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Construction Summary <br /> Construction consisted of completing a number of pre-earth moving tasks. These tasks included: <br /> - Locate and flag high water mark of the adjacent Coal Creek. This was the northern boundary of the Project area. <br /> As no cutting or filling of materials from the area north of the high water mark occurred, an Army Corps 404 permit <br /> was not required. <br /> - Grade the base of the fill area to drain to the north toward Coal Creek. This also allowed the accumulation of <br /> clean rock to be used as a draining foundation under the excavated earthen material. <br /> - Place up to 3 feet of clean gravel along the base of the planned fill area, and up the south and south eastern <br /> portions of the slope against which fill material was to be placed. This rock material was covered with a geotextile <br /> in order to allow for water to infiltrate into the rock foundation, while holding fine grained materials in the earthen <br /> fill. <br /> - Sediment control measures were constructed near the anticipated toe of the fill slope in order to minimize the <br /> potential for sediment to migrate into Coal Creek during earth work operations. <br /> - Cut and fill operations began, with cut material being pushed onto the prepared foundation. The fill was <br /> compacted in about two foot lifts to 90% proctor. The compacted fill was tested by an independent geo- <br /> engineering lab to confirm that compaction specifications were being met. <br /> - The outslope formed by cut and fill operations was graded to an average 2.4H : 1V slope. <br /> - Topsoil substitute was placed over the graded cut and fill to an average depth of eight inches. <br /> - The cut and fill areas were fertilized and mulched using weed free straw at two tons per acre. <br /> - The cut and fill surfaces were then severely roughened using a track hoe to create hundreds of berms/ <br /> depressions. These small features disrupt surface water flows and velocities, thus minimizing erosion potential, <br /> and act to create micro-environments for plant establishment. <br /> - The area was seeded using the standard Coal Basin Mine seed mixture. <br /> • An exclosure around the perimeter of the Project Area was constructed by installing a four strand barbed wire <br /> fence. <br /> - Willow bundles were planted along the toe of the fill area. The willows were collected locally. Willow cuttings were <br /> cut into 24 inch lengths, and tied into bundles of 10 cuttings. The bundles were placed under 2" —3" of soil. <br /> - 450 mixed species trees (approximately equal numbers of Engleman spruce, Colorado blue spruce, and Douglas <br /> fir) were randomly planted throughout the Project Area. <br /> - More permanent sediment control was placed at the toe of the fill. <br /> V. FUTURE MAINTENANCE <br /> The site needs to be monitored for erosion, to evaluate the function of the rock underdrain, and to determine success <br /> of tree and shrub plantings. <br /> VI. SUMMARY <br /> An area approximately one acre in size was stabilized through construction of a rock underdrain, cut and fill <br /> operations, management of surface water flows, tree and shrub planting and revegetation. <br /> Project Manager: Steve Renner <br /> Date: November 20, 2001 <br /> b:\closeout.form <br />