The objective of this Statement of Need (SON) was to seek innovative approaches for both monitoring and implementing in situ remediation of contaminated aquatic sediments. The goal of this research was to ultimately reduce costs associated with monitoring and treating contaminated aquatic sediments, while still being protective of human health and the environment.

Specific objectives included:

• Development of new and more effective amendments or other technologies for in situ treatment.
• Design of more effective methods to deliver amendments as part of caps or in situ treatment approaches.
• Development of optimal strategies to reduce monitoring costs through composite or incremental sampling methods.
• Improved understanding of the utilization of lower cost bioavailability measures as surrogates for higher trophic level sampling events.

The focus of this SON was contaminated aquatic sediments, either marine, estuarine, brackish, or freshwater. Contaminants of interest included the predominant contaminants at Department of Defense sites, such as PAHs, PCBs and metals, but also emerging contaminants of concern such as per- and polyfluorinated alkyl substances. Proposers clearly stated the contaminants that were addressed by their proposed research approach.

Research proposals should have involved laboratory-, bench-, and field-scale studies, as well as computer modeling to support such efforts; however, all proposals must have demonstrated how the proposed research would ultimately be used to improve management of contaminated sediment sites. Proposers should have addressed one or multiple of the objectives listed above.

SERDP co-sponsored a Workshop on Research and Development Needs for Long-Term Management of Contaminated Sediments in August 2016 that identified high priority research topics in this area. A more detailed description of these issues can be found in the workshop report. It was strongly encouraged for proposers to review the workshop report for additional detail.

Funded projects will appear below as project overviews are posted to the website.

Developing innovative new monitoring and remediation technologies for contaminated aquatic sediments will improve the ability of site managers to manage contaminated sediment sites and ensure protection of human health and the environment.

Aquatic sediments are often the ultimate repository of discharged contaminants. According to an estimate by the U.S. Environmental Protection Agency (U.S. EPA), approximately 10% or 1.2 billion cubic yards of the sediment underlying the country’s surface water is sufficiently contaminated with toxic pollutants to pose potential risks to fish and to humans and wildlife that eat fish (U.S. EPA, 1998). Contaminated sediments can pose a threat to human health when pollutants in sediments accumulate in edible aquatic organisms (U.S. EPA 1998 and references therein).

Highlighted in the 2016 Workshop Report, developing in situ remedial strategies is important for all contaminants in sediments, but especially for the emerging contaminants. Much of the recent work on amendments for in situ remediation of sediments has focused on adsorption by carbon or other substrates (e.g., organoclays, apatite). There remains continued interest from the regulatory community and public in approaches that remove the mass of the contaminants through treatment. These new technologies should meet the following criteria for in-placement management: reduce exposures through a combination of chemical adsorption, degradation and transformation; have low impact on native biota; have long-term effectiveness; be competitively priced from a life cycle perspective that considers all benefits and costs, and should be applicable to complex mixtures of contaminants.

Monitoring costs represent a significant and increasing burden for contaminated site management. The development and demonstration of innovative and lower-cost monitoring techniques should result in cost effective monitoring. Development of methods that provide more temporal and spatial data will reduce uncertainty in assessing long term monitoring (LTM) goals. Sample compositing strategies should be rigorously evaluated and demonstrated for potential broader application in sediment, in particular with respect to advantages for LTM. Sediment-specific methods for determining the numbers of samples per composite and the number of composites per test condition as determined by a statistical power analysis should be evaluated. Trade-off analysis and optimization of the increased field sampling costs of these methods versus the lower analytical costs would help to guide practitioners in the application.

At many sites, monitoring for reduction in biological endpoints such as fish can drive a substantial fraction of the monitoring cost. Such monitoring can be very labor intensive, complex and costly. In addition, it is often performed at time intervals that have no basis to the known or unknown recovery rate of the site. Alternative monitoring methods that utilize lower cost bioavailability measures such as passive samplers or laboratory exposures as initial proxies for recovery could be used in an adaptive framework to guide decisions on when fish sampling or other complex monitoring events should take place.

The cost and time to meet the requirements of this SON are at the discretion of the proposer. Two options are available:

Standard Proposals: These proposals describe a complete research effort. The proposer should incorporate the appropriate time, schedule, and cost requirements to accomplish the scope of work proposed. SERDP projects normally run from two to five years in length and vary considerably in cost consistent with the scope of the effort. It is expected that most proposals will fall into this category.

Limited Scope Proposals: Proposers with innovative approaches to the SON that entail high technical risk or have minimal supporting data may submit a Limited Scope Proposal for funding up to $200,000 and approximately one year in duration. Such proposals may be eligible for follow-on funding if they result in a successful initial project. The objective of these proposals should be to acquire the data necessary to demonstrate proof-of-concept or reduction of risk that will lead to development of a future Standard Proposal. Proposers should submit Limited Scope Proposals in accordance with the SERDP Core Solicitation instructions and deadlines.