Answer:
St. Lawrence River
Explanation:
The pollution is caused by agricultural industries. The industries discharge a lot of chemicals and waste such as pesticides. Even though some people swim in that river and is tested frequently due to those discharge, the water isn't considered safe drinking water because of bacteria. A lot of people decided to not swim in the water because there have been reports of plastic being found and the color of the river changed to a brownish nasty looking water. It used to be clear water before the pollution started.
In the pictures below are some before and after pollution
