Engineered wetland systems are a passive treatment technology which are versatile,
environmentally-friendly, and cost-effective for the remediation of acid mine drainage (AMD) and
leachate.
Experience derived from a site in Ohio, United States, showed that the preliminary design of an
engineered wetland system downstream of a former coal mine/landfill could be significantly improved by
the performance of bench-scale treatability studies. Results from the bench-scale treatability study
showed that in order to achieve significant reductions of iron in the water discharging to the surface water
bodies. The pH of the water would have to be increased to 8 by the addition of limestone.