These Wisconsin beaches aren't safe for swimming. See which have elevated E. coli levels

Elevated rates of bacteria can result in unsafe swimming conditions at local beaches during the summer. The Wisconsin Department of Natural Resources monitors water quality to determine whether it's safe to swim at your favorite beach.

The state has about 190 beaches along the Lake Michigan and Lake Superior coasts, and about 106 of those are regularly tested for bacteria in the water.

Here's a look at which beaches in the Milwaukee area are closed and/or under advisory status as of July 11, according to the Wisconsin Department of Natural Resources.

Which Milwaukee area beaches are currently closed for swimming?

• Big Bay Park Beach (Whitefish Bay): Closed due to the sinkhole at the entrance of the park.

Which Milwaukee area beaches are under advisory status?

Milwaukee County:

• South Shore Beach: Under advisory due to elevated E. coli levels.

Racine County:

• Zoo Beach: Under advisory due to dangerous currents
• North Beach: Under advisory due to dangerous currents
• Myers Park Beach: Under advisory due to elevated bacteria levels.

To search for the latest beach report, you can click here.

Why are beaches closed in Wisconsin?

Most beach closures are caused by bacterial contamination, with E. coli being the one tested as an indicator of the possible presence of other pathogens, said Water Resources Management Specialist Diane Packett.

Sources of E. coli levels vary by particular beach. The greatest sources of the E. coli contamination, according to research done by the UW-Milwaukee's School of Freshwater Sciences, are:

• Storm water runoff
• Gulls and waterfowl excrement
• Boat mooring fields

City of Milwaukee health officials preemptively close Bradford, Bayview, McKinley and South Shore beaches for rainfall.

What are the classifications for Wisconsin beach closures?

Local health departments post signs to inform beachgoers about the most current water conditions based on testing for E. coli. A level of 235 colony-forming units is advisory level, and 1000 is closure level, said Packett.

What Milwaukee beaches are closed most frequently due to E. coli?

South Shore beach is the most frequently closed beach due to bacterial contamination, said Packett.

Water circulation is poor at the current location, which borders a boat mooring. The swimming beach is being relocated to the south closer to the opening in the breakwater that allows more mixing with lake water. You can find more about the project plan on the county's website.

What is E. coli?

According to the Wisconsin DNR, E. coli is a bacteria commonly found in natural bodies of water. Strains of E. coli at beaches usually pose a low risk for making swimmers ill, and instead serve as an indicator of other possible health risks in the water, such as bacteria, viruses and other organisms.

E. coli is also found in feces, which means that if high levels of E. coli are detected in water, there's a significant chance that fecal matter is in the water.

Drew Dawson contributed to this report.