On-lookers were surprised when Massachusetts' frequently spontaneous Governor William F. Weld '66 jumped into the Charles River last summer, in an event publicizing the river's clean-up.

What was even more shocking to some was that he emerged from the water unscathed.

The slow-moving river that meanders through the Harvard campus before emptying into Boston harbor has been a mess for years.

Earlier in the century, when sewage pipes were draining directly into the Charles, the river gained infamous national status for its brown color with a pop hit's refrain that claimed Boston residents "love that dirty water."

But in recent years, local cities and clean water advocacy groups such as the Massachusetts Water Resources Authority (MWRA), the Environmental Protection Agency (EPA) and the Charles River Watershed Association (CRWA) have begun to address the problem.

Over the past six months the MWRA dramatically increased the capacity of pipes that, during wet weather, carry raw sewage and storm water to its state-of-the-art $43.1 billion Deer Island sewage treatment plant.

Independently of the MWRA, some Charles River communities such as Cambridge are beginning to separate their sewer lines from their storm drains.

With major construction going on at the intersection of Quincy, Broadway and Cambridge streets, the Cambridge Public Works Department is now in the second phase of its project.

With a greater capacity to clean waste-water generated during storms, raw sewage that mixes with storm water and empties into the river from combined sewer outflows (CSOs) will be almost totally eliminated--a major boon for water quality.

The MWRA's steps come as part of a major new effort to re-think the waste-water treatment process in the entire Boston Metropolitan area.

Over the course of the next 10 years, the MWRA plans to spend $423 million dollars to reduce CSO's output in Boston Harbor and its contiguous waterways, including the Charles River.

Yet even with this substantial commitment, some are upset that the MWRA's program has not done enough to address problems in the Charles.

Ken Moraff, assistant to the EPA's regional administrator and one of the agency's lead lawyers for water quality standards said that the MWRA program is a step in the right direction, but that it is just a start.

"We think that it is a good first step, but that won't do the job on the Charles," Moraff said.

Indeed, this year's events indicate that there is much work left to be done on the river.