Metal-mining associated wastes in the Lefthand Creek watershed in Boulder County, Colorado have been implicated as a major source of stream water contamination due to acid generation and toxic metal solubility. This watershed hosts hundreds of now inactive mine openings and dozens of sites of former ore milling. No complete analysis of mine sites or their environmental impacts exists to date. This report documents research and analysis of the sources, transport, and fate of aluminum, copper, iron, lead, manganese, uranium, and zinc in the Lefthand Creek watershed.
