1999-05-14_GENERAL DOCUMENTS - C1981017

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FEB-02-99 10 :30 AM ESCO_ASSOCIATES 303 499 4276 P. 05 Mine #4 Downslope Revegetation Work GLA Comment No. 3 Response: "Depressions" and benches that might be sought on the steep slopes fall into a more general category of "surface roughness" that reflects greater diversity of microtopography. The presence of diverse microtopographic features on sites exposed to severe conditions allows seeds that are sown, bits of mulch that are spread, and moisture that falls, the chance of ending up in a site, though small, where there is sufficient protection to allow successful germination, establishment and growth of new plants. Since MCR was granted permission to leave such steep slopes, the overall degree of slope of areas to be revegetated cannot be changed, but the creation of small protected sites so critical to the establishment of plants should be considered in the overall design of revegetation. GLA Comment No. 4 Response: Bonded fiber matrix mulch has been used throughout the country including Colorado for the past several years. It was not available in Colorado when the MCR Coal Basin reclamation plan presented in the permit was developed in the mid 1980's. Bonded fiber matrix generally consists of long- strand wood fiber applied at fairly high rate (3,000 to 3,500+ pounds per acre) in combination with proprietary tackifier that has generally higher capacity to "glue" the applied material to itself and to the substrate than the tackifier generally used for hydromulch (e.g. Psyllium-based products). Its proper application results in an erosion-resistant "mask" over the surface, however irregular, that has sufficient small holes or thin spots to allow the shoots of seedlings to penetrate. Compared to other mulches that offer a high level of surface protection, especially the rolled fabric mat products, it has the ability to conform to irregular surfaces much more effectively. Fabric materials 5