The Lake Is the Boss blog in a post back in 2008 told the story:
Around the time I was entering the first grade, the US Army was developing a new weapon at Honeywell in Minneapolis called the cluster bomb. During that period of the Cold War we were pretty sure that commie spies were lurking around every corner and Kruschchev's shoe pounding and promise to 'bury us' didn't do much to reassure the populace. I still remember practicing 'air raid drills' and being reprimanded for pointing out that the air raid drills were suspiciously similar to the tornado drills; get under your desk, place your head between your legs and, as the cynics said, kiss your ass goodbye. In any event, parts, chemicals, prototypes, and other detritus of cluster bomb development needed to be disposed of. You couldn't really bury it because Boris Badenov and Natasha might find it and dig it up. So clever army intelligence experts decided to load all the crap into 55 gallon drums and dump it into Lake Superior, some of it within a mile of the intake pipe for the Duluth water supply. Between 1959 and 1962 they dumped around 1500 barrels into the lake and since then there have been a number of efforts to find out just exactly what was in them and whether the contents posed a health hazard when the inevitiable leaking began to occur.
Between 1959 and 1962 the United States Department of Defense for some reason ordered more than 1,400 fifty give gallon barrels dumped into Lake Superior. The Department claims the dumping was done to keep secret ammunition parts from falling in the hands of the Soviets.
The project was kept from the public for years but eventually almost all secrets get out.
Meanwhile the Minnesota Pollution Control Agency decided the barrels of "ammunition parts" were no threat to the lake and a small effort to recover barrels came to a close. Hoenywell, Inc. says the barrels contrain some scrap metal from grenades.
That was not to be the end of the story. As Wisconsin Public Radio reported earlier this year:
Enter the Red Cliff Band of Lake Superior Ojibwe and the Department of Defense. The DoD and tribe signed an agreement to investigate the barrels. Red Cliff released a report in 2006 after examining Army Corp documents and concluded the barrels are rusted and may be leaking several kinds of dangerous chemicals, including PCBs, mercury, lead, possibly even uranium.
Western Lake Superior is part of the ceded territory allowing tribes to use and protect it as sovereign governments.
The plan is to raise seventy barrels and to scientifically test them as to just what's inside.
The Twin City Daily planet reported in 2008:
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.
Hopefully, we will know some day just what is sitting down their on the floor of Lake Superior.
The following is from Indian Country Today.