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12/20/79 Memo, n. 2, #8 r~ "8. Two different sets of assumptions were used to size sediment storage. For all ponds except pond A, three different values were used as the CP (VM) factor in the Universal Soil Loss Equation; one for base land, one for early reclamation, and one for natural or fully reclaimed land. For pond A, only two values were used for the CP factor. The applicant should clarify how these values are obtained and used. Which set of calculation are more conservative? For how many years is an area in each state of reclamation?" The VM factor was used by LRCWE in the USLE sediment calculations in lieu of the C and P factors. C and P factors are related to crop and agricultural practices, while VM is related to vegetation and mechanical practices, which is more appropriate for reclamation of surface mines. The VM factors which were used by LRCWE came from a reference provided us by EFC (See p. 11 of Exhibit 13). The National Cooperative Highway Research Program, in 1976 reported VM factors which range from 1.30 for bare soil compacted by bulldozer to 0.01 for permanently seeded areas after 12 months. LRCWE assigned a value of 0.05 for undisturbed areas and areas which had been reclaimed for longer than 12 months. From the attached refer- ence, which reports the 1976 VM factors as CS factors, this corresponds to seeded areas from 2 to 12 months, and is conservative beyond that. A value of 0.40 was used for areas in the first year of reclamation. This corresponds to seedings 0 to 60 days old, and is also conservative beyond 60 days. Any areas which were still bare were assigned 1.0. This would correspond to a freshly disked bare soil, which is conservative for any reclamation practice which tends to decrease sediment yield, such as contour plowing. At the Eckman Park site values of 1.0 and 0.05 only were used, since in the worst case year of 1980, which was used in the hydrologic analysis, there was no first year reclamation. This will