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Table of Contents Abstract Methods Results Narrative & Discussion Table 1 -Colorado Test Conditions Abstract Page 2 Table 2 -Methods and Equipment Page 5 Page 2 References Page 5 Page 3 Discharge Monitoring Report Form(s) Pg. 6-7 Page 4 Reference Toxicity Data Chart(s) Pg. 8 Page 5 Supplement Forms' Pg. 9 SGS North America, Inc. conducted a two species chronic bioassay on Western Fuels New Horizon Mine effluent discharge. This discharge has been designated as ouffa11007. The purpose of this bioassay was to determine if the facility complies with the chronic WET portion of the Colorado State Permit System Authorization to Discharge. The test organisms utilized were the fathead minnow (Pimephales promelas) and cladoceran (Ceriodaphnia dubia). Test results indicate that the effluent was not chronically toxic to fathead minnow or to Ceriodaphnfa dubia survival. Therefore, outfa11007 is in compliance with the chronic WET portion of its Colorado State Discharge Permit for thesecond quarter of 2007 Methods A two specie chronic bioassay was conducted with effluent from Western Fuels New Horizon Mine, Outfa11007. An effluent composite sample was collected on April 30, 2007, stored on ice, and delivered to SGS North America Inc. on May 1, 2007. The effluent sample was received at a temperature of 6.4° C and assigned sample tracking number TA7-EO-P004-001. The bioassay was initiated approximately 24 hours after sample collection. Because of the remote location of the facility, only one sampling event was required for this examination. Sufficient sample volume was collected on Day 1 for the entire test. Testing was conducted in accordance with the most recent protocols specified by the Water Quality Control Division of the Colorado Department of Health (1998) outlined in Table 1. Basic characteristics of the effluent and dilutions were measured by the methods and equipment outlined in Table 2. The tests exposed the cladocerans, Ceriodaphnia dubia, and fathead minnows, Pimephales promelas, to five concentrations of effluent, 100%, 75%, 50%, 25%, and 12.5%, prepared using reconstituted laboratory water. Control replicates were exposed to 100% laboratory water. Statistically, fathead minnow survival and growth data were analyzed for significant differences using Dunnett's test and Steel's Many-One Rank test, respectively. Ceriodaphnia dubia survival and reproduction data were analyzed for significant differences using Fisher's Exact Test and Steel's Many- One Rank Test, respectively. IG252 values were determined using the Bootstrap Linear Interpolation method. ' Supplemental forms include statistical analysis and chain-of-custody forms 2 Inhibition Concentration at 25% reduction