Merrimac, WI – A carcinogenic explosive which has been found in drinking water wells near the Badger Army Ammunition Plant should have lower standards than those proposed by the Wisconsin Division of Public Health (WDPH), a local environmental group says. According to Dr. Peter deFur, a technical scientific consultant hired by CSWAB, the health-based threshold for drinking water should be 10 times lower or 0.005 parts per billion.
The WDPH recently issued an Interim Health Advisory Level for dinitrotoluene (DNT), a common constituent of explosives. DNT exists in six (6) different forms, termed isomers. All 6 isomers have been detected in groundwater beyond the plant boundary and in private drinking water wells. The WDPH has recommended that the total concentration of all 6 isomers of DNT should not exceed 0.05 parts per billion in drinking water.
Wisconsin has standards for the more common isomers of DNT (2,4-DNT and 2,6-DNT) but the remaining 4 isomers do not have enforceable state drinking water or groundwater standards.
The Army does not support the establishment of any health-based thresholds and wants the remaining 4 isomers to stay unregulated. Lack of regulation releases the Army from cleanup of contaminated soils and groundwater. It also relieves the military of requirements to replace affected wells. In an August 14 memo submitted to the WDPH, Army toxicologists argued that available data is “not sufficient to support the development of a health advisory for these isomers.”
Dr. deFur maintains that the WDPH used the correct approach by combining all the isomers together in one limit. “If each isomer were evaluated separately, risks could be substantially underestimated by ignoring the cumulative risks to human health,” he said.
At the same time, deFur said that proposed Health Advisory Level does not account for the high concentrations of the more toxic isomers of DNT that are found in the environment, compared with mixtures used to determine toxicity in laboratory studies.
“DNT mixtures at contaminated sites like Badger are likely to be significantly more toxic than those evaluated by health officials,” deFur cautioned. “Some sensitive individuals may suffer health effects from long term exposure to DNT concentrations that are less than the proposed limit, evidence that the Advisory Level selected by WDPH needs to be lower.”
DNT is a powerful carcinogen, and can also cause dizziness, headache, muscle weakness, and a blood disorder known as methemoglobinemia. Infants are particularly susceptible to this anemic condition.
Citizens for Safe Water Around Badger (CSWAB) was first organized by neighbors of the Badger plant in 1990 and continues to work for the cleanup and sustainable reuse of the site. Dr. deFur’s report, together with the memorandums from the Wisconsin Division of Health and the U.S. Army, are available to the public through CSWAB’s website at www.cswab.org.
- Technical grade DNT is a mixture composed of approximately 76% 2,4-DNT, 19% 2,6-DNT, and 5% other DNT isomers (3,4-DNT, 2,3-DNT, 2,5-DNT, and 3,5 DNT). In groundwater and drinking water, however, these isomers can be found independently and in different ratios.
- At the Deterrent Burning Grounds, a hazardous waste site at Badger Army Ammunition Plant, the concentration of 3,4-DNT in groundwater was recently detected at 3.98 ppb and 2,3-DNT concentrations were detected at 1.16 ppb. The total concentrations of these less common isomers are more than 100 times the safe drinking water guidelines recommended by the Wisconsin Division of Public Health. In comparison, 2,4-DNT and 2,6-DNT concentrations in the same groundwater monitoring well were both found at less than 0.05 ppb.
- In Wisconsin, the 2,3-DNT isomer has been detected in 103 groundwater and private water wells at concentrations as high as 2,200 ppb. The 3,4-DNT isomer has been detected in 37 wells at levels as high as 419 ppb. The 3,5-DNT isomer has been detected in 20 wells at concentrations as high as 23.9 ppb and the 2,5-DNT isomer has been detected in wells at concentrations as high as 1.5 ppb.
- In northern Wisconsin, the E.I. DuPont de Nemours & Co. ran the DuPont Barksdale Explosives Plant from 1905 to 1971. The company produced TNT, dynamite and other explosives for the military during World Wars I and II, and for the mining industry. Starting in 1997, tests found residues of explosive chemicals in 17 drinking water wells located between the site and Lake Superior. Two forms of dinitrotoluene (DNT) found in private well water were above the State of Wisconsin groundwater standard.
- According to the Wisconsin Division of Public Health, DNT has been detected in soils and groundwater at Fort McCoy, an active military installation near Sparta, Wisconsin.
- DNT is an environmental contaminant at dozens of military bases nationwide including Fort Wingate Army Depot in New Mexico, the Joliet Arsenal and Savanna Army Ammunition Plant in Illinois, Camp Edwards in Massachusetts, Weldon Springs Ordnance Works in Missouri, Umatilla Army Depot in Utah, the Hawthorne Army Depot in Nevada, and Radford Army Ammunition Plant in Virginia.