New Research Explores the Interactions of Coal Ash and Wetland Ecosystems


Leif Olson (MEM 2016) samples a wetland microcosm as part of a recently published study of the interactions of coal ash and wetland ecosystems.  Photo:NSOE

NSOE alumnus and former DUWC member Leif Olson is the lead author of an article exploring the potential interactions of coal ash and wetland ecosystems. Wetland Center director Curtis Richardson is also one of the authors. The article is published in the September 2017 issue of Water, Air, & Soil Pollution.


Coal is still the leading source of energy in the world. Advances in coal burning technology have led to reduced emissions from power plants but have also been accompanied by increased production and shifts in the chemical composition of coal combustion residue (CCR), commonly referred to as coal ash.


Surface water impoundments, also called lagoons, are commonly used to store CCR. The volume of stored CCR is immense and has the potential to affect nearby water quality when stored in surface impoundments. This method of storage came under scrutiny following recent impoundment failures in the U.S. Southeast. Aside from large spills, coal ash lagoons can cause contamination through leachate discharges into surface waters and the leaching of trace elements from unlined lagoons into groundwater aquifers.


The interaction of CCR leachates with wetland ecosystems is of interest, because wetlands tend to be sinks and transformers of contaminants, filtering water passing between lakes, rivers, and aquifers.


The group's experiments examined trace element leachability into freshwater from fly ash, the most common form of CCR. The study results presented in the new article indicate that emergent macrophytes could help ameliorate downstream water contamination from CCR storage facilities and could potentially be utilized in wetland filtration systems to treat CCR wastewater before discharge.


Olson, L.H., J.C. Misenheimer, C.M. Nelson, K.D. Bradham, and C.J. Richardson. 2017. Influences of coal ash leachates and emergent macrophytes on water quality in wetland microcosms. Water, Air, & Soil Pollution 228:344. DOI 10.1007/s11270-017-3520-4