Nominations for The Post's second annual Liberty Medal Awards are pouring in, with New Yorkers looking to honor the unsung heroes of the city.

Today, we introduce a few of the nominees who have already made New York a better place through their selfless actions and unflagging dedication.

When they were boys, Steven Irgang taught his younger brother, Doug, to swim. Now he's helping other kids make a splash in memory of his brother, a competitive swimmer who died in the attack on the Twin Towers.

"We've helped out so many kids and I feel closer to my brother by doing it," he said of "Swim for the Future" - an annual swim-a-thon to raise money for the Andrew Fisher and Doug Irgang Scholarship Fund.

Irgang and Fisher were both on the masters swim team at Asphalt Green on the Upper East Side, and both perished on 9/11.

So far, 16 swimming scholarships have been awarded in their names to city kids 8 to 17 "who want to swim but can't afford to" join Asphalt Green's youth competitive swim team, Irgang said.

One of Doug's Asphalt Green teammates phoned Steven Irgang after 9/11 and told him that Fisher, too, had lost his life and that the team wanted to do something to honor both men.

The idea was born.

"I wanted to turn Doug's tragic death into something positive and, when I see these kids swimming, I know it would make Doug proud," Steven said.

The Irgang brothers grew up in Roslyn, L.I., and their dad - who died when Steven was 14 - taught them to swim and encouraged them to be lifeguards.

"A lot of kids in the city don't know how to swim and it's expensive to join a swim club," said Steven, who lives in Manhattan.

"Not only is swimming a great survival skill, it is great for discipline, for health. It emphasizes the importance of hard work, attaining goals and team work."

Irgang's friend Michael Kessel nominated him for the Liberty Community Medal for spearheading Swim for the Future.

Doug Irgang, an associate director at Sandler O'Neill on the 104th floor of the WTC's south tower, was engaged to be married when he died at age 32.

Fisher, director of sales for Imagine Software, was at a conference at Windows on the World atop the north tower. His family takes an active part in Swim for the Future.

In the months after the disaster, Steven Irgang gave free swimming lessons at Asphalt Green to young children who lost a parent at the World Trade Center. Some remembered going into the water with their late fathers.

The group's next swim-a-thon is scheduled for Nov. 15 at Asphalt Green on York Avenue.

For more info, go to www.swimforthefuture.- com.