How does that work?

TALL DRINK OF WATER Intake cribs filter the nasty stuff out of our H2O.

Photo: Kathryn Ware

How does that castlelike offshore intake crib turn nasty lake water into thirst-quenching refreshment?
All manner of pollutants collect in the watery depths of Lake Michigan: germs, bacteria, unlucky mob informants. Thankfully, those majestic water intake cribs two-and-half miles offshore help make our water safe to drink. Lake water enters the intake cribs through a port at the bottom of the crib—at a depth of about 30 feet—and then rises around the outside of a central shaft before making its way back down to a tunnel in the lake’s bedrock anywhere from 75 to 200 feet below the surface, explains Gary Litherland of the city’s Department of Water Management. From this tunnel, the water is filtered through screens to catch debris before being pumped to purification plants that add chemicals such as chlorine to disinfect, activated carbon to remove unpleasant tastes and odors, and fluoride to help fight cavities in our chompers.—Rod O’Connor

How does Willis Tower, né Sears Tower, prevent its new Ledge viewing area from shattering?
Surely that’s not just glass holding up gawkers on the see-through Ledge at Willis Tower (233 S Wacker Dr, 312-875-9696; theskydeck.com). Right? Wrong. The quartet of observation decks jutting out four feet from the building’s 103rd floor—1,353 feet above street level—is, in fact, made of glass. Well, a special “laminated glass,” assures Ross Wimer, a partner at Skidmore, Owings and Merrill, which designed the structures. Strong enough to hold “three midsize cars or an elephant,” Wimer says, the Ledge comprises three half-inch-thick layers of glass with two layers of bonding plastic between them. The material was “tested to failure,” Wimer explains. So what did it take to break it? “A very serious projectile.” Even in a worst-case scenario, you’d still be flying high, Wimer says: If cracked, the glass wouldn’t fall out but instead would stay inside its steel frame. Comforting.—Novid Parsi

Now that city landfills have closed, how is garbage processed? Where does it go?
“First, haulers take it to transfer stations, where it’s compacted to reduce space and moved to larger trucks,” explains Maggie Carson, spokeswoman for the Illinois Environmental Protection Agency. “Chicago has a moratorium against building new landfills, so there aren’t any in the city, but there are eight throughout the northeast Illinois region accepting waste. The closest is probably in Calumet City.” The county where your trash ends up, Carson adds, is based entirely on how much your local hauler is willing to fork over in transportation costs and landfill fees, as well as on how much landfill space is available. Most likely, she says, it’s headed downtstate to Dalton City. “That one’s the most active,” she says. “It’s estimated to have space available until 2013.” —Christina Couch

Illustration: Jude Buffum

Several of the Shedd’s belugas are pregnant now: How does one go about impregnating/birthing a beluga?
It’s not as sexy as you might think, says Ken Ramirez, senior vice president of animal collections and training for the Shedd Aquarium (1200 S Lake Shore Dr, 312-939-2438, sheddaquarium.org). “The entire mating and birth process happens underwater,” he explains. “Like all mammals, male and female [belugas] copulate, then the gestation period is between 14 and 16 months.” Ramirez adds that copulation occurs belly to belly and usually lasts a few seconds to a few minutes. Females can be in labor anywhere from 90 minutes to 12 hours, after which baby belugas weighing 110 to 130 pounds emerge tail first with Shedd staff on hand in case of emergency. Unlike pandas, which have to be coaxed and prodded into doing the humpty bumpty, the Shedd’s seven belugas roam their habitat freely and pick their own partners, usually in late spring.—Christina Couch

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