highest potential for contributing such sediments to the system. To facilitate such measures, EPA should develop a quantitative model for sediment dynamics, deposition, and geochemistry for the basin watershed. In designing and implementing remedies, consideration should be given to possible unintended effects, such as impacts to fluvial behavior and migration of resuspended sediments.

Superfund megasites are often defined as those sites with projected cleanup costs expected to exceed $50 million. In this section, the committee restricts its conclusions to mining-related megasites that, in addition to their high costs for remediation, include massive amounts of wastes resulting from many years of mining activities. Wastes at these sites are dispersed over a large area and deposited in complex hydrogeochemical and ecologic systems that often include human communities and public natural resources.

The committee concludes that an effective program for mining megasites should emphasize long-term adaptive management. The desirable program components are a stable management structure, long-term monitoring components, active state and local involvement in the remediation process, a broad perspective regarding what actions should be undertaken in addition to cleanup, and long-term funding.

Most of the committee’s recommendations regarding mining megasites can be implemented within the Superfund framework; some reflect actions that EPA has already undertaken to some extent in the Coeur d’Alene River basin; and some probably cannot be implemented under the current framework, at least not without private or nonprofit partnerships.

Design the data collection, evaluation, and decision-making process at mining megasites so that the remediation program focuses on establishing a durable process for long-term management of the sites, as final remedies may not be realistic at some megasites.

Be ready to waive specific “applicable or relevant and appropriate requirements” (ARARs) if an effective monitoring program demonstrates that those numeric standards are not necessary to achieve the basic goals of protecting human health and the environment.

Where final remedies cannot be realistically implemented, establish a rigorous and responsive adaptive management process for environmental remediation. ERAs at such sites should be designed to support remedy selection, and move beyond documentation of the presence or absence of