Representatives of the Army, EPA, and WDNR have announced that 6 additional groundwater monitoring wells ill be installed in and around the northeast corner of the Badger Army Ammunition Plant. The plan is in response to the detection of the explosive DNT (dinitrotoluene) in 2 deeper monitoring wells that were recently installed at the plant boundary, officials said. Contaminant levels are more than 4 times health advisory levels set by the Wisconsin Division of Public Health for drinking water. DNT is classified by the U.S. Environmental Protection Agency as a probable human carcinogen (causing cancer).
A group (nest) of 3 wells is planned for outside the plant boundary near homes at Weigand’s Bay, a deeper “bedrock” monitoring well will be installed at the plant boundary near an existing well group, and a group of 2 wells will be installed inside the plant. The wells are being placed southeast of the Deterrent Burning Ground, a hazardous waste disposal site that is the suspected source of the contamination.
The WDNR is also monitoring trends in 1,1,2-trichloroethane and tetrachloroethylene (also known as perchloroethylene) in groundwater. Current levels are well within the safe standard of 5 parts per billion for both contaminants. The suspected source of the industrial solvents is a landfill which is located adjacent to the Deterrent Burning Grounds.
The Army has also announced it will be testing private drinking water wells in the Weigand’s Bay area for DNT in August. These homes are located in the rural township of Merrimac. Previous testing by the Army has not detected DNT. Low levels of another solvent, trichloroethylene (TCE), were detected in several private wells in the Weigand’s Bay area but the source of this contaminant is currently not known.
CSWAB is pressing for additional offsite monitoring well nests to provide much-needed information about offsite groundwater flow patterns. This information will help identify residential wells that are at greatest risk. CSWAB is also asking for an evaluation of the cleanup remedy at the burning grounds and adjacent landfill in order to determine if better source-control remedies can be implemented.
CSWAB will be presenting this information at the regular meeting of the Merrimac town board set for August 5, 2008 at 7:00pm. For more information, contact CSWAB at (608)643-3124 or visit their website at www.cswab.org.
CSWAB’s Recommendations:
- Require an immediate evaluation of the cleanup remedy at the Deterrent Burning Grounds and adjacent landfill in order to identify and implement better source-control remedies that will protect groundwater from any further contamination
- Require ongoing quarterly testing of private wells for explosives that are part of the current round of testing to help identify trends in groundwater quality and movement
- Require annual testing of nearby private wells for all potential site contaminants, not just explosives
- Install additional offsite monitoring well nests to the east of the Deterrent Burning Grounds to monitor groundwater quality and movement, and help identify susceptible private drinking water wells
- Install deeper monitoring wells east and northeast of the Existing Landfill to identify groundwater movement and quality at depth, and help identify susceptible private drinking water wells