Operable Unit III Record of Decision

June 2000

Operable Unit III Record of Decision

Sampling groundwater


In 1989, BNL was added to the U.S. Environmental Protection Agency's (EPA) National Priorities List under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, more commonly known as the Superfund Act, as the result of contamination found during a 1988 Department of Energy (DOE) Environmental Survey. Investigators initially identified 28 areas at the Laboratory with some contamination. These areas became known as Areas of Concern (AOCs) and included Solid Waste Management Units (SWMUs) that had been identified earlier by the NYSDEC under the Resource Conservation and Recovery Act (RCRA) permitting process. Cleanup operations at the Laboratory were geographically subdivided into seven Operable Units (OUs) to focus efforts and assign priorities (Later, OU II and OU VII were combined into one OU.).

Operable Unit III

Operable Unit III addresses groundwater contamination in the central and southern portions of the BNL site and in the off-site areas where groundwater contamination has migrated. It is bounded by the Laboratory's northern, southern, and western boundaries and encompasses approximately 50 percent of the Laboratory's total area. The AOCs for OU III include 7, 9 and 9D, 11, 12, 14, 15, 19, 21, 22, 24A, B, and C, 25, 26A and B, 27, and 29. Additionally, groundwater cleanup from contamination in AOC 2 (the landfills and chemical pits under OU I) was included.

The AOCs were investigated as suspected source areas of groundwater contamination. As the work for OU III proceeded, groundwater contamination from other OUs and additional areas were included in the investigation and assessment. Based on the investigations and findings of the Remedial Investigation/Risk Assessment, DOE, BNL, EPA, and the NYSDEC determined that the groundwater was the only medium in OU III that required action. The primary contaminants of concern were volatile organic compounds (VOCs) both on- and off-site, and tritium and strontium-90 in on-site groundwater.

The remedial action objectives for OU III are to restore groundwater quality to maximum contaminant levels (MCLs) for drinking water or background, and prevent or minimize leaching of contaminants from soil into groundwater; human exposure from surface and subsurface soil; and the uptake of contaminants in soil by plants or animals.

The following is an article outlining the highlights of the OU III ROD that was published in the April 2000 edition of the stakeholder newsletter cleanupdate.

Groundwater Cleanup Plans Near Finalization

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 (NYSDEC) 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 NYSDEC, 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 to determine if treatment is needed.


Shortly after the on-site tritium plume was discovered, the Lab constructed a groundwater extraction system at Princeton Avenue 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.

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. 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.


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 steps

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.

Community Input

There were numerous opportunities for the community to participate in the decision-making process for the OU III clean up. In accordance with CERCLA, a Community Relations Plan was finalized in September 1991, and the Laboratory established Administrative Record repositories to hold cleanup documents were established in local libraries. The Community Relations program focused on public information and involvement. A variety of activities including direct mailings, community meetings, poster sessions, tours, workshops, and public meetings were held on the cleanup actions.

As with other Operable Units, Removal Actions, which seek to remove contamination sources as quickly as feasible in order to eliminate any potential threat to the public or environment, were also completed prior to the finalization of the OU III ROD. The Removal Actions included installation of several groundwater treatment systems (Removal Actions IV and V.). Public Notices on the actions were published in local newspapers and poster sessions were held for the first off-site treatment system in Longwood Jr. High School on April 4 and 6, 1998 to community questions.

To ensure early and effective input into the process, DOE and BNL began reaching out to the community before the Proposed Plan for cleanup was released. In August and September of 1998, stakeholders were invited to participate in four Community Roundtables, and canvassing of residents was conducted. In October 1998, a Community Workshop on OU III cleanup options was held. Community members had the opportunity to discuss their concerns directly with the BNL and DOE staff. Some of their input was incorporated into the Feasibility Study. For example, stakeholders requested consideration of an option that would complete VOC cleanup faster (in approximately 10 years). This alternative was added to the list of the alternatives evaluated in the Feasibility Study. Concern was also expressed about the impact of VOCs on the Carmans River; additional groundwater modeling was done and a new cleanup alternative was developed which included possible treatment systems for the western low-level VOC plume. Stakeholder support for leaving the tritium and strontium in the ground rather than extracting it was strong, and this also affected the alternatives recommended for cleanup. This input was used to help develop and evaluate cleanup alternatives in the Feasibility Study.

The Laboratory held several information sessions (March 10, 16, and 18, 1999) during the comment period on the Proposed Plan and Feasibility Study. A Public Meeting was held on March 24, 1999 in Berkner Hall. Additional community relations activities included briefings to elected officials and community groups, and articles in cleanupdate, the Environmental Restoration Division's newsletter. Over 2,300 people on the BNL mailing list received the newsletter along with frequent mailings about specific remediation activities. Invitations to roundtables, information sessions, or public meetings were often included in the mailings. BNL employees and retirees (a combined total of nearly 5,000) also received cleanupdate and articles in the Brookhaven Bulletin, which provided updates on specific remediation topics. The Community Advisory Council was another avenue for stakeholder groups to have access to BNL and DOE management and to learn about BNL.

Documents / Links

OU III FS Executive Summary

OU III Record of Decision