Description of Groundwater Projects
During initial environmental studies, the Brookhaven National
Laboratory (BNL) site was subdivided geographically into seven
Operable Units (OU). The main Operable Unit dealing with groundwater
contamination is OU III. OU I, IV, V, and VI also address
Operable Unit I
includes groundwater contamination in the southeastern area of the
Laboratory that is being addressed by a removal action.
Operable Unit III was developed to
address groundwater "plumes," or areas of contamination,
emanating from the central and southern portion of the BNL site. The
main contaminants of concern are volatile organic compounds (VOCs),
strontium-90, and tritium. VOCs have been found both on and off
Laboratory property, while strontium-90 and tritium contaminants are
confined to the Laboratory site.
Operable Unit IV
included groundwater contamination at BNL's Central Steam Facility.
Regulatory agencies have approved the decommissioning
of one of BNL's earliest groundwater treatment systems.
The five-year review of the Operable
Unit IV treatment system is now available.
Operable Unit V
includes groundwater in the eastern-central area of the Laboratory.
Operable Unit VI includes groundwater
in an area about 1,000 feet west of Weeks Avenue at depths of 90
- 130 feet below ground. Groundwater in this area contains the
chemical EDB (ethylene dibromide), once commonly used as a pesticide
and gasoline additive.
Volatile organic compounds
A large area of groundwater
in the central and southern portion of BNL is contaminated with
VOCs. Some VOC contamination extends off site, south of BNL into the
East Yaphank area. The off-site contamination is generally below the
depths of most private wells. Nevertheless, as a precautionary
measure, the U.S. Department of Energy paid for approximately 1,500
homes in the area to be hooked up to public water.
Five treatment systems are already in place and operational to
treat this VOC contamination, including two systems at the southern
site boundary and one system off site in an industrial park just
south of the Long Island Expressway. A new on-site treatment system
is scheduled to begin operating this spring. An additional seven
treatment systems are planned to be installed and operational by
2006 or earlier.
There are concentrated areas of strontium-90 contamination in the
groundwater at three on-site
locations: the Chemical Holes area in the southeast, the Waste
Concentration Facility, and the Brookhaven Graphite Research
Reactor. The latter two are in the central, developed portion of the
This groundwater will be extracted and treated using "ion
exchange" to remove the strontium-90. The clean groundwater
will be returned to the aquifer. Residual waste containing
strontium-90 will be disposed of at a licensed off-site facility.
Tritium from the spent fuel pool of Brookhaven's High Flux Beam
Reactor has leaked into groundwater in the central portion of the
BNL site. The spent fuel pool has been emptied and the High Flux
Beam Reactor permanently shut down, removing the source of the
A pump-and-recharge system was installed in 1997 to remove
groundwater containing tritium from the aquifer and pump it to a
recharge basin further north. There, the water was allowed to
re-enter the aquifer. Groundwater monitoring shows that this system
was effective in halting the southward migration of the tritium
plume. Tritium levels at this
location have been undetectable for over two years, therefore
the system has been placed on standby. It can be restarted if
monitoring indicates a need.
In addition, low-flow pumping has been conducted to extract the
highest levels of tritium from the area south of the reactor. In
2000 and early 2001, a total of approximately 90,000 gallons of
water were removed from the aquifer and disposed of off site.
Further actions to address the on-site tritium plume are currently
Unit VI (EDB)
Historically, the Laboratory has found levels of EDB in OU VI
groundwater (in the Manorville area)
as high as 6.0 parts per billion (ppb), compared to the drinking
water standard of 0.05 ppb. Recent measurements show levels up to
3.6 ppb. Although no residential wells in Manorville contain EDB
from the Lab, the U.S. Department of Energy (DOE) offered public
water hookups to residents in this area in 1996. Most hookups were
completed in 1997. A groundwater
treatment system is being installed in this area to remove the
EDB from the aquifer. Treatment by carbon filters will be used to
reach cleanup goals and to continue to assure that public health is