Yes, studies were conducted in the 1980s to determine whether the canal itself should be decontaminated or simply reopened without being decontaminated.
The decision was to stand pat, not to stir up the sediments on the bottom of the canal, but to be watchful so as not to put them back into suspension in the water. That permitted a first phase of investment in order to reopen the canal to navigation in 2002.
Here's the gist of my remarks today: the work isn't finished.