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C -2010 -089 PARNos. 1- 1A -1B, 2- 2A -2B, 3 <br />New Horizon North Mine Page 35 of 60 <br />construction design is required. Please revise the three sediment pond cross sections to <br />state the exact diameter of the principle discharge tube. <br />I "c r c111cd l c ie1g i c m� -1 irere revived Item r esoh,etl n c-201 <br />resImnse. <br />5. Map 2.05.3 (3) -1, "Surface Water Hydrology ", has several depictions that are not explained, <br />either on the map or in the neap legend. Such depictions include the black, blue, dark orange <br />and magenta colored lines, as well as the mine plan year numbers 2013 through 2015. <br />Under Rule 2.05.3(3) and (4), please add labels on the map or explanations in the map <br />legend that describe what the depictions represent. Itent r sol rl in J111ay -2011 res ons . <br />However, the Division has one additional request regarding this map. <br />a) On Map 2.05.3(3) -1, please add aline to connect the SW FA notation with the SW -FA <br />drainage area. Rem <br />resohwd in Dee-2011 response% <br />6. On Map 2;05.3(3) =1, "Surface Water Hydrology", the green lines that depict the collection <br />ditches are obscured in some areas by the magenta lines. Also; the ditches' names are not <br />shown. Under Rule 2.05.3(3) and (4), please revise this map to show the full extent of the <br />collection ditches and the appropriate ditch names. It art resoh,etl in Mitjy-2011 r° vponse. <br />7. 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 <br />DBMS, since the DRMS has primacy in Colorado. ftem resolved in lay -2011 res c nse <br />8. 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. Item resolve(l in ,11aj7 -2011 resj)one <br />9. In Table 2 of the pond memo in Appendix 2.05.3(3) -1, design capacities of the three <br />sediment ponds are listed. Each pond's listed capacity is the total pond volume up to the <br />emergency spillways. However, since a sediment pond cannot be dewatered below the <br />lowest discharge elevation of the discharge structure, a sediment pond's designed capacity <br />has to be able to contain the runoff from the 10 year -24 hour event as measured from the <br />elevation of the lowest discharge point up to the elevation of the emergency spillway. Please <br />provide demonstrations that the three ponds have sufficient capacity above the lowest <br />discharge elevation to contain the runoff from a 10 year -24 hour event and revise the <br />sediment pond design capacities in Table 2 accordingly. It nt resolt,ed in 1111ay -200 / <br />However; the response to question number 12 -B of this section may require another review <br />if the elevations of the primary discharge pipes are raised. <br />l'1)llc1 v(1htme,v 1i'ere re vi,vecl in the Dec-201 L§tfbinitlaL <br />ej- ='it it". ., b., . atfi. >C..� »z �t,.� r,., trs �....:7 t <br />