Laserfiche WebLink
Evaluation of Potential Subsidence Impacts of Longwall Mining in the Spruce Stomp Lease Area <br />to Aquatic Life and Water Supply <br />include many of the constituents relevant to aquatic life (e.g., metals, dissolved oxygen, <br />nutrients). <br />4.2.3 Biological <br />I. Aquatic and Riparian Vegetation <br />Aquatic vegetation within the West Fork Terror Creek channel is limited likely due to highly <br />variable flows and the absence of fine- grained silt and loam soils within the channel banks. <br />Algal mats were not observed during 2012 site visits. As is common in headwater streams, the <br />primary source of organic carbon in the system is likely woody debris and leaf litter which falls <br />or is washed into the stream from adjacent areas. Riparian vegetation is dense along West Fork <br />Terror Creek through the Spruce Stomp Lease Area, with thick stands of willow shrubs flanked <br />by spruce, fir and aspens which cumulatively provide dense canopy cover. <br />Benthic Macroinvertebrates <br />Miller Ecological Consultants, LLC (MEC), at the request of Bowie, conducted benthic <br />macroinvertebrate sampling at five locations using EPA methodology and at one location using <br />the WQCC multi metric index (MMI) methodology. The results of this work are presented in <br />Appendix 3 and summarized in Figure 7. To summarize, West Fork Terror Creek within the <br />Spruce Stomp Lease Area has consistently high measurements for density (1,965 - 5,399), <br />Shannon - Weiner diversity (3.23- 4.07), Hilsenhoff Biotic Index (3.12 -4.58) and MMI (81). <br />Please refer to Appendix 3 for detailed description of these index scores. These values indicate <br />that existing water quality, riparian vegetation and sediment composition are supporting a robust <br />montane stream invertebrate community. <br />III. Fish <br />Fish species reported to be present in West Fork Terror Creek include cutthroat trout <br />(Onchorynchus clarki), speckled dace (Rhinichthys osculus) and mottled sculpin (Cottus bairdii) <br />(see Appendix 3). Of these, potential impacts to cutthroat trout are expected to be of particular <br />interest to USFS and BLM based on the genetic lineage of fish present in West Fork Terror <br />Creek (discussed in detail in following paragraphs). <br />121 - 014.000 Wright Water Engineers, Inc. Page 11 <br />January 2013 <br />