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Diligent care must be exercised by the CONTRACTOR to ensure that the contribution of <br /> sediment to Coal Creek during construction of the diversion is minimized. Sediment control <br /> measures must be instituted immediately upon excavation of the northern most portion of the <br /> diversion to the elevation of Coal Creek, or as directed by the PROJECT MANAGER. <br /> Appropriate sediment control measures may include, but may not be limited to: <br /> - Silt fence, such as Mirafi Prefabricated Silt Fence with Posts, or approved equivalent Silt <br /> fence will be installed as per manufacturers specifications. <br /> - Straw bales, placed on edge and butt to butt, and anchored with rebar at each end, and <br /> driven into the underlying ground. Bales shall be placed and maintained so that under <br /> drainage does not occur. <br /> - Earth work as needed to prevent surface flows from the diversion from reaching Coal <br /> Creek. <br /> An eighteen inch (18") tall berm will be constructed adjacent to each side of the diversion as the <br /> work progresses. Side slopes of the berm will not be steeper than 2.51­1:1 V. This berm will act <br /> to prevent runoff from adjacent areas from entering into the diversion. <br /> Any trash, debris or other non-earthen materials encountered during excavation of the diversion <br /> will be segregated from the excavated earthen materials. The trash and debris will be properly <br /> disposed of by the CONTRACTOR on site, in the case of concrete materials, or at an approved <br /> County Landfill, in the case of other trash and debris. Concrete materials will be disposed of by <br /> excavating a hole at a designated location within the vicinity of the Project Area, placing the <br /> concrete materials, and covering the hole with a minimum of four feet(4) of the earthen <br /> materials. <br /> Construction Sequence <br /> In order to maximize the use of rock materials located within the Project Area, one potential <br /> construction sequence is detailed below. Note that the CONTRACTOR may develop an <br /> independent construction sequence. Prior to initiating construction, the CONTRACTOR must <br /> present for the PROJECT MANAGERS approval the proposed construction sequence and <br /> Project Schedule to be followed during the course of this Project. The construction sequence <br /> and Project Schedule must be approved by the PROJECT MANAGER prior to the <br /> CONTRACTOR initiating construction activities. <br /> Refer to Map 6, Potential Construction Sequence <br /> 1. Excavate the downstream section of the diversion between contours 7,995 feet and <br /> 8,035 feet (Map Item 1); <br /> 2. Stockpile excavated material in the three (3) designated locations (Map Item 2); <br /> 3. Construct a temporary diversion channel on the north side of Dutch Creek between the <br /> top of the flume and the top of the diversion (Map Item 3); <br /> 4. Direct haul and place rock from rock berm (Map Item 4) and Dutch Creek to the lower <br /> section of the diversion (Map Item 1); <br /> 9 <br />