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S <br /> FINDINGS FROM MONITORING WELL SAMPLE ANALYSIS FOR OXYGENATES <br /> The presence of 1,2-DCA was detected in samples extracted from MW#1D, MW#5D, MW#7D, <br /> MW#8D, and MW#9S &9D The highest concentration of 1,2-DCA was found in monitoring well <br /> MW#8D which is located in the building EDB was not detected in any of the monitoring wells for this <br /> event TBA was detected in monitoring wells NfW#8D, and MW#9S & 9D (See groundwater analysis <br /> recap attached) <br /> CONCLUSIONS <br /> The water table elevations on this site continue to fluctuate Concentrations of TPHg have continued <br /> fluctuating in the shallow wells with the rise and fall of the groundwater elevation(See contour map of <br /> Max TPHg levels attached) The groundwater gradient was to the southwest for this event, which is <br /> in the opposite as the second quarter event It may be concluded that when the groundwater elevation <br /> lowers, the gradient changes from easterly to westerly <br /> RECOMMENDATIONS <br /> It is recommended that the site continue to be monitored on a quarterly basis Monitoring well MW#1D <br /> was installed to a depth of 150' Groundwater samples from this event indicate the presence of 1,2 DCA <br /> above drinking water standards at a depth greater than 150' in area of monitoring well MW#1D The <br /> groundwater sample from MW#1D for this event verifies that the sample analysis from the second <br /> quarter was correct and the site has 1,2 DCA contamination below 150' below the surface Vertical <br /> delineation of 1,2 DCA should continue to depths deeper than 150'below the surface A monitoring well <br /> in the same area as MW#1D should be installed to a depth of 175'below the surface <br /> WORK IN PROGRESS AND FUTURE WORK <br /> Quarterly monitoring of the existing monitoring wells continues From this date forward monitoring of <br /> this site will be done by Advanced Geoenvironmental Inc of Stockton California Any questions or <br /> directions for future work on this site should be directed to them <br /> INSTALLATION OF MONITORING WELL MW#1D REPORT <br /> Installed 10/23/03 <br /> PROCEDURE <br /> On October 23,2003, Spectrum Drilling completed an 8"bore hole to a depth of 100'and installed a 2" <br /> PVC well casing to that depth Soil samples were extracted from 40' of depth to 100' of termination <br /> depth at five foot intervals A 2"PVC casing was installed with screen from 90'to 100' The monitoring <br /> well was developed and purged to industry standards by Del-Tech Geotechnical Support Services <br /> SOIL SAMPLE ANALYSIS <br /> Soil analysis did not detect the presence of TPHg in detectable ranges from 40 to 100 feet of depth The <br /> same soil samples were analyzed as non-detect for oxygenates in sof 1 by EPA Method 8260(See attached <br /> recap of analysis) <br /> 3 <br />