Volume 12, Issue 3 (May 1984)
The Quality of Runoff from Model Coal Piles
Four different coals were tested under controlled laboratory conditions of simulated rainfall events over a 120-day period to determine some of the changes in the quality of the runoff. Illinois #6, Western Kentucky, Montana Nerco, and Central Texas lignite coal-pile runoffs were analyzed for 13 standard water quality parameters. Ranges of the average values for those runoffs were pH, 2.2 to 7.1; oxidation-reduction potential, −3 to 284 mV; conductivity, 200 to 5833 μmhos/cm; turbidity, 5 to 98, number of transfer units; ammonia, 0.2 to 1.0 mg/L; nitrate 0.3 to 27.0 mg/L, organic nitrogen, 9 to 50 mg/L; sulfate, 65 to 7211 mg/L; total organic carbon, 6 to 70 mg/L; inorganic carbon, 2.6 to 21 mg/L; biochemical oxygen demand <5 to 20 mg/L; chemical oxygen demand, 65 to 744 mg/L; and suspended solids (nonfiltrable residue) 54 to 596 mg/L. This research demonstrated some of the qualities of runoff that may be expected from stockpiles of these four representative coals.