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• Unsuitable clay strata comprise 18.6 to 52.4 portent of the overburden section at Sites 43-C, 99-C, 508-C, 1128-E, and 1130-E. The excessive clay values are associated with the shaley overburden strata that overlies the Lennox coal seam. Because these elevated clay levels are found in The upper half of the overburden section, Peabody anticipates the material will be buried by typical overburden handling operations and will occupy the central portion of the backfilled spoil profile. Cast blasting will be used to fracture the consolidated overburden. During cast blasting, part of the lower half of the overburden consisting predominantly of hard sandstone, will likely be projected into the adjacent pit. The shaley overburden will then be uncovered by the dragline and placed over the sandstone rubble. Lastly, the shaley spoil will be covered 6y the remaining fractured sandstone. Typical overburtlen handling will be used to blend, dilute, or bury strata with unsuitable nitrate levels. Blending and dilution will be effective at Sites 1127-E, 1129-E, and 1130-E where unsuitable nitrate strata comprise 13.8, 4.2, end 7.2 percent, respectively, of the overburden section. Excessive nitrate levels were identified in 45 percent of the overburden at Site 1128-E, mostly in the upper 65 feet. Typical overburden handling wilt • effectively bury this strata in the central portion of the spoil profile. Peabody also believes that sampling error (improper sample handling or sample contamination from drilling additives) may have contributed to the excessive nitrate levels identified in the 1981 overburden cores. Nitrate tontamination problems were also identified for three overburden cores that were collected in August end September 1981 from the Seneca II Mine (Peabody Coal Company, 1986). Typical overburtlen handling will be used to blend, dilute, or bury strata with unsuitable manganese levels. Blending or dilution will be effective at Site 1128-E where unsuitable manganese strata comprised 5.1 pe rc enC of the overburden section. Excessive manganese levels were identified in 30 percent of the overburden at Site 1127•E, mostly in the upper 13 fee[. Typical handling will effectively bury this strata in the central portion of the spoil profile. Like most trace elements, .manganese is fairly insoluble over a pH of 6.0. Manganese stability is expected in the spoil pile because of the neutral reaction and excess carbonates. Reoraded Sooil Monitoring Program. In order to provide a feedback system to check the • reliability of the overburden sampling end analysis program, a regraded spoil monitoring program will be initiated. A sampling plan will be used near [he Lennox Coal outcrop as 3 Revised 04/24/91