as possible. <br /> Please copy Steve Osborn, Roger Lucich, and myself on your <br /> correspondence to EHD so we can stay abreast of the developments. <br /> We appreciate your prompt attention to this short notice. Please let us <br /> know if you have any questions. <br /> Thanks <br /> Mark <br /> 2 <br />