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0 0 <br /> Thank you for taking the time this morning to discuss the work plan denial for the above referenced project. As discussed, <br /> Chevron is working with Tylor McMillan of Welenco on an experimental well destruction methodology utilizing blast <br /> perforation to determine a safe distance away from our tanks at active service station sites. In order to model a safe <br /> distance away from the USTs during blast perforation, we are looking to over-drill two soil vapor probe locations(SVP-3B <br /> and SVP-413)to the total depth and then back-fill these two boreholes to 10' bgs with a clean cement. Upon hardening of <br /> the clean cement, Geophones will be placed in these two boreholes to simulate the bottom of the tanks. A seismograph <br /> will be attached to each of the Geophones to monitor peak particle velocity at these locations during the detonation of <br /> surrounding wells. <br /> As discussed, Chevron will work with Tylor to ensure that detonation cord is strung from the bottom of the hole up to <br /> within a clay lens/bentonite seal to ensure that there is no pathway for the downward migration of contaminants. To <br /> ensure that we are properly evaluating a safe distance away from our UST's when utilizing blast perforation, Chevron <br /> respectfully requests permission to abandon all %" or greater casing diameter wells utilizing the blast perforation process. <br /> Attached you will find a copy of Table 1 —Soil Boring and Well Construction Details that outlines which wells we would like <br /> to detonate. <br /> Thank you, <br /> Brian A. Waite, P.G. <br /> Project Manager <br /> Chevron Environmental Management Company <br /> Marketing Business Unit <br /> 6101 Bollinger Canyon Road <br /> San Ramon, CA 94583 <br /> Tel 925-790-6486 <br /> bwaite@chevron.com <br /> .19 <br /> J_ <br />