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iii iiiiiiiiiiiii iii ~ © CLIMAX MOLYBDENUM COMPANY A niwim of (~ptie Gimea McUls Cu February 23, 1996 Mr. Allen Sorenson Environmental Protection Specialist Division of Minerals 8 Geology 1313 Sherman Street, Room 215 Denver. Colorado 80203 RE: Emergency tvoritlcaiion information Henderson Mine and Mill Permit No. M-77-342 Dear Mr. Sorenson: RF~;EIVFR ~E6 26 1996 Division of iviulerals a ~z01poy Cotouoo Oaewmaes Henderson Mill 19302 County Roed •3 Parshall. Colorado 80468 Metro (3031 271-0107 O.n of State 13031 5693221 Fax (9701725-0036 The purpose of this letter is to inform you of an incident which occurred at the Henderson Mill on Wednesday, February 21, 1996, and is intended to meet the requirements of Rule #8. At approximately 7:00 a.m., the Mill experienced multiple power bumps causing a power outage to the Ute Park Pump House. At 8:00 a.ln., a tailing pond employee, following procedures, closed the valves separating the seepwater collection pool from the trench leading to the pump house, thereby stopping the source of potential increased seep water levels at the pump house. The power failure adversely affected a process water pneumatically-operated v<Ilve at the pump house. The air pressure slowly bled off which in turn, slowly opened the valve. As the valve opened, the process water discharged to the seepwater collection trench. But after several hours, the seepwater trench storage capacity was excl:eded and the process water was drained onto the pump house floor. A pond technician drove by the pump house at 11:45 a.m. and saw no evidence of water running out of the pump house. At 1:20 p.m., another tailing pond employee noticed water running under the door of the pump house. After opening the doors at 1:35 p.m., a heavy volume of water began to discharge out the doors, across the road and ultimately into the unlined lower flood bypass ditch. The lower flood bypass ditch flows into the Williams Fork Rider approximately 1 mile downstream of the pump house. This point has been designated discharge point 006 in the CDPS discharge permit (CO-0000230), when it contains process water. The valve was manually closed at approximately 1:40 p.m. and all flow was stopped by 3:33 p.m. Flow out the door of the pumphouse is estimated at 400-500 gpm between 1:20 p.m. and 2:00 p.m., 300-400 gpm between 2:00 p.m. and 3:00 p.m., and 50-100 gpm between 3:00 p.m. and 3:30 p.m. The total volume of process water relea:;ed from the valve was in the range of 35,000 to 47,000 gallons. Discharge point 006 was inspected by Mill personnel shortly after the open valet: was