In the last 18 months, the Environmental Restoration Division has continued to move the Superfund cleanup program at BNL from assessment and investigation to active remediation. That process continues this summer with several important remediation projects going on simultaneously.
These projects embody the three cleanup philosophies that are central to our mission at BNL: 1) removing sources of contamination, 2) preventing the spread of contamination, and 3) remediating existing areas of contamination (groundwater plumes, for example). These projects represent the culmination of several soil and groundwater investigations that stretch back to 1991 (when ERD was created) and earlier.
Waste pit remediation
Our biggest project this summer consists of removing waste from 51 former waste pits (see story, this page). These pits, known as the Chemical/Animal Pits and Glass Holes, were used from the late-1950s to 1981 for the disposal of chemical containers, drums, laboratory glassware and animal carcasses. Our investigations determined that the pits were a source of contamination of area soil and groundwater, so the contents are currently being excavated, sorted, and disposed of off-site.
Chemicals removed
To prevent the spread of contamination and remove existing contamination, several projects are under way. Two pump-and-treat systems are now operational, extracting more than 1,300 gallons per minute of contaminated groundwater from the Lab's southern boundary. The water is being treated to remove the contamination, and the cleaned water is then returned to the aquifer. These systems are all expected to run for several years, working around-the-clock to clean the aquifer. A third system, constructed to prevent further southward migration of the tritium plume associated with the Lab's High Flux Beam Reactor, has been operating since May.
ERD has also begun construction on a cleanup system in the central part of the Lab known as Operable Unit IV (see story, page 3). Soil and groundwater in this area contain remnants of fuel oil and solvents from a 1977 spill. Two technologies are being combined to remediate the area. Air sparging and soil vapor extraction work together, forcing pressurized air into the groundwater to bubble these volatile compounds out of the water and into the soil. Once in the soil, powerful vacuum pumps recover the resulting vapors and pipe them to a treatment facility. The combination of these two technologies is expected to be quite successful in this area.
More work ahead
While these projects represent a large percentage of the cleanup work being done at the Lab, they are not the first. Several important projects have been accomplished in the past few years, including the capping of two landfills, the removal of nine radioactive waste storage tanks, and remediation of more than 30 cesspools.
They are not the last, either. Investigations in three other areas of
the Lab are still under way, and as we move into 1998, several more remediation
efforts will begin. These include the cleanup of radioactive soils at the
Hazardous Waste Management Facility and other areas of the site. The Superfund
cleanup at BNL is a long, involved process, but it certainly is encouraging
to see remediation taking place at the pace and scale it is right now.