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<br />Dudash <br />Page 3 <br />March 14, 2003 <br />2. The Division is concerned that the floor elevation of the B-Seam mine entries coincides <br />closely with the water table elevation of the Lower Perched Water Zone -Mesa Verde <br />Formation. The piezometric surface shown on Map 11 is between approximately 6,600 and 6700 <br />feet in the location of the B-Seam portal entries. The proposed floor elevation of the B-Seam <br />mine entry is 6,640 feet. Please provide a proposed plan for handling/discharging of potentially <br />significant ground water discharges that maybe encountered. <br />3. BRL indicates on page 2.04-37 of the PAP that if mine-water discharge were to occur, the <br />effluent would need to be piped over or around the Deer Trail Ditch and the Fire Mountain Canal <br />to avoid any potential quality degradation. On page 2.05-74 of the PAP, BRL indicates that a <br />pipeline will be constructed to convey mine water to D Gulch. These discussions appear to be <br />for mine-water discharges from the D-Seam portal entries. Please update these referenced <br />sections of the PAP to also include a plan for handling potentially large mine-water discharge <br />flows from the B-Seam portals. Please also update the PAP to indicate that CDPS Point 006 in <br />D Gulch will be the permitted dischazge for mine-water flows to the North Fork of the Gunnison <br />River. <br />4. The Probable Hydrologic Consequences (PHC) section of the PAP contains a statement <br />on page 2.05-69 indicating, "The quality of water that may discharge by gravity from the mine is <br />unknown". On pages 2.05 - 72 through 74 of the PHC, BRL provides a table with the estimated <br />affect that the mine discharge will have on the quality of water in the North Fork of the Gunnison <br />River with regard to TDS. BRL further indicates, "The mine discharge should not effect, total <br />iron, pH, and manganese in the receiving stream". This PHC discussion should be consolidated <br />and updated to include all available information on mine discharge water quality. If data are <br />available for mine discharge water quality from the D-Seam portals, this information should be <br />included in the PHC discussion. If available, please update the table on page 2.05-73 to include <br />mine discharge water quality data for iron, manganese, and pH. <br />The Division is concemed that mine discharge to the North Fork of the Gunnison River may <br />adversely affect the quality of the receiving stream. If mine discharge water quality is available <br />for iron, manganese, and pH, then the PHC should be expanded to include a discussion of <br />potential impacts to the receiving stream with respect to these constituents and compliance with <br />in-stream standards. <br />