Operable Unit V, STP, Record of Decision

January 2002

Operable Unit V, STP, Record of Decision

BNL's Sewage Treatment Plant

Background

In 1989 BNL was added to the U.S. Environmental Protection Agencys (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 V

Operable Unit V is located in the northeastern quadrant of the BNL property along the eastern property border. OU V addresses contamination from the operation of BNLs Sewage Treatment Plan (STP) that was found in soil and groundwater and Peconic River sediments. The AOCs for this OU include 4, 4A through 4E, 21, 23, and 30 (Peconic River). Cleanup of the STP, leaking sewer pipes, and the eastern tritium plume in OU V were addressed under this Record of Decision (ROD). Remediation of Peconic River sediments (AOC 30) was deferred to allow further evaluation of the cleanup alternatives.

The primary contaminants identified in OU V were metals, including mercury, silver, copper, lead, zinc, chromium, and thallium. Radionuclides found included americium-241, cesium-137, and plutonium-239/240. Tritium, trichloroethene (TCE), and manganese were found in the eastern groundwater plume.

The OU V remedial action objectives for groundwater are to protect public health and the sole source aquifer and to continue to collect the data needed to characterize and monitor levels of contamination. For STP soils, the objectives were to reduce the levels on contamination in the sand filter beds and berms, to prevent or minimize: the migration of contaminants present in the surface soil via runoff and windblown dust; human and environmental exposure to contaminants in the surface or subsurface soils; the potential for uptake of contaminants present in the soil by ecological receptors; and the potential for migration of contaminants from soil to groundwater.

The following is a press release dated February 27, 2002 outlining the highlights of the OU V ROD.

Department of Energy, EPA, and N.Y. State Reach Agreement on Cleanup of Brookhaven Lab's Sewage Treatment Plant - Peconic River Sediment Cleanup Decision Expected Later This Year

Upton, NY The U.S. Department of Energy (DOE), the U.S. Environmental Protection Agency (EPA) and the N.Y. State Department of Environmental Conservation (NYSDEC) have agreed on cleanup plans for soil and groundwater contamination at Brookhaven National Laboratory's Sewage Treatment Plant. The agreement, reached after extensive regulator and public review and comment, allows the Energy Department and Brookhaven to implement the selected remedies. It also marks an important milestone in DOE's plan to complete cleanup of the Laboratory site.

The remedies are detailed in a document called the Operable Unit V Sewage Treatment Plant Record of Decision. The document is available at local libraries and will also be posted on the Brookhaven web site.

The Record of Decision (ROD) presents the selected remedial actions for portions of Operable Unit V, which includes the Laboratorys STP and associated components: sand filter beds and berms; sludge drying beds; sewer lines; and an off-site plume, or area of groundwater contamination, containing low levels of tritium and the chemical solvent trichloroethene. It also documents the final remedy for several accelerated cleanups, known as removal actions, that have either been completed or are ongoing.

Operable Unit V also includes contaminated sediments found in the portion of the Peconic River headwaters on the Laboratory site and extending just beyond its eastern boundary. These sediments, which are targeted for cleanup due to contaminants including silver, mercury, polychlorinated biphenyls, and DDD (a breakdown product of the pesticide DDT), will be addressed in a separate cleanup plan. That document will be drafted following a series of pilot studies of innovative cleanup technologies scheduled to begin this month.

The ROD agreement follows extensive public participation activities held by the Department of Energy and Brookhaven since 1994 to obtain input on the Operable Unit V investigation and potential cleanup approaches. These activities included dozens of briefings to area civic groups, public and private organizations, and the Laboratorys Community Advisory Council and Brookhaven Executive Roundtable; 12 roundtable and informational sessions with interested community residents; public comment periods on related cleanup documents; and informational mailings to and canvassing of homes in the Operable Unit V area. These events generated comments and concerns that have been made part of the public record. The ROD contains a Responsiveness Summary, which documents public comments on the proposed remedial actions, DOE responses to those comments, and changes made as a result of them.

Details of Selected Remedy

The major components of the selected remedy are summarized below:

Sand Filter Beds and Berms and Sludge Drying Beds

The selected remedy for the cleanup of the sand filter beds, berms, and sludge drying beds, which are the primary focus of this ROD, involves excavation and off-site disposal of radiologically and chemically contaminated sand and soil found in these areas at levels above cleanup goals set by Brookhavens regulatory agencies. Follow-up sampling will be conducted to ensure these cleanup goals are met.

Sewer Lines

No longer in use, these sewer lines contain sludge contaminated with chemicals and radionuclides including nickel, thallium, cesium-137, and americium-241. The sewer lines were previously capped at both ends, eliminating any pathway for potential exposure for Brookhaven workers or the public. As part of the selected remedy, any remaining sludge will be removed through 10 manholes along the sewer line, and institutional controls will be put in place to ensure any future construction in the area will not disturb these sewer lines.

Eastern Off-site Tritium Plume/Groundwater Monitoring

Groundwater containing low levels of tritium and the solvent trichloroethene (TCE) will be monitored and allowed to naturally degrade and decay. The highest levels of tritium seen in off-site sampling during 2000 were approximately one-tenth of the drinking water standard. TCE was seen at levels ranging from two to four times the drinking water standard in on- and off-site samples taken in 2000. Off-site homes and businesses in the OU V area were offered connection to the public water system in 1997 to prevent the potential for future exposure to TCE.

Imhoff Tank

The ROD also adopts as a final action the 1995 cleanup of this tank, used to process solid sewage waste. Contaminated sludge in the tank was removed, treated and disposed of off site, and the remaining concrete structure was demolished, backfilled with clean soil, and capped with concrete.

The next step in the cleanup project involves the detailed planning and design of the remedy. Once this design phase is complete, the cleanup will proceed under the guidance of DOE, EPA, and NYSDEC.

Environmental remediation at Brookhaven Lab is carried out under requirements of the federal Comprehensive Environmental Response, Compensation and Liability Act of 1980, commonly known as the Superfund Law. The Laboratory is on the EPA's National Priorities List due to past operations that have resulted in soil and groundwater contamination.

Remediation work is conducted under the framework of an Interagency Agreement among the U.S. Department of Energy, the U.S. Environmental Protection Agency and N.Y. State Department of Environmental Conservation. The Department of Energy owns the Brookhaven property and oversees and pays for all cleanup costs at the site.

Community Input

There were numerous opportunities for the community to participate in the decision-making process for the OU V clean up. In accordance with CERCLA, a Community Relations Plan had been finalized in September 1991, and the Laboratory established Administrative Record repositories in local libraries to hold cleanup documents. 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, a Removal Action, which sought to remove the contamination source as quickly as feasible in order to eliminate any potential threat to the public or environment, was completed prior to the finalization of the OU V ROD. Under the Action, two World War II-era waste settling tanks at the STP were removed in 1995. More than 64,000 gallons of sludge was removed from the "Imhoff tanks" and shipped to an off-site waste disposal site. The concrete tank structure was demolished in 1997 and the area was backfilled with clean soil.

A chronological list of outreach for Operable Unit V may be found in the Responsiveness Summary of the Record of Decision (ROD). Outreach began in 1994 with the release of the OU V Remedial Investigation / Feasibility Study Work Plans. Additional highlights of BNLs outreach includes briefings to 13 local civic organizations in 1995, briefings to regulators and elected officials in 1997, a second round of briefings and five roundtable sessions held in 1998 after plutonium was found in river sediment. Articles updated stakeholders, the Community Advisory Council (CAC), and the Brookhaven Executive Roundtable during 1999 (in fact, as of this writing some 58 presentations have been made to the CAC on the Peconic River). The OU V proposed cleanup plan was released to the public in February 2000. Several hundred written comments were received. In June 2000, a letter summarizing the path forward (announcing additional research into cleanup alternatives for the Peconic River) was mailed to 2,500 stakeholders.

As the result of community input, a Peconic Work Group was established and pilot tests were conducted on several alternative cleanup methods over the next year. After the results were analyzed, a cleanup plan was developed and the Peconic River ROD was finally signed on January 24, 2005. Work to address the contamination at the STP was completed in 2003.

Documents / Links

OU V RI/RA Summary

OU V 1999 Fact Sheet

OU V Sewage Treatment Plant Record of Decision

Additional OU V Documents