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<br />2.05.6.3.2 SURFACE WATER, continued <br />encountered during the coal stripping operation. There srs a <br />number of reasons why this concern should not be significant: <br />1) Pnst investigations in the area such as that conducted <br />for the Raton Creek mines (approximately 3 miles to the <br />south) have shown that water inflows in the old mines have <br />not been a problem. Old records have shown that all of the <br />mines in the Engleville-Starkville area have never pumped <br />any significant amount of water, and some of these mines <br />have been quite extensive. The Rimrock Mine will mine the <br />same seams as these mines. <br />2) Actual portal and mine entry inspections of the old mines <br />in the area have revealed no xater buildup. Most of these <br />mines are in the same mining sequence in the Verme3o ' <br />Formation as the Rimrock Mine. <br />3) If n flooded working wns encountered, the mining pit <br />• would likely contain the water. The pit will always be a <br />depression that will be 5 to 15 feet below the surrounding <br />terrain nt all times. with a typical pit area of 5000 <br />sq.ft., and a minimum depth of 5 feet, the piL would hold a <br />volume of .57 ncre-feet. Although an inflow this large is <br />very unlikely, the pit would contain it. <br />4) in the extreme case where an inflow would exceed the pit <br />volume, the collection ditch system would also provide <br />additional safety factor to transport the flow to the <br />sediment pond. <br />5) The minor amounts of water encountered in old mine <br />working of the area have had a water quality which is <br />usually very similar to the groundwater of the area. This is <br />supported by comparing the Engleville Mine Drainage (EMD) <br />nnnlysis with the water quality from the USaS well ss shown <br />in Appendix 4. Acid water has never been a problem in the <br />area from underground mine discharges or old gob piles. <br />6) tf a pit inflow or sediment pond inflow occurs from old <br />workings, the water will be immediately tested for the <br />parameters on the standard groundwater annlysls list. If <br />there is a Problem such es high iron content or low pM, the <br />water will be treated prior to its discharge from the site. <br />-5- <br />