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STATE OF COLORADO DIVISION OF MINERALS AND GEOLOGY Department of Natural Resources 1313 Sherman St., Room 215 Denver, Colorado 80203 Phone: (303) 866-3567 FAX: (303) 832-8106 .~ September 21, 2004 ~' Marcia Talvitie Four Comers Materials, Inc. FO EIoX 2707 Durango, CO 81302 ~ECE~~/~D SEP27 2004 Division of Minerals ano L,~,,,,,er COLORADO DIVISION O F MINERALS GEOLOGY RECLA MATION•MIN ING SAFETY•SCIENCE Bill Owens Governor Russell George Executive Director Ronald W. Cattany Division Director Natural Resource Trustee ~% Re: Cugnini Gravel Pit, Permit M-1986-061, Amendment AM-O1, Preliminary Adequacy Review Letter. Dear Ms. Talvitie, I have reviewed the amendment application named above, and though most of the information is well presented and adequate, I have a few questions that need to be addressed. I have listed them in the paragraphs below in the order in which they were arranged in the application. Parts of the application not included in this letter are considered to be adequate at this time. Please arrange and label the responses to these items to facilitate their review and inclusion in the application. Exhibit C -Pre-mining and Minin¢ Plan Mans (Rule 6.4.3) The surface elevation indicated at thelocation of the gas well in the south mining azea seems to vary slightly: it is shown at 6625 ft on the pre-mining map, and shown at 6620 feet on the mining map. Please explain whether mining will or will not, in fact, impact this location. Exhibit D - Minine Plan (Rule 6.4.4) Please describe whether mining will continue in the area of current mining in the south mining azea at the same time mining activity commences in the north mining area. If mining is first to occur only in the north mining area, please describe how and when existing disturbance in the south mining azea will be reclaimed or stabiiized. If groundwater is exposed, please commit to replacing at least atwo-foot depth of material (to include topsoil and/or growth medium, as approved) in order to provide an adequate rooting depth for the reclamation vegetation. The reclamation will be tamed out following mining in each area, though reclamation will not be finished in an azea before moving on to the next azea. The possible life span of each of the mining aeeas shows that there will be disturbance and/or reclamation of varying degrees at most times across the site. This timing and sequencing will be useful for determining an appropriate amount disturbance and for calculating the bond amount. (No response to this item is necessary.) Fill of the natural gulches with the expected large volume of overburden or natural reject material will occur during the course of mining and processing. During this time, please note that mnoff and sediment control will be of high importance, not just on mining and staging areas, but in the fill areas also. (No response to this item is necessary.) Topsoil will be important to the successful reclamation of the site. It is expected that topsoil resources are scazce and variable across the site. Prior to the placement of fill material in the gullies, it is suggested that the usable topsoil be salvaged for use in reclamation. Since this will also be where sediment is trapped during mining, it may be valuable to periodically "hazvest" some sediment for use as a growth medium. Please comment on these items. Office of Office of (Tlnradn