WORK PLANS - Laserfiche WebLink

Home Browse Search

AEI Project No. 306556 April 6, 2012 Page 2 of 4 County Environmental Health Department (SJCEHD), the property was historically equipped with a diesel underground storage tank (UST). A Permit was issued by the SJCFPB on August 23, 2006 for the removal of one diesel UST at 20963 South Brennan Avenue. The volume and exact location of the UST were not stated. Based on the addressing and the site reconnaissance performed by AEI during the Phase I ESA, it is likely that the UST was located in the vicinity of the tractor shed on the southeastern corner of the property. No documentation pertaining to the removal or post-removal confirmation sampling was on file with the local regulatory agencies. As such, AEI recommended that a geophysical survey be conducted in the vicinity of the tractor trailer shed (southeastern portion of the property) in order to determine the former location of the historical UST. AEI also recommended the performance of a Phase II Subsurface Investigation to evaluate if the historical UST has impacted the subject property. II Geology and Hydrogeology According to the United States Department of Agriculture (USDA), soils in the area are characterized as loamy sand, loamy coarse sand and fine sand which are well to excessively well drained, with slopes of 0-5 percent. According to nearby groundwater monitoring data obtained from the Regional Water Quality Control Board Geotracker online database, the depth to groundwater is approximately 65 feet below ground surface (bgs). The regional topographic gradient direction slopes toward the west and, therefore, the direction of groundwater flow beneath the property is inferred to be to the west. The Main District Canal is located approximately 0.48 mile to the south, and the Stanislaus River is located approximately 0.88 mile to the south. III Scope of Work Drilling permits will be obtained from the SJCEHD for this investigation. The public underground utility locating service Underground Service Alert (USA) will be notified to identify public utilities in the work area at least three business days prior to any drilling. Private utility locating will be conducted an independent utility locating company to identify underground utilities on the property. A site-specific health and safety plan will be prepared, reviewed by onsite personnel, and kept onsite for the duration of the fieldwork. This work will be performed under the oversight of a licensed professional. Geophysical Survey A geophysical survey will be conducted within the area of the location of the former diesel underground storage tank (UST), located to the east of the tractor shed on the southeastern corner of the property (Figure 3). The purpose of this survey is to determine the location of the former diesel UST and whether the diesel UST remains in place. The locations of the borings proposed below will be based on the results of the geophysical survey. Should additional anomalies be identified and should the scope be altered based on the geophysical survey, the SJCEHD will be contacted prior to any drilling.