Copper Speciation in Highway Stormwater Runoff as Related to Bioavailability and Toxicity to ESA-Listed Salmon

The objectives of this study were to 1) identify the effects of site location, storm hydrology, and water quality parameters on the concentration of dissolved copper (Cu2+diss) in Oregon highway runoff; 2) establish an analytical technique suitable for the determination of copper speciation in highway stormwater runoff; 3) compare analytically determined free ionic copper (Cu2+free) concentrations in highway stormwater runoff with modeled concentrations; and 4) develop a qualitative understanding of where and when copper toxicity has the most potential to be problematic for receiving waters. In this study, stormwater runoff from an urban high annual average daily traffic(AADT) site had consistently higher event mean concentrations of measured Cu2+diss and Cu2+free than the non-urban sites with lower AADT. First flush samples displayed consistently higher concentrations of both Cu2+diss and Cu2+free. A modified Competitive Ligand Exchange-Cathodic Stripping Voltammetry (CLE-ACSV) technique utilizing salicylaldoxime as an added ligand can be used to determine the speciation of copper in highway stormwater runoff. Analytical results from composite stormwater samples suggest that dissolved copper in highway stormwater runoff is largely complexed by organic matter (typically > 99.9%), and that very little of the copper in stormwater is bioavailable; the concentrations of Cu2+free were generally several orders of magnitudes below levels found to inhibit olfaction in Endangered Species Act listed fish species. Elevated Cu2+diss levels proved to be the greatest indicator of high Cu2+free concentrations. Urban sites with AADT and first flush samples characterized by elevated concentrations of Cu2+diss are of the greatest concern with respect to elevated free ionic copper concentrations. Available dissolved organic matter models in Visual MINTEQ overestimate Cu2+free concentrations when compared to analytically determined Cu2+free concentrations. This imparts a conservatism that makes these models potentially useful for regulatory purposes.

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• Record URL:
  • https://rosap.ntl.bts.gov/view/dot/20317
• Corporate Authors:

  Oregon State University, Corvallis

  School of Chemical, Biological and Environmental Engineering
  Corvallis, OR  United States  97331

  Oregon Department of Transportation

  Research Section, 200 Hawthorne Avenue, SE, Suite B-240
  Salem, OR  United States  97301-5192

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Nason, Jeffrey A
  • Nelson, Peter O
  • Bloomquist, Don J
  • Sprick, Matthew S
• Publication Date: 2011-4

Language

• English

Media Info

• Media Type: Print
• Edition: Final Report
• Features: Appendices; Figures; Glossary; References; Tables;
• Pagination: 196p

Subject/Index Terms

• TRT Terms: Copper; Endangered species; Environmental impacts; Hydrology; Runoff; Salmon; Toxicity; Urban areas; Water quality
• Uncontrolled Terms: Bioavailability
• Geographic Terms: Oregon
• Subject Areas: Environment; Highways; Hydraulics and Hydrology; I15: Environment; I26: Water Run-off - Freeze-thaw;

Filing Info

• Accession Number: 01342276
• Record Type: Publication
• Report/Paper Numbers: FHWA-OR-RD-11-11
• Contract Numbers: SPR 663
• Files: TRIS, USDOT, STATEDOT
• Created Date: Jun 21 2011 9:28AM