WORK PLANS - Laserfiche WebLink

Home Browse Search

0 DRAFT 0 excavation and removal action. If the soil is left in drums, the soil will be evaluated prior to potential disposal by the client. Kleinfelder proposes to analyze two (2) soil samples from each boring. The first soil sample will be collected at 10 feet bgs. The second soil sample will be collected just above estimated first encountered groundwater. After collection, the soil samples will be labeled, logged on a chain-of-custody, and immediately stored in an iced cooler. The samples will be analyzed as described in Section 6.5. Following completion of the drilling, a 2-inch diameter PVC well will be installed in the borings. The soil borings will be advanced approximately 10 feet into groundwater. The wells will be constructed with Schedule 40 PVC, a 15 foot long 0.020 inch screened section surrounded by and covered by a sand filter pack (#2/12), 3 foot thick bentonite transition seal above the filter pack, and grouted to the surface with a neat cement mixed with no more than 3% to 5% bentonite powder to retard the heat of hydration and limit the possibility of damaging the PVC casing. The wells will be finished with a locking pressure cap situated within a monument or flush style well vault (depending on surface conditions). See proposed Monitoring Well Installation Diagram (Plate 5). Once the monitoring wells have been installed, the top of each well will be surveyed (by a licensed surveyor) so that depth to groundwater measurements in the wells can be converted to groundwater elevations used to assess groundwater gradients. The wells will be surveyed relative to a local benchmark. If a local benchmark is not available near the site, the wells will be surveyed relative to an onsite, assumed benchmark with an assigned elevation. The wells will be surveyed as described in Appendix B Section A-3.4 Monitoring Well Development A minimum of 48 hours after installation, the monitoring wells will be developed to remove fine silt from the well bore and to effectively increase the hydraulic radius of each monitoring well. Surging along the screened interval of the well will be performed to set the sand pack. The monitoring wells will be developed as described in Appendix B Section A.3.2. In addition to developing the monitoring wells until the discharge runs relatively clear of fines, the discharge will be periodically monitored for pH, temperature, and specific conductance. The well development purge water will be contained in 55-gallon drums pending chemical analysis and disposal by the client. Monitoring Well Sampling Groundwater samples will be collected from the three new monitoring wells and the wells will be incorporated into a quarterly groundwater monitoring schedule. It is anticipated that the three new monitoring wells will be sampled during the Fourth Quarter 2005 groundwater monitoring event. 44843.T04/ST05R997/DH:ly Page 9 of 14 ©2005 Kleinfelder, Inc. August 16,2005