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Bulldog Mine Tailings Ponds Evaluation 1.0 INTRODUCTION • This report presents the results of an evaluation of the Upper and Lower Tailings Ponds at the Bulldog Mine site near Creede, Colorado. This evaluation was conducted by Shepherd Miller, Inc. at the request of Homestake Mining Company (Homestake) for reclamation planning for the tailings ponds. The purpose of the evaluation was to assess the source conditions of the tailings relative to the potential impact to underlying ground water. Homestake operated the mill at the Bulldog Mine from the late 1960s until 1985 to recover silver from ore produced from underground mining operations. Tailings from the mill were discharged into the Upper and Lower Tailings Ponds. The operational history of these tailings ponds is presented in Section 2 of this report. One of the reasons for this evaluation pertains to the corrective action measures due to seepage from the Lower Tailings Pond that occurred during milling operations in the early to mid-1980s. When seepage loss was identified, a corrective action program was implemented to intercept and return the collected seepage. Corrective action measures included the construction of a slurry • cutoff wall and a ground water collection and pumpback system downstream from the Lower Tailings Pond. With the cessation of milling operations, the seeps and shallow ground water associated with the seepage interception system dried up, and the system was abandoned. 1.1 Background for 1996 Activities During a meeting the DMG in January 1996, Homestake agreed to review azchived files for information on the effectiveness of corrective action measures implemented at the Lower Tailings Pond site in eazly to mid-1980's to intercept tailings seepage. The review also included the results of available ground water monitoring data down-gradient from the Lower Tailings Pond. In April 1996, Homestake provided a summary report prepared by P.M. De Dycker & Associates, Inc. to [he DMG summazizing the corrective action measures and ground water monitoring results from the Lower Tailings Pond site (P.M. De Dycker & Associates, 1996). In • May 1996, the DMG concluded that the information provided in the P.M. De Dycker & Horttetrake ilfining Company Shepherd Miller, lnc. y.v--trnn,dmoF.ryr 1 Apri! /l. /997