LA CROSSE, Wis. -

The next time you take a dip in the Mississippi, you might want to think twice about what you're splashing around in.

The La Crosse County Health Department had to close Pettibone Beach and issue a warning at Goose Island Beach last week after they found soaring counts of fecal contamination in the water.

All of La Crosse County's public beaches are testing at safe levels again, so they're all open for swimmers.

"The reason we close the beaches is for E. coli. It's in the water. It usually occurs during rain events. It's washed in," said La Crosse County Health Department Sanitarian David Sawvell.

The department tests Pettibone, Goose Island and Black River Beach twice a week during the summer.

Pettibone Beach was closed for four days last week after the county discovered 1,600 E. coli colonies per 100 milliliters of river water.

"When the count reaches 1,000, we have to close it. Then they test every day after that. And if they get consistent results, then you know that there's something lingering there, said city of La Crosse Aquatics Coordinator Steve Briggs.

Briggs said high levels of E. coli at La Crosse beaches aren't unusual thanks to manure run-off, but it usually happens earlier in the year.

"Because of the rain, the farmers didn't get out in their fields until later. So normally if there was a high count, it would have been earlier, like in the spring time," said Briggs.

Read more from the original source:

Beaches back to normal after fecal contamination