Laserfiche WebLink
iGeological rTechnws ine Page 8 <br /> Soil Investigation Report <br /> Bank of Stockton <br /> Project No 443 2 <br /> June 19, 1996 <br /> lowered to the bottom of the well where total depth was found to be 110 feet The <br />' casing proved to be entirely blank to a depth of 101 feet The well has a "barefoot" <br /> completion meaning the casing is open ended at 101 feet and has no slots or <br /> perforated liner along the entire length The interval from 101 feet to 110 feet <br /> appeared to be open borehole <br /> The casing appeared to be caked with rust and scale but generally intact A <br /> probable hole exists at about 65 feet The condition of the well between 35 and 45 <br /> feet was not determined due to the opacity of the water The source of the wood <br /> chips is not known, however, a sample of them was collected <br /> 5.0 CONCLUSIONS AND RECOMMENDATIONS <br /> 5.1 Conclusions <br /> There following conclusions are drawn from the results of the investigation <br /> described herein above <br /> 1 Based on the record review, evidence the former presence of at least 1 UST and <br /> 3 ASTs was documented These previously unknown tanks were in the <br /> vicinity of the former "oil supply building" <br /> 2 Borings advanced at locations near the former oil supply l building found <br /> evidence of the location of a former 1,000 gallon gasoline UST Soil samples <br /> collected from borings show that gasoline and diesel range petroleum <br /> hydrocarbons have been released in significant quantities to the soil <br /> 3 It is interpreted from the distribution of hydrocarbons that the principal source <br /> of the released petroleum was from a leak in the gasoline UST It seems clear <br /> that at sometime after the tank leaked, it was removed and the excavation was <br /> back filled with clean material The date of the tank removal is not known <br /> There is no evidence of any attempt to clean up the site beyond the confines of <br /> the tank pit which was found to be about seven feet deep <br /> I 4 A secondary source of petroleum may have existed in addition to the gasoline <br /> UST The proximity of the diesel impacted soil to the former pump island <br /> suggests that underground piping associated with a diesel tank may have <br /> leaked It is not clear whether the diesel tank was one of the ASTs or a second, <br /> unknown UST <br />