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Enhanced Attenuation: Chlorinated Organics

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Many sites with chlorinated organic contamination in groundwater throughout the nation have gone through extensive remedial evaluations and actions. The remedial alternatives for many of these sites include high-energy treatments such as pump-and-treat systems. After years of operation, the effectiveness of these high-energy processes has begun to diminish without remedial objectives being met. Other more effective remedial alternatives need to be implemented however, there is a lack of guidance available to regulators and the environmental community regarding how and when to transition these sites to lower-energy remedial alternatives and eventually to monitored natural attenuation MNA. To answer this need, the ITRC Enhanced Attenuation Chlorinated Organics EACO Team developed this guidance, which includes a protocol to assist in a smooth transition or a bridge between aggressive remedial actions and MNA, and thus the concept of enhanced attenuation EA was born. EA is that bridge, incorporating three important features the evaluation of mass balance, defined as the relationship between mass loading and attenuation capacity of an aquifer a decision framework that provides guidance for site decisions, and a toolbox of potential EA technologies known as enhancements that optimize aquifer conditions to provide a sustainable treatment or, at least, minimize the energy needed to reduce contaminant loading andor increase the attenuation capacity of an aquifer. The decision framework, in the form of a flowchart presented in Chapter 2, provides direction to regulators and practitioners on how to integrate EA into the remedial decision process. The EA approach is consistent with the current regulatory environment and can be accommodated within a broad range of regulatory programs such as those that follow the Comprehensive Environmental Resource Conservation Liability Act or state dry cleaner regulations.

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  • Solid Wastes and Pollution and Control
  • Water Pollution and Control

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