1990-04-27_REPORT - C1980005 (3)

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Four types of Wolf Creek spoil were identified during the 1989 sampling program. A ' yellowish brown, neutral (pH = 7.0) spoil was identified at sampling locations WC-124 through WC-127, WC-130, and WC-131 where a topdressing of subsoil had been replaced by scraper. This spoil has suitable salinity (EC = 1 .4 mmhos/cm) and manganese (3.7 ppm) concentration and typically has a negligible level of carbonates (ABP = 1.3 TCaCO3/1000T spoil). This scraper handled subsoil has characteristics similar to the fractured, highly weathered, fine grained sandstone found in the upper overburden section. ' A grayish brown and yellowish brown, mildly alkaline (pH = 7.5) spoil was identified at sampling locations WC-103 through WC-106, WC-108 through WC-111, WC-114 through WC-117, and WC-119 where a topdressing of subsoil had been replaced by dragline and dozer. This spoil has suitable salinity (EC = 2.7 mmhos/cm) and manganese (5.5 ppm) levels and typically contains a moderate excess of carbonates (ABP = 36.2 TCaCO3/1000T spoil). This ' dragline and dozer handled subsoil has characteristics similar to the oxidized, fine grained sandstone in the 10 to 40 foot portion of the overburden section. Brown, grayish brown, brownish gray, and gray, neutral (pH = 7.3) spoil was identified at ' sampling locations WC-103, WC-104, WC-106 through WC-109, WC-111 through WC-113, WC-115, WC-118, WC-120 through WC-123, and WC-128 where the spoil was casted and graded by ' standard dragline and dozer techniques. This mixed spoil has suitable salinity (EC = 3.3 mmhos/cm) and manganese (13.5 ppm) levels and typically contains a slight to moderate excess of carbonates (ABP = 18.1 TCaCO3/1000T spoil). Spoil mixing by standard dragline ' and dozer techniques at these deep overburden sites has been sufficient to blend and dilute or bury unsuitable acidic overburden strata. A brownish gray and dark gray, strongly acid (pH = 5.1) spoil was identified at site ' WC-129 and the lower sample increment of sites WC-125 through WC-128 and WC-130. This spoil has a calcium carbonate (CaCO3) deficiency of 3.8 tons per 1000 tons of spoil . Spoil salinity (EC = 3.9 mmhos/cm) and manganese (39.3 ppm) values are moderate and within acceptable spoil suitability limits (see Seneca II Mine PAP, Tab 6, Table 6-3). Unsuitable pH levels were identified at sites WC-127 and WC-129 while unsuitable ABP ' values were recorded for sites WC-126 and WC-128. Spoil mixing by standard dragline and dozer techniques at these shallow overburden sites has not been sufficient to blend and ' dilute or bury unsuitable acidic overburden strata. The Wolf Creek spoil generally contained about 40 to 45 percent (by volume) sort :hale and moderately hard fine-grained sandstone rock fragments. These rock fragments are PEABODY COAL COMPANY 4 Western Dlvlslon