Acid mine drainage (AMD) from an abandoned underground coal mine in the Jones Branch watershed in McCreary County, KY, substantially reduced water quality in Jones Branch. Downstream from the mine seeps, the pH was routinely below 4.5 and concentrations of most heavy metals, especially iron, were elevated. A cattail wetland (1,022 m2) was constructed on Jones Branch in 1988-1989 to obviate the effects of the AMD. Monthly chemical monitoring was performed on the water from above, from below, from the inlet and outlet of the wetland, and from the 25 cells within the wetland. Based on chemical monitoring, the wetland initially improved water quality, increasing the pH and removing substantial amounts of heavy metals. Beginning in the winter of 1991, water quality at the wetland outlet began to decline, but was above levels reported for most contaminants prior to construction. To augment the chemical monitoring, a biomonitoring study was initiated in the spring of 1990. Acute 48-hr static tests were conducted with newly hatched fathead minnows (Pimephales promelas). Water samples were obtained from the seep inlet, four cells within the wetland, and from Jones Branch above and below the wetland site. Median lethal concentration (LC50) values determined monthly reflect the decline in water quality at the outlet over time. However, within the wetland there was gradual improvement in survivability from inlet to outlet, providing evidence that the wetland was responsible for a modest improvement in water quality. Although there was modest overall improvement in the water quality of Jones Branch due to wetland treatment, additional remediation will be required before the stream can support vertebrate organisms.
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The work upon which this report is based was supported in part by funds provided by the United States Department of the Interior, Washington, D.C. as authorized by the Water Resources Research Act of P.L. 101-397.
Ramey, Barbara A.; Chalfant, George; and Walker, Jon A., "Chemical and Biological Monitoring of a Constructed Wetland on Jones Branch Treating Acid Mine Drainage" (1995). KWRRI Research Reports. 16.