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NOV CV-2008-001 Abatement Step 2 <br />Page 2 <br />Sco e. <br />1) Advance 7 to 8 test holes across the slide area situated north/northeast of the existing Pond 12 with an all <br />terrain drill rig. In addition, 5 to 6 test pits will be excavated with a trackhoe. The depth of the test holes will <br />be determined in the field as the drilling and excavations progress and as the subsoil profiles become evident <br />We have assumed that the test holes will be drilled to a minimum depth of 20 to 40 feet and the test pits will be <br />excavated to depths ranging from 10 to 20 feet, depending on the subsurface conditions encountered. The test <br />holes and pits will be advanced to investigate'the subsurface profiles, to obtain samples for laboratory testing, <br />to estimate the groundwater level and the depth to bedrock. Slotted PVC pipe will be installed in several of the <br />test holes so that groundwater levels and soil movement can be monitored. The test holes will be drilled with <br />an all terrain drill rig using 4-inch diameter continuous flight augers. <br />2) Conduct a laboratory-testing program to determine the strength, compressibility or swell characteristics, <br />_ _ classification and_permeability of the soil_and bedrock materials obtained from the site. <br />- <br />3) Analyze the results of the field and laboratory investigations so that we can provide alternatives for repairing <br />and/or stabilizing the existing slope failure. <br />4) Prepare a final report that will summarize thel data obtained and present our conclusions and recommendations <br />for stabilizing the slope. The field work and report preparation will be conducted under the direct supervision <br />of a registered professional engineer. <br />Schedule: <br />We can initiate the field investigation within. 4 weeks of being given notice to proceed. However, the site will need <br />to dry out significantly before the site can be accessed, even with tracked equipment. We anticipate that it will take <br />3 to 6 days to complete the drilling of the test holes and excavation of the test pits. We anticipate that the final <br />report should be completed within 3 to 5 weeks after the laboratory investigation is completed. It should be noted <br />that it will take approximately 2 to 4 weeks to complete the laboratory testing. <br />The notice to proceed was issued by SCC on 6/1/08. Review of the schedule, provided by the certified geotechnical <br />engineer, indicates that under the most optimal conditions, the technical revision application cannot be prepared before <br />August 31St. <br />b) The remedial plan will identi <br />.b, and assess the factors that contributed to the failure, mill include specific remedial measures to be <br />implemented to repair the slide and effect compliance with the applicable requirements of Rule 4.14, and shall include a geotechnical _ <br />stability analysis demonstrating that the remedial plan will result in a final slope that will comply with Rule 4.14.2(1)(b). <br />Response: The remedial plan will address the above items. <br />c) The application will also address both short term and long term measures that will be taken to provide adequate sediment controls in the <br />Pond 12 watershed, consistent with long term mass stability of the failed slope. Short term measures may include cleanout of Pond 12, if <br />thegeotechnical report demonstrates that such cleanout can be accomplished without compromising slope stability. <br />Response: A major portion of the mandated remedial plan is awaiting approval of Technical Revision 37, which <br />includes proposed Pond 012A (submitted March 2008). 'Pond 012A will provide sediment control for the majority of the <br />original Pond 012 watershed, leaving only 37 acres of watershed for Pond 012 to provide sediment control.