The Serenity of Freediving Lake Superior

Now that's a man who can hold his breath!  Nice...

A fecal coliform (British: faecal coliform) is a facultatively anaerobic, rod-shaped, gram-negative, non-sporulating bacterium. Coliform bacteria generally originate in the intestines of warm-blooded animals and can be found in and around the shores of old Duluth in the summertime, where free divers must hold their mouths closed for extended periods of time to avoid ingesting this insidious pestilence.

I watch bacteria counts closely and the above quote is heavily exaggerated. Notices to avoid water contact are infrequent, localized to single beaches, and clear up in a day or two. Superior is clean even after it rains and you'd expect filth to spike, but the frequent water testing shows little room for concern.