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<br />'~. <br />1 <br />1 <br />~' <br /> <br /> <br />iE <br />i~ <br />I' <br />1i <br />I' <br />I1 <br />1 <br />1 <br />ii <br />i~ <br />March 2, 1994 -3- 933-2714 <br />Thought mines. There are no duect underground connections between the Bulldog and <br />Commodore workings. Generally there is about 2,500 ft separation between the two mines. <br />Hvdrogeologic Framework <br />Based on surface topography, the general dvection of groundwater flow in the azea of the <br />Bulldog Mine is south towards the Rio Grande River. The northwest-southeast trending <br />faults in the azea are expected to provide preferential paths for groundwater flow. Thus, <br />groundwater flow in the azea of the Bulldog Mine should preferentially flow southeast along <br />Windy Gulch which is aligned with a major fault zone. Discharge of groundwater flowing <br />along the trend of fault in Windy Gulch would be to Willow Creek above Creede. It is <br />possible that shallow groundwater in the Bulldog Mine azea is contained in alluvial <br />sediments in Windy Gulch and dischazges via subsurface flow to Willow Creek above <br />Creede. However, Windy Gulch is dry except for storm runoff indicating that there is not <br />sufficient groundwater discharge in the gulch to maintain stream baseflow. <br />The water level in the Bulldog Mine was measured last in November 1992 at 9176 ft. <br />During mine development significant groundwater was not encountered in the mine above <br />approximately elevation 9200 feet and pumping was conducted from the 9000 foot level of <br />the mine. The 9360 Portal of the Bulldog Mine does not dischazge groundwater. Windy <br />Gulch is an ephemeral stream indicating that the water table neaz the gulch is below the <br />surface elevation. Groundwater in the Bulldog Mine should not recover to an elevation that <br />would allow discharge out of the portal. <br />Discharge from the Nelson Tunnel is derived from the extensive workings of the <br />Commodore and other interconnected mines located to the northwest. The source azea for <br />this discharge is topographically and hydraulically upgradient from the Bulldog Mine. <br />Therefore, groundwater will not flow from the Bulldog Mine to the Nelson Tunnel. <br />Historic flows from the Nelson Tunnel are not documented. Therefore, it is difficult to <br />determine what, if any, effect dewatering in the Bulldog had on flows from the Nelson <br />Tunnel. However, assuming that there was some effect, it would have resulted from the <br />Bulldog workings intercepting upgradient groundwater that was previously flowing into the <br />Nelson Tunnel. Groundwater will not flow from the Bulldog Mine to the Nelson Tunnel <br />given the geological and hydrogeological setting of the area. <br />Water Ouali[y <br />Water samples were taken in December 1993 at five locations shown in Attachment 1 <br />including Willow Creek above the Nelson Tunnel (WCANT), Willow Creek below the <br />Nelson Tunnel (WCBNT), Willow Creek above Windy Gulch (WCAWG), Willow Creek <br />below Windy Gulch (WCBWG) and Willow Creek below Creede (WCBC). These samples <br />were analyzed for cadmium (total and dissolved), copper (total and dissolved), iron (total <br /> <br />