Laserfiche WebLink
Creek/Little Grassy Creek confluence. The Division previously determined that Cow <br /> Camp Creek, an ephemeral tributary of Fish Creek, is not an AVF. <br /> The Division affirms its previous AVF determination for the Fish Creek AVF that is <br /> documented in the findings documents of the Foidel Creek Mine (C1982056). Alluvial <br /> deposits on Fish Creek meet alluvial valley floor criteria based on existing flood <br /> irrigation,potential for flood irrigation and subirrigation. <br /> The Division affirms its previous AVF determinations for the Grassy and Little Grassy <br /> Creek AVFs. Prior to regulatory recognition of AVFs, the Seneca II Mine (C 1980005) <br /> established the Grassy Creek and Little Grassy Creek AVFs. As allowed under Rule <br /> 2.06.8(5)(a)(i) and (ii) for operations conducted prior to August 3, 1977 within or <br /> adjacent to an AVF, this exemption will continue to apply to those areas of PSCM that <br /> were transferred from the Seneca 11 Mine. The exemption does not apply to areas in the <br /> PSCM where underground mining activities are conducted because PSCM underground <br /> mining activities occurred after August 3, 1977, the exemption qualification date of <br /> Rule 2.06.8(5)(b)(ii)(B). <br /> During the review of the original PSCM application, the Division conducted field visits <br /> along the segments of the following streams that were within the area of influence of <br /> PSCM's mining during the initial permit term: Scotchman's Gulch, Annand Draw, and <br /> Grassy and Little Grassy Creeks upstream from their previously determined AVFs. Of <br /> these stream segments, only Scotchman's Gulch near its confluence with Grassy Creek <br /> appears to have the geomorphic characteristics of an AVF (unconsolidated stream-laid <br /> deposits holding streams). Annand Draw and the upper reaches of Scotchman's Gulch <br /> lack unconsolidated stream-laid deposits sufficient to hold a stream, and therefore these <br /> stream segments do not meet the criteria of an AVF. Grassy Creek and Little Grassy <br /> Creek, upstream from their two previously determined AVFs, lack farmable acreage <br /> next to their channels as a result of the channels' incisement into bedrock; therefore, <br /> these upper reaches of Grassy and Little Grassy Creeks are determined to not be AVFs. <br /> Although Scotchman's Gulch has unconsolidated stream-laid deposits sufficient to hold <br /> a stream, the Gulch does not meet the criteria of an AVF based on insufficient water for <br /> irrigation use and lack of subirrigation characteristics, as documented in Exhibit 2.06.8- <br /> Elof the PAP; therefore, Scotchman's Gulch near its confluence with Grassy Creek is <br /> determined to not be an AVF. <br /> Surface coal mining and reclamation operations will be conducted to preserve the <br /> essential hydrologic functions of alluvial valley floors outside the permit area and to <br /> reestablish the essential hydrologic functions of alluvial valley floors within the <br /> affected area throughout the mining and reclamation process (4.24.2). <br /> Effect of Mining on Identified Alluvial Valley Floors <br /> The PSCM will discharge mine disturbance runoff, coal spoil leachate, and <br /> underground mine water into the stream channel in the Grassy Creek AVF via pond <br /> 002. Pond 004 collects runoff from Phase III released areas within the permit boundary as <br /> 23 <br />