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iRo~v1: HOM AKE • • I O `DECEIVED ROY R. CELLAN MAR 2 p 2000 CORPORATE MANAGER ~ ~j~ A`e ~~ ~~ ~. •~ o(Vinerab 8 Geology RECLAMATION p ~ v 6 March, 2000 ~~~~:~~g., `2/®P~I'' ~y% ~~ State of Colorado ~; ~ A ~0,. Division of Minerals and Geology eP°r Durango Field Office ~O~6h 701 Camino Del Rio, Room 125 Durango, CO 61301 ENVIRONMENTAL, HEALTH. SAFETY AND GOVERNMENT AFFAIRS Received ~uR i ~ zoou Din of Fats 3 HfCe Geolpgj, Attn: Mr. Steve S. Shuey, Reclamat' Doc. l/a~C RE: Bulldog Mine Reclamation Proiect ~ February, 2000 Monthly Monitoring Report ~_ Dear Mr. Shuey: Pursuant to the Technical Revisions to the Reclamation Permit for the Bulldog Reclamation Project, this is the twenty-seventh monthly report pertaining to 11 installation and operation of an infiltration trench to accommodate seepage from the 9360 adit, and 2) closing the valve at the 9360 adit plug. The Division of Minerals and Geology IDMGI, in a letter dated March 6, 1999, issued a conditional approval for Homestake Mining Company (HMC) to close the valve at the 9360 adit plug. Subsequent to DMG's approval, HMC closed the valve to the adit plug on April 1, 1999. Since closure of the adit plug valve, no flow was directed into the infiltration trench. Monitoring of the hydraulic conditions behind the adit plug indicated that as of August 25, 1999, conditions had stabilized (ie pressure measurements stabilizedl. As a result, DMG approved initiation of the planned tracer test (Ref: Letter from WMCI to Mr. Steve Shuey, dated August 27, 19991. The tracer test subsequently began on September 9, 1999. With the initiation of the tracer test, HMC is committed to the monitoring summarized in Table 1 in accordance with the approved Technical Revisions. The revised monitoring program was initiated in September 1999. A summary of the monthly monitoring data is presented in Table 2. Based on the required visual inspection around the adit plug, the plug is impounding water behind it with no signs of seepage and/or development of seeps around the portal area. No flow was observed in DT-1 or DT 2 during the monthly sampling activities. Windy Gulch was either frozen or dry in all observed reaches, including the 9700 Weir and the WGL Weir. As a result, no water or charcoal samples were collected for tracer analysis during this period. As part of this monthly report and in accordance with the 9360 Level Adit Closure Monitoring Plan, dated April 1998, Windy Gulch monitoring was continued during this period. Significant freezing of Windy Gulch was observed in early November 1999. Consequently, the instrumentation recording flow measurements at the WGL Weir was removed to prevent damage, and continuous flow monitoring, initiated in April 1999, was discontinued for the winter. As such, a water quality sample and record of flow rate were not taken at the WGL Weir during this period. Water levels in the Creede Formation Well, locatedupslope of the 9360 Adit, have been recorded continuously since its installation, and data for the last year are presented graphically in Figure 1. HOMESTAKE MINING COMPANY P O RO% 90 • GRANTS, NM 81020-OOi I