Ten beaches across Hennepin County are temporarily closed after routine testing detected high levels of E. coli bacteria in the water.

Beaches along the Chain of Lakes in Minneapolis and around Lake Minnetonka are among those affected. Officials believe recent rainfall and animal waste runoff are contributing to the spike in bacteria levels.

"So in the United States, most swim-related illnesses are associated with disease-causing organisms that are linked to fecal contamination, a.k.a. poop," Leah Larson with Hennepin Public Health said. "One of the most common sources that we see is going to be from goose, duck and other animal runoff, especially after a big storm event."

Blue-green algae blooms are also a concern in some areas, which can pose health risks to both people and pets.

Minneapolis resident Sydney Reuter said she monitors water quality before deciding to swim.

"I don't swim in lakes if I know that it's not safe," Reuter said. "And I do check online. There's a that I like to use for Minneapolis parks."

Reuter added that closures are common this time of year, particularly at Lake Hiawatha.

"Every year, pretty early on for this lake, at least Hiawatha, it gets hot, we get enough rain, and it just shuts down for either bacteria or algae," she said.

Health officials advise swimmers to avoid murky water, rinse off before and after swimming, and wait at least 24 hours after heavy rain before entering a lake.

Beaches will reopen once bacteria levels return to safe levels based on state health guidelines.

• E. coli
• Minneapolis