FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

Stantec January 6, 2010 Page 2 of 3 E-8). In addition on November 12th and November 13, 2009, Stantec supervised Ramsey Engineering (Ramsey) of Sacramento, California as they re-paved the former locations of the wells in accordance with the CSPWD Encroachment Permit (Attachment B). Stantec's field notes are included in Attachment C. A 2-foot by 2-foot (2X2) square was saw cut around wells E-7 and E-8 and cleared with an air knife to three feet below ground surface (bgs). Wells E-7 and E-8 were tremmie grouted with neat cement from total depth (20 and 24 feet bgs, respectively) to displace the water column in the well. The wells were then pressure grouted to surface to assure a complete seal of the screened interval. The top three feet of casing was removed from each well along with the traffic rated well boxes. The 2X2 square around each former well was filled in with cement to 6-inches below grade and completed to surface with hot asphalt patch. As required by the City of Stockton, a 5-foot by 8-foot (5x8) rectangle was saw cut around well BHD-1 to account for cracking that had occurred in the asphalt around the well. When the asphalt was removed from around BHD-1 a layer of concrete was encountered. The City was contacted to discuss alterations to their asphalt requirements. The City agreed that removing the concrete down to 13-inches bgs would not be necessary. In addition, a 12-inch PVC conductor casing surrounded the monitoring well and was kept in place with concrete making it impossible to clear the excavation for utilities using an air knife or hand auger to three feet bgs. The SJCDEH was contacted regarding the situation. SJCDEH agreed that pressure grouting the well to surface and removing the well box would suffice. Well BHD-1 was tremmie grouted with neat cement from total depth (28.5 feet bgs) to displace the water column around the well. The well was then pressure grouted to surface to assure a complete seal of the screened interval. The top 1-foot of well casing was removed and concrete was added to the gap where the well casing had been removed. The 5x8 rectangle was completed to surface with hot asphalt patch. WASTE DISPOSAL Investigation derived waste (IDW) including solids (soil, concrete and asphalt) and purged water generated during tremmie grouting are being temporarily stored on site in California State Department of Transportation (DOT)-approved 55-gallon drums. IDW will be transported off site by Integrated Wastestream Management, Inc. (IWM)for disposal. LIMITATIONS This report has been prepared for the exclusive use of Chevron Environmental Management Company and Atlantic Richfield Company, a BP affiliated Company and its representatives as it pertains to 2905 and 2908 West Benjamin Holt Drive Stockton, California (or as it pertains to the site). The evaluation of subsurface conditions at the site for the purpose of this investigation is inherently limited due to the number of points of investigation. There are no representations, warranties, or guarantees that the results are representative of the entire site. Data from this report