2016-04-14_HYDROLOGY - C1981035 (5)

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,5toner L,ngineering F 1urveying Engineering, Testing & Surveying Date: April 8, 2416 To: Tom Bird Manager, Coal Services GCC Energy, LLC 6473 County Road 120 Hesperus, CO 81326 3 (970) 385-4528 ` ..... From: Ryan Griglak, P.E. p Project Manager -� Stoner Engineering & Surveying Re: King Coal I — Quarterly Water Quality Improvements Inspection On March 31, 2016, Ryan Griglak, P.E. visited the GCC Energy, LLC King I Mine site to conduct the quarterly inspection of the water quality features installed to prevent contaminated storm water runoff from escaping the site in events smaller than the 100 -year storm event. There were approximately 2 -inches of water in the west pond and 8 -inches of water in the east pond (see Pic. 1) at the time of the inspection. The ponds are both in generally good condition. The required storage volume is adequate at this time based upon the sedimentation gages installed in the ponds (see Pic. 2). The ponds should continue to be monitored after storm events to ensure that excess sediment does not reduce the required storage capacity available for storm water runoff. The drainage ditches and pipes were generally good condition. There were signs of recent maintenance work done on the sediment traps as well as the onsite ditches (see Pics 3 & 4). All pipes, ditches and sediment traps should be inspected and repaired as necessary, especially after storm events. The drainage for the overall site is functioning well and is generally in good shape. There were no specific items noted during the inspection which required attention. The drainage features have been constructed and are operating as stated in the drainage plan submitted to the Division of Minerals and Geology. P.O. Box 1163 28 South Washington Street Cortez, Colorado 81321 970.565.7483 stonerengineer2frontier.net 970.565.7704