Laserfiche WebLink
Limited Groundwater Investigation 4 <br /> 3.0 FIELD SAMPLING ACTIVITIES <br /> This section describes the field sampling activities at both the Lathrop and French Camp facilities, and <br /> includes the following tasks: <br /> ■ Site preparation and health and safety <br /> ■ Grab groundwater sampling and analysis <br /> ■ Field quality assurance/quality control (QA/QC) samples <br /> ■ Sample storage, transport and analyses <br /> ■ Equipment decontamination and waste containment <br /> ■ Sampling location survey <br /> These activities were conducted as described in the workplan. Deviations from the workplan are <br /> described below. <br /> 3.1 Site Preparation and Health and Safety <br /> Brown and Caldwell prepared a site-specific health and safety plan to conduct the stockpile and <br /> groundwater sampling activities. The health and safety plan included the physical hazards expected <br /> to be associated with both sampling activities. <br /> Prior to the commencement of drilling activities,permits were obtained from the San Joaquin <br /> County Public Health Services Environmental Health Division (PHS-EHD) for both facilities. Once <br /> the approved County permits were obtained,the proposed sampling locations were delineated by <br /> marking each location. Sample locations were adjusted in the field to account for subsurface <br /> obstructions, utilities, and/or above grade obstructions. Copies of the approved permits are included <br /> in Appendix B. <br /> Because the Lathrop and French Camp facilities are active manufacturing plants, a geophysical survey <br /> was conducted at each facility by Subtropics located in Concord, California on May 4, 2001 to assess <br /> the presence of underground utilities and/or subsurface obstructions at each proposed sampling <br /> location. In conjunction with the geophysical survey, Underground Service Alert (USA) was notified <br /> 48 hours prior to implementing intrusive work at each Site, and a USA dig alert number was be <br /> obtained for each facility. Based on the layout of surrounding structures and utilities, the results of the <br /> geophysical survey, and the results of the USA notification, the final sampling locations were selected <br /> and clearly marked. Because direct push drilling methods were used at both facilities,hand auger <br /> drilling methods were used to clear the upper 5 feet of each sampling location. MonierLifetile <br /> personnel conducted the hand auger activities at several of the locations. <br /> 3.2 Grab Groundwater Sampling <br /> Prior to the onset of drilling activities, the surface area around each probe location was cleared of <br /> surface covering and debris (dirt, reject file material,asphalt, etc.). The sample locations were placed <br /> as close as practically possible to the stockpiles without impacts to safety. The sampling locations are <br /> shown in Figures 2 and 3. Each sampling location was advanced into first groundwater using a <br /> truck-mounted direct push drill rig operated by Precision Sampling, Inc. located in Richmond, <br /> PAwp\jobs\20587\LP FCG\X'.doc—DCN 102300 June 2001 <br />