Attenuation-based remedies for metals and long-lived radionuclides rely primarily on immobilization of contaminants as stable and/or nontoxic species. This stabilization and toxicity reduction can result from natural processes, geochemical gradients, or biogeochemical manipulation. Except for a few radionuclides, the original contaminant remains in the subsurface so that documentation of the sustainability or permanence of stabilization and detoxification is crucial to assessing performance. Another challenge in applying the existing and emerging guidance is the need to simultaneously address multiple contaminants at a target site.
ITRC's Natural Attenuation Processes for Metals and Radionuclides (APMR) Team developed a framework to facilitate implementation of EPA guidance for monitored natural attenuation (MNA) of metals and radionuclides. This framework provides a consistent basis for states, stakeholders, federal agencies, and site owners to evaluate and implement attenuation-based remedies. The project encompasses a process that encourages regulatory cooperation and sharing of successful technological approaches. In December 2010, the APMR Team released a technical and regulatory guidance document entitled A Decision Framework for Applying Monitored Natural Attenuation Processes to Metals and Radionuclides in Groundwater (APMR-1). The companion Internet-based training was released in 2011.
The ITRC APMR Team operated from 2008-2010 followed by one year in implementation.