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' We are requesting a changeftwell destruction methodology 0 the 3 deeper wells. Our <br /> work plan stated that we would over-drill the wells and grout the original boreholes to <br /> surface. This is feasible for the shallow SVE wells but not the deeper wells. The deeper <br /> wells are constructed with 8-5/8" steel conductor casings grouted inside 15" <br /> diameter boreholes to approximately 301 . The 2" PVC well casings are grouted inside the <br /> 8-5/8" conductor casing. Removal of the 8-5/8" <br /> conductor casing and annular grout seal can not be feasibly over drilled short of a <br /> monumental effort which could actually drag contamination down from the shallow zone to <br /> the deeper water-bearing unit. The intermediate step of drilling-out the grout and 21' PVC <br /> casing inside of 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 casing in place and <br /> would be extremely expensive. <br /> We are requesting that the 3 deeper wells be destroyed by pressure grouting them in place. <br /> The annular grout seal between the 8-5/8" <br /> conductor casing and 15" boring was specifically installed to protect the deeper water- <br /> bearing unit from the shallow contamination in the area of the 3 deeper wells. This seal <br /> will continue to provide this <br /> protection in the future. <br /> Roger Lucich with CH2M HILL is currently working with Frank Girardi at EHD <br /> (fgirardi@sjcehd.com or 209.593 .7868) to obtain the well destruction permits. Frank <br /> Girardi and EHD require a letter of concurrence from RWQCB that pressure grouting the 3 <br /> deep wells is acceptable before issuing the permits. If you are in agreement, please send <br /> a letter (or <br /> e-mail) to Frank Girardi stating your concurrence. As noted above, we are scheduled to <br /> perform the well destruction activities June 4-6 so we need this concurrence as soon as <br /> possible. <br /> Please copy Steve Osborn, Roger Lucich, and myself on your correspondence to EHD so we can <br /> stay abreast of the developments. <br /> We appreciate your prompt attention to this short notice. Please let us know if you have <br /> any questions. <br /> Thanks <br /> Mark <br /> 2 <br />