ARCHIVED REPORTS_SOIL AND GROUNDWATER INVESTIGATION

Home Browse Search

1 ' 1.3 Limitations The services provided under contract as described in this report include professional opinions and ' judgments based on data collected. These services have been provided according to generally accepted environmental protocol. The opinions and conclusions contained in this report are typically based on information obtained from: 1. Observations and measurements made by our field staff. 2. Contacts and discussions with regulatory agencies and others. 3. Review of available hydrogeologic data. 2.0 Description of Field Activities Drilling and sampling activities were conducted on Tuesday January 28, 2000. All activities were conducted in accordance with applicable State and Federal guidelines and statutes. 2.1 Prefield Activities ' Prior to implementing field activities, a soil boring installation permit was obtained from San Joaquin County Public Health Services Department. A copy of this permit is contained in Appendix A. In addition,proposed boring locations were marked with white paint,and a private underground ' utility locator cleared proposed boring locations prior to drilling. Prior to initiating drilling activities, a Site Safety Plan was prepared, and a tailgate safety meeting was conducted with all site workers. ' 2.2 Location of Borings The locations of the eight investigative soil borings, IB-1 through I13-8, are shown on Figure 2. In order to assess possible hydrocarbon releases from the clarifier,three borings(IB-1,I13-2,and I13-3) were located in the vicinity of the clarifier outlet at the north end of the clarifier. In addition, five of the borings (I13-3 through I13-8)were located in the vicinity of the clarifier inlet at the south end of the clarifier and catch basin. 2.3 Drilling and Sampling of Investigative Soil Borings The eight soil borings were drilled to a total depth of about 12 feet by a Gregg Drilling using ' Geoprobe hydraulically-driven soil coring equipment. The coring system allowed for the retrieval of almost continuous soil cores, which were contained in a clear plastic acetate tube, nested inside a stainless steel core barrel. After the core barrel was brought to the surface and exposed,the core was examined, logged, and field screened for hydrocarbons by a qualified scientist using sight and smell. Boring logs for the eight borings are contained in Appendix B. Following completion,the eight investigative soil borings were grouted to match existing grade using a cement\sand slurry. Soil cuttings generated during this investigation were stored onsite in sealed DOT-approved containers. ' Subsurface soils were sampled at depths of approximately four and nine feet below surface grade. After the sample and core barrel was raised to the surface,each sample was collected as follows:(1) ' The filled acetate tube was exposed for visual examination; (2)The selected sampling interval was collected by cutting the sample and acetate plastic tubing to the desired length (typically about six ' GRIBI Associates Pagel REPORT OF SOIL AND GROUNDWATER INVESTIGATION 15700 SOUTH MCKINLEY AVENUE GA 110.05-01