Hazardous liquids are impounded in pits, ponds, and lagoons at many uncontrolled hazardous waste sites across the country. As the ranking, remedial investigations, and feasibility studies proceed at these sites, many of the lagoons gradually fill with rainwater and threaten to overflow, thus requiring frequent pumpdown of the impounded liquids to prevent overtopping and subsequent transport and treatment of the collected wastes. This practice can be expensive, costing up to $0.40/gallon depending on the chemicals and haul distances involved. The overall objective of this project was to investigate alternative methods for preventing overtopping of a lagoon, with specific application to the Old Inger Site in Darrow Louisiana.