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L J <br />BOWIE RESOURCES LIMITED <br />SMALL AREA EXEMPTIONS <br />SAE -9 <br />Small area exemption 9 is located on the west end of the unit train loadout. Run-off from this area <br />is contained by a berm or ditch and filtered through a silt fence. An analysis of the vegetative <br />cover associated with the small area exemption was performed on May 26, 2004 by Cedar Creek <br />Associates, Steven R. Viert. Following are the results of the vegetation analysis: <br />Percent <br />Total Plant Cover........................................................... 54.4 <br />RockCover................................................................. 7.6 <br />Litter Cover................................................................ 29.6 <br />BareGround.............................................................. 8.4 <br />Total.................................................................... 100.0 <br />Plant Cover Consists of: <br />Grasses (23.8%) <br />Intermediate wheatgrass..................................................... 13.8 <br />Thickspike wheatgrass........................................................ 7.4 <br />Pubescent wheatgrass ........................................................ 2.6 <br />Forbs (30.6%) <br />Yellow sweetclover.......................................................... 23.6 <br />Tumble mustard............................................................. 0.2 <br />Alfalfa..................................................................... 6.8 <br />Average plant height ................................................... 22.7 inches <br />Average grass steam density ................................. 0.88 stems per square inch <br />The small area exemption was examined using SEDCAD 4 to show that a grass filter will <br />effectively treat runoff from the SAE so the peak settleable solids concentration in the runoff is <br />less than 0.5 ml/I. <br />Notes for SEDCAD Calculation: <br />1. 10 -year 24-hour storm event 1.8 inches. <br />2. Particle size analysis Loam, clay loam. <br />3. Roughness; coefficient, 0.012. <br />4. Hydraulic spacing of 0.88 was used based on vegetation study. <br />5. An low infiltration rate of 0.05 iph was used because of the clay loam soils. <br />6. A stiffness factor of 2 was used for wheatgrass. <br />7. A curve number of 87 was used to model a disturbed area above a grass filter even <br />though the entire area is basically a grass filter. <br />8. A "K" factor of 0.32 represents clay loam soil. <br />9. Results indicate a grass filter 600 feet long, the length of the SAE, and 40 feet wide will <br />effectively treat the site so the peak settleable solids concentration in the runoff is less <br />than 0.5 ml/I. <br />The calculations and information prese <br />during the month of June 2004, and the <br />knowledge and belief. <br />/ James EaSt*er, P.E. <br />Registered PrWsjonal Engineer•; , <br />State of Color d-3ar 19230 e� <br />A MOv eD 't�iaWe.�s198 - <br />'V/a/0y <br />198 through 204 were prepared by me <br />his true and correct to the best of my <br />e <br />i <br />6/04 <br />