Schwartzwalder Mine – Underground Uranium Mine Bulkheads
Client: Cotter Corporation
Location: Colorado, United States

In 2007 and continuing into 2008, MES performed the design and construction of two hydrologic bulkheads at this inactive uranium mine, located directly above a public drinking water supply. MES participated with the client in regulatory meetings with two state agencies to obtain approval for the plan.

These bulkhead locations were complicated in close proximity of large stopes to the surface, which tightly constrained the possible locations for the plugs. Work to evaluate the locations included longhole probe drilling to confirm the location of void areas, site inspection, and map reviews. As a result of the near-surface placement of the plugs dictated by the stope locations, MES designed and conducted an extensive contact and bedrock grouting program to reduce the amount of potential seepage around the seals.

Additional contracting work included equipment salvage for the owner and removing explosives and other materials from the underground workings.

Additional consulting work included reviewing the mine reclamation plan, recommending amendments, and preparing submittals to the Division of Reclamation, Mining & Safety.

MES utilized Dr. John F. Abel, P.E. and Stephen Phillips, P.E. as peer reviewers for the bulkhead and grouting program designs, respectively.