Laserfiche WebLink
the atmosphere. We request that this be allowed because of 1) the proximity of the excavations <br /> to the streets and sidewalks, 2) the nearby presence of children at the adjacent elementary school, <br /> and 3) to restore onsite business operations as quickly as possible. <br /> The two options for the disposition of potentially contaminated soil overburden, as previously <br /> discussed during our telephone conversation, are 1) removal from the site for offsite aeration, and <br /> 2) backfill material for the base of the excavations. Based on previous work performed at the <br /> site by our registered geologist, we believe that overburden material generated from the <br /> excavation containing the 8,000-gal tanks will be contaminated, as will soil from the base of this <br /> excavation. Removing the soil from the site will involve a costly sampling program and create <br /> an unnecessary liability for the owner. Considering the small volume of soil relative to the size <br /> of the excavation, we feel that there will be no additional impact to the environment by using this <br /> material for backfill. The remaining excavation will be backfilled with pea gravel, which will <br /> be capped with a minimum of 1 ft ol'base rock and a minimum of 3 ins of asphaltic concrete. <br /> The asphaltic concrete will provide an impermeable barrier to prevent infiltration of storm water <br /> during the upcoming winter months. In addition, pea gravel backfill will provide an excellent <br /> medium for future remediation of hydrocarbon vapors. We recommend therefore, that option 2 <br /> be exercised in the field or some combination of options based on field evidence observed at the <br /> time of the tank removal. <br /> Following receipt of the laboratory results, a letter report accompanied by the laboratory reports <br /> shall be submitted directly to the San Joaquin Environmental Health Division. Based on these <br /> results a Corrective Action Plan (CAP) will be prepared and sent to the county for approval. <br /> s.- Thank you for your consideration and suggestions on this matter. We look forward to working <br /> with you on this project. <br /> Sincerely, <br /> WALSH & ASSOCIATES, INC. <br /> e rey A. Clayton, R.G. <br /> Senior Project Manager <br /> cc: Mr. Russell Chapin <br /> XMalsh <br /> ht As%ocime�, Inc_ <br /> Lnvir«nmental Scicntist� and F.ngineerti <br />