• Credit: Playlab/Family

?by Rebecca Robledo Among the stories of pool openings and water safety that appear each summer comes a project that has captured global attention.

Three young, New York-based architects would like to see people be able to swim in Manhattan’s East River, but the water is too dirty. Their solution is to design a pool that floats on the river with walls that act as a passive filtration system to make the water suitable for humans. This water eventually would be passed back into the river in a cleaner state. While the vessel couldn’t clean the whole river, designers expect it to process approximately 500,000 gallons of water each day.

In honor of its shape, the project has been dubbed + Pool (pronounced Plus Pool). Each leg will serve a separate function — one for children, sports, laps and lounging.

The project has gained considerable press coverage due to the technical challenges, potential social impact and the organizers’ use of crowdfunding to raise revenue. “The press and people all over the world started [regarding] + Pool as a precedent for crowdfunding civic architecture,” said Archie Lee Coates IV, partner in PlayLab, a New York-based architectural firm.

The + Pool has appeared on the pages of USA Today, the Economist, Wired and several websites, added Coates, who, along with business partner Jeff Franklin, is collaborating with Dong-Ping Wong of the New York architecture firm Family on this project.

In 2010, the organizers launched a campaign on crowdfunding website Kickstarter, and surpassed their goal of $25,000 to raise $40,000 from 1,200 supporters. In addition, they were approached by a variety of organizations, including global engineering firm Arup and Columbia University, hoping to partner with them on research and development.

The group now plans to float a 35-by-35-foot test pool in the East River to learn more about the water and see how the current filtration design performs. This will be funded by another successful Kickstarter campaign, which raised $273,114, exceeding its goal by more than $23,000. As part of the campaign, organizers sold tiles to be placed in the pool and deck. For as little as $25, backers could have their names etched on a tile, with upgraded packages available. Eventually, the team hopes to sell all 70,000 tiles, which would fund the entire project.

Because it is still in development, the partners can’t share exact technologies. But while the pool’s filtration was originally conceived as being completely passive, designers now may introduce some pressure. “This hybrid is pulling the water — not pumping the water,” said Wade McGillis, a research professor at Columbia University.

They expect this to play out in a layered process that combines a geotextile, various membranes and a disinfection layer.

“We are looking at initial layers of screening and pre-screening ... and the types of materials that could be used,” said Nancy Choi, a senior environmental engineer at Arup’s New York office. “[We are] also looking at other, traditional water-treatment-type filtration methods — your sand filters, membrane filters, etc. One of the goals is trying to not use chemicals if possible, but that may be required.”

The designers originally planned to have the walls perform all filtration and sanitation. However, the finished design may incorporate mechanical technologies built inside the walls to help with the process, she added.

Having so much surface area to work with in the pool walls presents certain benefits. Because water is essentially seeping into the pool rather than being forced in through pressure, there is nothing pushing particulate into the filtration material, which likely will mean there’s no clogging. Instead, particulate will stay outside the pool walls, McGillis said.

As for the shell, it will literally float, but will be tethered somehow. Coates likens it to a barge. “It’s basically just floating concrete — it’s a pretty simple structure,” he said. “The concrete is what is largely making up the pool in terms of its structure. But the section that has the filters obviously is open in some way to the outside.”

The pool shape, however, may pose a challenge. Because of its four appendages, the plus sign may have the potential to get pushed around by the river flow. “Maybe the technical challenge is the shape … and how can we design that to work and not spin around or tear off or break off?” Choi said. “If you look at it, sometimes you think it can be a giant fan, where the currents could just spin it around and around. Or you have corners, so there’s a tendency for buildup of debris.”

Putting this together has meant more bureaucracy than the average public pool. Organizers must work with the Army Corps of Engineers, the Coast Guard and the departments of Health, Environmental Conservation, Environmental Protection, and Parks and Recreation to see what each requires.

“The city has been 100 percent supportive and helpful in that,” Coates said. “The city wants to see people back on the waterfront.”

Like all pools and spas, this project started with a simple desire that has taken on a life of its own. “Here we have this thing that we thought of one day when it was hot outside and we just wanted to swim, and it’s become this kind of worldwide effort,” Coates said.