Hennepin County has reopened Excelsior’s public beach on Lake Minnetonka, a day after shutting it down due to high E. coli levels.

The county, which monitors 31 swimming beaches across the west metro area, closed Wayzata’s public beach last week for the same reason and reopened it two days later.

It’s not uncommon for Minnesota beaches to be closed due to E. coli contamination in the summer, since it can be produced by waste from geese, ducks and other wild animals as well as boaters dumping waste overboard.

The bacteria can sicken swimmers, causing diarrhea, abdominal cramps and occasionally more serious problems.

In 2013, three swimmers contracted E. coli near Big Island in Lake Minnetonka, leaving one swimmer hospitalized.