NEW YORK (CBSNewYork) — A swimmer who plunged into the filthy Gowanus Canal in October took  his clean water message to another dirty New York City waterway on Wednesday.

Clean water activist Christopher Swain, of Mamaroneck, swam for three hours along the Newton Creek Superfund Site — a 3.5-mile stretch of polluted water which runs between Brooklyn and Queens and flows into the East River.

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“This is one of the dirtiest waterways in the nation, and it runs through one of the greatest cities in the world,” Swain told 1010 WINS. “What if we cleaned them up until they were jewels, until they were one of the reasons people said the city was great?”

Swain conquered the canal, but never put his head under the filthy water — a move he referred to as a “granny swim.” He said the water was filled with oil slicks, trash, industrial chemicals and other miscellaneous items that made its way into the water from the streets.

First person in history to swim the entire length of #NewtownCreek #firsttime #firstdatelastdate #shesafreak #poop #trash #oil #swimwithswain

A photo posted by Christopher Swain, Swimmer (@swimwithswain) on

“The most disgusting things are the floating turds and two used condoms that we saw,” Swain told WCBS 880’s Marla Diamond.

The swim is a part of Swain’s “Campaign for Swimmable Waterways,” meant to increase awareness for cleanup of New York City’s most polluted bodies of water.

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Small efforts have been made to clean up the superfund site. 

“What I want to do is change the goal, change the finish line,” Swain said. ” I want the finish line for Newtown Creek to be a creek that’s safe for swimming every day.”

The first leg of Swain’s clean water mission began in April, when he attempted to swim the Gowanus Canal on Earth Day. Swain managed to swim for several blocks before police stopped him due to impending storms. The Environmental Protection Agency also urged him not to follow through, saying it’s wasn’t even safe to touch the soil around the canal.

PHOTOS: Swain Swims the Gowanus Canal

Swain made a second attempt at swimming the entirety of the 1.8-mile canal in October, and was successful.

Swain said on his Twitter page that he was the first person to ever swim the entirety of Newton Creek. He also said it was dirtier than the Gowanus.

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“I’m willing to freeze, I’m willing to swim in poop because I think unless someone puts themselves on the line, nothing changes,” Swain said.