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sum bid will cover all costs for excavating, hauling, placing and rip-rap Iining as described in <br /> these specifications. <br /> Task 3 <br /> Rock Check Dam Construction: <br /> Rock Check Dams are required in three areas; along the access road, on the portal bench and <br /> the outslope of the fill. See drawing for locations. Rock check dams shall be installed as <br /> follows: f c 2 <br /> • Accces�Road-Small erosion featuresse bend down the slope approximately 200 feet. <br /> insta—if a rocck`check dam every 20 ffeet as directed by the Project Manager. Rock check <br /> dams shall consist of 18 to 24 �f,rock using on site material. Rock check dam <br /> 00 dimensions will be 3' long by 3'wide by 2'deep at the base of the dam and be keyed in <br /> to a depth of 2' below ground. Placement will be such that voids will be eliminated to the <br /> best extent possible with rock contacting rock and smaller rock used to fill any voids. <br /> • Portal Bench-One large erosion feature extends down the graded portal slope for a <br /> dlstan'� c approximately 50 feet. Rock check dams will be installed every 10 feet as <br /> directed by the Project Manager. The Rock Check Dams will be; constructed according to <br /> the attached Drawing 2, Drainage Course Rock-Rock Outcrop to Slope and Check Dam- <br /> X-Section& Plan. Rock check dam rip rap, available on-site will consist of an evenly <br /> distributed combination of 60% minimum 4'diameter rock rip rasp,20%2'to 3'foot <br /> diameter rip-rap and 20% 12"to 18" rock. The 4'diameter rock:will be keyed into the <br /> C bottom of the constructed 3H:1V channel through excavation placement not to extend <br /> more than 30"in depth. The 12"to 18"rock will be placed and compacted around the 4' <br /> diameter rock. The 2'to 3'diameter rock will then be placed over the smaller rock to <br /> fulfill the 30" minimum riprap depth requirement. Tlka� c The check dam <br /> will be constructed in a V-shape with the middle of the V situated 4'in slope length, up <br /> stream in elevation. Rip-rap will extend a minimum 4' up the side slopes. Side slopes to <br /> the constructed channel will be at a maximum 2H:1 V slope. Positive drainage will be <br /> maintained from the bench cut to into the drainage channel. Sere Drawing 2 for more <br /> detail. <br /> S� <br /> • Fill,O"tsloue-Small erosion features extend down the slo apprroximately 100 feet. <br /> InstalE a rock check dam every 20 feet as directed by the Project Manager. Rock check <br /> y dams shall consist of 18"to 24" using on site material. Rock check dams will be 3' long <br /> by 3'wide by 2'deep at the base of the dam and be keyed in to a depth of 2'below <br /> ground. Placement will be such that voids will lie eliminated to the best extent possible <br /> with rock contacting rock and smaller rock used to fill any voids.. <br /> Material excavated as a result of drainage course construction may be excavated and hauled to <br /> or graded against the excavated bench cuts as noted on the drawing. Prior to depositing or <br /> grading excavated material against the excavated bench cuts, existing vegetation and soils to a <br /> n�(ef� 24"depth will be graded off and stockpiled. Stockpiled vegetation and soils will be evenly <br /> 7 redistributed over the material deposited following drainage course construction upon <br /> completion of earthmoving procedures. <br /> Measurement and Payment <br /> -8- <br />