Bioretention and Stormwater Research

We have an active research team studying the fundamental performance of bioretention and other stormwater treatment and control measures.  We aim to understand the water balances important to stormwater control measures (SCMs) and the specific unit processes that control pollutant fates, removals, and accumulations. 

The multiple challenges of SCM research are being addressed through laboratory, pilot-scale, and field-scale research.  Although the majority of our research has been and continues to be with bioretention, we have worked with vegetated swales, subsurface storage, infiltration basins, permeable pavers, sand filters, geotextile filters, and various treatment trains.

Work has evaluated hydrologic management, mostly through volume control.  Most SCMs have a defined volumetric storage capacity.  For small events that produce rainfall volume less than this capacity, the SCM will hold the entire inflow volume and produce no runoff discharge.  This volume can be estimated based on the size of the SCM and other physical properties.  For bioretention, this capacity has been defined as the Bioretention Abstraction Volume (BAV).

Multiple mechanisms for water quality improvement are available in SCMs.  These can include sedimentation, filtration, adsorption (and desorption), precipitation and dissolution, and myriad biological processes.  Biological processes can include various nitrogen transformations (ammonification, nitrification, denitrification), hydrocarbon degradation, plant uptake, and bacterial survival and predation.  The presence and absence of specific unit processes and conditions will control the water quality improvements expected in the SCM.

Current research is trying to understand the hydrologic and water quality performances of various SCMs, but also developing and designing systems the improve performance over that of the traditional SCM.  Enhanced systems are being evaluated for removal of heavy metals, phosphorus, and nitrogen.  This is being accomplished through media modifications, novel flow path and storage designs, and treatment train approaches. 


Research Collaborators: