REMOVAL_1998 - Laserfiche WebLink

Home Browse Search

Page 2 Underground Storage Tank Report After receiving an acceptance of an Underground Storage Tank Removal Excavation Permit from the offices of the San Joaquin County, Public Health Services, Environmental Health Division, dated October 28, 1999, a permit was issued for the removal of three 10,000 gallon, diesel fuel, underground storage tanks(copies of permits are included in Appendix B). Tank product and residual was previously removed and disposed by American Valley Waste by the owner previous to the excavation of the tank by Bowen Construction- Engineering, documentation included in Appendix B. On March 10, 1999, Bowen Construction-Engineering mobilized to work site and commenced on the removal of three single walled, steel, 10,000 gallon, diesel fuel, underground storage tanks. It is the understanding of Bowen Construction-Engineering that the tank had historically contained diesel fuels and was used for the fueling of on-site diesel equipment. Two, hp diesel pumps, were used to pump fuel from the UST's to equipment on site. se pumps were removed and returned to the owner for future use prior to excavation of the UST. The tanks were buried under4" of asphalt concrete and approximately T of soil. Location of tanks were approximately 45' west of East property line, 300' north of Diamond Way Street, and an estimated 61' east of existing office building. Location of tank and fuel pumps are given in site plan (Appendix A). During the removal of the overburden,there were no signs of discoloration's and petroleum odors were not noted. i Excavated soils, an estimated 258 cubic yards, were placed on black 10 mill. visqueen and covered. At completion of tank removal, the tank pit was an estimated 14' in depth, r. 32' in length and 40' in overall width. Tank backfill consisted of medium grained sand, while the native soils appeared to be medium sands to sandy clays. On March 12, 1999, carbon dioxide, sublimated from 900 lbs. of dry ice, was introduced into the tanks to displace potentially explosive vapors. Under the supervision of the County of San Joaquin Environmental Health Division, represented by an LEL and oxygen reading was taken by a Bowen Construction-Engineering technician, using a Gas Tech 1214 SMPM combustible gas/oxygen detector to determine that the UST was safe to remove.