TOMMYKNOCKER HEAVEN: ATTEMPTING QUANTITATIVE HYDROGEOCHEMISTRY IN THE LEADVILLE MINING DISTRICT AND ITS HINTERLAND
Three large mine pools exist beneath OU6 and were created when the workings associated with Fryer Hill, Carbonate Hill and Downtown sub-districts filled after mining declined in the 1930s. The mine pools are connected by workings and hold a total of approximately 4 million cubic meters of water. Prior to 1953 these mine pools were drained primarily by Canterbury Tunnel to to the north of Evans Gulch and intermittently through shafts in lower California Gulch to the south of Evans Gulch. Since 1953 the mine pools have been drained primarily through the LMDT. In recent years there has been a growing concern that collapses within the LMDT have significantly reduced its efficiency as a drain tunnel. Source-control techniques (including plugging and /or backfilling tunnels and shafts, grouting water inflows to tunnels and shafts, and segregation of clean inflows) are being considered to: isolate contaminated mine pool waters, divert clean inflows around mine workings, reduce the volume of discharge from tunnel portals and reduce the risk of large unregulated discharges into surface streams.
Wells have been constructed along the LMDT and in the bedrock nearby. Multiple tracers, including stable isotopes, tritium, cation and anions have been used and quantitative tracing with fluorescent dyes in the mine workings and in the LMDT. Additional evaluation will be done using end member mixing analysis and cluster analysis.