To swim or not to swim? A Lamont-Doherty scientist and the group Riverkeeper are trying to answer that question about the Hudson River.

Since the fall of 2006, Dr. Greg O'Mullan and Riverkeeper have been collecting samples at 27 sites from New York Harbor to Peekskill, and the results may surprise some people.

"A given location will be good some days and very bad other days, and some of those places are where I would have sworn ... it would be fine because they're not in the city," says John Lipscomb, of Riverkeeper.

Water quality surrounding Piermont was consistently poor. The researchers also say after storms, sewage and bacteria counts far exceeded federal and state standards.

In general, the middle of the river from Peekskill to Yonkers has proved to be safe.

The goal of the project is to provide the public with scientific data, something that hasn't been done in the past.

"We don't yet have the answer and that's going to require a new commitment to monitor and manage the river to let people know when and where it's safe to swim," says O'Mullan.

Many residents say they'll just wait for the final report before even considering taking a dip.

Riverkeeper