State regulators have ordered the U.S. Army to improve soil test methods for a carcinogenic explosive that has contaminated groundwater and drinking water wells in rural communities near Badger Army Ammunition Plant. The precedent-setting decision by the Wisconsin Department of Natural Resources (WDNR) is expected to prompt similar requirements at other military bases where dinitrotoluene (DNT) contamination has been found.
For decades, the military has routinely limited soil testing at Badger and other Department of Defense sites to only two of the six known isomers (forms) of DNT. Environmental testing at Badger will now include four additional forms of DNT which state health officials said are “as toxic or more toxic” than those currently monitored by the Army.
DNT can affect the blood, nervous system, liver, kidneys, and male reproductive system in both humans and animals, and is a suspected human carcinogen. Once in the environment, DNT can be transferred to plants via root uptake from soil or irrigation with contaminated water. Soil contaminants may also be carried to aquatic environments and wetlands through storm water run-off, erosion and through the air as fugitive dust.
The WDNR’s decision follows a formal petition last month from Citizens for Safe Water Around Badger (CSWAB) asking that 2,3-DNT, 3,4-DNT 3,5-DNT and 2,5-DNT be added to soil testing and cleanup requirements at Badger. The state’s September 15 letter to the U.S. Army requires the military to include these forms of DNT in all future soil testing where it is a contaminant of concern and to establish appropriate soil remediation goals for all forms of the explosive compound.
“This additional testing requirement will aid in the evaluation of potential direct contact risks (to humans) and possible sources for leaching of DNT to groundwater, and will test the idea that the ratios of DNT isomers in soil at the facility approximate those found in technical grade DNT,” the WDNR wrote.
CSWAB first petitioned for regulation of DNT in 2006 when it became evident that adequate cleanup of Badger Army Ammunition Plant and other contaminated military sites would only be achieved with enforceable standards.
On January 1, the State of Wisconsin adopted groundwater standards for all six isomers of DNT. The new health-based standard, measured as the summed total concentration of all DNT isomers, is 0.05 micrograms per liter (parts per billion). Wisconsin is the first and only state to regulate all six forms of DNT in groundwater.