Laserfiche WebLink
04 August 2004 <br /> AGE-NC Project No 04-1168 <br /> Page 2 of 5 <br /> The Modesto, Riverbank and Turlock Lake Formations and overlying Recent alluvium are the <br /> principal sources of domestic ground water in the 13,500-square mile San Joaquin Valley Ground <br /> Water Basin (Basin 5-22) <br /> IThe nearest surface water feature to the site is the Stockton Diverting Canal, located approximately <br /> 1,600 feet northeast of the site Based upon ground water maps prepared by the San Joaquin County <br /> Flood Control and Water Conservation District and well information obtained from nearby sites, <br /> ground water flow direction is variable near the site, depth to water is currently estimated to occur <br /> between 55 and 65 feet below surface grade (bsg) However, this may vary greatly due to local <br /> recharge and discharge patterns <br /> 22 PREVIOUS INVESTIGATIONS <br /> According to records on file with the SJCEHD, four underground storage tanks (USTs) were <br /> formerly located on the property Three of the USTs were located in a common excavation,west of <br /> the on-site building, a fourth UST, presumably used for waste oil, was located south (behind) the <br /> on-site building <br /> In 1998,the four USTs were removed by Paydirt Excavation The USTs had been out of commission <br /> and empty at the time of removal Soil samples were collected from the UST excavation, former <br /> piping areas and dispenser island area Petroleum hydrocarbons were not detected in soil samples <br /> collected at the time of removal <br /> 1 <br /> 3.0. PROCEDURES <br /> The field work reported herein was performed in accordance with procedures outlined in the AGE <br /> prepared Limited Subsurface Investigation Work Plan, dated 02 July 2004 <br /> I <br /> 31 DRILLING <br /> On 19 July 2004, three soil probe bonngs (B 1 though B3)were advanced at the site utilizing a van- <br /> mounted Geoprobe 5400 direct-push probing unit equipped with 1 125-inch probing rods Boring <br /> B 1 was advanced in the former tank pit to a depth of approximately 30 feet bsg at which point probe <br /> advancement ceased due to subsurface refusal as the result of pea gravel falling into the boring from <br /> the overlying tank pit Boring B2 was advanced as a continuation of B 1,located 10 feet north of B 1 <br /> dust outside the tank pit Samples were collected in boring B2 starting at 35 feet bsg to a total depth <br /> of 45 feet bsg Boring B3 was advanced in the former dispenser location to a total depth of 20 feet <br /> Advanced GeoEnvironmental,Inc <br /> I <br />