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Final West Elk Mine 2005 Annual Hydrology Report 34 • tests for acute (48-hour) and chronic (96 hour) were completed in WY 2005. The test organisms included the daphnid (Daphnia magna) and the fathead minnow (Pimephales promelas). The test results indicated that the effluent from outfall 017 was acutely toxic to daphnid in the 2"a 3`a and 4a' quarters of 2005 as detailed in the quarterly Discharge Monitoring Report (DMR) submittals. MCC established that high alkalinity is the probable cause of the Daphnid mortality. 4.5 Mine Water Inflows In WY 2005, only one significant ground water inflow occurred during mining in the Panel 9 headgate, Entry 3, crosscut 39 to 42. The flows originated from the BEM Fault Zone with total flow between 140 to 160 gpm. In addition, some small inflows (<15 gpm) were encountered during mine development and longwall mining. These flows and drips occurred as roof drips, rib seeps, and minor fault zones. Total mine inflows during WY 2005 were estimated at 100.0 ac-ft from B-Seam faults and 25.0 ac-ft from F Seam inflows for a total of 125.0 ac-ft (MCC, 2006a). Mine inflows are illustrated on Map 1 and the water balance is shown on Figure 8. 4.5.1 NW Panels Sealed Sump • During WY 2005, MCC water from the NW Panel Sealed Sump was drained through a borehole to the NE Panels Sealed Sump, There was no discharge from the NW Panels Sealed Sump to the Lone Pine Pipeline (MCC, 2006a). 4.5.2 NE Panels Sealed Sump During WY 2005, 414 ac-ft of water collected in the NE Panels Sealed Sump was pumped out of the sump using the mine water pumping facility (MWPF) up the vertical well. Of this amount 7.3 ac-ft was used for surface drilling operations and 406.7 ac-ft was discharged to Sylvester Gulch. A clarifying pond and energy dissipater system is located at this discharge point. 4.5.3 Mine Water Sampling i• During WY 2005 representative mine water samples were collected and analyzed at 9 locations including the following: • lE 32 crosscut 24 headgate • Pane124 headgate roof water • Box Canyon Main E2 crosscut 63 Pane124 headgate E3 crosscut 36 • Box Canyon Main crosscut 66 E-7 Sump • Panel 19 headgate E3 crosscut 14 • Pane122 tailgate Sump September 2006 HydroCeo, Inc.