Farallon reviewed leases, the operational history, reclamation plans, regulatory agency correspondence, and previous investigations to evaluate the nature and extent of hazardous substances in the environment released from mining operations. Farallon developed an engineering cost estimate to complete the mine reclamation/cleanup action defined by the former mine operators and EPA, and evaluated past costs to determine whether the costs were reasonable and necessary. Additional technical support included reviewing mine closure and permitting requirements to determine whether the proposed mine reclamation/cleanup action was required by the mine permits, and evaluating industry knowledge of acid rock drainage during the early 1970s to determine whether the potential for contamination was known to the mine operators and what was done to contain the releases of contamination. Farallon provided expert reports, rebuttal reports, and deposition. The case was settled prior to trial.