Syracuse, N.Y. — When the cleanup of the Onondaga Lake bottom was ordered 20 years ago, the primary goal was to make the mercury-laden fish safe to eat.
The way to do that, the state Department of Environmental Conservation decreed, was to dredge 2 million cubic yards of muck contaminated with mercury and lay a sand mixture over 475 acres of the lake bottom.
That work was finished in late 2016 by Honeywell, which was responsible for the contamination…