SGER: Estimating the Magnitude of Stormwater Heavy Metal Mass Loading from Urban Battery Litter

Case Western Reserve University, Cleveland OH

Investigators

Abstract

Jennings, Aaron A., PI Case Western University 0650675 Estimating the Magnitude of Stormwater Heavy Metal Mass Loading from Urban Battery Litter Consumers purchase about 15 million disposal batteries each year in the US. Preliminary research indicates that a surprisingly large number of these end up in street and parking lot litter in urban areas. As the batteries deteriorate metals such as Ag, Cd, Co, Cr, Cu, Hg, Li, Ni, Pb, Sn, Ti, and Zn can be released to stormwater. Data from the Cleveland area indicate that annual parking lot litter rates can be as high as 2 or more batteries for every retail parking space. Annual street litter rates can be as high as 1 battery for every 3 linear feet of curb. Condition analysis indicates that over 60% of these batteries are leaking or have already discharged their contents. "Alkaline" batteries release 20-40 mg/l Zn when they are ruptured. Zinc-chloride (Zn-Cl) or Zinc-carbon (Zn-C) batteries release 400-1300 mg/l Zn. Ultimately, both types release 3 to 6 g (for AA cells) of Zn, and this can be toxic to aquatic environments at concentrations as low as 30 ug/l. This work will focus on determining the significance of the contribution of metal loading to stormwater from discarded batteries. The mass loadings will be established (maximum expected value, uncertainty bounds, etc.) for approximately 10 case-study locations and the results will be compared to the magnitude of other sources of similar contamination. This will supply the essential information necessary to evaluate the importance of this research topic. The research will leave many questions about factors such as deterioration kinetics, chemical speciation, "snow battery" loading, particulate metal transport and "discount" battery impacts, and remediation methods unanswered, but it will yield the primary information necessary to gauge the magnitude of this source relative to other, better-known sources of urban stormwater heavy metal contamination. The research will evaluate the importance of an urban water quality problem that is currently overlooked. The work will also illustrate how recent developments in international trade (many batteries are imported from Malaysia, Indonesia, and China) and consumer economics are impacting U.S. water quality. It is very likely that results will lead to new strategies for improving urban water quality and new international trade standards to address the most problematic class of imported batteries. The project will also introduce REU scholars to advanced concepts of environmental science and engineering.