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XIV. Protection of Underground Mining <br /> No underground mine workings were identified in the vicinity of the Seneca II West permit <br /> area. <br /> XV. Subsidence Control <br /> No underground mining was identified in the area, and only auger mining operations <br /> were planned for the Seneca IIW Mine. As such, subsidence control planning and <br /> mitigation efforts were incorporated into the permit for the area affected by auger mining. <br /> The Division finds the operation in compliance with Rule 4.23.2. <br /> XVI. Concurrent Surface and Underground Mining <br /> This section does not apply to the Seneca IIW operation. <br /> XVII. Operations on Alluvial Valley Floors <br /> As part of PRI, the applicant submitted adequate information for the Division to make <br /> the required alluvial valley floor (AVF) determination and findings in accordance with <br /> Section 2.06.8 of the Regulations. Additional information was submitted during the <br /> review of PR2, PR3, and TR50. Information on alluvial valley floors comprises Tabs 16 <br /> and 17 of the application. <br /> AVF Determination <br /> SPL conducted an extensive alluvial valley floor investigation of the permit and adjacent <br /> area. Two AVF areas were identified downstream of Seneca II-W mining operation. A <br /> flood irrigated field located within the Dry Creek drainage in Section 16 and 21,T5N, <br /> R88W and a flood irrigated field within the Sage Creek drainage in Section 30,T6N, <br /> R87W. Two subirrigated fields in Section 9,T5N,R88W of the Dry Creek drainage <br /> were originally identified as AVF's. Subsequent assessments of these fields in 2005 by <br /> ESCO Associates(Dr. David L. Buckner)determined that these parcels do not meet the <br /> AVF criteria. A more detailed discussion of these findings can be found in Tab 17 <br /> Probable Hydrologic Consequence section of the mine permit. <br /> The Division concludes that the Dry Creek Section 9 parcels do not constitute an alluvial valley <br /> floor. This finding is based on the fact that the native wetland community does not support <br /> agriculturally useful vegetation and as such does not meet AVF criteria. Further,the meadow <br /> parcels, due to small size, split ownership, and limited production potential, do not play a <br /> significant role in support of an economically viable ranching or farming operation, nor do <br /> they serve a special role in agricultural land use in the region. As such, the meadow parcels do <br /> not meet AVF criteria. <br /> AVF Findings <br /> The Division determined that an alluvial valley floor exists within the affected or adjacent area <br /> and that mining operations will be conducted a half mile or more from the alluvial deposits of <br /> Hubberson Gulch, Dry Creek, and Sage Creek. Therefore, the following findings are in order <br /> for these alluvial deposits. <br /> 1. With regard to Dry Creek, the Division finds that activities proposed by the applicant will <br /> Page 34 of 37 <br />