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1995 RecLuutim Bids July 7, 1995 Page 10 <br /> Further, triangular ditches are much easier to construct with an angled <br /> dour blade. Trapezoidal ditches require special equipment or multiple <br /> passes or both, adding to the construction cost. <br /> Furrow placement and location could not be evaluated since this <br /> information was not provided in the bid document. <br /> Task 7 Revegetation <br /> This task entails the revegetation of the backfilled and disturbed areas at <br /> Mine # 3. CDMG, in Amendment 1 to the bid has accepted <br /> hydromulching and hydroseeding as acceptable methods for revegetating <br /> the slopes at Mine #3. This could reduce the cost for seeding these areas, <br /> as the previously required broadcast seeding is labor intensive. <br /> The seed mix concerns I identified in Task 6 Bid PKA-5-356 are applicable <br /> here as well. <br /> At Mine#3, on slopes flatter than 3H:IV, CDMG is requiring the <br /> placement of five tons per acre of native grass hay, presumably as an <br /> amendment to the shaley and carbonaceous material of the bench. <br /> Addition of hay as an amendment or soil builder is a questionable practice, <br /> as the hay tends to bind available nitrogen and adds little to the soil <br /> structure. As with elevated seeding rates, too much hay mulch may <br /> impede plant growth through moisture deprivation and light reduction to <br /> seedling plants. I sincerely question this practice. A more appropriate <br /> action would be to mix rock, available bench material, and any more <br /> desirable parent material (any sandstone, fine concrete remnants) during <br /> backfilling of the highwall and retain some of this material on the flat <br /> bench remnants. <br />