Which one of the 5 great lakes is the cleanest and how do you know?

Question

If you had a choice to drink water out of one of the five which would you choose first and which last

Answer 1

Here's a website that shows water clarity measurements of the Great Lakes:
http://www.epa.gov/glnpo/glindicators/water/trophicb.html

I think the data shows that Lake Superior is the cleanest and Lake Erie has the most clarity problems.

Answer 2

Lake Superior