The Environmental Protection Agency (EPA) has issued long-awaited toxicity values for technical grade dinitrotoluene (tgDNT) – an explosive that is a widespread environmental contaminant at Badger Army Ammunition Plant and hundreds of other military sites across the country.
This announcement is the culmination of decades of work by CSWAB to help provide federal and state regulators with the leverage needed to require testing and cleanup of all six DNT isomers present in tgDNT. CSWAB’s campaign gained momentum in 2011 when EPA regional officials involved in managing federal facilities cleanups asked EPA headquarters to establish toxicity values to help address all the potential hazards associated with the DNT contamination found at sites like Badger.
The new PPRTV (provisional peer-reviewed toxicity value) is the first toxicity value to address all the known isomers of DNT. The weight of toxicological evidence led the EPA to conclude that tgDNT is likely to be carcinogenic to humans and that all six DNT isomers must be considered.
In 2011, the Wisconsin Department of Natural Resources (WDNR) failed in its attempt to require the U.S. Army at Badger Army Ammunition Plant to test contaminated soils for all six DNT isomers. “This additional testing requirement will aid in the evaluation of potential direct contact risks and possible sources of 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 said in its September 15, 2011 letter to the Army.
The following month, the U.S. Army issued a statement refusing to comply with the order and questioning the state’s regulatory authority to require such testing. “Department of Defense policy is not to test for unregulated analytes,” the Army wrote. “…the Army will wait for WDNR’s response to (our) questions before doing any additional work at sites where DNT is a contaminant of concern. Work on those sites stopped when Badger received WNDR’s letter on September 15, 2011.”
Two weeks later, the WDNR buckled and withdrew its requirement to sample soil for the presence of the following DNT isomers: 2,3-DNT, 2,5-DNT, 3,4-DNT, and 3,5-DNT. The State decided to defer any further action on the required testing until the EPA established toxicity values that included these same DNT isomers.
With this decision in hand, EPA headquarters is now working on an implementation memorandum on the use of the new toxicity values for screening and risk assessment when the other isomers may be detected. CSWAB will continue to work with EPA on the next phase of this national policy initiative.