SUMMARY OF THE REMEDIATION TECHNOLOGIES DEVELOPMENT FORUM
SEDIMENTS REMEDIATION ACTION TEAM
NATURAL RECOVERY SUBGROUP CONFERENCE CALL

1:30 p.m.-2:30 p.m.
April 4, 2002

On April 4, 2002, the following members of the Remediation Technologies Development Forum's (RTDF's) Sediments Remediation Action Team, Natural Recovery Subgroup, met in a conference call:

John Davis, The Dow Chemical Company (Subgroup co-chair)
Tim Dekker, Limno-Tech, Inc.
Steve Ells, U.S. Environmental Protection Agency (EPA)
Mike Erickson, Blasland, Bouck, and Lee, Inc.
Peter Klaver, Limno-Tech, Inc.
Douglas McLaughlin, Blasland, Bouck, and Lee, Inc.
Ralph Stahl, DuPont Corporate Remediation
Mike Swindoll, ExxonMobil Biomedical Sciences, Inc.

Christine Hartnett of Eastern Research Group, Inc., (ERG) was also present.

INTRODUCTION

John Davis said that he, Mike Swindoll, and Clay Patmont have been working on a monitored natural restoration (MNR) project. He said that the three-person team has been evaluating historical data from sites where MNR is an integral component (either by design or default) of remediation management strategy. The team's goal is to identify a streamlined approach for data analysis. At some sites, Davis noted, boxes and boxes of data have been collected. People will need a framework for assessing these data--something to help them determine which data are the most important to look at during an MNR efficacy evaluation. Toward this end, the group has identified five lines of evidence that can be used to evaluate efficacy:

• Characterization of historical contaminant sources and controls.



• Characterization of fate and transport processes.



• Compilation of a sufficient historical record for chemicals of interest to evaluate temporal trends.



• Compilation of historical trends in biological endpoint data to corroborate chemical data.



• Development of an acceptable and defensible predictive tool (or tools) to allow prediction of future MNR.

Davis said that the team has started applying the five lines of evidence at two sites in Washington (Bellingham Bay and Spokane River). A "bare bones" analysis has been performed; a more rigorous analysis will be completed, and hopefully published, before the end of the year.

Davis said that this conference call was being held to: (1) determine whether other people are interested in participating in the MNR project, (2) outline activities and deliverables, and (3) define a path forward. Davis said that he wanted to initiate discussion before the group meets face to face on April 9, 2002.

DELIVERABLES

One call participant advised creating a formal guidance document that describes an MNR efficacy assessment approach for contaminated sediments sites. Call participants expressed reluctance, noting that it is difficult to produce a formal "how to" technical guidance document. They agreed that it would be better, at least at this point, to create a flexible assessment framework, apply this framework to a number of sites, and release findings in a series of case study reports. Call participants also suggested releasing the case study findings in a series of fact sheets. These would describe the assessment framework employed and summarize results.

OTHER ACTIVITIES

Call participants identified other activities that would be useful to pursue:

• Speak at meetings. Davis said that abstracts have been submitted for two different Society of Environmental Toxicology and Chemistry (SETAC) meetings. If accepted, Natural Recovery Subgroup members will speak about the Bellingham Bay and Spokane River sites.



• Compile information on long-term attenuation rates. One participant advised compiling information on natural attenuation rates for different chemicals and different sites.



• Identify statistical techniques. One call participant advised forming a small subteam (perhaps one or two people) to evaluate statistical techniques and offer recommendations on which are best to use.

PATH FORWARD

Davis said that the Natural Recovery Subgroup is meeting face to face on April 9, 2002. During this meeting, participants will discuss the "lines of evidence" approach to determine whether it adequately assesses MNR efficacy. Once an assessment framework has been agreed upon, call participants said, individual Subgroup members will apply it to different sites. Call participants agreed that it would be useful to hold conference calls regularly. In addition, they hope to hold face-to-face meetings periodically.

ACTION ITEM

• Ideally, Davis said, the "lines of evidence" assessment framework should be applied at 6 to 12 sites. Davis asked Subgroup members to identify candidate sites and bring a list to the April 9 meeting.



• Davis said that he, Swindoll, and Patmont have already identified some candidate sites. These are summarized in a matrix, which includes information about the sites' contaminants, characteristics, and available data. Davis agreed to distribute the matrix to call participants.



• Doug McLaughlin said that he would research different methods that could be used to incorporate visuals into conference calls.



• ERG will set up the next call for May 3, 2002, between 11:00 and 12:00 Eastern Daylight Time.