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West Elk Mine <br />(Portal No. 5) mine portals. Additional data for mine discharges is contained in the MCC <br />• Quarterly Hydrology Reports (1982 to 1987) and the Annual Hydrology Reports (1982 to <br />present). Data and test results indicate these mine water discharges have not adversely impacted <br />the North Fork. <br />The quality of mine water dischazges from the B Seam in the current permit azea and in the <br />South of Divide permit revision area, and from the B and E Seams in the Apache Rocks permit <br />area, are expected to meet NPDES discharge standards. Table 53 shows well water quality for <br />wells in the B Seam. With the exception of pH for wells SOM C-72-H (likely from grout <br />contamination) and SOM 127-H, quality parameters appear to be such that B Seam mine water <br />will be suitable for treatment and discharge under current NPDES/CDPS permit requirements. <br />This high pH situation, if encountered in mine water discharge, can be corrected by dilution with <br />surface runoff in the sediment pond or by chemically adjusting the pond pH prior to discharge. <br />The following text evaluates the water quality implications of dischazges from NW, NE, and Box <br />Canyon Panels sealed sumps and the fault inflows to the North Fork. Rather than analyzing the <br />individual water quality impacts, these dischazges have been aggregated to determine water <br />quality changes. Individual dischazges which were aggregated include: (1) North Fork <br />diversions and return flows; (2) Pond MB-1 and MB-2R releases; (3) direct discharges to the <br />North Fork from the fault inflows; (4) mine water discharges to Lone Pine Gulch and to <br />Sylvester Gulch out of the NW Panels sealed sump and NE Panels sealed sump, respectively; <br />and (5) minor groundwater seepage from the NW Panels sealed sump. <br />• The principal water quality implications associated with sump construction and fault inflows <br />include: <br />1. The total volume of discharges to the North Fork during 1996 was considerably larger than in <br />previous years, due to the fault water. Although constituent concentrations of the discharges <br />during 1996 were not significantly different from concentrations in past years, the total <br />constituent loads to the North Fork were higher by virtue of the increased outflow volume. <br />While the constituent loads were higher, the impact to the North Fork was insignificant, <br />primarily due to the relatively small contribution of the mine discharges to the total flow of <br />the North Fork. During succeeding years; however, total constituent loads to the North Fork <br />are expected to decrease for a variety of reasons, including: availability of underground <br />sumps; the new mine water pumping facility; and a leveling off of the fault inflows to lower, <br />steady rates. <br />2. MCC experienced multiple NPDES permit exceedances associated with fault inflows in 1996 <br />due to: (1) the heavy hydraulic load which started in Mazch 1996 and continued through the <br />yeaz, and (2) a different kind of colloid which was very difficult to treat. MCC has taken <br />many steps to minimize the probability of future exceedances such as: separating inflows <br />within the mine; lazge capacity sealed sump utilization; optimizing surface water <br />management strategies; and constructing pumping facilities in Sylvester Gulch to handle up <br />to 2,000 gpm. <br />• <br />2.05-133 Revised June 2005 PR/0; Rev. March 2006; Rev. May 2006 PRl0 <br />