2012-03-07_PERMIT FILE - C2010088 (28)

Home Browse Search

McClane Canyon Mine Expansion and Fruita Loadout Facility Biological Assessment 50 a 40 m m i� 30 U 20 0I 10 Month Figure'l Average Monthly Discharge In East Salt Creek, 1973 to 1982, Measured at USGS Gage 09163310. Vertical Lines are Minimum and Maximum Monthly Flows. Selenium (Se) occurs in East Salt Creek upstream and downstream from the McClane Canyon Mine. The trace element also occurs in groundwater, in Cameo coal, in the rock matrix, and in soils at the Mine -site. One sample of coal from the Cameo coal seam contained 0.001 mg /kg of selenium (equivalent to 1 pg /kg or 1 part per billion, 1 ppb).' Two samples of soil that would be affected contained <0.02 Trig /kg. Leachate derived by a Toxicity Characteristic Leaching Procedure (TCLP), from the projected coal mine waste Was anal I zed with a high detection limit (0.05 mg /L or 50 pg /L), and thus failed to detect any selenium. However, selenium in water when it was discharging from the Mine (prior to 2008) averaged 0.182 mg /L of selenium (equivalent to 182 pg /L).' Water recently sampled fr "om a sfanding .pool'in the existing sediment pond at the Mine was found to contain 0.022 mg /L (22 -pg /L) of selenium e In groundwater 5, ,the average (2005 — 2007) selenium concentration was 115 pg /L (ranging from 3 to 378 pg /L) for one monitoring well located above the coal seam (Monitoring Well 7 -34- 7). Dissolved selenium for groundwater in the Cameo coal seam (Monitoring Well 8 -3 -10) averaged 248 pg /L (ranging from 34 to 508 pg /L) and selenium in groundwater below the coal seam (Monitoring Well 8 -2 -8) averaged 89 Ng /L (ranging from 2 to 212 pg/L). Average selenium concentrations in East Salt Creek upstream and downstream from the Mine were reported from 2005 through 2009.8 At the upstream site (station SW-11) selenium The sample was taken on February 11, 2008, analyzed by ACZ using AB -DTPA Extraction see Table 2.1- 7_•Cameo Coal Geochemical Data in McClane Canyon Mining, LLC Permit Revision Application Number 2 submitted to M. Bouiay, Division of Reclamation, Mining and Safety, Denver, Colorado by J.E. Stover & Associates, Inc. Grand Junction, Colorado. z See Table N -7 in Appendix N. McClane Canyon Mining, LLC Permit Revision Application Number 2. 3 See Table N -9 in Appendix N, McClane Canyon Mining, LLC Permit Revision Application Number 2. a Analysis conducted by Enviro -Chem Analytical, inc., Grand Junction, CO reported to CAM Colorado, LLC on June 28, 2011. s See Table 4 -2ii Surface Water Operational Data in McClane Canyon Mining, LLC Permit Revision Application Number 2. e See 'fable 4 -2iii Surface Water Operational Data in McClane Canyon Mining, LLC Permit Revision Application Number 2.