On most summer days, at least one Chicago beach has elevated fecal bacteria levels.
Regan Burke used to love taking her dog, Usher, down to Oak Street Beach for morning walks — until about a decade ago, when she says a lifeguard came up to her and told her to get her dog out of the water because E. coli levels were too high.
Ever since, Regan's been worried about water safety at Chicago beaches.
Still, for a while, she felt confident the city was responsibly warning people and closing beaches when fecal bacteria (measured through E.coli) got too high.
"In the early 2000s, they really reported that every day, and you'd hear it on WBEZ," she recalls. "It was on the regular Chicago news. But I don't hear it at all now."
So Regan wrote in to Curious City with a few questions:
Is that water safe for dogs? Why don't they close the beaches for E. coli anymore? Are Chicago beaches safe [from bacteria]?
The answer to that last question depends on a lot of things, like which beach you visit, what day you visit, and how old and healthy you are. But it's an important question because, on most summer days, at least one Chicago beach has elevated fecal bacteria levels. In fact, one city beach recently saw a level more than 300 times the federal notification level — and remained open. Also, the public appears to be confused about how to interpret the city's new swim advisory system. And so, in an effort to clear up any such confusion, we offer this handy primer on fecal bacteria on Chicago beaches.
Regan Burke used to love taking her dog, Usher, down to Oak Street Beach for morning walks — until a lifeguard came up to her and told her to get her dog out of the water because of high E. coli levels.
How do I find out how dirty a beach is?
Each morning at dawn, University of Illinois at Chicago researchers collect two water samples from at least 20 Chicago beaches. The samples are delivered to a UIC lab where they are tested for enterococci, a fecal indicator bacteria. The park district then takes the two readings for each beach and calculates a geometric mean (which is not the method recommended by the EPA; more on that later).
The city communicates its recommendations to beachgoers in three ways: on the park district's website, through the city's data portal, and through a flag system at the beach. Here's how you can find it online:
Keep in mind that the Chicago Park District only posts the average (geometric mean). If you're good with spreadsheets and you'd like to find the highest sample at your favorite beach on a given day, go to the city's data portal after 1 p.m., export the data into Excel, and then sort to find the correct day and beach. Look under the "DNA sample" columns to find that day's readings.
You can also check the flags posted at each beach:
Lifeguards post flags at each beach to alert swimmers about bacteria levels and weather conditions.
How can I stay safe?
Check the levels for your beach before you go. If fecal bacteria levels are anywhere near 1000 CCE, UIC public health scientists Sam Dorevitch and Abhilasha Shrestha say to consider avoiding contact with the water, particularly if you are:
-Or have an open wound
If you go to the beach before the website is updated, keep in mind that hard rains the previous day often result in high fecal levels the next morning.
If you swim on a day when levels exceed 1000 CCE, be careful not to swallow water or dunk your head.
Always wash your hands after swimming, especially before eating.
What can I do to make beaches safer?
Clean up your:
Don't feed the birds.
Wait. What? The city doesn't follow EPA suggestions on when to warn people?
That's right. The EPA suggests advising the public to take precautions when any single sample is above 1,000 CCE. The Chicago Park District, however, determines whether to notify the public based on the geometric mean of its two samples (which will always be lower than the highest single sample). In its 2012 guidance, the EPA suggests using the geometric mean "to assess the longer-term health of the waterbody"; not to determine whether to issue a daily warning. None of this EPA guidance is legally enforceable; it's just a suggestion based on extensive research.
Officials from the park district defended their use of the geometric mean in a statement, saying: "Densities of [fecal indicator bacteria] are highly variable in ambient waters therefore a measure based off of a distribution, such as [geometric mean]..., are more robust than single estimates."
Chicago Beach Poop By the Numbers, 2018 Edition
We crunched enterococci data from last summer, totaling 101 days. Below are some highlights, which take into account the differing standards used by the city and suggested by the EPA. Here are some highlights:
And what about the dogs and E. coli?
Chicago veterinarian Dr. Vaishaili Joshi says that dogs are exposed to E. coli all the time and usually don't get sick. But, like humans, "immunocompromised pets, juveniles and seniors may be at higher risk of infection secondary to heavy exposure."
More about our questioner
Questioner Regan Burke (middle) visited the lab at University of Illinois at Chicago where scientists Abilasha Shreshta (left) and Sam Dorevitch (right) analyze Chicago beach water samples.
Regan Burke is a Chicago writer who worked in local and national politics — for Gary Hart, Bill Clinton and Adlai Stevenson — for most of her professional life. She details that part of her life in the upcoming book, I Want To Be In That Number, which she says is all about "politics and nervous breakdowns."
As Regan grew up in Chicago and around the Midwest, she says her mom would often tease her for being a "nature lover."
"I always thought of myself as a city person, but I do love nature," she says. "That's one of the reasons I'm more interested and cognizant of what's outside my window than what's inside my apartment."
When she heard the final answers to her questions about the nature on the lake, she had a couple of reactions.
"Well, I'm very impressed at the level of testing that they do on the Chicago beaches," she says. "But, at the same time, we don't get the results until 1:30 in the afternoon."
Still, Regan was pleased to hear that dogs are not very susceptible to E. coli., despite what the lifeguard seemed to imply.
But when she heard that the city will never puts up a red flag or close a beach, even when fecal levels skyrocket, she was not pleased.
"That, to me, is appalling," Regan says. "The idea that at 1000 CCE there is a health risk — I can buy that. But when it's 300,000 and they don't close the beaches? I mean, how sick are people getting? And people go to the beach with their dogs, their children and their grandchildren. They must close the beaches when that happens. It's just appalling."
You can read Regan's writing on nature and more at www.backstoryessays.com
Monica Eng is a reporter for Curious City. You can follow her @monicaeng.