An Evaluation of Current Methods and Alternatives for the Disposal of Motor Vehicle Waste Funds

Abstract

Threats to groundwater from the various products and wastes generated at auto repair facilities are a real concern to groundwater quality. Potential contaminants include heavy metals, volatile organic compounds (VOCs), and polynuclear aromatic hydrocarbons (PAHs). This study was conducted through two research projects on two University of Wisconsin campuses. Objectives were to determine the current methods of disposal, of automotive wastes, to evaluate possible alternative products and practices, to determine the extent of treatment currently occurring, and to examine groundwater contamination occurring at several sites. The study was funded by the Wisconsin Department of Natural Resources through a grant from the United States Environmental Protection Agency. The study involved three subprojects. The first was to survey motor vehicle repair facilities. The survey included the following: investigation of normal operations for motor vehicle waste disposal, an inventory of production of motor vehicle waste fluids, and determination of the extent of recycling and other waste minimization techniques. Next, four sites having an on-site waste treatment system and a connecting floor drain in a service bay area were identified and their groundwater monitored and analyzed. Third, workshops were held to involve state agency and private sector representatives in discussions to identify and resolve some of the issues related to automotive waste disposal. Another objective of the workshops was to assist in the development of best management practices both for existing systems and for future waste generators. In addition, a UW-Madison study, working concurrently with this project, followed the waste stream from catch basins to septic tank to soil absorption fields and was valuable in identifying the components of the waste stream and degree of treatment occurring at various points. The study also looked at the fate of components as they proceed through these systems. Results of the survey confirmed that for the most part, owners/operators were interested in the project and would be willing to implement practices to prevent possible groundwater pollution if they were provided the necessary assistance with cost-effective alternatives to current practices. In the monitoring portion, investigation of the waste streams at automotive repair facilities showed a wide range of toxic chemicals are commonly used, and many of these chemicals were found in detectable amounts in the catch basins or septic tanks of the monitored sites. Contaminants included VOCs and metals as well as PAHs. Groundwater testing results indicated that metal concentrations, Pb and Cd in particular, were not found in groundwater at the sites. According to the Madison study, metals were in general removed in the sludge of the catch basin and septic tank, with most remaining metals being removed in the soil absorption field. Groundwater in the contaminant plume remained low in metals. VOCs were found in septic effluent, and some were found to be impacting groundwater. This suggests that the waste treatment systems are not effective in treating automotive waste fluids. In general, the concentrations of VOCs and PAHs were fairly low with fewer compounds found in groundwater than in septic tank effluent. The workshops identified areas of greatest concern within the automotive repair industry. However, a cooperative program is still needed from state agencies to provide education on management and disposal alternatives for motor vehicle waste fluids and to address the issues of groundwater protection.