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Overlying the Wadge is about 560 feet of sandstones, shales, and coal, including the Lennox Coal Seam, which has been eroded away in places. Peabody will mine the Lennox where economical as it occurs in overburden above the Wadge mining areas. Overlying this lower unit of the Williams Fork Formation is the 130 feet thick Twenty Mile Sandstone. The upper most unit of the Williams Fork Formation consists of interbedded sandstones, shales, and thin coals. The applicant has submitted detailed analysis of the geochemical characteristics of the over and interburden found in the Seneca II-W permit area. The parameters which were sampled for were agreed upon by the Division, OSM and Peabody Coal Company. during meetings held in 1980 and 1981. Parameters sampled are listed in the permit application Volume 2, Tab 6, Pages 6-9 and 6-10. The permit application (Volume 2, Tab 6, Page 6-11) states that these parameters were used to "...document the physical and chemical properties of the overburden and underburden, to compare these properties to ground water quality, and to determine potential reclamation success." The data obtained from the geochemical analysis was compared to criteria derived from state and Federal agencies (USDA, BLM, Wyoming DEQ, and others). The criteria used for comparison and relative degrees of suitability are listed in Yolume 2, Tab 6, Table 6-3, Page 6-19 of the permit application. The mixing of materials containing these elements during reclamation should dilute any adverse effects which would inhibit revegetation or degrade ground water. In four percent or less of the samples analyzed, pH acid/base potential, boron, manganese, cadmium and zinc exceeded suspect levels. Nitrate-nitrogen levels were excessive in fourteen percent of the overburden core samples taken at the proposed Seneca II-W mine. The locations of the holes which exhibited elevated levels were distantfrom one another. Furthermore, the stratigraphic location of the elevated nitrate-nitrogen samples are not correlative. Due to the vertical and horizontal distances between locations containing elevated nitrate-nitrogen levels, percolating ground water will not be adversely effected. The dilutional effects of a predicted spoils aquifer should buffer the concentration of nitrate as nitrogen by the time the aquifer discharges to the surface system. -15-