So much for the old warning flag on a stick.
Confronting an almost unwinnable battle against E. coli and other bacteria on public beaches, Chicago and some of its suburbs have taken the fight into the digital age.
From computer models that can predict conditions where bacteria will thrive, to swimming alerts and beach closures sent out via Twitter, Facebook and text message, officials have adopted high-tech strategies to better inform beachgoers of unhealthy conditions.
"That's how people live now," said Cathy Breitenbach, manager of the Chicago Park District's Office of Green Initiatives. "People have an expectation today to get information quickly and in multiple ways. We're doing our best to meet that expectation."
As thousands across Chicago and the suburbs hit the beach this Memorial Day weekend, health officials warn of the dangers lurking out of sight.
The popular beaches that line the lakefront in Chicago and communities to the north have long been a melting pot for E. coli and other harmful bacteria. Stormwater runoff, pet waste, bird droppings and urban trash contribute to microscopic mountains of filth that can lead to sore throats, stomachaches and all kinds of ailments.
The number of swimming bans has increased in recent years, officials say, likely due to more frequent testing for bacteria than an actual drop-off in water quality. Twice a day, researchers walk the city's 31 beaches collecting water samples in small plastic tubes and sending them to a lab for analysis.
The trouble with that method of water sampling is that results aren't known until the next day. The U.S. Environmental Protection Agency and U.S. Geological Survey are pioneering research off Chicago's beaches, using DNA analysis to test for bacteria, that will one day shorten the lab work to a couple of hours, allowing for almost instantaneous water monitoring, said Richard Whitman, a USGS ecologist.
"The results we've been living with are yesterday's numbers, and that's not always good enough," Whitman said. "We know water conditions can change pretty quickly."
This month, Whitman and other scientists dumped red dye into the water a half-mile off 63rd Street Beach, one of the most problematic waterfronts in the city, to track the speed and direction of lake currents in the hopes of better understanding how bacteria builds up along the shoreline.
Thanks to EPA funding, the scientists have developed computer models that can calculate weather data, wave height, wind direction, rainfall and other measurements to project when and where bacteria counts will rise to unsafe levels.
This software, launched in Lake County in 2005, has revolutionized beach research. Instead of having to wait 18 or 20 hours to issue a swimming alert to beachgoers, predictive modeling can anticipate unsafe swimming conditions.
"It's keeping people out of the water when they should be, and not a day after the testing is done," said Mike Adam, a senior biologist for Lake County, which oversees 15 public beaches along the lakefront and several dozen inland beaches. "E. coli levels can change dramatically just between morning and afternoon tests. Imagine how much they change a day later."
Officials in Chicago and Evanston are now compiling data that will enable them to use predictive modeling in a year or two. It is a step toward the ultimate goal of being able to predict high bacteria levels days in advance, Whitman said.
"Wouldn't it be wonderful to know on Friday what the water conditions will be like at your favorite beach on Saturday or Sunday?" Whitman asked. "That's where we want to be."
Until that day arrives, the best defense of our beaches involves a mix of high- and low-tech solutions, Breitenbach said.
Last year the Chicago Park District debuted a specially crafted titanium rake with four-inch teeth capable of turning over deeper layers of sand, reducing bacteria by exposing it to UV light and oxygen. Think of it as a sand Zamboni that refreshes Chicago's beaches each morning.
This spring, the Chicago Park District board unanimously passed an ordinance banning the feeding of birds and wildlife along city beaches. The ordinance is designed to reduce the number of gulls, particularly the most common ring-billed gulls, that congregate and defecate on the sand, Breitenbach said.
And once again this summer, the park district plans to station rescued border collies and their handlers on a few of the city's beaches to disrupt gulls when they try to land. The dogs have proven to be a simple, effective and popular answer to the bird problem, Breitenbach said, and is about as low-tech as it gets.
"They stay in the open areas and try to prevent birds from landing and loafing," Breitenbach said.
The time-honored practice of flying brightly colored flags on the beach, to warn swimmers of dangerous water, has not yet gone the way of the typewriter. Flags will still fly this summer, officials said, but park district two years ago set out to modernize how it reached the public.
District officials set up a Facebook page and a Twitter account, @chicagoparks. In addition to the automated phone line (312-742-3224) that for years has offered recorded messages about beach conditions, this spring the district plans to send swim-ban notifications via text message.
As scientists learn more about the relationship between waterborne bacteria and public health, getting out the information as quickly as possible becomes the next great challenge, Breitenbach said.
"We've made this a commitment because we know it's a public service," she said. "These beaches are meant for all to enjoy."