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Response: Figure 2.04.7-F7.1 and related discussion have been removed from the <br />text for the reasons described above in SCCC's response to Comment 12a. <br />14. Please replace the calculation of vertical bedrock discharge into Grassy and Little <br />Grassy Creek alluvium with a calculation of bedrock discharge into those streams that <br />uses the same bedrock subcrop seepage area of 78 acres as previously used in the <br />vertical discharge calculation, and a hydraulic conductivity value of 2.5 ft/day (the <br />average of 0.03 and 5 feet per day shown for interburden, SCCC's overburden, in <br />Williams and Clark's Table 4). Also add a statement or two describing expected <br />seasonal variation of this bedrock discharge. The calculation of bedrock discharge as <br />only a "vertical" discharge is not acceptable because it assumes that most of the <br />discharge from bedrock occurs normal to the bedrock bedding plane, which would <br />occur only if the alluvium were deposited on a single uneroded bedding plane. The <br />alluvium probably was deposited on an irregular bedrock erosional surface, resulting <br />in most discharge from bedrock occurring parallel to the bedding plane. <br />Response: The subject calculation has been revised to address horizontal discharge from <br />the bedrock to the alluvium, per this comment and discussions related to this comment <br />during conference calls with CDRMS on February 19 and 24, 2010. The seepage area <br />was changed to 240,000 square feet (the cross-sectional area along the length of the <br />valleys) and the hydraulic conductivity was changed to 2.5 ft/day. Also, the gradient was <br />changed to 0.02 - the average horizontal gradient for the overburden near the Grassy <br />Creek and Little Grassy Creek valleys, as shown on Figure 2.04.7-F5. As discussed, <br />seasonal variation was addressed qualitatively. Text on or about page 2.04-50 in Section <br />2.04.7, Hydrology Description has been revised and is included in this PAP response <br />package. <br />16. Please add to the permit application the following historic reclamation information <br />pertaining to the Seneca 11 lands that will be transferred to the PSCM: <br />(Responses to items a and b of this Comment 16 are adequate as submitted.) <br />c) A summary of past husbandry practices; <br />i. Weed control measures; method-chemical, biological, or mechanical, <br />describe, and what species was being controlled. Although the weed <br />management plan provided says what will be done if weeds are found, the <br />history of weed control measures previously employed are needed. <br />ii. (This response is adequate as submitted.) <br />iii. Mowing, location and dates (year would be adequate, for example: <br />Mowed parcel 89-2 in 2001). This information is needed because mowing <br />can be used as a weed control measure. <br />Response: A summary of historic weed control practices at the Seneca II Mine has been <br />added to Exhibit No. 2.04.13 - E3 "Historic Husbandry Practices and may be found <br />following the weed management plan contained in that Exhibit. In addition to a general <br />discussion of these practices, the annual weed control record for years 2006 through 2009 <br />are included. The response to his comment has been coordinated with Janet Binns of the <br />4