Merrimac, WI – CSWAB is urging the WDNR to immediately expand testing of private drinking water wells near the northeast corner of Badger Army Ammunition Plant in the Town of Merrimac.  The recommendation follows confirmation of explosives in groundwater monitoring wells along the plant boundary and more than a mile from the suspected contaminant source inside the closing military base.

The community-based group is recommending that initial testing of nearby private wells include all homes within 1/2 mile of any groundwater monitoring well detecting contamination.  This testing should be expanded to one mile if any contamination is detected during the initial round of tests.

Moreover, CSWAB is recommending that this testing be conducted on an ongoing basis as the Army has found that concentrations often vary over time.  Tracking these trends is important to understanding the scope of the problem and the potential risk to public health.

Testing of private wells is a priority that will assure that no one is unknowingly exposed to Badger contaminants through their drinking water but this is not a long term solution to the problem.  CSWAB is urging local government to hire an independent consultant to look at the long-term security of drinking water supplies in and near Badger.


The Deterrent Burning Grounds, located in the northeast corner of Badger Army Ammunition Plant, is a known source of dinitrotoluene (DNT) and other military toxins.  DNT, which is actually a mixture of 6 different forms (isomers) of the chemical, was used in the manufacture of propellants and is classified as a probable human carcinogen.  For this reason, the safe drinking water standard is only 0.05 parts per billion.

Unlike the neighborhoods south of Badger, where dozens of monitoring wells have been installed as far south as the Village of Prairie du Sac, there are no offsite monitoring wells in the Town of Merrimac.  The system of groundwater monitoring wells inside Badger is also inadequate.  Outside the immediate source area, groundwater wells monitor only the shallow aquifer.  Additional monitoring well nests (multiple wells screened at varying depths) are needed to correctly measure water quality and movement.

The WDNR is currently requiring the Army to regularly test a small number of private wells in the township but the majority of private wells in the area have not been tested since 1992.

DNT was first detected at the northeast plant boundary in 2004 but WDNR staff did not believe that the Army’s data was reliable.  The WDNR subsequently required the Army to change its laboratory test method.  Test results from March 2006, which were recently released to the public, confirm that DNT is present far from the source and is likely past the northeast plant boundary.

CSWAB representatives have already shared their concerns and recommendations with members of the Merrimac Town board, the Sauk County Board of Supervisors, the WDNR, the Army, and other local government representatives.


South of Badger, DNT and other groundwater contaminants have been detected as far south as the Village of Prairie du Sac.  The Army is currently testing the public well for these chemicals and no detections have been reported.  The Army recently volunteered to test 67 additional private wells near the southeast corner of Badger in the Town of Prairie du Sac, including the Windings and Dam Heights neighborhoods, later this month.  Monitoring wells installed on private properties in the area have detected low levels of DNT and other contaminants in groundwater.

CSWAB is also pressing for expanded private well testing on the west side of Badger in the Town of Sumpter where very high levels of trichloroethylene, a carcinogenic solvent, have contaminated the groundwater.

MAP: DNTs in Groundwater (March 2006)

MAP: Areas of Concern in Merrimac Township