I was thinking that it would be interesting to link Agriculture, Water, and Waste Disposal with the example of the Great Lakes. There have been numerous accounts of the lakes at some point or another being contaminated.
The contamination is largely due to inadequate water treatment facilities in the toronto, and generally poor waste disposal. It allows for toxins to flow in to the lake and causes numerous bach closing and affects the ecosystems in the lake.
In the articles below they mention how the fish populations in lake ontario are dwindling and even the fish caught are some times unfit to eat.
The fishery business in the great lakes is a great way to supply local food to the surrounding areas, keeping the environmental impact low.
Anyways here are some links that I found interesting.