2010-03-22_GENERAL DOCUMENTS - M1977285

Home Browse Search

USDA i" Dolores Public Lands Office USDA Forest Service 29211 Highway 184 USDI Bureau of Land Management San Juan National Forest Dolores, CO 81323 San .)uar -Center Dolores Ranger District Ph (970) 882-7296 Fax (970) 882-6841 Dolores Field Office hftp://www.fs.fed.us/r2/sanjuan hftp://www.co.bim.gov PMEM In reply refer to: MAR 2 5 2010 March 19, 2010 3809 (COS04) Div"n of Htclarnatio", Mining and Safety CERTIFIED MAIL - Return Receipt Requested: 7009 0820 0000 6804 1791 i?7 / Christy Woodward - DUr ! ? 2010 Denison Mines DiVision of Fuld 170' Street, DenOver CO 80265te 950 Mining aRacSla t/oh ty SUBJECT ADDITIONAL DATA REQUIREMENTS FOR SUNDAY MINES GROUP EA Dear Ms. Woodward, Thank you for meeting with us at the DPLO on February 23, 2010 to discuss how we will address the items identified in the Colorado BLM State Director's September 17, 2009 remand of the January 20, 2009 EA and Decision for the Topaz and Sunday group mine plan. The main point of contention in the State Director's remand is that an "adequate baseline water and soil data is required for the waste pile area prior to allowing wastepile expansions, and for groundwater impacts at the mines. After meeting with Denison and from discussions between personnel at the DPLO and the San Juan Public Lands Center, we have concluded that the Environmental Protection Plan (CDM-06/2009) submitted to the Colorado Department of Mining Reclamation and Safety (DBMS), and its amendments (12/2009), should satisfy the State Director's remand, if supplemented with additional data-pertaining to mine pool-water and development rock pile chemistry, as described below. Mine Pool Water Hydro eog logy In order to properly characterize the mine pool water and determine whether or not mine affected waters are likely to daylight in the future, a monitoring well network needs to be emplaced in the hydro-stratigaphic zone of interest. BLM will coordinate with DRMS in the location of monitoring wells, and where possible integrate the objectives of each into a coordinated effort. The number and location of wells needs to be sufficient to measure the velocity, gradient, and flow direction of groundwater. This data should be used to generate an updated potentiometric surface map which more closely reflects the surface and subsurface geologic structures and other flow boundaries affecting the groundwater regime of interest. The wells and mine pool water should initially be sampled and characterized on a quarterly basis to establish a baseline of current conditions. Table 1 shows the target analytes and preferred testing methods. Sampling frequency and target analytes can be re-evaluated once a baseline is established and any trends are identified. Please ensure that any S V FS-6200-12a