ARCHIVED REPORTS_XR0008002 - Laserfiche WebLink

Home Browse Search

00t. 1 " Mr James L Barton ' January 26, 2005 Page 2 tflow direction for Unit A was generally to the northeast, with a hydraulic gradient of approximately 0 004 feet per foot (fttft) ' Groundwater measurements recorded on October 18, 2004 from wells screened in Unit B were used to construct the groundwater elevation contour map included as Figure 4 The groundwater flow direction for Unit B was generally to the east, with a hydraulic gradient of approximately ' 0 006 ft/ft Groundwater measurements recorded on October 18, 2004 from wells screened in Unit D were ' used to construct the groundwater elevation contour map included as Figure 5 The groundwater flow direction for Unit D was generally to the east southeast, with a hydraulic gradient of approximately 0 001 ft/ft ' Copies of the groundwater sampling information sheets are included as Attachment B Tabular results of recent depth to water (DTW) measurements are summarized in Table 1 A tabular ' summary of well construction details is included as Attachment C Groundwater Sampling and Analytical Results • Groundwater samples were collected on October 19 through 22, 2004 Groundwater samples were submitted to California Laboratory Services (CLS) in Rancho Cordova, California, for analyses of total petroleum hydrocarbons as gasoline (TPHg) by EPA Method 8015 Modified, and volatile organic compounds (VOCs) by EPA Method 8260B Tabular results of recent groundwater sampling analytical results are summarized in Table 1 A summary of groundwater elevations measured to date is presented in Table 2 Cumulative groundwater sampling analytical results are summarized in Table 3 Maps depicting dissolved concentrations of TPHg and benzene in groundwater are included as Figure 6 through Figure 13 Laboratory analytical results with chain-of-custody documentation are included in Attachment D Redox Analytical Results Groundwater samples were collected from wells MW-2, MW-4, MW-7, MW-8D, MW-11, MW-14, MW-16, MW-27, MW-31, and MW-32 on December 17, 2004 Groundwater samples were submitted to CLS, for analyses of groundwater parameters related to intrinsic biodegradation, speckrcaiiy, Vo1lLefktratllJnJ of Iiltrates and sulfates by EPA Method 300, iron (II) by Standard Method 3500 Fe D, manganese (II) by EPA Method 2007, and methane EPA Method RK Selected wells were chosen due to their proximity to the axes approximating the plume centerline and along a transverse axes Tabular results of recent groundwater sampling analytical results are summarized in Table 4 The results were also plotted on radial redox diagrams as a visual aid in analyzing intrinsic degradation within the boundaries of and at the outer edges of the plume Figure 14 is a Site Map depicting radial redox diagrams for the selected wells The outermost data series on the diagrams represent the typical background J Trojects10694OW98-2931WorianglReports15098 4th Qtr 04-QMR doc r Celebrating 35 Years of Excellence in Environmental Services