2009-09-25_PERMIT FILE - M2009076 (43)

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Reclamation Feasibility Report - Virginia Canyon IL._J INTRODUCTION This report is intended to be a guidance document for use in reclaiming mining sites in Virginia Canyon. The Colorado Division of Minerals and Geology (DMG) inspected approximately 200 mine waste piles in this study. DMG also sampled water quality in 2000 during spring snowmelt and during a summer thunderstorm. In 1999, the Colorado School of Mines (CSM) sampled stream sediments and collected water quality samples during spring snowmelt, low-flow, and following a summer thunderstorm. The water quality, mine waste and sediment data were used in conjunction with site observations to prioritize mining sites for reclamation. The ultimate goal of this work is to reduce metals loading to Clear Creek from Virginia Canyon by reclaiming the mining sites contributing the largest metal load. GENERAL SITE DESCRIPTION LOCATION Virginia Canyon is located in Clear Creek County immediately north of the town of Idaho Springs. Virginia Canyon begins approximately 2 miles north of Idaho Springs. Figure 1 is a general location map of the area. Mining began in Virginia Canyon in 1860 following the discovery of Placer Gold by George Jackson near present day Idaho Springs and the discovery of lode gold by John Gregory near present day • Central City. Gold was the principal product mined in Virginia Canyon; although the mines in the Seaton Mountain area were principally silver. Most of the ores were hauled by wagon to the Idaho Springs area for milling. Most of the larger mines operated until World War II, when a presidential order required cessation of all mines not mining "strategic metals". Investigation of the water quality of Virginia Canyon was initiated as part of an effort to improve the water quality of Clear Creek. Virginia Canyon is one of the largest sources of heavy metals to Clear Creek. The lower portion of Virginia Canyon has perennial flow most years, while the mid- elevations are intermittent, and the upper reaches are ephemeral. Most of the flow from Virginia Canyon enters Clear Creek as ground water. Heavy metals in the flow from Virginia Canyon originate from leaching of eroded mine waste in the stream channel, direct leaching of mine waste piles, and leaching of un-mined sources. BASELINE DATA COLLECTION WATER QUALITY SAMPLING The DMG sampled along Virginia Canyon during a snowmelt event and a thunderstorm event. Twenty-four stream sites and 4 draining mine adits were planned to be sampled (Figure 2). Snowmelt was sampled on May 9, 2000. Because the snow pack was lower than normal, there was very little runoff during May of 2000. A total of 14 stream sites and 3 draining mine adits were sampled. Stream flow was measured using one-inch and four-inch Baski cutthroat flumes. Field measurements included pH and electrical conductivity. Water samples were collected at each site • in 250 ml pre-acidified HDPE bottles. Total recoverable metals and dissolved metals samples were collected. The dissolved metals samples were filtered through 0.45 micron filters in the field.