As you approach the edge of the trendy, industrial Brooklyn neighborhood of East Williamsburg, you can smell what divides it from Queens: sewage. That plus oil and other industrial contaminants make the three and a half miles of the Newtown Creek one of the most polluted watersheds in New York.

But architect Rahul Shah has a solution: Build a swimming pool.

The Exorcise Pool–proposed as Shah's master's thesis at Parsons The New School For Design–wouldn't use water directly from the Newtown Creek, but its water supply would be the same, and its purpose is both to mitigate and reveal the woeful state of local water pollution.

"It makes people feel uneasy knowing what the condition of the water you might be consuming once was," Shah says. "I want to instigate that."

Right now, storm water combines with sewage in a pipe-overloading combination that sends over a billion gallons of wastewater into the creek each year. Shah's project would divert an estimated 76,000 cubic feet per year of that run-off into "bioswales": ravines full of cattails, bulrush, and algae that would both absorb and carry water downhill. "They're a series of plantings that can absorb toxins and, kind of the nasties of the water," says Shah.

These bioswales would replace sidewalks on eight blocks of East Williamsburg, covered by grates where there are garages or doors to warehouse apartments. "Fortunately, there's not a lot of pedestrians walking through there," says Shah.

Water not absorbed by the plants would be carried to a series of water treatment technologies, using everything from algae to UV light to a bed full of reeds that will help trap solids. "I really wanted it to be kind of a showcase of different methods of water treatment," says Shah. But he didn't want to refine water to the point of drinkability. "It would be like pond-quality water," he says.

The provocative main attraction is what it does with that pond-quality storm runoff, which starts with a patio full of misters. "That's kind of like a moment of faith that everyone has to take once they enter the project," says Shah. "They're like, 'Okay, this water is coming from the street and the rooftops around here, but it's been treated well enough that I'm going to take a shower in it.'"

After the first tentative, misty steps, visitors can dive into a public pool of the stuff.

Of course, Shah's project isn't likely to happen any time soon, but considering the success of pools made out of garbage dumpsters, I don't think New Yorkers would be scared by a little Williamsburg grime.