Elevated Bacteria Levels Close Two Popular Lake Minnetonka Beaches

Public health officials have closed a pair of Lake Minnetonka public beaches until further notice due to elevated levels of E coli bacteria.

Hennepin County Public Health ordered Wekota Beach in Tonka Bay and Mound Park Beach closed earlier this week, and exactly when the popular swimming spots will reopen remains unclear.

Health supervisors routinely test Lake Minnetonka's public beaches for a variety of bacteria, and closing a beach is far from an anomaly.

In 2012 Hennepin County closed several beaches for brief stretches due to elevated bacteria levels—including Wayzata Beach, Summit Beach in Orono and Excelsior Beach.

Click here for an updated list of beach closings.

The two Lake Minnetonka beaches are currently the only two in Hennepin County closed due to elevated bacteria.

Elevated bacteria levels can be caused by significant rain events (such as the one experienced last week), storm water discharge, migrating waterfowl, high boat traffic and water temperature.

Bacteria and viruses in the water can cause some ear and eye infections, stomach aches, diarrhea and flu-like symptoms, according to the Center for Disease Control.

Locally, most beach closures historically occur on the northern shores of Lake Minnetonka. Duanne Hudson, an environmental health supervisor with Hennepin County who oversees the testing of Lake Minnetonka's public beaches, told Patch last summer that the general shape and geography of the lake make them prone to impaired water quality during the peak summer months—particularly after heavy rains like those seen over the last month.

Small, shallow bays with high boat traffic—such as Wayzata Bay—traditionally see higher occurrences of increased bacteria levels during the summer.

"Lake Minnetonka's water basin is different throughout the lake," Hudson said last May. "Lake Minnetonka is a series of bays and inlets, and the distribution of water is so varied from one part of the lake to another."

Hennepin County samples the water at about 30 Lake Minnetonka public beaches on a weekly basis and sends the specimens out to an independent, third-party lab for analysis. Results are typically returned within 48 hours and compared to standards set by the U.S. Environmental Protection Agency, which Hennepin County uses to determine a beach's water quality.

Beaches found to have elevated bacteria levels are recommended for closure, and Hudson said most cities and municipalities go along with Hennepin County's suggested course of action.

Tips for staying healthy at the beach

The Centers for Disease Control has the following recommendations for staying healthy while enjoying the beach:

• Wait 24 hours before swimming after a heavy rainfall.

• Shower after being at the beach.

• Don't mouth or swallow beach water.

• Wash hands thoroughly before eating and after using the bathroom.

• Don't swim if you're sick, or have a weakened immune system.