FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

�» Site Characterization,Clovertdle School,51 East Beverly Place,Tracy, C4, Page 4 ., aquifer at a depth of 500 ft. BGS. The well diameter was 12 in, and it had a total depth of 575 ft. The well was abandoned and sealed by grouting on August 17, 2000 under the permit and oversight of the SJCPHS. 3.0 SITE CHARACTERIZATION PROGRAM .- The site investigation program conducted at the Alfred Clover Middle School by SJC is described below. To provide geotechnical drilling support, SJC contracted with Spectrum Exploration, Inc. (Spectrum) of Stockton, California, which holds the necessary C-57 license. To allow the use of push-probe equipment for exploration of subsurface conditions, the necessary Boring Permit (No. SR0023312) was applied for and NOW issued by the SJCPHS prior to the commencement of the fieldwork. 3.1 Detection of Underground Utilities To provide safe working conditions, before undertaking any site characterization work that involved digging, drilling or probing into the subsurface, the whole of the on-site and off-site areas where such work was to be performed was surveyed by the United Services Agency (U.S.A.). That agency marked the locations of gas and water supply pipes, electric lines and other utility infrastructure that are present beneath the surface. 3.2 Lateral and Vertical Exploration of Subsurface On July 10, 2000, Spectrum mobilized a geotechnical drilling rig equipped with push-probe equipment to the site in order to explore the environmental quality of soil and groundwater in and around the site of the former gasoline storage tank. A- 3.2.1 Borings The locations of the borings drilled by Spectrum are shown on Figure 2. Boring PP-1 was located at the closest down gradient location to the former site of the underground storage tank that could be safely reached by the drilling rig while avoiding obstructions due to buildings and overhead wires. The push probe was advanced to a total depth of 16 ft, at which point the probe reached refusal and could not be further advanced even when the drill stem was hammered in addition to being thrust downward under the full weight of the drilling rig. SJC