Last September when heavy rains flooded old mining tunnels and sent heavy metals into the local watershed, many government agencies assessed the damage, trying to determine how toxic the run off was, where it was coming from, and how to prevent it from happening again.
Test results showed high concentrations of lead and arsenic in water, soil and waste rack samples at the Lead Queen Mine which is on land owned by the US Forest Service (USFS). At the time, the Sierra Vista Ranger Station told the PRT that they had no funds for emergency clean up, but that they were going to assess the situation and request the funds.
Earlier this month the Forest Service issued a Time Critical Removal Action Approval Memorandum. This is a lengthy and detailed history of the mine, the September overflow, the heavy metals present in the area, the kind of harm those metals can do to humans and wildlife, and what needs to be done to correct the situation.
To strengthen its case in asking for these funds, the USFS stresses the biodiversity of the Patagonia Mountains and notes that it is popular with birders and home to a variety of endangered species.
The proposed action for the Lead Queen site “is to remove soil, ochre sediment, and waste rock containing excessive amounts of lead, zinc, arsenic, copper, cadmium, mercury, iron, and aluminum and other heavy metal and dispose onsite at a consolidation cell.” In addition, the proposed action includes closure of other mine features such as adits and shafts. It also proposes to reconstruct parts of the forest service road that accesses the site.
The work on this project will be done by an environmental firm and is estimated to cost $175,000. The document, issued by Regional Forester Calvin Joyner on February 10, states that work on the Lead Queen Mine is scheduled to begin in April. They plan to wind up before this year’s monsoon season.
For further information regarding the USFS Removal Action Memorandum, contact Eli Curiel, P.E., On-Scene Coordinator, at 520-388-8413; or Maria McGaha, P.E., Regional Environmental Engineer, at 505-842-3827.