Laserfiche WebLink
rC,VA, <br /> �Tc <br /> A S S O C I A T E S I N C <br /> installed on the well and a watertight wellhead labeled "monitoring well" was set in concrete <br /> over the well. Well construction details are presented on the diagram contained in Appendix A. <br /> All drill cuttings and drilling mud were stored on site in 55-gallon drums pending proper <br /> disposal. <br /> 2.2 Well Development <br /> F. Groundwater monitoring well MW9 was developed on May 2, 2003. The well was purged using <br /> surge and bail techniques until the extracted water was relatively sediment free. Development <br /> logs are included in Appendix B. Purgewater was temporarily stored on site in 55-gallon drums <br /> Fpending proper disposal. <br /> F. Well MW9 was surveyed on May 5, 2003 by ATC. The wellhead elevation was tied into the <br /> elevations of the existing wells. Survey data is included in Table 2. <br /> Fil 2_3 Groundwater Sampling and Analysis <br /> Fluid levels were taken from well MW9 on May 5, 2003, utilizing an electronic water probe : <br /> capable of measuring with an accuracy of 11100 of a foot. Monitoring data is presented in Table <br /> Groundwater sampling was conducted on May 5, 2003. One groundwater sample from the deep <br /> i . well MW9 was collected after purging a minimum of three well volumes and stabilization of <br /> electric conductivity, pH, and temperature. Field purge logs are presented in Appendix B. ' <br /> Subsequent to purging, groundwater was sampled and transferred to appropriate sample <br /> F containers, using a clean, disposable bailer with a bottom emptying device to reduce <br /> volatilization. Groundwater samples were placed on ice and delivered under chain-of-custody <br /> documentation to Excelchem Environmental Labs (FLAP #2119) in Roseville, California for <br /> F analysis of. hexavalent chromium using EPA method 7199; total chromium using EPA method <br /> 200.7; turbidity using EPA method 180.1; and total hardness as CaCO3 by method SM2340C. <br /> Following groundwater sample collection, a dissolved oxygen measurement was taken in the <br /> field and recorded on field purge logs. <br /> FCopies of the analytical reports and chain of custody documentation are included in Appendix C. <br /> 3.0 SUBSURFACE CONDITIONS <br /> F3.1 Geology <br /> Soil from the boring CPT-1, adjacent to well MW9 consisted of alternating layers of silt and ' <br /> clayey silt to a depth of approximately 55 feet b s. Soil from approximately 55 feet to 60 feet <br /> consisted of layers of sandy silt and clayey silt. Soil from approximately 60 feet to 105 feet <br /> consisted of silt, clayey silt with layers of cemented sand from approximately 70 feet to 75 feet <br /> ` w:lw0rdpro1625831repodsldeep well inst.doc. 4 <br />