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<br /> <br />• Composite Particle Size Analysis: Reclaimed Area La Plata No. 1 Mine (1995) <br />Sieve Size <br />reclaim 139.8 4.0 0.9 1.1 1.8 4.0 15.5 5.7 <br /> Pipet Size <br />Semple .0016 .008- .OOI- .002- .001- <.001 <br /> .031mm .016mm .008mm .004mm .OOZmm mn <br />reclaml 17.0 1.4 1.5 1.2 2.4 3.7 <br />CN NUMBERS <br />Table 2 of the vegetation report shows the breakdown of the vegetative cover at the <br />reclaimed area. Vegetation cover values for the undisturbed adjacent pinyon juniper <br />community were derived from the SEDCAD+ program and SCS Technical Release-55. <br />Using these cover data and the Hydrologic Soil Group of the native community as type <br />"D", based on SCS classification of the soil series Lazear, and type "B" for the <br />reclaimed area (soil series Sampson and Vosburg), the following curve numbers were <br />derived. <br />• Area % veg. cover % litter vegetation type CN <br />cover <br />Reclaimed Area 44.9 25.6 sagebrush/grass 51 <br />(fair cover) <br />Native adjacent pinyon juniper 80 <br />(fair cover) <br />SOIL ERODIBII.TI'Y FACTOR "K" <br />The soil erodibility factor "K", was determined from the USDA SCS publication, Soils <br />of Colorado: Loss Factors and Erodibility Hydrologic Groupines. The Lazear soil <br />series was used for the native adjacent pinyon juniper community and the Sampson and <br />Vosburg soil series were used for the reclaimed area. A "K" factor of 0.22 was used in <br />the SEDCAD+ modelling for the reclaimed area and 0.24 for the native area. <br />CP FACTOR <br />The CP factor in the SEDCAD+ input is the control practice factor. For the varying <br />land and vegetation types such as that at the Meadows No. 1 Mine, Table 7 (found in <br />SEDCAD+ also) is used in conjunction with the vegetation data to develop the <br />• appropriate factors. <br />_~ <br />