With one system currently in full-scale operation, the construction of a second pump-and-treat-system at the Lab's southern boundary is expected to be completed this spring.
The two systems will work in concert to stop the migration of volatile organic compounds and remove them from groundwater near BNL's southern boundary.
How it works
Pump-and-treat systems work by extracting contaminated groundwater and pumping it to an "air stripping" facility, where volatile organic compounds (VOCs) are separated from the water. The clean water is recharged (returned to the ground) and the VOCs are released into the air at concentrations below state and federal emission standards.
Groundwater monitoring wells will be sampled and analyzed regularly to ensure the pump-and-treat systems are working effectively. The U.S. Environmental Protection Agency (EPA), N.Y. State Department of Environmental Conservation (DEC) and the U.S. Department of Energy (DOE) will oversee all monitoring.
Construction under way
Construction of the Operable Unit III system is on schedule for a planned June start-up. Access roads have been cleared, and water piping, an electrical distribution system, six groundwater extraction wells and 16 additional monitoring wells are currently being installed. Work is also continuing on the treatment facility itself, with the air stripping unit scheduled to arrive in May.
The system is being constructed to treat a plume of VOCs moving south from an unidentified source (still under investigation) in the developed central portion of the Lab site. When complete, it will process approximately 600-700 gallons of water per minute. The treated water will then be discharged into a new recharge basin located approximately one mile north of the site boundary.
While the system is expected to operate for several years, an approximate operating period will be determined in the OU III Feasibility Study, due out in spring 1998.
First system on-track
Meanwhile, the Operable Unit I/Removal Action 5 stripper has been running since the end of December, and is now treating 700 gallons of water per minute. Two wells located approximately 3,000 feet east of the OU III system are treating groundwater contaminated with VOCs emanating from the areas associated with a closed landfill and Hazardous Waste Management Facility area.
Project manager Michael Hauptmann said monitoring of the air and water emissions has shown they are within state and federal standards.
Brookhaven National Laboratory and the Department of Energy expect this system will operate from seven to 12 years before design goals are met. That is, it will have reduced the contamination to such low levels that no further remediation is practicable.
Additional use possible
The timetable could be extended, however, by current plans to use the basin to recharge water associated with the on-site tritium plume (see related story, page 1). Approximately 120 gallons per minute of tritiated water, at levels below state and federal drinking water standards, would be piped to the basin from the three tritium extraction wells located on Princeton Avenue (see map, page 1). It will then take this water approximately 19 years to reach the Lab's southern boundary.
If the DOE, EPA or DEC determines that the tritium has not decayed and diluted sufficiently, it may be recirculated using the system currently remediating groundwater associated with the closed landfill and hazardous waste management area.