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V <br />ti <br />Stoner Engineering & 5urveying <br />Engineering, Testing & Surveying <br />Date: September 30, 2013 <br />To: Tom Bird <br />Manager, Coal Services <br />GCC Energy, LLC <br />6473 County Road 120 <br />Hesperus, CO 81326 <br />(970) 385 -4528 <br />From: Ryan Griglak, P.E. <br />Project Manager <br />Stoner Engineering & Surveying <br />Re: Annual King Coal II - Water Quality Improvements Inspection <br />On September 24, 2013, Ryan Griglak, P.E. visited the GCC Energy, LLC King Coal II site to <br />conduct the annual inspection of the water quality pond installed to prevent contaminated <br />storm water runoff from escaping the site in events smaller than the 100 -year storm event. <br />There have been several localized storm events within the past month which have resulted in <br />rainfall accumulations in excess of one inch per hour. These types of storm events when <br />combined with the increased frequency in which they have recently occurred generally result in <br />significant damage to water quality features. <br />The King Coal II storage pond which collects all the contaminated runoff from the site via <br />surface runoff or culvert was found to be in good condition. Offsite runoff (clean) is routed <br />along the outside of the site via channels. The inside area of the pond area normally covered <br />with grasses was not readily visible due to the water present in the pond due to the recent <br />localized storm events (see Pic. 1), though the overall vegetation looks good. <br />The dual staged elevation outlet control structure (See Pic. 2) appears to be in good condition <br />as well as the downstream riprap and grass lined channel. The only portion of the water quality <br />features found in need of repair is the inlet channel going into the detention pond. The channel <br />experienced larger than normal flows due to the recent storm events and was subject to <br />significant erosion (see Pic. 3 & 4). These flows resulted in the exposure of the underlying <br />geotechnical fabric as well as the migration of the riprap used to line the channel. The channel <br />section should be repaired to its original condition to prevent further damage as a result of <br />additional runoff or storm events. <br />P.O. Box 1163 28 South Washington Street Cortez, Colorado 81321 <br />970.565.7483 stonerengineer @frontier.net 970.565.7704 <br />