Two Chanhassen beaches on Lake Ann joined Lake Minnewashta Regional Park on the “do not swim” list after elevated levels of fecal coliform were found in a sample at Lake Ann Beach.
The city of Chanhassen also closed Greenwood Shores Beach on Lake Ann as a precaution.
Water samples were taken at Lake Ann Beach on Aug. 4, in part due to elevated levels of E.coli reported at the beach at Lake Minnewashta Regional Park that same week, according to Chanhassen Water Resources Coordinator Terry Jeffery.
The results, which are sent to a water testing firm for incubation tests, take about a week to come back.
The results showed elevated levels of fecal coliform that exceeded state standards, Jeffery said.
Fecal coliform bacteria can be transmitted to water bodies through the feces of animals, according to the Minnesota Department of Health. Other potential sources of contamination could include sewage leaks.
Jeffery said the cause is unknown but the city isn’t aware of any sewage or septic leaks.
“I don’t have a cause,” he said. It’s conceivable that geese could have been in the vicinity of where the sample was taken, Jeffery said.
According to Chanhassen Park and Recreation staff, it’s the first time in 25 years that city beaches have closed due to water issues.
The city also tested water at Lotus Lake and near Roundhouse Park on Lake Minnewashta and the water samples detected no problems, Jeffery said.
“Our main objective is to make sure that everything is safe for the public, Jeffery said, adding that the city is following state Department of Health guidelines.
Samples were taken at Lake Ann on Monday, Tuesday and Wednesday of this week and the beach won’t reopen until levels return to acceptable levels.
The beach closure will likely affect plans for the Pinky Swear Triathlon planned this weekend at Lake Ann. The event is expected to draw more than 700 participants. (The triathlon may have to eliminate the swimming component).
E.coli (found at Lake Minnewashta Regional Park Beach) and fecal coliform (found at Lake Ann Beach) can cause health issues such as abdominal cramps, diarrhea and vomiting.
Once water levels are back to acceptable levels, the beaches are expected to reopen.
Chanhassen Park Superintendent Jerry Ruegemer said lifeguards were scheduled to be on duty through this weekend. When Lake Ann Beach reopens, it would be posted “swim at your own risk.”
The beach at Lake Minnewashta Regional Park beach remains closed, according to Carver County Park and Trails Supervisor Sam Pertz. Additional testing was conducted on Monday of this week and those results are expected back either Wednesday or Thursday. Those results will determine if the beach will reopen.