Provides a decision framework incorporating key aspects of EPA’s three-volume technical background series on MNA for metals and rads in groundwater, guidance on approaches and key issues associated with evaluating attenuation-based remedies, and a process to incorporate enhanced attenuation.

Provides a technical overview of natural source zone depletion for LNAPLs, addressing the processes involved, assessing their rates, and predicting long-term progress.

Provides direction to regulators and practitioners on integrating EA into remedial decision making for a smooth transition between aggressive remediation and monitored natural attenuation. The CD also contains the Enhanced Attenuation of Chlorinated Organics: Electronic Resource Guide.

Description of practices to be used to recognize and evaluate the presence of natural attenuation of chlorinated solvent contamination.

Presents a summary of results of surveys returned by people who took the natural attenuation course.