Don't drink the water. Don't even swim in it.
E. Coli has spiked at the Lake Calhoun beach at 32nd Street, reaching a level of 855 on Monday. The EPA thinks any reading over 235 is nasty, so this seems a particularly proud accomplishment. All this info comes from the Minneapolis Park and Rec board web site, and it appears as though other Minneapolis beaches and lakes are less foul for now.