For decades, the U.S. Environmental Protection has been pushing for a cleanup of the Hudson River. While there's plenty of work to be done to improve that, one endurance swimmer is now using the river to spread a larger message about clean water across the world.

It’ll be everything but a short swim.

The Hudson River is about 315 miles long. It begins in the Adirondacks and drains out into the Atlantic Ocean at New York City.

Lewis Pugh calls it a river with a story he’s anxious to tell.

“The Hudson is one of the most incredible rivers on this planet,” said Pugh, a United Nations patron of the oceans and endurance swimmer.

But like many waterways around the world, a wide array of pollutants cloud the Hudson River’s rich history.

“It has been put into service to be everything for this nation," said Tracy Brown, Hudson Riverkeeper and president of Riverkeeper. "It was our first highway. It was our first sewage system. It was our first breadbasket for fish, and it’s a drinking water supply, even still.”

Today, experts consider the Hudson to be in recovery mode and stable, thanks in large part to the Clean Water Act implemented more than 50 years ago.

“But I would never say we’re there because we still have a lot of bad practices and legacy pollution like our PCBs,” Brown said.

That's the history Pugh wants to highlight while swimming the length of the river later this summer.

“It’s story about hope,” Pugh said.

As the U.N.'s patron of the oceans, he’s completed various swims like this around the world, promoting this message.

“Healthy rivers are essential for healthy seas. Because everything that goes into a river goes into our ocean,” Pugh said.

The 53-year-old said the Hudson presents some unique challenges, including wildlife at its start on Lake Tear of The Clouds in Keene.

“You’ve got to go through rapids and through gorges and around waterfalls," he said. "That has to be done very carefully.”

As Pugh makes his way south, conditions will vary, but the most challenging will be toward the end of the journey.

“Thirty days of swimming is a lot for anybody, and I need to do that safely because there are very strong currents as you come into Manhattan,” Pugh explained.

Local clean water advocates are looking forward to having a front-row seat to the adventure, and are appreciative of the awareness he’ll raise.

“He’ll be talking about pollution in the river and talking about the additional work we need to do to make the whole bank swimmable,” Brown said.

The journey is scheduled to begin on Aug. 13.

While Lewis has been doing this sort of stuff for more than 30 years, he’s spent the last nine months swimming every day to prepare for this unassisted swim along the Hudson.