‘Tis the season for swimming and bacteria alerts in lakes, rivers

Jun 14, 2024, 6:21 PM

Juanita Beach Kirkland...

Kirkland's Juanita Beach was closed in 2023 due to bacteria. (Photo courtesy the City of Kirkland)

(Photo courtesy the City of Kirkland)

With summer about to start, many people flocking to their favorite swimming holes may also want to read up on bacteria warnings.

During the busy Memorial Day weekend and shortly afterward, at least 20 people, most of them children, reported E. coli infections after they swam in Lake Anna, a popular recreational destination in central Virginia. Nine of those people were hospitalized. An additional 10 cases are under investigation.

In Massachusetts, 22 beaches were closed across the state as of Friday morning. “Bacteria exceedance” accounted for more than half of the shutdowns. On the West Coast, high bacteria levels shut down three beaches in Seattle.

Here’s what to know about the most common concerns.

E. coli bacteria

E.coli bacteria normally live in the intestines of healthy people and animals. Most strains are harmless, cause relatively brief diarrhea and most people recover without much incident, according to the Mayo Clinic. But small doses of some strains — including just a mouthful of contaminated water — can cause a range of conditions, including urinary tract infection, cystitis, intestinal infection and vomiting, with the worst cases leading to life-threatening blood poisoning.

Other news: Measles case reported at West Seattle clinic; know the symptoms


Cyanobacteria — also referred to as blue-green algae — are plant-like organisms that live in water. They can quickly grow out of control, or “bloom,” and some produce toxins that make people and animals sick, according to the U.S. Centers for Disease Control and Prevention. They can look like foam, scum, mats, or paint on the surface of the water. They can also grow underneath the water.

“The things that are causing blooms are the excessive nutrients that are flowing into our surface waters through stormwater, fertilizers, pet waste, septic systems. That, coupled with the increased sunlight and heat, is just the perfect recipe for cyanobacteria,” David Neils, the chief aquatic biologist with the New Hampshire Department of Environmental Services, said.

He was checking out the blooms in Tuftonboro, along Lake Winnipesaukee, the state’s largest lake. State officials warned people not to swim there and in Wolfeboro because of cyanobacteria readings.

Neils said this year, the lake had very little ice cover and never really froze over.

“Warmer water temperatures due to lack of ice cover certainly promotes blooms,” he said.

Symptoms of cyanobacteria exposure can include skin irritation, stomach cramps, vomiting, nausea, diarrhea, fever, sore throat, headache, muscle and joint pain, mouth blisters, seizures and acute liver damage.

Brain-eating amoeba

Brain-eating amoeba, also known as Naegleria fowleri, is a single-celled organism that lives in soil and warm freshwater, such as lakes, rivers and hot springs, according to the U.S. Centers for Disease Control and Prevention. It can cause a brain infection when water containing the amoeba goes up the nose. Only about three people in the United States get infected each year, but these infections are usually fatal.

Last year, an Arkansas resident died after being infected. State health officials concluded that the person was likely exposed to it at a country club’s splash pad.

Naegleria fowleri infects people when water containing the amoeba enters the body through the nose, according to the CDC.

Past closures: Juanita Beach in Kirkland reopens after high levels of bacteria

Taking precautions

If you’re going out for a swim, shower before and afterward and try not swallow the water, the National Institutes of Health advises. Wash your hands before you eat or drink after playing in recreational waters or in the sand.

People also shouldn’t go to the bathroom in the water and should stay out if they’ve had diarrhea recently to protect others, the organization said.

They should also check out the water itself.

“The message to swimmers is that they should really do what we call a self-risk assessment and look at the water and see if they consider it safe for swimming,” Neils said.

Check for warning signs, talk to lifeguards, and do your homework by checking on specific beaches through state and local alert systems.

MyNorthwest News

Photo: A law enforcement vehicle's lights....

James Lynch

SPD: Armed good Samaritan saves pregnant woman from attacker

Seattle police said an armed good Samaritan came to the rescue of a woman during a domestic violence incident and shot her attacker.

4 hours ago

NAACP kamala harris...

Sam Campbell

‘It’s about time’: NAACP leader in WA applauds possibility of Harris as presidential nominee

NAACP members reportedly scrambled to regroup following President Joe Biden’s sudden withdrawal from the race on Sunday.

8 hours ago

hit-and-run lake city...

Frank Sumrall, MyNorthwest; James Lynch, KIRO Newsradio

Hit-and-run in Seattle’s Lake City kills one early Monday morning

A man was killed in a hit-and-run in Seattle’s Lake City neighborhood at Northeast 125th Street and 30th Avenue Northeast Monday morning.

12 hours ago

kent kidnapping...

Frank Sumrall

Kent Police: Second attempted kidnapping in less than a week

A 911 caller contacted Kent Police July 19 after an unknown adult male reached inside a window of the caller's home and grabbed their young daughter.

14 hours ago

Photo: Detectives are investigating a Seattle drive-by shooting that happened early Saturday mornin...

Julia Dallas

Seattle police: Woman shot in both hands in early morning drive-by shooting

Detectives are investigating a Seattle drive-by shooting that happened early Saturday morning. A woman was shot in her hands.

1 day ago

Photo: President Joe Biden delivers remarks on the 75th anniversary of NATO at the Andrew W. Mellon...

MyNorthwest and KIRO Newsradio staff

‘Bring it on:’ Washington officials react to Biden dropping out of the race

Washington officials have reacted to President Joe Biden dropping out of the 2024 presidential election.

1 day ago

‘Tis the season for swimming and bacteria alerts in lakes, rivers