More work needs to be done before the Thunder Bay Harbour can be cleaned up.
Cole Engineering told members of the public last night recommending they remove the mercury sludge outright from the harbour and dispose of it at the Mission Bay facility.
Spokesperson Mark Bassingthwaite says they are far way off from actually doing the work.
The cost of dredging the harbour would be anywhere from 40 to 50 million dollars.
(Photo by Sheri Leviski of collected mercury sludge)