ARCHIVED REPORTS XR0011423 - Laserfiche WebLink

Home Browse Search

' Geological reania lnt. Page 3 Groundwater Monitoring Report ' Project No.425.2 March 21,2005 Zone B The average groundwater elevation is 73.11 feet AMSL and indicates a decrease of 0.05 feet from the previous monitoring event. The groundwater gradient for Zone B was 0.0043 ft/ft flowing N45°W. The predominant groundwater flow is to the northwest with the slope ranging from 0.0018 to 0.0040 ft/ft. Table 3 of Appendix A summarizes the historical intermediate and deep groundwater data, Table 4 summarizes Zone B groundwater data and Figures 4 shows the groundwater gradients for January 21, 2005 groundwater monitoring event. Zone C The average groundwater elevation in Zone C for the January 2005 monitoring event was ' 73.06 feet AMSL. This represents an increase of 0.07 feet since the November 2004 monitoring event. Groundwater bearing and slope for this zone cannot be calculated due to the linear positions of MW-101, MW-102, and MW-201. Table 5 summarizes the ' groundwater data from the Zone C. Zone D The groundwater elevation in Zone D is 73.80 feet AMSL. This represents a decrease of 0.08 feet from the previous monitoring event. Groundwater bearing and slope for this zone cannot be calculated because there is only one well associated with this zone. Table 6 summarizes the groundwater data from the Zone D. ' The historical groundwater gradient and bearing data for Zone A are included in Figure 3 & 5. The groundwater gradients and bearing data for Zone B for the last three monitoring events are included in Figure 4 & 6. 1.1.3 Vertical Groundwater Gradients Vertical groundwater gradients were calculated using groundwater-monitoring wells: MW- 2/MW-2X (Zone A/Zone B well pair) and groundwater monitoring wells: MW-2X/MW-202 (Zone B/Zone D well pair) (Table 7) for the last four monitoring events. The site-specific vertical groundwater gradient for January 2005 monitoring event for the MW-2/MW-2X pair ' is 0.0524 ft/ft. The site-specific vertical groundwater gradient for the MW-2X/MW-202 pair is 0.0093 ft/ft. The historically positive vertical groundwater gradients do not suggest downward movement of contaminants between different zones. Vertical groundwater gradient calculations have been performed at regular intervals since August 25, 1997. ' 1.2 Groundwater Sampling Procedure P g On January 21, 2005, Del-Tech Geotechnical Support (Del-Tech) personnel arrived on-site, opened the wells, and measured the depth to water with an electrically actuated sounding tape. The water level reading was recorded to an accuracy of 0.01 foot.