Remediation Technologies Development Forum (RTDF)
Sediments Remediation Action Team Meeting Summary

Wilmington, DE
July 31, 1996

Welcome and Overview

Dave Mount (EPA/Duluth Laboratory), co-chair of the RTDF Sediments Remediation Action Team welcomed participants to the second Action Team meeting. Dave recalled that there was a significant amount of interest expressed at the first meeting. He thanked Ralph Stahl (DuPont) for hosting the meeting and Ralph welcomed participants on behalf of DuPont. Dave Mount then reviewed the mission statement of the Action Team, as developed at the first Action Team Meeting:

To develop cost-effective on-site technologies to remediate contaminated sediments and enable recovery of biological systems. The initial focus of the RTDF Sediments Remediation Action Team effort will be in the following areas:

• Developing in-situ remediation approaches;

• Evaluating ex-situ onsite remediation technologies;

• Considering of existing soil remediation techniques for applicability to sediments;

• Understanding the mechanisms and rates of natural attenuation; and

• Enhancing or developing assessment procedures to evaluate the need for and success of remedial activities.

It was agreed to modify the fifth bullet to read, "... to evaluate the need for, impact of, and success of remedial activities." It was agreed to add a sixth bullet, "Evaluating existing technologies." In addition, the Action Team agreed to develop two parallel mission statements—one to address objectives regarding assessment and one to address objectives pertaining to remediation. Dave Mount indicated that he, with the aid of the Mission Statement Subgroup, will revise the mission statement accordingly and circulate it for comment.

Dave Mount gave a brief overview of the RTDF, which was established in 1992 by EPA after industry representatives met with the Administrator to identify ways of working together to solve complex hazardous waste remediation problem. He indicated that RTDF meetings we open and that all interested organizations are welcome to participate. RTDF members include chemical, petroleum, and pharmaceutical companies, various manufacturers, federal agencies, national Laboratories, research centers and institutes, as well as universities. The RTDF forges public-private partnerships to develop and improve hazardous waste remediation technologies. He noted that participating organizations share knowledge, experience, equipment, facilities, and proprietary technology to address mutual remediation problems. The RTDF establishes action teams, such as the sediments Remediation Action Team that bring members together to work on common remediation problems. A participant asked how proprietary technologies were protected and expressed concern regarding potential anti-trust violations. In response, Mark Searles (SCG) indicated that proprietary technologies are typically shared by action teams, such as the Lasagna™ Partnership and the Bioremediation Consortium, only after a legal agreement is in-place among the members to protect the ownership of the technologies. He also mentioned that these consortia are registered with the Department of Justice in compliance with anti-trust laws.

Overview of Efforts by EPA's Duluth Laboratory

Dave Mount provided an overview of investigations undertaken by EPA's Duluth Laboratory. He indicated that the equilibrium partitioning model for bioavailability was used during recent investigations with the following principal assumptions: (1) pore water is the route of exposure for aquatic organisms, and (2) pore water concentrations can be predicted from bulk phase concentrations and sediment organic carbon. He also provided the following adsorption approach to sediment detoxification:

• Focus on controlling pore water, not bulk sediment concentrations.
  
• Add high affinity binding substrate to bulk sediment.
  
• Provide in-situ control of pore water concentrations and, therefore, toxicity.

Dave mentioned that EPA/Duluth recently investigated the effect of Ambersorb on contaminated sediments via a controlled field application. Field sediment was collected downstream from a refinery, homogenized, and treated with Ambersorb. The treated sediment, as well as untreated sediment, were then reintroduced in small trays near the original sediment collection point. After a two month colonization period, a chemical analysis of the sediments was performed. Dave indicated that colonization was more extensive in the Arnbersorb-treated sediments. However, the DDT levels (the primary contaminant) in the Ambersorb-treated sediments were not appreciably less than in the untreated sediments.

More favorable results were seen in a laboratory study in which Ambersorb was added to fluoranthene-spiked sediments. Originally uncontaminated sediments were spiked, physically mixed, and then allowed to equilibrate over a period of 2-3 days. The pore water fluoranthene, oligochaete tissue fluoranthene, and mortality levels of oligochaetes exposed to UV light were significantly less in the treated sediments. The field and laboratory studies raised the following uncertainties to the adsorption approach; (1) conditions for success have not been established, "permanence" of the treatment is uncertain, and (3) cost effectiveness.

Dave indicated that research on metals remediation has also been performed and two promising treatments have been identified. One treatment involves the use of acid-volatile sulfide, which binds to the metal contaminant. The second treatment uses a form of iron monosulfide, which also binds to the metal contaminant. Dave cautioned that these efforts have only been performed in the laboratory.

Overview of Monsanto's Retrievable Organic Carbon Scavengers

Rich Kimerle (Monsanto), co-chair of the Action Team, provided an overview of retrievable organic carbon scavengers (ROCs), an in-situ sediments remediation technique developed by Monsanto. Rich noted that the studies were performed with, among others, Michael Heitkamp (Monsanto), who is a member of the RTDF Bioremediation Consortium Steering Committee. The ROCs can be engineered as beads, strands, or netting. Rich noted that a retrievable "net" of ROCs would both remediate the contaminants and art as a physical barrier and containment layer. The ability to easily retrieve the ROCs could be beneficial. Removal of the ROCs would eliminate any associated risk and would allow the ROCs to be replenished if necessary. Kepone-contaminated sediments were investigated under laboratory conditions and results were promising. He also noted that although the ROCs appear promising, a number of questions still remain. In response to a participant's question concerning the biodeg! radability of ROCs, Rich stated that the ROCs are probably not biodegradable, but also noted that this issue has not specifically been investigated. Rich hopes to build upon this preliminary laboratory work in the future.

Overview of Dredging Technology

John Haggard (GE) provided an overview of issues pertaining to dredging technologies. There are a number of distinctions between remedial dredging and maintenance dredging as outlined in the table below.

GE has developed a database of nearly 100 dredging efforts, but John noted that data are minimal for a number of the dredging projects, because it is often difficult to reconstruct prior activities (e.g., why it was necessary, benefits). He indicated that substantial data have been difficult to acquire regarding the "effectiveness" of dredging. It is often difficult to compare pre- and post-dredging sampling as pre-dredging sampling is often surficial, whereas post-dredging sampling is often composite. In addition, post-monitoring is often minimal, perhaps due to lack of resources. A participant indicated that the dredging effort often requires more funding than originally budgeted, which may cause redistribution of funds from postmonitoring efforts to the dredging effort. John noted that disposal of contaminated sediments and constraints regarding return water are very important and dredging costs vary significantly depending upon the parameters of the given task.

John provided the following reasons for inability of dredging to remove all contaminants:

• Surface sediments areas are missed because furrows are passed over by dredgehead.
  
• Residual sediments are left on/in the bedrock.
  
• Sediment contamination levels are deeper than the total depth of dredging.
  
• Resuspension.

John also provided the following rationale for design/documentation deficiencies:

• Technology transfer is inconsistent.
  
• Purpose and means of measuring success are often ill defined.
  
• Documentation of protocols and results is deficient.
  
• Target cleanup levels are variable.

John noted that it would be helpful to define risk-based goals and also suggested that it would be helpful to initiate a project from "ground zero" so that it could be thoroughly documented. Cost data are especially difficult to find and even more difficult to compare between two dredging projects as different reporting measures are typically used. He suggested that dredging technology is at a similar stage of development as groundwater technology was during the 1980s.

Overview of Efforts by Naval Facilities Engineering Service Center

Ernie Lory (NFESC) provided an overview of a Strategic Environment Research and Development program (SERDP) project undertaken by NFESC to develop an in-situ reactor method for remediation of contaminated sediments. Ernie indicated that the project will begin in FY97 and identified the following highlights of the problem statement:

• Navy harbors have a contaminated sediment problem.
  
• Cleanup of contaminated sediment "hot spots" is problematic and expensive.
  
• Conventional dredging technologies result in contaminant losses and off-site migration.
  
• Dredge spoils may be classified as hazardous material.
  
• Technology development is needed to reduce the environmental risk and cost of contaminated sediment cleanup.

The objective of the effort is to develop an effective remediation system for the in-situ treatment of contaminated harbor sediments using a novel semi-batch-reactor. Remediation approaches include chemical, biological, and physical methodologies. Ernie indicated that there are two major development thrusts: (1) in-situ reactor development, and (2) remediation process development. The reactor under development has been designed based upon recent advances in related technologies. For example, the containment vessel utilizes suction-emplaced piles technology, which was developed by Shell for other purposes, and recent developments in the submersible slurry pump design now allow the excavation and transport of sediment material consisting of up to 80% solids.

The following steps will be taken in developing the reactor vessel:

• Sediment characterization study
  
• Development of containment study
  
• Test of vessel at National Test Site
  
• Development and test of slurry system
  
• Test of slurry system in vessel at National Test Site.

The following steps will be used to develop the remediation process:

• Expert panel
  
• Sediment characterization
  
• Bench-scale evaluation of potential alternatives
  • Advanced oxidation processes (AOPs)
    
  • Soil slurry bioreactors (SSBs)
    
  • Physical (solidification)
• Scale up of best remedial approach.

Ernie indicated that Port Hueneme, CA, a National Test Site, is expected to be selected as the field site. He noted that heavy metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) are present at Port Hueneme. Although A0Ps and SSBs have not been used to remediate contaminated sediments, they have been used to remediate PAHs and PCBs in other media. In response to a participant's question, Ernie indicated that although the remediation process under development is directed towards an in-situ application, it could also be used from a barge. However, the process is expected to be less expensive when implemented in-situ. Additional payoffs are expected to include:

• A new tool for the in-situ cleanup of contaminated sediments.
  
• Environmental impact greatly reduced.
  
• Potential to cleanup "deep sites."
  
• HAZMAT handling of spoils is eliminated.

Ernie indicated that opportunities are available for those Action Team participants interested in becoming actively involved in the project.

Overview of U.S. Army Corps of Engineers Efforts

Norm Francingues (USACE) provided an overview of activities involved with the U.S Army Corps of Engineers Waterways Experiment Station (USACE/WES). He noted that the USACE has accumulated a significant amount of data and expressed a willingness to share information with the Action Team. USACE/WES has an interest in capping/geofabric methods of containment, particularly long-term efficiency of capping. Norm identified two issues regarding long-term efficiency of caps—organisms burrow into the caps, and caps alter the indigenous habitat. Capping/geofabrics are methods of isolation—they do not treat the contamination. The following table is a partial list of sediment remediation efforts performed by numerous organizations:

Norm provided information on SEDTEC, a computerized directory of technologies for removal and treatment of contaminated sediments. SEDTEC was developed by Evironment Canada's Great Lakes 2000 Cleanup Fund and Water Technology International Corporation to identify technologies most suitable for remedial actions. A user may, therefore, identify a remediation technology based upon need. Approximately 250 technologies are cataloged and the technology parameters cataloged on SEDTEC include:

• Details: Technology type and description
  
• Cost: Operational performance costs and production rates
  
• Projects: Case studies and projects with contacts for technology auditors
  
• Developers/Vendors: Company names, locations, and contacts
  
• Photo/Schematic: Diagram and picture of technology
  
• Literature: Technology literature references.

Overview of EPA's Contaminant Sediment Management Strategy

Tom Armitage (EPA) provided an overview of EPA's Contaminant Sediment Management Strategy. He indicated that the goals of the strategy are to: (1) manage existing sediment contamination through pollution prevention, source controls, and natural recovery where appropriate; (2) remediate high-risk sites where neural recovery is not acceptable; (3) ensure environmentally sound management of sediment proposed for dredging and disposal; (4) prevent future contamination of sediments; and (5) develop and apply methodologies for analyzing and assessing contaminated sediments. Tom indicated that EPA has taken a number of steps to meet these goals—EPA will adopt standard sediment bioassays, bioaccumulation tests, and analytical chemistry methods for cross-program use and a tiered testing framework will be developed to promote efficient use of resources and screening of sites. The standard sediment bioassay tests are currently under development and Tom noted that a white paper on bioaccumulation testing and interpretation for sediment quality assessment has also been developed.

The white paper addresses:

• Approaches for modeling bioaccumulation.
  
• Summary of EPA regulatory program collection and interpretation of bioaccumulation data.
  
• Recommendations for further research on bioaccumulation and sediment quality.
  
• Information on potential chemicals of concern highlighting: chemical characteristics, effects on human health, and effects on wildlife and aquatic organisms.
  
• Field and laboratory methods for assessing bioaccumulation.

Tom provided an outline of the Water Resources Development Act of 1992 (WRDA), from which the Contaminant Sediment Management Strategy was developed. He noted that the WRDA was developed to:

• Conduct a comprehensive national survey of data regarding aquatic sediment quality.
  
• Identify the location of contaminated sediments that are and the probable sources of sediment pollutants.
  
• Report to Congress the findings, conclusions, and recommendations for actions to prevent contamination on a biennial basis.
  
• Develop a system to manage, store, and disseminate aquatic sediment quality data.

The National Sediment Inventory (NSI) was also developed as a result of the WRDA. The NSI created the Site Inventory Evaluation Methodology, which delineates a 3-tiers to classify systems:

• Tier 1: Higher probability of adverse effects to aquatic life or human health.
  
• Tier 2: Intermediate probability of adverse effects to aquatic life or human health.
  
• Tier 3: No indication of adverse effects (data may be limited or extensive).

A database has been developed that provides statistics on the tier-classification of sites. Tom noted that the statistics are probably skewed, because it represents only those sites reporting data, which are sites where, typically, contamination is present or expected to be present. As a result of the tiered-classification system, 96 watersheds (5% of all U.S. watersheds) were identified as areas of potential widespread sediment contamination (APC).

Tom made the following observations regarding sources of sediment contamination: (1) the extent of pesticide in APC watersheds correlates with the extent of agricultural land use; (2) the extent of mercury, metal, and PAH contamination in APC watersheds correlates with the extent of urban land use; and (3) watersheds receiving significant point source discharges of sediment contaminants are more likely to be designated an APC. He provided the following conclusions and recommendations pertaining to sediment contamination: (1) there is a co-occurrence of evidence of sediment and point source discharge of sediment in a number of watersheds; (2) further evaluation of these chemical releases is needed to determine if action is necessary to protect downstream sediment quality and promote natural recovery; and (3) further evaluation should incorporate appropriate methods to determine site specific contaminant fare and transport, accumulation and bioavailability in sediment, and acceptable risk to potential human and ecological receptors.

Discussion of Site Assessment Issues

Ralph Stahl initiated a discussion of site assessment issues. He suggested that there are three common approaches used in sediment bioassessment—sediment quality triad (depicted below), effects based approach, and the numerical criteria approach.

The Action Team discussed assessment at length, and developed the following list of issues pertaining to assessment:

• Development of risk-based goals, cleanup measures
  
• Development of cleanup goals, numbers, and approaches
  
• Identification of assessment tiers, triggers
  
• Understanding of the impacts and benefits to the environment and the ecological costs of "active" remediation
  
• Identification of data gaps in current understanding of risks and benefits
  
• Definition of success
  
• Identification of the mechanism of chemical sequestration
  
• Development of a decisional matrix/weight of evidence (are certain data elements more important than others)
  
• Definition of risk/definition of acceptable risk
  
• Interpretation of test data, which may be influenced by the nature of the decision at hand
  
• How are multiple contaminants factored into risk assessment?
  
• How are multiple sources of contaminants most appropriately addressed?
  
• Extrapolation and scale-up of laboratory studies to the field
  
• Identification of appropriate exposure unit for ecological effects?
  
• What is an appropriate reference sediment?
  
• Development of models for understanding recovery time
  
• Development of user-friendly communication tools for risk management, showing costs, benefits, etc.

Discussion of Potential Resources

Rich Kimerle asked participants to identify areas of sediments remediation expertise within their organizations and/or resources they may be able to contribute to a cooperative effort.

EPA's Duluth Laboratory. Dave Mount indicated that EPA/Duluth may be able to provide toxicological and analytical support. He noted that funding, especially travel funding, is often limited and the laboratory would be able to more easily provide in-kind contributions. Dave also indicated that although the laboratory has worked primarily on fresh-water sediments, it may be able to investigate marine sediments as well. Dave agreed to that he would contact EPA/Region V officials and determine if they are interested in a cooperative effort and the Action Team in general.

DuPont. Ralph Stahl indicated that DuPont also has a toxicology laboratory and a number of other resources. He also noted that DuPont may be able to provide information on a number of case studies where sediment remediation has been performed (primarily dredging efforts). Dick Jensen added that DuPont may be able to contribute to a cooperative field effort by providing either in-kind contributions, direct funding, or both.

EPA's National Risk Management Research Laboratory. Jim Ryan (EPA/NRMRL) indicated that EPA/NRMRL has expertise in numerous fields, including natural attenuation, in-situ treatment (primarily biological), and treatment within confined disposal facilities, and may be able to provide ecological/toxicological schemes and case study information. He noted that EPA/NRMRL is interested and involved in studies at a number of sites.

Naval Research Laboratory (NRL). Tom Boyd (NRL) indicated that NRL has not performed a significant amount of work in the sediments remediation field to date. However, he indicated that NRL has expertise in a number of related fields. He expressed interest in bioremediation pathways and natural abundance of isotopes, and added that NRL has been involved in remediation efforts at Pon Hueneme, CA.

Naval Facilities Engineering Services Center. Ernie Lory mentioned that he manages the Bay Area Defense Conversion Action Team (BADCAT), which is overseeing the closing of seven area military facilities. BADCAT is investigating heavy metals, PAHs, and PCBs. Ernie indicated that NFESC could provide a test location in the San Francisco Bay area for a demonstration and that additional test site opportunities may be available dependent upon the chosen technology. He noted that it would be beneficial to standardize workplans, if the Action Team does perform a field project. The Federal Remediation Technologies Roundtable (FRTR) has developed a guide to documenting cost and performance data for remediation projects and Ernie indicated that a number of organizations are adhering to this guide for uniformity.

General Electric. John Haggard indicated that GE has a strong knowledge base regarding PCBs. GE has investigated in-situ technologies, difficulties handling materials, and risk-based analysis, among others. John believes that it would be beneficial to continue information sharing regardless of whether or not a specific technology is identified for investigation.

Chevron. Will Gala (Chevron) indicated that Chevron is interested in intrinsic bioremediation to address sediments contamination. Chevron would be able to share its knowledge base and may be able to provide data from previous investigations. Chevron is also interested in natural capping and semi-permeable membranes. Will suggested that the Action Team focus on the remediation aspects rather than assessment issues—industry is currently able to assess sites with greater expertise than it is able to remediate them. Will also suggested that the remediation technology of interest should either directly restore the site or ease the restoration Process.

Ciba-Geigy. Jeff Spencer indicated that Ciba is currently remediating sites with sediment contamination. However, Ciba's ability to contribute in-kind contributions or direct funding is limited until the next calendar year because of internal constraints.

BBL. David Hohreiter indicated that BBL has primarily investigated in-place containment and may be able to provide information that has not been published, including cost information. Several participants indicated that cost data would be helpful.

Exxon. Ray Arnold indicated that Exxon has ecological and toxicological expertise. Ray suggested that a comprehensive database, if not currently available, be developed detailing sites where sediment remediation is on-going, planned, or has been performed. He also suggested that the Action Team also consider technologies used in Canada and Europe.

Dow. John Davis indicated that Dow has a significant effort underway to investigate natural attenuation—the effort is not limited to sediments. He added that an affiliate has significant expertise in sediment remediation. John suggested that an innovative technology be developed and felt that a cooperative laboratory/field effort would be mutually beneficial to all involved parties.

Naval Command Control and Ocean Surveillance Center (NCCOSC). Victoria Kirtay indicated that NCCOSC is able to provide information and noted that NCCOSC has ongoing efforts in biomarkers, bioavailability, and biosensors. She indicated that the leveraging of funds would be helpful.

ICI. Martin Bell indicated that ICI is interested in "better, safer, more cost-effective" technologies.

EPA's Office of Science and Technology. Tom Armitage indicated that EPA's Office of Science and Technology would be able to provide access to collected/analyzed data.

U.S. Army Corps of Engineers. Norm Francingues noted that he works at a Resource Conservation and Recovery Act (RCRA)-permitted facility. He also indicated that he is involved in a number of field sites, and has significant amounts of contaminated dredging materials, which could be utilized by the Action Team. It would be helpful to have laboratories investigating similar sediments, and Norm would be able to fill that need. A full-scale analytical laboratory is also available. Norm also mentioned that USACE has significant experience with in-place capping, implementation, and import of sediments onto and off of barges. Norm also noted that USACE has worked with EPA's National Exposure Research Laboratory to investigate phytoremediation in wetlands. A number of other efforts have been undertaken by the USACE, including bioremediation of PAHs, chlorinated solvents, and PCBs. Norm offered to host a future meeting of the Action Team, including a tour of USACE's facilities.

Monsanto. Rich Kimerle indicated that he is also interested in performing a cooperative laboratory/field study and expects to be able to contribute in-kind contributions and perhaps funding as well.

Concluding Remarks

Norm Francingues suggested that a topic of the next meeting should be in-situ capping, and including such issues as efficacy and permanence. A combination of studies could be performed, providing opportunities for any interested party to participate. It was agreed to hold a 2-day meeting at USACE\WES, hosted by Norm Francingues, on October 29-30, 1996. The first day of the meeting will provide an opportunity for the subgroups to meet in breakout sessions; the second day will allow the Action Team to reconvene and report the progress made during the previous day. A tour of USACE/WES will also be scheduled on the second day. Dave Mount and Rich Kimerle thanked Ralph Stahl for hosting the meeting, and thanked Norm for offering to host the upcoming meeting.

RTDF Sediments Remediation Meeting Participants