Environmental, Safety & Health

Potomac River Acid Mine Drainage Abatement

CSS developed a restoration strategy and implemented its demonstration phase for the restoration of water quality throughout the mainstem and selected tributaries of the North Branch of the Potomac River, upstream of Jennings Randolph Dam. Acid mine drainage (AMD), mostly from abandoned coal mines, had severely affected this watershed. During the initial phase of the project, we developed engineering design specifications and estimated annual costs for an AMD neutralization program that involved the installation of streamside devices capable of dispensing chemical neutralizing agents into the water column. The optimal chemical dosing strategy was preceded by a comparison of the costs and effectiveness of several chemical neutralization scenarios that represented deployment of different technologies, dosing locations, and neutralizing agents designed to meet specified water quality targets in the North Branch. Water quality targets were selected to be compatible with fishery management objectives and varied between different reaches and tributaries. Fish management objectives included a put and take trout fishery, self sustaining brook trout populations, and a self sustaining smallmouth bass fishery. Task activities included historic data collection and review; definition of water quality targets; and evaluation and recommendation of neutralizing strategies (using hydrological and acidity mass balance models). CSS completed a feasibility study; determined sites to deploy selected technology; prepared engineering bid specifications; obtained all necessary construction permits; installed two of four dosing devices; and completed the project demonstration phase of the program. The work was closely coordinated with Maryland and West Virginia fisheries managers and resource agencies. Today the North Branch of the Potomac River has recovered to the extent that it has a viable sport fishery and is the destination of guided sport fishing trips.