Synthetic coolant leaks from power cables in Great Lakes

In the caucus we have discussed the issues of the Enbridge Line 5 that runs through the great lakes. Upon reading some news this morning I came across an article that talks about the hundreds of gallons of potentially toxic coolant fluid that have leaked from two electric power cables in the waterway that links Lake Huron and Lake Michigan. The fluid is a mineral-based synthetic oil used for insulation that can be harmful if released into the environment. It is too early to know the exact damage of this event yet, but how do we prevent things like this from happening? What do you all think will happen to the straits of Mackinac from this event? The cables have been taken out of service, but there are probably more. How can we make sure that all cables of this type are taken out of service?