The United States may not be able to make all hazardous-waste sites as clean as possible. Therefore, priorities must be set for the timing of waste site remediations. This book assesses several of the government’s methods of ranking sites for remediation and compares the performance of three such models using input data developed from the same set of waste sites. Because inconsistent methods may be neither effective nor prudent, the book recommends that the government consider developing a unified national approach to setting priorities to replace the current multiple approaches.