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23. As shown in the surface water monitoring data sheets in Appendix 2.04.7-2, monitoring sites <br />SW-N202 and SW-N203 experienced flows throughout the year but no full water quality <br />analyses were completed. Please explain. <br />24. On the first and third pages of the pond memo found in Appendix 2.05.3(3)-1, there are two <br />references to design criteria of the Office of Surface Mining. Please change this to the DRMS, <br />since the DRMS has primacy in Colorado. <br />25. On the third page of the pond memo in Appendix 2.05.3(3)-1, it is stated that the design <br />capacity pond volume is the volume of the pond up to the emergency spillway. However, the <br />required design capacity volume of a pond is the pond volume measured from the lowest <br />discharge elevation up to the elevation of the emergency spillway. Please revise this page <br />accordingly to include this explanation. <br />26. In Table 2 of the pond memo in Appendix 2.05.3(3)-1, design capacities of the three sediment <br />ponds are listed. Each pond's listed capacity is the total pond volume up to the emergency <br />spillways. However, since a sediment pond cannot be dewatered below the lowest discharge <br />elevation of the discharge structure, a sediment pond's designed capacity has to be able to <br />contain the runoff from the 10 year-24 hour event as measured from the elevation of the lowest <br />discharge point up to the elevation of the emergency spillway. Please provide demonstrations <br />that the three ponds have sufficient capacity above the lowest discharge elevation to contain the <br />runoff from a 10 year-24 hour event and revise the sediment pond design capacities in Table 2 <br />accordingly. <br />27. The three sediment ponds each use a gated drop inlet primary discharge structure. However, the <br />Sedcad program cannot model pond volumes, discharges and sedimentology for a gated pond <br />to show compliance with Rule 4.05.6 and 4.05.9. The Sedcad designs that were submitted use <br />an ungated, self-dewatering drop inlet structure. As a consequence, the designs do not match <br />the proposed construction and the designs may be confusing. For example, the Sedcad designs <br />show that runoff from the 10 year-24 hour precipitation event will flow out of the emergency <br />spillway, which is not allowed under Rule 4.05.9(2)(b). Please provide sediment pond designs <br />that demonstrate that the gated sediment ponds will comply with Rules 4.05.6 and 4.05.9. The <br />demonstration can rely on pond water and sediment storage volumes without the pond <br />discharging and without sedimentology demonstrations. <br />28. In the first full paragraph on the fourth page of Appendix 2.05.3(3)-1, the first sentence states <br />that an emergency spillway with a height that is one foot below the top of the pond <br />embankment can be used. However, Rule 4.05.9(7)(d) requires that there be at least one foot <br />difference in elevation between the 25 year-24 hour precipitation event water level flowing <br />through the emergency spillway and the top of the embankment. For the sake of clarity, please <br />revise this statement on the fourth page to reflect the rule requirement. <br />29. On the fourth page of Appendix 2.05.3(3)-1, it is recommended that modifications to sediment <br />ponds NHN-001 and NHN-002 be used in order to avoid short circuiting. Please revise the text <br />to describe which modifications will be used, especially for pond NHN-002. Also for pond <br />NHN-002, please explain per Rule 4.05.6(7) why the spillway pipe could not be located more <br />4