Research Idea Details

Research Idea Scope

Highway stormwater runoff is a source of copper to receiving streams.  Trace levels of copper have been shown to have detrimental effects on threatened and endangered salmonid species.  However, little is known about how that copper will partition once it enters the environment.  Because the bioavailablity and toxicity of copper is highly dependent on complexation with inorganic and organic constituents in the water, the water quality of individual streams is likely to be extremely important in predicting the likely effects of copper discharges from highway runoff.  A better understanding of how roadside streams respond to copper discharges will allow DOTs to more effectively monitor and manage roadway runoff to minimize environmental impacts.

The proposed research would involve sampling roadside streams that are impacted by highway stormwater runoff, targeting streams that are inhabited by threatened and endangered salmonid species.  Because water quality characteristics are likely to vary regionally, sampling sites would be chosen in the various eco-regions and at different times during the year.  Upon collection, waters would be characterized in terms of the pH, alkalinity, hardness, trace metals concentration, and organic carbon.  Copper speciation will be measured using competitive ligand exchange-cathodic stripping voltammetry.  The research would also investigate differences in the functionality of organic carbon present in regional waters and explore how stormwater copper would ultimately partition when discharged into such water through bench-scale testing and chemical equilibrium modeling.

Related Research (Added by TERI Administrator, March 2011):
Copper Speciation in Highway Stormwater Runoff as Related to Bioavailability and Toxicity to ESA-Listed Salmon; Oregon Department of Transportation, 2007, Active