General Methods for Remedial Operation Performance Evaluations January 1992

All research projects making conclusions or recommendations based on environmentally related measurements and funded by the Environmental Protection Agency are required to participate in the Agency Quality Assurance Program. This project did not involve environmentally related measurements and did not involve a Quality Assurance Project Plan. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. iii Foreword EPA is charged by Congress to protect the nation's land, air and water systems. Under a mandate of national environmental laws focused on air and water quality, solid waste management and the control of toxic substances, pesticides, noise and radiation, the Agency strives to formulate and implement actions which lead to a compatible balance between human activities and the ability of natural systems to support and nurture life. The Robert S. Kerr Environmental Research Laboratory is the Agency's center of expertise for investigation of the oil and subsurface environment. Personnel at the Laboratory are responsible for management of research programs to: (a) determine the fate, transport and transformation rates of pollutants in the soil, the unsaturated and saturated zones of the subsurface environment; (b) define the processes to be used in characterizing the soil and subsurface environment as a receptor of pollutants; (c) develop techniques for predicting the effect of pollutants on ground water, soil, and indigenous organisms; and (d) define and demonstrate the applicability and limitations of using natural processes, indigenous to soil and subsurface environment, for the protection of this resource. The pump-and-treat process, whereby contaminated ground water is pumped to the surface for treatment, is one of the most common groundwater remediation technologies used at hazardous waste sites. In fact, pump and treat is a necessary component of practically all ground water remediation systems, whether for restoration or for plume containment. However, recent research has identified complex chemical and physical interactions between contaminants and the subsurface media which may impose limitations on the extraction part of the process. This has raised questions about the effectiveness of ground water restoration systems and methods for evaluating that effectiveness. This report was developed to summarize the technical considerations involved in evaluating the performance of groundwater remediation activities.