Since 1989, when BNL was listed as a Superfund site, the Environmental Restoration program has been working towards one primary goal - the long-term protection of human health and the environment. To reach this goal the program has focused on eliminating sources of contamination and cleaning up areas where contamination has migrated (i.e., groundwater plumes).
Over the past three years, the Environmental Restoration Division (ERD) has continued to move the cleanup program from investigation to active remediation. This has included the construction of several soil and groundwater treatment systems; the conclusion of two "fast-track" cleanup actions; and research into new technologies.
Following are ERD highlights since 1994, keyed by number to their location (see map, below):
Groundwater projects
1,2 - Groundwater Treatment Systems Installed: These two systems, completed in December 1996 and June 1997, use extraction wells at the Lab's southern boundary to remove more than 1,300 gallons per minute of contaminated water from the aquifer, preventing further off-site migration of contaminants. After extraction, two "air strippers" are used to remove the contamination before the clean water is recharged.
3 - HFBR Tritium Plume: ERD completed extensive characterization of the tritium plume originating from the High Flux Beam Reactor spent fuel pool and constructed a pump-and-recharge system to prevent tritium at levels above the drinking water standard from migrating off-site. The system, which also employs a carbon filter to remove chemical contamination, began operating in May 1997.
4 - Soil/Groundwater Treatment System Constructed: As part of the cleanup of the Central Steam Facility, ERD completed the design and initiated construction this summer of an air sparging/soil vapor extraction system to remediate residual soil and groundwater contamination at the site of a 1977 oil/solvent spill. The system is expected to be operational later this month (see story, page 7).
5 - Off-site Treatment System Designed: This fall, ERD initiated the design of an offsite groundwater treatment system for part of a contaminant plume that has moved south of the Lab's southern boundary at depths of 180 to 300 feet below land surface. System construction is expected to begin in summer 1998.
Landfill projects
6 - "Current" Landfill Capped: The eight-acre "Current" landfill, used by the Lab from 1967 to 1990, was capped with an impermeable liner in a project completed in November 1995, preventing rain from carrying contamination into the groundwater.
7 - "Former" Landfill Capped: The eight-acre "Former" landfill, used by the U.S. Army until 1947 and BNL until 1966, was capped in a project completed in November 1996.
8 - "Interim" Landfill Capped: This fall, ERD completed the design and initiated construction of an impermeable cap for the Lab's "Interim" landfill, used in 1966. The project was completed in October 1997.
9 - Chemical/Animal Pits-Glass Holes Excavated: This project, begun in June 1997, involved the excavation of 55 former waste pits near the Lab's "Former" landfill. The pits, used from the late-1950s to 1981, were a source of groundwater contamination. Excavation was completed in August, and sorting and off-site disposal of pit contents is ongoing.
Storage tank removal
10 - D-Tanks Dismantled: in a project that began in August of 1994, ERD dismantled three 100,000-gallon low-level radioactive waste storage tanks and transported them off-site for disposal.
11 - Storage Tanks Removed: In this project, begun in July 1995, six out-of-service underground storage tanks that formerly contained hazardous and radioactive waste were emptied, removed and disposed of off-site.
12 - Imhoff Tanks Emptied: ERD removed 64,000 gallons of sludge, some containing low levels of radionuclides, from aging settling tanks at the Lab's Sewage Treatment Plant in 1995. The sludge was taken off-site to a permitted waste disposal facility, and the tanks themselves were dismantled in the spring of 1997.
13 - Cesspools Removed: As part of ERD's mission to remove potential sources of contamination, the office began the sampling and removal of 28 former site cesspools in 1995. The project was completed in 1997.
Water hookups
14 - Public Water Hookups Offered: Beginning in January 1996, the U.S. Department of Energy offered free hookups to public water as a precautionary measure to approximately 1,300 residents and business owners in the North Shirley, East Yaphank and Manorville areas south and east of the Lab.
While ERD has made substantial progress in the ongoing Superfund cleanup at BNL, more work remains to be done. Investigations in three other areas of the Lab are still under way, and, as 1998 approaches, several more cleanup efforts will begin. These include the removal of eight additional underground storage tanks and treatment of an off-site groundwater contaminant plume.
For a complete schedule of past and future cleanup activities and document release dates, see BNL's Superfund schedule.