Demonstration projects were sought for tools, methodologies, or technologies that can reduce the cost of managing the Department of Defense’s (DoD’s) long-term liability associated with groundwater impacted by chemicals of concern. Such chemicals of concern include per- and polyfluoroalkyl substances (PFAS), chlorinated solvents, energetic compounds, emerging chemicals of interest to the DoD, or mixtures of these chemicals.

The primary focus of this topic area was development of innovative technologies and approaches for managing sites impacted by chemicals of concern. The following topics are of particular interest:

• Development of cost-effective modeling tools or technologies to specifically address chemical source zones that cause persistent groundwater plumes.
• Development of cost-effective modeling tools or technologies to manage and treat soils and groundwater impacted by chemicals of concern, particularly PFAS. Such technologies also must address common co-occurring chemicals with these chemicals of concern.
• Assessment of how to better combine existing or new technologies to address complex sites and make informed decisions on transitions from active remediation to passive technologies.
• Optimization, assessment, and/or long-term monitoring tools related to remediation of impacted groundwater.
• Development and evaluation of tools to collect more site data of better quality at lower cost. Site data on groundwater quality, including chemicals of concern and biogeochemical conditions is of particular interest.

For those proposing projects addressing PFAS issues, review the SERDP and ESTCP Workshop Report on Management of PFAS in the Environment for more detailed information on demonstration needs in this area.

In situ or ex situ treatment options were of interest, but proposers had to be clear on the need for and advantages of ex situ treatment. Technologies and methods were sought that have well-defined demonstration/validation questions to address. Proposed technologies should have completed all required laboratory work, although site-specific treatability work prior to the field demonstration is acceptable. Demonstrations should address technical and/or regulatory issues that inhibit the widespread use of the proposed approach across the DoD. ESTCP supports demonstrations at a scale sufficient to determine the operational performance of the remediation technology and to estimate its expected full-scale costs. Full-scale cleanup of specific sites is not performed under ESTCP. Specific DoD demonstration site(s) may be suggested in the pre-proposal, but are not required.

Results from this work will provide the DoD with an improved capability to cost-effectively characterize, remediate, and manage soil and groundwater sites impacted by chemicals of concern.

Of the DoD’s Installation Restoration Program (IRP) sites, groundwater impacted by chemicals of concern is often the most intractable problem. Impacted soils are inextricably linked to this issue as they may encompass the source area of impacted groundwater or may require treatment after excavation. Substantial progress has been made in the past 20 years in the development of technologies for remediation of impacted soils and groundwater; however, challenges remain. Remedial costs are particularly high at sites where (1) impact from chemicals of concern is extensive, but concentrations are low, (2) site hydrogeology is complex (e.g., fractured bedrock), or (3) site conditions require extensive long-term monitoring. Of particular concern are issues associated with PFAS in the environment; more cost-effective treatment technologies are needed.

ESTCP has supported the demonstration of a number of technologies designed for protection and remediation of soils and groundwater. Proposers should be familiar with the ESTCP portfolio of technologies and tools in order to avoid duplication of previous efforts. Project descriptions are available on the ESTCP website.