Metal attenuation processes in a landfill containing coal combustion waste: Implications for remediation
Christopher Barton, Lindy Paddock, Christopher Romanek, Sally Maharaj,
and John Seaman
ABSTRACT
The
488-D Ash Basin (488-DAB) is an unlined, earthen landfill containing approximately
1 million t of dry ash and coal reject material at the U.S. Department
of Energy's Savannah River Site, South , Carolina. The pyritic nature
of the coal rejects has resulted in the formation of acidic drainage,
which has contributed to groundwater deterioration and threatened biota
in adjacent wetlands. Establishment of a vegetation cover to both deplete
oxygen through biological means and optimize evapotranspiration has been
established as a remedial alternative for reducgin acidic drainage generation
in the 488-DAB. To determine the potentail benefits of a cover, a series
of characterization studies were condcuted prior to field deployment to
gain a better understanding of the metal attenuation process and to use
water quality and substrate data to evaluate the potentail effectiveness
of this remedial approach. The characterization study indicated that metal
attenuation was primarily controlled by fluctuating redoc and pH gradients
assocaited with alternating satuarted and unsaturated conditions in the
basin. Based on this information, a vegetative cover could reduce the
productions of acid leachate over time, pending oxygen transport to the
subsurface is limited.
SREL Reprint #2865
Barton, C. D., L. S. Paddock, C. S. Romanek, S. Maharaj and J. Seaman. 2005. Metal attenuation processes in a landfill containing coal combustion waste: implications for remediation. Environmental Geosciences 12:45-55.
