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• Page 4 of 4 <br /> Thank you for taking the time this morning to discuss the work plan <br /> denial for the above referenced project. As discussed, Chevron is <br /> working with Tylor McMillan of Welenco on an experimental well <br /> destruction methodology utilizing blast perforation to determine a safe <br /> distance away from our tanks at active service station sites. In order to <br /> model a safe distance away from the USTs during blast perforation, we <br /> are looking to over-drill two soil vapor probe locations (SVP-3B and SVP- <br /> 4B)to the total depth and then back-fill these two boreholes to 10' bgs <br /> with a clean cement. Upon hardening of the clean cement, Geophones <br /> will be placed in these two boreholes to simulate the bottom of the tanks. <br /> A seismograph will be attached to each of the Geophones to monitor <br /> 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 <br /> is strung from the bottom of the hole up to within a clay lens/bentonite <br /> seal to ensure that there is no pathway for the downward migration of <br /> contaminants. To ensure that we are properly evaluating a safe distance <br /> away from our UST's when utilizing blast perforation, Chevron <br /> respectfully requests permission to abandon all %" or greater casing <br /> diameter wells utilizing the blast perforation process. <br /> Attached you will find a copy of Table 1 —Soil Boring and Well <br /> Construction Details that outlines which wells we would like 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 /> <Table 1 - Soil Boring and Well Construction Details 306415.pdf> <br /> <MASTER FILE RECORD UNIT IV 8_4_1 l.pdf> <br /> 9/9/2014 <br />