The Charles River has been awarded a `B-' grade for water quality this year, up from a `D' in 1996 and a `C' just last year, the Environmental Protection Agency (EPA) announced yesterday.

"You'd be hard pressed to find another river in the United States with that kind of improvement," said Bob Zimmerman, executive director of the Charles River Watershed Association, an environmental group.

But don't go swimming just yet.

The river was clean enough to swim in just 51% of the time last year, and clean enough to boat in 83% of the time, according to statistics from the watershed association.

Harvard, MIT and 10 other waterfront institutions have formed a partnership to help the EPA clean up the river, the institutions announced yesterday.

The Clean Charles 2005 Coalition is dedicated to helping the EPA make the river safe for both fishing and swimming by 2005, a goal which EPA Regional Director John P. DeVillars said may be met ahead of time.

Participating institutions in the coalition will "develop and implement storm water management techniques," according to Ken Moraff, the enforcement chief at the EPA's New England office.

MIT will also contribute a boat equipped with a skimmer to collect trash, as well as the assistance of a graduate student with environmental expertise, said Paul Parravano, codirector of government and community relations at MIT.

Brandeis, Northeastern, and Boston universities are also participating in the coalition, along with six companies and the non-profit watershed association.

But while environmental group representatives acknowledge the river has a long way to go, they said conditions have improved greatly, thanks to increased efforts from the EPA and other government organizations.

"They're just becoming aware that this is not adeal where you take some shopping carts out of thewater and wash your hand wash your hands,"Zimmerman said.

Since the Charles received its dismal `D' gradein 1996, the EPA has stepped up its enforcement ofpollution regulations and dealt with sewagedisposal problems.

"We discovered that there were a lot of sewersaround greater Boston that were connected to stormdrains illegally," Moraff said. "A lot of sewagewas going directly into the Charles."

Water cleanliness problems--as measured by highfecal bacteria counts--have led to health problemsin the past.

Two years ago, two crew team members got bloodpoisoning after river water came into contact withopen sores on their hands