FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

C O N S V L T V N G E N I N E E R S Ms. Margaret Lagorio, REHS January 27, 2004 Page 2 L. This WorkpIan includes the following tasks: • Installing a deeper groundwater monitoring well, along the presumed downgradient edge of the site, to assess the vertical extent of the groundwater contaminant plume; • Collecting groundwater samples from the new deep monitoring well and three existing shallow monitoring wells; Preparing a summary report documenting the findings of this investigation for submittal to • the EHDSJC, as required; • Performing three semi-annual groundwater sampling events to include the new deep anr, monitoring well d three existing shallow monitoring wells; and Preparing semi-annual groundwater sampling reports. The proposed tasks are further described in detail below: Task 1 --Workplan This task includes preparation of this Workplan and the Site-Specific Safety Plan included in Appendix B. Task 2—Monitoring Well Installation Winzler&Kelly will install a 30-foot deep, on-site groundwater monitoring well(MW-4) at the northern edge of the property adjacent to MW-I (Figure 2), to determine the vertical extent of TPH-G, BTEX, MTBE, TAME, tert butyl alcohol (TBA), di-isopropyl ether(DIPE), and ethyl tert-butyl ether(ETBE) in groundwater. The location of MW-4 was chosen to represent groundwater along the presumed downgradient edge of the site. The location of monitoring well MW-4 may be modified if underground utilities are identified at the proposed location. Prior to implementing the proposed drilling activities, Winzler&Kelly will obtain a monitoring well installation permit from the EHDSJC. The EHDSJC will be notified at least five days in ' advance of the scheduled field activities. The proposed monitoring well location will be marked with white paint. Underground Service Alert (USA)will be notified a minimum of two working days before work begins to verify that the boring location is clear of utilities. +.. Drilling will be performed using a hollow-stem auger drill rig equipped with 8-inch hollow stem augers in accordance with Winzler&Kelly's Site-Specific Monitoring Well Installation Procedures in Appendix C. #A.. The approximate depth of the well is anticipated to be 30 to 35 feet bgs. The estimated depth of the well is based on continuing the investigation below the 25-foot depth to monitor the vertical extent of contamination. It is anticipated that Lonestar#2112 Monterey sand or equivalent will be used with 5 feet of#10-slot screen. A typical well construction diagram is shown in the Site- Specific Monitoring Well Installation Procedures (Appendix Q. w