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COAL CREEK RE=SOURCE • Page 2 • Center, Fort Collins), Dave Cooper (Plant Ecologist, Colorado School of Mines, Golden), Glen Crouch (Forest & Range Experiment Station, Fort Collins) and Brad Miller (Physical Scientist, EPA Region VIII, Denver). I can provide phone numbers and addresses on request. EXHIBIT D (Mining Plan) Page D-2, fourth paragraph, indicates that "approximately 83% of the trees will be preserved." In light of the opinions I have obtained from persons with expertise in this area, I feel this statement is unjustifiably optimistic. EXHIBIT E (Reclamation Plan) Page E-1, second paragraph, reiterates the above referenced statement and suggests that preserved tree groups, because they will be connected to the high ground by unmined peninsulas, will continue to receive water from the upland ground water. If the trees received sufficient ground water From the valley sideslopes, this argument would be logical. All of the available evidence, however, indicates that the ground water which sustains these trees is pretty well ~oonfined to the coarse alluvium within the bed of Coal reek. A drop in the streambed elevation will lower the water table. A 1.2 foot drop over 1/4 or 1/3 mile in a year's time will likely result in the mortality of most of the trees. Page E-1, last paragraph, contains information about "contour ridging." Strictly speaking, contour ridging does n~reduce slope length--at least where the Universal Soil Loss Equation is used to estimate soil loss from sheet and rill erosion. Contour ridging is a land management technique, most appropriately treated in the "P factor" of the USLE. Soil ridging may, indeed, help prevent wind erosion--if the ridges are big enough and perpendicular to the direction of prevailing erosive winds. Contour ridging in this valley, however, will actually align ridges roughly parallel to the direction of erosive winds. Applying a protective vegetative cover would help reduce this problem. Page E-2, third paragraph, discusses "straw mulching." Because of the wind erosion hazards, tackifiers alone won't be very effective in holding mulch in place. For best results, the mulch should be anchored with a mulch crimper. Cereal straw is brittle and tends to break where crimped. We, therefore, normally recommend that weed-free, long- stemmed grass hay be used. If applied at a rate of two_tons per acre and crimped into the soil four inches deep, it will withstand most of our hard winds.