2012-03-07_PERMIT FILE - C2010088 (28)

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McClave Canyon Mine Expansion and Fruita Loadout Facility . Biological Assessment the rail bed. In addition, there would be 0.031 acre of rip -rap placed on the east bank of Reed Wash extending from the ordinary high water mark (OHWM) -to the concrete abutment supporting the bridge on the east side. There are approximately 40.53 acres of critical habitat that have been mapped within the 100 - year. floodplains of Reed Wash and Loma Drain combined, as mapped bjr the Federal Emergency Management Agency - FEMA (Mesa County, 2011): The project would physically alter 0.124 acre (railroad bed and rip -rap) within the 100 -year floodplain in Reed Wash, about 0.3 percent of the mapped total. Five rows of pilings that the support the rail bridge would be within the 100 -year floodplain however, the spacing of pilings has been adjusted so that none would be located within the OHWM of Reed Wash. Consequently, flows within the OHWM 'would not be affected by the bridge and supporting piles. Evaluation of a - 100- yearflood event was conducted with a discharge rate of 1,861 cfs at the bridge site with and without the bridge present. The presence of the bridge increased the. 100-year flood surface water elevation by 0.61 'feet over the surface water .elevation without the bridge. The maximum increased water elevation would allow 1.75 feet separation between the water surface and bridge bottom. The analysis concluded that the presence of the railroad bridge would not cause avulsion of the 100 -year floodplain . or inundation beyond Reed Wash.- Acoustic Impact. Driving pilings in water can physically injure fish from the impact of percussive sound pressure (Popper et al.,'2006). Effects to fish are dependent on numerous factors including -the size of fish, pile size ,and material, .impact equipment, distance of fish from the source, water depth, bottom material, bottom- topography, currents -or tidal flux, and- river sinuosity (Washington State Department of Transportation, 2008).• The railroad bridge_ has been designed so that pilings would not be placed within'-the OHWM of Reed Wash. Underwater noise - may be generated by driving piles on stream banks (dry piles) because some noise propagates through ground and sediments - (especially harder sediments such as rock and clay), and, may transfer to the water . column somewhere else (known as sound flanking). Sound in the water column would be at,"a iower level than at the source (Washington State Department of Transportation, 2008) because most sound energy, does -not travel through water but through the sediment.' Fish' presebt in Reed Wash would be expected to hear (sourtii -transduced by the swim bladder•) noise"'produced by dry pile_ driving but sound levels would not result in injury because the 'shock wave energy would be dissipated (Laughlin, 2006; Washington Department of Transportation; 2008). Hazardous Materials. Reed Wash and the 100 -year floodplain could be adversely affected if petroleum products were accidentally discharged into - surface waters and the floodplain. Such materials are toxic to algae, invertebrates, and fish. Diesel fuel spills affect freshwater stream macroinyertebrates over space ,(some distance downstream from the spill) and over time, for more than one year after a spill (Lytle and Peckarsky, 2001). During 96 -hour tests of acute toxicity, the LCso for juvenile coho salmon exposed to diesel fuel ranged between 2,186 and 3,017 mg /L (World Health Organization, 1996). Water accommodated fractions (standardized preparation of water systems with dissolved oil components -for toxicity studies) prepared from oils higher in aromatics (e.g. the middle distillates, including Fuel Oil No. 2, kerosene, and diesel) are generally more toxic than those prepared from crude oils and gasoline (e.g. Anderson et al., 1974; Rice et al., 1976; Markarian et al., 1994). Consequently, the LCsa for crude oil would most likely be higher and less toxic than those values, above, for diesel fuel. Impacts to aquatic habitats that primarily 'affect aquatic substrates — hence fish - spawning, incubating and rearing habitats '— can remain for much longer periods (Lytle and Peckarsky, 2001; Markarian et al., 1994). 25