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(b) A minimum static safety factor of 1.3 for a normal pool with steady state seepage <br />saturation conditions is required. Lambert's study evaluated the sudden drawdown condition, <br />but did not determine a factor of safety for the required condition. The unit weight used in the <br />calculation was 115 pcf, which seems too low (average constructed was 123.5 pcf). <br />5. Please review and revise the parameters used, as appropriate, and provide a <br />stability analysis for the condition described in 4.05.9(8)(b). Please also provide <br />the laboratory strength test results (direct shear strength) referenced by <br />Lambert. <br />WFC Response: Included with this submittal is an additional letter document dated January 7, <br />2013 from Lambert & Associates, provided for inclusion into Appendix 2.05.3(4) -6 that addresses <br />the compliance with the safety factor for a normal pool steady state seepage saturation condition. <br />Also included is a tabulation of the direct shear strength test of remolded material. This safety <br />factor analysis was done for soil moist unit weight of 122.6 pcf, Lambert's assessment of the <br />average reconstructed moist density of the passing field density tests. The document states the <br />safety factor results for a soil moist unit weight of 115 pcf. This unit weight was analyzed to <br />demonstrate the minimal variation in safety factor results between the two approaches. Re- <br />analysis using a soil moist unit weight of 123.5 pcf would not result in materially different safety <br />factor results. <br />4.05.9(9)- Will embankment faces and slopes be vegetated or stabilized by other means? <br />6. Please provide a statement addressing this requirement. <br />WFC Response: Included with this submittal is a document for inclusion into Appendix 2.05.3(4) -6 <br />the addresses that the faces and slopes of the embankment are being planted during the first <br />growing season to establish vegetation. <br />4.05.9(10) - <br />Is there adequate freeboard to prevent overtopping by waves or sudden increases in volume? <br />7. Please provide a statement addressing this requirement. <br />WFC Response: Included with this submittal is a document that addresses adequate freeboard. <br />As stated in the WFC response to Item 5. in the Surface Water Hydrology section of this document <br />above, the freeboard of the pond during the sudden increase in volume as a result of a 25yr -24hr <br />event is 2.88 ft. This freeboard is sufficient to prevent overtopping by waves. <br />4.05.9(14)- Was the impoundment inspected by qualified registered P.E. or specialist? <br />(a) Regularly inspected during construction, and upon completion of construction? Lambert <br />and Associates inspected the operation and conducted compaction tests on a regular basis, <br />and the certification has been provided. <br />Item satisfactorily addressed. <br />Upon approval, please insert the page titled Appendix 2.05.3(4) -6 Pond NHN -001 As -Built document at <br />the beginning of Appendix 2.05.3(4) -6. Please insert the SEDCAD runs and Lambert and Associates <br />documents directly behind the aforementioned page titled Appendix 2.05.3(4) -6 Pond NHN -001 As- Built. <br />Two copies of these revision documents are also being mailed via FedEx to Sandra Brown at the DRMS <br />Denver office. <br />5 <br />