CSWAB has asked the Wisconsin DNR to consider re-testing of residential wells near Badger Army Ammunition Plant given the annual sampling failed internal quality controls.

In August and September of 2016, the Army tested 52 residential wells near Badger. Cloromethane was detected in 36 residential well samples, tetrahydrofuran was detected in one sample and bromodichloromethane was detected in four samples. However, the detections of these industrial solvents were “flagged and rejected based on professional judgment,” according to the Army’s September 29 letter to state regulators.

The decision was prompted by an internal quality control review of sampling data which found that trip blanks and/or method blanks were also contaminated with chloromethane and tetrahydrofuran.  Similar quality control issues were noted by the laboratory in the April 2016 round of groundwater sampling.

The primary purpose of blanks is to trace sources of artificially introduced contamination. Trip blank results include shipping and laboratory sources of contamination. Method blank results show only laboratory sources of contamination.

In addition to residential well testing, semi-annual sampling of groundwater monitoring wells was conducted in September 2016. Army contractors collected groundwater samples from 133 monitoring wells associated with the Deterrent Burning Ground Plume, Nitrocellulose Production Area Plume, and Propellant Burning Ground Plume.

The Army reports that concentrations of the explosive DNT decreased or stayed relatively unchanged since last tested. However, an internal quality control review of the groundwater data found that trip blanks and/or method blanks were contaminated with the following compounds at varying concentrations: acetone, chloromethane, and tetrahydrofuran.

The laboratory reported that acetone was detected in four groundwater samples, chloromethane was detected in 36 samples, and tetrahydrofuran was detected in 42 samples. The following compounds were also detected: 2-butanone in one sample, benzene in 25 samples, bromodichloromethane in 27 samples, chloroethane in one sample, and dibromochloromethane in two samples.  As with recent residential wells testing, the Army reported that “all these detections were flagged and rejected based on professional judgment.”

Altogether, nearly 200 monitoring and residential well test results were deemed invalid in the August and September 2016 rounds of testing, according to Army reports.  CSWAB believes that follow-up is important given a number of the detected compounds are known contaminants of concern in groundwater at Badger.

Army letter to WDNR re Annual Residential Well Results Sept 2016
Army letter to WDNR re Groundwater Monitoring Well Results Sept 2016
MAP: Central Plume Groundwater Summary Results CSWAB June 2016
MAP: Propellant, Deterrent & NC Area Plume Results CSWAB Sept 2016
MAP: Residential Well Sampling Badger Army August 2016
Table: Army Residential Well Results August 2016