Environmental Management Directorate

Building 51
P.O. Box 5000
Upton, NY 11973-5000
Phone 631 344-8192
Fax 631 344-5844
grigoletto@bnl.gov

managed by Brookhaven Science Associates
for the U.S. Department of Energy

Tuesday, February 19, 2002

Dear Peconic River Working Group:

This letter recalls some highlights from our January 22 meeting, and announces our next standing meeting.

HIGHLIGHTS FROM OUR JANUARY 22 MEETING

Skip Medeiros, the Peconic River Project Group Manager, opened the meeting with a status on risk assessment. Of particular interest is that the project team is preparing a response to the regulators to reconcile fish consumption rates to be used in scenarios of the risk assessment.

Next, Kevin Shaw, the Project Manager, discussed the cleanup technology of "Sediment Removal and Wetlands Reconstruction." Work is being done with the Department of Environmental Conservation (DEC) to identify ways to access Area D, a single upland area, to ensure the least amount of disruption. Based on comments from the DEC, the project team anticipates removing 7-12 small trees to enable vehicles to access the site. Kevin is also working to create a re-vegetation plan. Much of this plan will be based upon input from members of the working group and regulatory agencies staff members. Pointing to a large map of the area, Kevin said that after removing contaminated sediment he wants to re-vegetate the area with local plants. He requested input from the working group toward that end. During open discussion, significant points included the following:

• Sediment near Area "D" will be removed and tested prior to the installation of the sediment trap.
• Working-group members encouraged the project team to plant something early, to cover the area and to keep out Phragmites. A nurse crop was suggested to help stabilize the area. The working group also acknowledged that the new plants would return organic matter that was removed by the sediment excavation.
• Standard topsoil should not be used to replace the sediment removed by excavation. The surrounding soil, however, may contain an existing residual seed source. BNL should consider growing some samples in a greenhouse and see what comes up.
• Part of the re-vegetation plan will be Phragmites control. One of the working group members suggested that the project team cut the flowers off the top of the Phragmites to avoid seed from returning to the soil. Five percent of the seed comes from the flowers; the rest comes from rhizomes. Eventually, any Phragmites would have to be pulled out to prevent their spread.

Skip next spoke about the preliminary data from the native plant phytoextraction screening study. Skip explained that the bioaccumulation factor of the contaminants in the plants has to be high for the technology to be effective. The bioaccumulation factor exhibited by the native plants evaluated is quite low. Significant points included the following:

• Both above-ground and below-ground plant samples and closely adjacent sediment samples were taken from Areas "B, " "C," and "D."
• Initial interpretation of the native wetland plant phytoextraction data indicates that to reduce contaminant concentrations by one-half may take several hundred years.
• Cesium would decay naturally, long before the extremely slow phytoextraction-- achieved by native wetland plants performing natural phytoextraction--would reach the same cleanup levels.

Further work is being done on the phytoextraction analytical results to verify calculations and to develop a written report before conclusions are final. Skip also reported to the working group that the CAC had recommended by consensus vote that we not go forward with the electrochemical technology. BNL and the DOE are now formalizing that decision.

OUR NEXT STANDING MEETING

Our next standing meeting will take place on February 26, 2002 from 6:30-8:30pm here at Brookhaven National Laboratory, in Berkner Hall, Room "B". Skip will not be present at the February 26 meeting.

VISIT YOUR WEBSITE

Thank you once again for participating on the Peconic River Working Group. If you have any questions, please contact me at your convenience:

Keith Grigoletto
email to: grigoletto@bnl.gov
(631) 344-8192