2016-08-10_GENERAL DOCUMENTS - M1981185 (2)

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Final -Restoration and Compliance Plan for May Day Idaho Mine Complex Administrative Order for Compliance, Docket No. CWA-08-2012-0011 5.1.2 Mine Access Road The portion of the Mine Access Road addressed in this Plan is located on the west side of the La Plata River adjacent to a wetland complex (see Figure 3a). The La Plata River in this area has a relatively moderate gradient and extensive floodplain with associated wetlands. The river channel is comprised of gravel and cobble materials and has moderate sinuosity. Wetlands exist along the La Piata River and in association with an oid beaver pond immediately adjacent to the Mine Access Road area (see Figure 3a). These wetlands were delineated in 2008 and were re-evaluated for this Pian (see Photos 7 to 11 in Appendix C). The wetlands are dominated by willows, dogwood, currant, field horsetail (Equisetum arvense), and sedges. Soils in portions of the wetlands contain old mining tailings, which are silty and lighter in color (Photo 12). Native soil is shown to be Pescar fine sandy loam and riverwash (see Figure 5). Hydric soil indicators in native soil include reduce matrix and gleyed soil (see Photo 13). Water is provided to the wetlands from the La Plata River and from shallow groundwater. Standing water and saturated soils were observed in the field on June 5, 2012 and May 17, 2016. The functions provided to the greatest extent by these wetlands include flood flow storage, wildlife habitat, and aquatic food chain support. The wetlands have relatively diverse, multi-layered vegetation and good connectivity to the La Plata River corridor. The wetlands appear to have a perennial water supply. Riparian forest occurs to the north of the Mine access road area (see Figure 3a). Dominant species include narrow leaf cottonwood, dogwood, rose, and brome grass. In places, there is a sparse understory. Areas of riparian forest generally lack hydric soil indicators and evidence of a wetland water supply and do not meet the criteria for wetland. However, this area provides important wildlife habitat, including for birds, and is integrated into the La Plata River corridor. WDDF's completed for the Mine Access Road area are included in Appendix D. 5.1.3 Wetland Mitigation Site The two wetland mitigation areas (see Figure 2) were observed on June 5, 2012. The results of these observations are summarized with the mitigation success criteria in Table 1 and in the 2012 Annual Wetland Mitigation Monitoring Report (BWC March 2013). The emergent wetland mitigation site is fully functioning and provides groundwater discharge, flood flow attenuation, and wildlife habitat. The scrub-shrub mitigation site meets the success criteria in terms of June 2016 Bikis Water Consultants, a division of SGM Page 9 Case 1:16-cv-02008-WYD Document 2 Filed 08/08/16 USDC Colorado Page 39 of 82