Number of Lake Minnetonka Beach Closures 'Not Unusual'

Elevated bacteria levels have forced the around Lake Minnetonka in recent weeks, but Hennepin County health officials say the summer of 2012 has so far not been an abnormal one.

"Historically, this is an average summer," Duanne Hudson, an environmental health supervisor with Hennepin County who oversees the testing of Lake Minnetonka's public beaches, said. "If we look at all of the year's we've been sampling, which is quite substantial, we are not seeing any unusual trends."

and were closed earlier this month due to high levels of E Coli, but both have since been reopened and been deemed safe for public use. The beach at in is currently the only public beach on Lake Minnetonka closed for swimming.

Overall, Hudson stressed that water quality at Lake Minnetonka's beaches is acceptable, safe for public use and tested regularly.

"The beaches that have been closed this year have been closed in the past because of water quality issues," Hudson said. "Many have storm water discharge pipes adjacent to them, which usually has a negative impact."

Hudson pointed to a variety of causes for elevated bacteria levels—including significant rain events, storm water discharge, migrating waterfowl, high boat traffic and water temperature.

"Because the weather has been warm recently we see increased activity at beaches and people using them," he said. "That is usually a factor when we're talking about elevated bacteria levels. If there are more people and more use, there is generally more bacteria."

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 occur on the northern shores of Lake Minnetonka, and Hudson said 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," he said. "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. 

"Once in a while we'll be asked if anything can be done to keep the beach open because of a holiday or something, but most of the time cities are very cooperative," he said. "If we have an idea of what is causing the problem we'll give them advice on how the beach can be reopened as quickly as possible. No city has ever defied our recommendation."

Weekly water sampling takes place around Lake Minnetonka from mid-May through mid-September. Click here for an updated list of beach closings.

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.
• Put tight-fitting rubber or plastic pants on children wearing diapers and those not toilet-trained.
• Take your children for frequent bathroom breaks.
• Don't attract waterfowl to the beach by feeding ducks, geese, gulls, etc
• Pick up your trash.
• If you boat, properly dispose of waste.