This spring, the Army tested 126 groundwater monitoring wells and two residential wells at and near the former Badger Army Ammunition Plant. Following is a summary of the April 2016 results provided by the Army.
RESIDENTIAL WELLS. Only two residential wells were tested this round. One had no contaminant detects, and the other had very low levels of the solvent 1,1,1-TCA at 0.083 ug/l (micrograms per liter), far below Wisconsin’s health-based groundwater standard of 200 ug/l. Both wells are deemed safe to use.
DINITROTOLUENE (DNT). Detected levels of the explosive DNT in all four groundwater contaminant plumes are similar or less than those detected last year, the Army reported. However, in certain areas inside Badger, concentrations of total DNT remain far above state standards.
The highest concentration of the explosive DNT inside the northeast corner of Badger (Town of Merrimac) was 5.652 ug/l. The health-based groundwater standard for total DNT is 0.05 ug/l.
Inside the southwest corner of Badger (Town of Prairie du Sac), the highest reported concentration of total DNT was 4.567 ug/l.
Offsite (south of Badger), solvents and the explosive DNT continue to be detected in groundwater, in some cases above groundwater standards. However, concentrations are reported as stable or decreasing. The highest concentration of the solvent carbon tetrachloride was 15 ug/l – the standard is 5 ug/l. Total concentrations of the explosive DNT were reported at or near the groundwater standard of 0.05 ug/l.
ETHYL ETHER continues to be elevated at the southwest boundary of Badger (Town of Prairie du Sac). The highest reported concentration was 4,900 ug/l. The groundwater standard is 1,000 ug/l. The Wisconsin DNR no longer requires the Army to test downgradient residential wells for this or other plume contaminants.
SULFATE continues to be elevated in groundwater at the northeast corner of Badger (Town of Merrimac). In April 2016, the highest reported detection was 900 mg/l (milligrams per liter). The secondary groundwater standard (based on aesthetic considerations, such as taste, color, and odor) for sulfate is 250 mg/l.
Tetrahydrofuran (THF) was detected in two groundwater monitoring wells at 1.1 ug/l and 20 ug/l. Detected concentrations are well below the health-based groundwater standard of 50 ug/l. The wells are located directly downgradient from Landfill #5 at the northeast corner of Badger. THF is now a contaminant of concern in this area, the Army reported. THF concentrations in these wells will be closely monitored during future sampling events, the Army said.
Map of Sampled Wells April 2016
April 2016 Certification Forms
March 2016 LF_Case Narratives-List-Map
April 2016 Sampled Wells List
Residential Well Lab Results Summary – Apr 2016
WDNR letter_Apr 2016 Groundwater Results_052316_signed