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%~ ~'~~~~~ ~I•/~~i~n~.n rvil~wlJI9~C.::~l j~7 CIrU~~y~1NnCioh Mr. Dennis Davidson Natural Resource Conservation Service 401 23`s St. Glenwood Springs, CO 81601 ~~~ ~~~~I~I~~~~~~I~~ March 4, 1997 Matthew S. Hayes Hayes Environmental Services, Inc. 300 Lafayette St. Denver, CO 80218 RE: Irrigated Hayland Production standard, Coal Ridge No. 1 Mine (C-84-065) Dear Mr. Davidson: I spoke to you by phone this past December regarding a production standard at the Coal Ridge No. 1 mine site. The mine was permitted in 1984. Areas that are disturbed during mining operations are required by the Colorado Division of Minerals and Geology to be reclaimed to an aceptable condition, generally measured by comparing the reclaimed vegetation with a success standard or a nearby natural reference community. Somehow, in 1984, neither a success standard nor a reference area were agreed upon for the irrigated hayland community at the Coal Ridge mine site. As a result, I am trying to determine a fair standard for the mine to allow a determination of reclamation success to eventually be made. The mine site is located near New Castle, Colorado in Garfield County, and is visible from Highway 70 on the south side. The irrigated hayland community lies in Map 12 of the Soil Survey of Rifle Area, Colorado, and within the Storm King quadrangle. According to permit documents and maps, the community is about evenly located within areas mapped as Heldt Silty Clay (6 to 12 % slope) and the Nihill Stony Loam (6 to 25% slope) soil designations. These would correspond to soil types 30 and 47 of the SCS Soil Survey map 12, identified as Heldt clay loam, 6 to 12% slope and Nihill channery loam, 6 to 25% slope respectively in the body of the Soil Survey document (see page 92, Table 4). According to Table 5 of the Soil Survey (p. 94-96, Yields per Acre of Crops and Pasture), yields for these two soil types "expected under a high level of management" would be 3.0 and 2.0 tons per acre of alfalfa hay per year. However, several characteristics of the mine's imgated hayland community are inconsistent with the assumptions of the Table 5. First, the crop planted on the mined area was predominantly of grass species. The seed mix listed in the approved mining permit was as follows (Orchard grass, 5.6 PLS/Acre; Brome grass, 2.4 PLS/Acre; Timothy grass, 3.7 PLS/Acre). The actual seed mix used in the 1994 reclamation may have included alfalfa, though at a rate not greater than 40%. Second, the area will receive an average rather than a high level of management. Finally, production will be estimated during vegetative