Thirty-five natural wetlands impacted by acid mine drainage (mostly in western Pennsylvania) were surveyed for abiotic and biotic parameters in relation to water quality. Using treatment efficiency and area-adjusted mass retention as wetland performance indices, correlation analyses and multiple regression techniques were employed to evaluate the influence of the wetland parameters on the mitigation of ph, fe, mn, and al. Elevation of ph was correlated with large, broad, low-flow wetlands with shallow, non-channelized surface water, inlet alkalinity, and dense populations of vascular plants and bryophytes. Moderate and high iron concentrations interfered with the mitigation of ph. High-fe treatment efficiencies were correlated to low flows, large areas, broad shapes, nonchannelized flows, explosed locations, a diverse and dense vegetative cover, and inlet alkalinity. Large wetlands having lush vascular plant cover and receiving alkaline waters low in total iron concentrations were implicated in significant mn treatment. Outlet fe concentrations were usually in compliance in wetlands that significantly lowered mn concentrations. Algae tolerate manganese but probably do not play an active role in its elimination. Reliable indices of wetland performance include area-adjusted mass retention (for ph) and treatment efficiency (for metals).
Bureau of Mines, Pittsburgh Pennsylvania, Pittsburgh Research Center, Available for Reference At Bureau Libraries