After many months of soliciting input from community members, holding public meetings and information sessions, giving presentations to the Laboratory Community Advisory Council, and working with regulatory agencies, final decisions are being agreed to for cleaning up the groundwater at and near Brookhaven National Laboratory (BNL).
The U.S. Department of Energy (DOE) has been working closely with the U.S. Environmental Protection Agency (EPA) and the New York State Department of Environmental Conservation (DEC) to reach concurrence and gain signatures on the Operable Unit III Record of Decision (ROD).
The ROD will mark an important milestone in BNL's environmental cleanup program. Once signed by EPA, with the concurrence of the DEC, it will clear the way for the Lab to begin constructing additional groundwater treatment systems to add to the six systems already operating on and off the BNL site.
Several changes from the proposed cleanup plan, which was released in March 1999, were made in response to community and regulator concerns. Some changes were discussed in the September 1999 issue of cleanupdate. Additional changes made since that time are detailed below.
Volatile organic compounds
BNL already has installed five treatment systems specifically to address groundwater containing volatile organic compounds (VOCs). Also, DOE provided public water hookups to a large area south of the Lab.
Current plans in the DOE-signed ROD call for the installation of eight additional treatment systems in locations both on and off the Laboratory site. BNL will extensively monitor the groundwater quality to determine the effectiveness of these treatment systems. The effectiveness of these systems will be evaluated quarterly and yearly.
Deep contamination in the Magothy aquifer will also be studied, as described in the update on page 2, to determine if treatment is needed.
Tritium
Shortly after the on-site tritium plume was discovered, the Lab constructed a groundwater extraction system at Princeton Avenue (see map below) to inhibit contaminated groundwater from moving toward the site boundary. This system removes the groundwater and pumps it to a basin on the Lab site, where it re-enters the aquifer. The additional travel time required to flow south from this basin allows the tritium levels to decrease, ensuring that levels higher than the drinking water standard will not leave the Laboratory site.
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| One system to address the on-site tritium plume is currently operating. Two additional extraction systems are planned. Plume contours shown above are draft contours from December 1999. |
The current remedy for tritium is a modification of the remedy proposed in March 1999. After an evaluation, the Princeton Avenue system will be placed on stand-by and restarted if needed. Also, BNL will construct two pumping systems on Cornell Avenue and Temple Place (see map). Both systems will be just south of the High Flux Beam Reactor (HFBR), whose spent fuel pool is the former source of the tritium.
The low-flow system at Cornell Avenue will be activated if tritium levels at the front of the HFBR exceed 2,000,000 picocuries per liter (100 times the drinking water standard of 20,000 picocuries per liter). It will be used to remove the highest concentrations of tritium. The detailed operational parameters of this system will be developed during the remedial design.
The Temple Place system will operate for up to one year as needed. It may operate longer than one year if necessary in order to meet the cleanup objectives. Groundwater monitoring will evaluate the effectiveness of these systems.
Evaluation of monitoring data shows that, at the observed concentrations, tritium will not reach the site boundary at levels above the drinking water standard. These systems provide further assurance of meeting cleanup goals.
Strontium
The ROD remedy for strontium-90 in groundwater is identical to the proposed remedy. Groundwater extraction wells will be installed in several locations on the Laboratory site where strontium has been found. The groundwater will be extracted and treated with ion exchange to remove strontium-90. The clean water will be returned to the aquifer. Before treatment begins, a pilot study will test its effectiveness.
Next step
Recent progress in the Operable Unit III cleanup is described in the article on page 5. Additional work will begin following the signing of the Operable Unit III Record of Decision.
DOE and BNL hope to have the ROD finalized this spring. Once it is signed, the additional groundwater treatment systems will be designed and constructed over the next several years. DOE expects that all of the systems will be operational by 2006 or earlier.
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Five VOC groundwater treatment systems already are operational both on and off the Laboratory site. An additional eight systems are planned. |