1. Scope

Keywords

Rationale

There are over 62,000 leaking underground storage tank remediation sites remaining to be cleaned up and closed in the US. The goal of this guide will be to provide a framework (and tools) for assisting and addressing uncertainties in the determination of when a petroleum UST site remediation is ready to close and when a remediation project is off track and needs to be rethought. Many of the remaining sites have had limited assessment and remedial action for a variety of reasons, such as being too low on the states priority list or risk ranking to receive funding, unknown or unwilling responsible parties, and access issues. Others have been in monitored natural attenuation status for many years. Some sites have had significant cleanup activities, have stable groundwater plume concentrations and are unlikely to reach a receptor, but the on-site concentrations are still above the sites target cleanup levels. Still others, despite significant remedial efforts are not stable and may be continuing to threaten human health and the environment. Guidance is needed to help raise awareness within the regulatory and practitioner communities of best practices, based on the latest scientific understanding for the systematic review of remedial progress and facilitation of UST site closure.