Wednesday 3:50 Mark B. Carew, Kentucky Division of Abandoned Mine Lands
Passive Treatment of Acid Mine Drainage with Open Limestone Channels in the Lower Rock Creek Watershed
Mark B. Carew
Acid mine drainage (AMD) from over 40 coal mine portals and eight pyrite-rich coal processing refuse dumps had decimated aquatic life in the lower Rock Creek watershed and rendered the stream virtually lifeless. Water quality data was analyzed from 41 portals and seeps in the study area. Acid and metal loading was calculated for each portal and passive treatment options were explored using the water chemistry analysis for each portal discharge. Water and biological monitoring were conducted in the watershed to document improvements in the watershed. In the fall of 2000 construction began on a reclamation project targeting several of the worst AMD sites in the lower Rock Creek watershed. As part of the reclamation project open limestone channels were installed routing AMD through the limestone before discharging into the stream. Reclamation continued in the fall of 2002 with the installation of additional open limestone channels routing AMD from mine portals to the receiving streams. Limestone channel lining was placed directly into four severely impacted tributaries of Rock Creek, treating the AMD in the tributaries before it enters Rock Creek. Over 20,000 feet (6096 meters) of open limestone channels have been installed in the lower Rock Creek watershed. Significant reductions in acidity and dissolved metal concentrations have occurred in the tributaries being treated with open limestone channels. Water quality in Rock Creek has improved, with fish populations rebounding with increases in numbers, diversity of species, and numbers of intolerant species.
Mark Carew is a registered geologist with the Kentucky Division of Abandoned Mine Lands. Mark received his Bachelor of Science and Master of Science degrees in geology from Eastern Kentucky University. He has over 20 years of field experience in the coalfields of Kentucky including 17 years with the Kentucky AML program.