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domestic use, although Basin is unaware that the Middle Fork of the Purgatoire is being used as a source of drinking water. The 1986 Edition of Water Quality Criteria indicates that there is no specific criterion for manganese in agricultural waters, unless acidophilic crops are cultivated. Analyses for total recoverable metals have not been analyzed by Basin, since it is assumed that any discharge from the mine will no[ contain any sediment. The total iron concentrations found in the thickener may be attributed to iron oxides and hydroxides surrounding the solids and potentially to magnetite. As these will settle into the mine workings, discharges will contain metals in solution, which can be analyzed by dissolved analytical methods. 6. Calcium, magnesium, potassium, sodium, iron and manganese were analyzed in their dissolved forms. Iron, manganese, lead, molybdenum, nickel and selenium were analyzed in their total forms. No metals were analyzed in their total recoverable form. Total recoverable analyses are typically performed on surface water samples discharging to the waters of the state. The two thickener samples show some variation, but probably reflect extremes which might be pumped into the New Elk Mine. The March sample had 2.9% solids while the March sample had 55% solids. Both are sodium sulfate waters. The slightly alkaline pH was roughly the same with a pH of 8.3 in March and a pH of 8.4 in April. The March sample had a moderately low hardness of 220 mg/l and the April sample had a low hardness of 47 mg/l. Total Dissolved Solids (TDS) ranged from 1996 mg/I in March to 1486 mg/I in April. Sulfate concentrations ranged from 1152 ntg/I in March to 597 mg/1 in April. The thickener slurry will have a variable chemical make-up due to geochemical variations in the raw coal. 7. This question will be answered under separate cover. 8. This question will be answered under separate cover. 9. The water in the thickener achieves a chemical equilibrium with the coal and rock found in the plant at any point in time. New raw coal, from different locations in the mine, is coming in continuously, mixing with new process water and recycled thickener water. This changes the specific chemical make-up of the thickener water, and is the source of the phrase, "the water in the thickener achieves a chemical equilibrium, albeit a changing one, with water running through [he plant." 10. Water from the Maxwell seam intersected by LA-221, from the mine discharge from [he Allen seam at [he New Elk Mine and from the mine discharge from the Maxwell seam at Golden Eagle Mine are all slightly alkaline, saline, sodium bicarbonate waters of low hardness. Table 8 within the updated PHC in Exhibit 6 compares historic data from mine discharge at New Elk as well as that from Golden Eagle, and the water found within LA-221 fits within the ranges noted on the table.