Raw sewage pouring into the Charles River may endanger rowers at the Head of the Charles Regatta this weekend if bacteria levels are too high, according to the Environmental Protection Agency.

The contamination is the result of sewage leaks exacerbated by wet weather, according to regional EPA official Ken Moraff.

"It can be dangerous," Moraff said. "When it rains, the whole river is contaminated. It can be hundreds of times the state level for boating."

Harvard crew coaches, however, said they do not think the regatta, which will feature 4,500 rowers and is expected to draw approximately 250,000 spectators, will be canceled.

"I doubt [the contamination] will affect the Head of the Charles," said Peter H. Morgan, assistant coach of the men's varsity heavyweight crew. "Even though you get splashed, you're not swimming."

Morgan said the authority to cancel the Regatta, now in its 32nd year, rests with BankBoston, the race's corporate sponsor. An EPA prohibition on boating on the Charles would have the same effect, he said.

"I'm sure if it was extremely dangerous there would be regulations by the EPA to bar rowing," Morgan said.

Moraff, however, said he was not certain the EPA had the authority to call off the regatta.

The Charles River Watershed Association, a non-profit citizen's group, will sample river water for levels of fecal coliform bacteria tomorrow as part of a five-year study on Charles River contamination.

Public attention has increasingly focused on Charles River pollution in the last few years, especially since this summer's sewage leaks in Cambridge and Newton.

"There have been a couple of occasions on the lower Charles where boaters have reported getting sick," Moraff said. "It might be dangerous, it's hard to predict."

Currently, the regional EPA is working to clean up the Charles through lawsuits against polluters and grants to local organizations and governments with the goal of making the Charles swimmable in 2005, Moraff said.

To combat the pollution problem, the EPA has filed enforcement actions against seven local governments: Cambridge, Brookline, Watertown, Waltham, Newton, Needham and Milford.

While the deadline for most of the towns to report illegal sewage dumping is November, the sewage connections must be fixed by the end of 1997.

In Brookline, the first city to receive an EPA action, the city's Public Works administration found that almost 300 housing units were dumping sewage into storm drains which empty into the river, Moraff said.

Most of the problems result from faulty connections between the buildings and the city's sewage system. The project to fix the connections has been budgeted by the city at $500,000.