ARCHIVED REPORTS XR0011425 - Laserfiche WebLink

Home Browse Search

Creolo IcalTechnicslju Page 3 g Groundwater Monitoring Report Project No.425.2 October 19,2004 Table 2 of Appendix A summarizes Zone A groundwater elevations, gradients and bearings. ' Figure 3 illustrates the July 23, 2004 groundwater gradient for Zone A. Figures 4 and 5 shows the groundwater gradients for April 27, 2004 and January 3, 2004 groundwater monitoring events. 1 Zone B The average groundwater elevation is 73.26 feet AMSL and indicates a decrease of 0.64 feet ' from the previous monitoring event. The groundwater gradient for Zone B was 0.0022 ft/ft flowing N61'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 Figure 6 illustrates the July 2004, groundwater gradient in Zone B. ' Zone C The average groundwater elevation in Zone C for the July 2004 monitoring event was 73.05 feet AMSL. This represents a decrease of 0.64 feet since the April 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 73.68 feet AMSL. This represents a decrease of 0.46 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 7. ' The groundwater gradients and bearing data for Zone B for the last three monitoring events are included in Figure 8. ' 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 three monitoring events. The site-specific vertical groundwater gradient for July 2004 monitoring event for the MW-2/MW-2X pair is 0.0609 ft/ft. The site-specific vertical groundwater gradient for the MW-2X/MW-202 pair is ' 0.0066 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.