It's a three-kilometre long toxic stew of oil, industrial waste, raw sewage and garbage, still activist Christopher Swain hoped that by swimming in it, he'd bring the Gowanus Canal one step closer to getting cleaned up.

"We put a man on the moon, we split the atom, we can clean up the Gowanus Canal," Swain said after swimming a nearly one-kilometre stretch.

The Gowanus Canal has been called one of the most polluted waterways in the United States. Built in the 19th century, it was lined with factories, power and chemical plants and other industries that dumped tonnes of toxic waste into the water.

Wearing a protective dry suit covering most of his body, along with water barrier cream on his face, goggles on his eyes and a cap on his head, the 47-year old made the plunge to raise awareness about the slow pace of cleanup.

'It tasted like mud, poop, ground-up grass, detergent, gasoline, and you know that if you drink one of those green drinks and you get that gritty sandy feeling in your mouth? Like that.' - Water activist Christopher Swain

He had originally planned to swim the entire 2.8 km length of the canal, but cut the attempt short due to deteriorating weather.

"It tasted like mud, poop, ground-up grass, detergent, gasoline, and you know that if you drink one of those green drinks and you get that gritty sandy feeling in your mouth? Like that," he said.

In 2010, the U.S. Environmental Protection Agency designated the Canal as a special site in need of cleanup, with the cost being carried by companies and parties responsible for the contamination, regardless of whether they broke any laws. But at a cost of $ 500 million US and with a timeframe of close to a decade, the work has been slow.

'It could turn out to be a beautiful waterway'

"Some of these cleanups are big they're intimidating, they're scary, they're discouraging. Even though it's discouraging, even though it's difficult let's find the courage to do it anyway, whatever it takes," he said. 

Canal Swim 2

Christopher Swain speaks to the media after cutting short his planned swim of the length of the Gowanus Canal due to poor weather. (Steven D'Souza/CBC News)

Dozens of media lined the route along with curious residents, construction workers and employees of nearby businesses.
"I hope the long-term effects are not too bad for him," said Emmanuelle Richard, who came down to the canal's edge.

"I really dream for a day when the kids can maybe swim in it, or at least play in it."

McKennie Charles, who works nearby, says Swain is brave to make the swim — knowing what's in the infamous canal.

"This a growing neighbourhood, and this is one area that could really use some work, it could turn out to be a beautiful waterway," he said.

The swim almost didn't happen when there was some concern by police about where Swain would emerge after the swim — and possible contamination of private property.

Gowanus Canal Swim

47-year old Christopher Swain pauses for a photo during his swim of the heavily-polluted Gowanus Canal. (Steven D'Souza/CBC )

The EPA warned against the swim, saying the canal contains elevated levels of bacteria and toxic chemicals and that direct contact with water, mud, or even air adjacent to the canal could cause exposure.

It's not Swain's first big swim: In 2003, he swam the entire length of the Columbia River, starting in B.C. and ending at the mouth of the Pacific Ocean. He's also swum the Hudson River and across Lake Champlain.

After cutting Wednesday's swim short, he promised supporters and media to work with the city and NYPD to return to the canal as soon as he can to swim the entire length.