March 21 Update on Groundwater Contamination at BNL

97-28
Issued March 21, 1997

BNL Contact: Mona S. Rowe 516/344-2345
DOE Contact: Jayne Brady 202/586-5806
EPA Contact: Rich Cahill 212/637-3663

MARCH 21 UPDATE ON GROUNDWATER CONTAMINATION
AT BROOKHAVEN NATIONAL LABORATORY

UPTON, NY -- The U.S. Department of Energy's (DOE) Brookhaven National Laboratory (BNL) today released data that better define the location of the tritium plume south of the High Flux Beam Reactor (HFBR). The laboratory is also considering interim cleanup remedies as possible solutions to ensure that the plume does not move further southward.

Both the U.S. Environmental Protection Agency (EPA) and the Suffolk County Department of Health Services have stated that the contamination poses no public health threat. The most recent findings are summarized below.

GROUNDWATER MONITORING

Partial results have been received from on-site groundwater monitoring wells two-thirds of a mile south of the HFBR and show that the highest tritium concentration is 5,815 picocuries per liter (pCi/L), slightly over one-fourth the EPA drinking water standard of 20,000 pCi/L. Results have been received from 12 of 22 wells at the location, at depths ranging from 40 to 200 feet below land surface. The peak concentration was found at 150 feet below land surface. Results from the samples taken from the remaining wells at this location are expected shortly.

The 22 wells were drilled as part of an effort to find the southernmost, or leading, edge of the contamination plume; groundwater in the area flows south at a rate of about a foot a day. The wells are two-thirds of a mile north of the BNL southern boundary.

Complete results are now available from seven wells located a third of a mile (1,900 feet) south of the HFBR. A total of four of the seven wells show tritium above the EPA drinking water standard, with a peak concentration of 140,700 pCi/L at 140 feet below land surface. This peak concentration was found in one well.

BNL continues to install and sample additional monitoring wells on the BNL site, including two sets of wells, 0.5 miles and 1.2 miles south of the HFBR, in order to more closely define the contamination's leading edge.

FINDING THE SOURCE

The most likely source of the tritium contamination is a spent fuel pool in the HFBR building. The 68,000-gallon pool contains tritiated water at a concentration of 130 million pCi/l. Beginning March 5, A&L Underground, Inc., of Olathe, Kansas, began drilling two horizontal wells 50 feet below the building's foundation to verify the source of the tritium. The drilling is now completed, and the wells should be ready for sampling next week.

PROTECTING DRINKING WATER

EPA is independently analyzing all of the water samples taken from BNL's network of monitoring wells around the HFBR. To date, BNL and EPA sampling results have been consistently in agreement.

No drinking water, either on or off the Laboratory site, is affected by the HFBR-related tritium contamination. Daily tests of BNL's drinking water have confirmed that it is not contaminated with tritium. Additional wells are being installed and sampled at the site boundary south of the HFBR to reconfirm that the contamination has not reached the boundary.

CLEANUP EFFORTS

DOE and BNL are currently working with regulators to determine the most effective methods for remediating the contaminated water. Until those decisions are made, county, state, and Federal regulators are considering potential interim remedies to prevent the tritium plume from moving further south.

A series of information sessions on the interim remedies will be presented to the public over the next few weeks. The first session is scheduled for Monday, March 24, from 6-8 p.m. in the Dowling College NAT Center on William Floyd Parkway (County Road 46). The second session is scheduled for Tuesday, April 1, from 6:30-8:30 p.m. in the Dayton Avenue School in Manorville.