Deep secret: Military waste remains a Lake Superior mystery

A mystery lies scattered on the silty bottom of Lake Superior a few miles from Duluth Harbor. On seven occasions between 1959 and 1962, U.S. Army contractors dumped more than 1,400 steel barrels of classified material from Honeywell operations at the Twin Cities Army Ammunition Plant (TCAAP) in Arden Hills into the cold waters Lake Superior. The dumping solved two problems for the Army — how to dispose of the waste economically and how to keep the contents secret.

The rationale seems fatally flawed today, and with many of the barrels within a few miles of drinking water intakes, many people would like to see the mystery solved.

The Lake Superior Classified Barrel Disposal Site has been a decades-long concern for local community leaders and environmentalists. The Army has stated that the barrels officially contain “classified” parts from grenades and waste associated with munitions manufacturing. But suspicions persist to this day that the barrels contained radioactive materials and poisonous chemicals, and there’s an oft-told story of tug operators having seen purple liquid seeping from barrels after they were unloaded.

A recently released “Health Consultation” from the Minnesota Department of Health (MDH) seeks to put those concerns to rest. The report compiles information from several prior investigations into the mysterious barrels, including two instances where nine of the 55-gallon drums were recovered in the early 1990s. Their contents contained what was expected from the anecdotal accounts of Honeywell employees and witnesses to the dump, previously recorded by the Army Corps of Engineers in 1977: munitions waste, scrap metal, pieces of timing mechanisms and assemblies for the BLU-3 “pineapple” cluster bomb.

The Health Department’s final “Public Health Action Plan” (.pdf) states that the agency “plans no additional action related to this site” and that it “will review new information on this site if there is additional investigations.” The report’s author, Health Department toxicologist Carl Herbrandson, told the Duluth News Tribune, “We’ve moved on,’’ but not everyone is willing to follow. For many, nine barrels out of the more than 1,400 is not a thorough enough sample to declare that the entire contents of the dump site pose no risk.

The incentive for the Army and the state of Minnesota to keep the mystery alive may be financial.

In 1995, when the issue last drew widespread attention, city officials in nearby Superior, Wis., made a push to force the Minnesota Pollution Control Authority (MPCA) to have the the barrels removed from the dump site, technically in Minnesota waters. While the city was unable to force the MPCA’s hand, the nearby Red Cliff Nation soon took up the charge. The Bayfield, Wis., tribe contracted Duluth-based environmental consultants EMR, Inc., to investigate the health threat posed by the barrels and whether remediation is warranted and feasible.

Any large-scale environmental cleanup is an expensive proposition, but an underwater cleanup of potentially hazardous materials and explosives is a daunting task. The difficult setting is not the only challenge. To date just 20 to 25 percent of the barrels have been located, and the rest may be buried under layers of muddy sediment. Previous attempts at retrieving barrels cost millions of dollars and yielded few.

There will be no immediate resolution to this issue, but as long as the steel barrels are slowly corroding on the bottom of Lake Superior, the state of Minnesota and the Health Department are unlikely to attract many followers in their effort to move on.