Love it when you post a map, Dawg. Very helpful to understand where things happen. I didn't know that was now a Homrich property. I'm guessing the toxic goo is related to the toxic fumes that used to emanate from the factory a few years ago when it was IKO (??). I remember seeing protest signs in the yards of neighbors with a skull and crossbones before the company closed up operations there.
So glad the previous and current owners are so conscientious about cleaning up their own messes. 
Unfortunately that has been going on for many, many years.... our waterways in Michigan are still contaminated from industrial waste over the last 100 years... even at the bottom of the River Raisin... it's why we have to limit the amount of fish we eat from Lake Erie...
Up at Midland the Dow Chemical company routinely just dumped all their waste into the local river which eventually ran all the way to Saginaw Bay on Lake Huron... They have finally been taken to task and have spent millions... I'm sure it would have been a lot less expensive not to have dumped it in the first place...
The Ford plant in Monroe was a big polluter in the River Raisin too.... the paper factories!!!
Now they're all gone along with their big profits and the taxpayers are left to foot the bill...