Laserfiche WebLink
Chapter IV <br /> The haul roads of the mine presently experience heavy <br /> truck traffic estimated at 60,000 trips per year. A large <br /> portion of their roads are located on steep slopes with <br /> • resulting steep outslopes. This factor along with the <br /> high degree of road maintenance required results in <br /> increased sediment loading to the stream systems <br /> during snowmelt and rainfall. This loading is mainly in <br /> the Dutch Creek drainage. <br /> The impacts of this sediment loading are partially <br /> mitigated by the fact that high rates of erosion off haul <br /> roads only occur during the high flow seasons of the <br /> surface water system where background levels of <br /> sediment loading are already elevated by the erosion fo <br /> the naturally occurring Mancos Shale slopes. Due to <br /> this coincidence of high flow and high suspended solids <br /> generation both off the natural areas and haul roads, no <br /> significant impact to the hydrologic system is expected. <br /> All other disturbed areas of the mine have runoff water <br /> routed through sediment ponds which release water <br /> with suspended solids levels below that of the natural <br /> undisturbed streams during high flow conditions. <br /> At the time of the permit application submittal, use of the roads and benches has <br /> idiminished substantially. The operating requirements for maintenance and snow <br /> clearing have also diminished as a result. <br /> As noted, the high rates of erosion from the haul roads occur during the high flow <br /> season in late spring. The Adit/Rock Tunnel has been operational only since the fall, <br /> during the low flow period of the year. <br /> The operator suggests that the analysis of hydrologic consequences of mining done <br /> during the mid-term review, prior to use of the tunnel, remains a good point of <br /> comparison of future impacts, particularly if the presently inactive mines should be <br /> brought back into production prior to completion of the lateral extensions of the <br /> Adit/Rock Tunnel to the workings of Entries No. 3, 4 and 5. <br /> The Findings Document for the permit (1982) of the preceding permit term, Stipulation <br /> No. 12, addressed the TSS of the road system for the operation . Seven samples were <br /> taken along the roads in 1982/83 and a report made to MLRD (12/23/82). Jim Herron, <br /> MLRD reclamation specialist, analyzed the data, reviewed other information, and <br /> summarized the report in a letter of February 17, 1984. <br /> 9 <br />