At the request of the independent Community Work Group looking into operations at Brookhaven National Laboratory, the Lab's Environmental Restoration Division reviewed cleanup methods under consideration for the so-called "chemical/animal/glass holes" at the group's May 14 meeting.
These 50 pits range in size from about 10 to 20 feet wide and eight to 15 feet deep. They are in the Lab's southeast quadrant, just east of the Former Landfill and southwest of the Current Landfill.
The pits were a disposal area for used laboratory chemical containers, glassware and animal carcasses, and were used from roughly the middle 1950s to 1980. The investigation included ground-penetrating radar and other sensing instruments, plus interviews with current and former BNL workers. As a test, one hole was excavated in spring, 1994.
Most of the pits contain empty or partially filled bottles and other small chemical containers which held or now hold acids and bases, solvents, or metals. Low-level radioactivity has been detected in two of the pits. A few small drums have also been detected.
In 1995, investigation of the soil contamination showed that approximately 10 percent of the holes had slightly contaminated soil under or adjacent to the pit.
Groundwater near the pits has shown solvent and strontium-90 concentrations above drinking water standards. Strontium-90 has not been found in the groundwater near the site boundary or off-site.
One possible cleanup method involves excavation, either by hand, robot or backhoe. The other three possible methods use containment, either by capping the holes, by encapsulating the pits using cement grouting and/or polymers, or by in-situ vitrification (melting the waste in place to form glass).