Laserfiche WebLink
Potential off-site surface and groundwater impacts from mining in the area proposed for bond release <br />with this application are discussed below. Amore detailed discussion of potential mine-wide impacts is <br />~.~ <br /> <br />found in Section 4.8.3 (Probable Hydrologic Consequences) of the Trapper permit document (C-81- <br />010). Historical hydrology, monitoring data can be found in Appendix W (annual report documents) of <br />permit document C-81-010. <br />4.1 Permanent Hvdroloaic Features <br />No livestock water tanks or diversion ditches are proposed to be left permanently in the post-mining <br />landscape with this bond release application. <br />4.2 Surface Water Impacts <br />Within the area of this proposed bond release application, surface water runs off through 10 different <br />watersheds, including discharge through seven active NPDES ouffalls. All runoff is tributary to the <br />Yampa River, except for a small area on the backside of the reclaimed hill slope that flows into the <br />Williams Fork River drainage through Elk Gulch. The seven active discharge points are all covered <br />under NPDES Permit CO-0032115 and include the following outtalls: 001 (Johnson Gulch), 002 (No <br />Name Gulch), 009 (Middle Pyeatt Gulch), 011 (East Pyeatt Gulch), 013 (West Pyeatt Gulch), 014 (Far <br />East Buzzard Gulch) and 015 (Grouse Gulch). All of the disturbed lands in former NPDES ouffalls 003 <br />(East Buzzard Gulch), 006 (West Buzzard Gulch) and 010 (Elk Gulch) have been reclaimed and at <br />least Phase II bond-released. These three sediment control systems are included in this SL-7 bond <br />release application. <br />Surface water consistently discharges only through Johnson, No Name and East Pyeatt Gulches. The <br />remaining seven watersheds seldom if ever record surface water runoff. Throughout the sampling <br />history of these discharge points, no violations of Permit No. CO-0032115 standards have occurred. <br />Spoil springs that were present in the bottoms of drainages at the down-gradient contact of spoils and <br />non-mined areas in Johnson and No Name Gulches were released from Phase III bond liability with the <br />approval of SL-4. A spoil spring (99-1) developed for a short time in East Pyeatt drainage in the bank <br />of a dozer basin located on currently disturbed ground. No spoil springs are present on any of the <br />reclaimed lands proposed for bond release in this application. <br />4 <br />