MWRA agrees to curb sewage flow in Charles

In a landmark settlement aimed at completing the transformation of the Charles River from one of the nation's dirtiest urban rivers to one of the cleanest, the Massachusetts Water Resources Authority has agreed to dramatically curtail the amount of sewage and storm water that pours into the waterway each year.

The agreement is being hailed by officials and environmentalists as a significant milestone in the court-ordered, two-decade-old cleanup of Boston Harbor and could play a key role in making the meandering river swimmable in the Boston area.

If the plan is approved by US District Court Judge Richard G. Stearns, who is overseeing the $4.5 billion harbor cleanup, the MWRA will activate a dormant 54-inch pipe under the Charles River by 2009 that will divert millions of gallons of raw sewage and storm water during heavy rains away from the river and directly into Deer Island Sewage Treatment Plant. The pipe, which has never been used, must be connected to the system before it can operate as a safety valve and redirect water that now flows into the Charles.

The agency also will oversee work to separate sewage pipes from storm-water pipes in Brookline and Boston, reducing strain on the system after heavy rains.

For more than a century, the metropolitan area's sewage system has been unable to handle the sewage and storm water that pours into it after a storm, forcing a filthy mix of untreated waste, polluted road runoff, and storm water into the river.

Today, about 20 such discharges overflow into the river each year. Under the agreement, it would probably happen about twice a year by 2013, say officials with the US Environmental Protection Agency.

The agreement among the MWRA, the EPA, and US Justice Department is supposed to cut the amount of filthy water discharged into the Charles from around 200 million gallons a year to 8 million gallons annually by 2013. The work will cost the MWRA about $20 million, and the agency says that once it is completed, 99 percent of the combined sewage and storm-water overflow will be controlled, from Eliot Bridge near Mt. Auburn Hospital in Cambridge to the locks next to the Museum of Science in Boston.

Frederick A. Laskey, the MWRA's executive director, said the $20 million cost has been figured into rate projections for the authority's 880,000 households. The financially strapped agency has had some of the highest water and sewer rates in the country because of harbor cleanup costs. Earlier this year, the agency announced a proposed rate increase of about $41 per household.

''It's great news. . . . It's a key element of bringing swimming back to Charles," said Robert Zimmerman, executive director of the Charles River Watershed Association.

EPA and the MWRA began studying how to improve efforts to clean up the river in 2002 after it became clear that previous efforts had been insufficient.

Negotiations over what the standards should be and how they would be met took years to complete.

Zimmerman said an annual grade the EPA gives the river has plateaued in recent years to around a B, but yesterday's news ''is going to get us most of the rest of the way" to an A.

The Charles River is a far cry from the stinking waterway that inspired The Standells to write ''Dirty Water," which became a hit in 1966.

Once so filthy that rowers sometimes required medical attention if they fell in, the pollution level is now low enough that a trip to the emergency room is no longer necessary.

Still, the river has never met the goal of state officials and environmentalists, set in 1995, of having the river swimmable by 2005. The Charles continues to register high bacteria counts after heavy rains.

In addition, contaminated sediments layer its bottom, which could be kicked up when swimmers wade in, and pollution still leaks in from nearby roadways, parks, and illegal sewer pipe hook-ups.

But it is the combined sewer and storm-water overflows that are one of the biggest contributors to pollution of the river and one of the prime target for remedial action, officials said.

In 1988, some 1.7 billion gallons of polluted overflow entered the Charles. In 1997, as part of the court-ordered cleanup, the MWRA agreed to measures that would have corrected most of the problem, promising to reduce sewage and storm-water overflow into the Charles to 30 million gallons a year by September 2006. With that deadline looming and presumably unattainable, the new settlement will supersede it.

Like the previous agreement, the new settlement is enforceable with quarterly reports and a broader yearly progress report to the judge, said Michael Wagner, EPA New England assistant enforcement counsel.

In addition, every three years, the MWRA's progress will be reviewed by state officials and the public who will have a chance to comment on it.

''We're getting down to the last 1 percent for the Charles River," said Wagner, who helped negotiate the new agreement. ''This should be underscoring to everyone we are committed to the Charles."

Although not part of the new agreement, other efforts are underway to improve the water in the Charles River Basin. For example, Cambridge is also separating its sewer and storm pipes to stem runoff, and Somerville is also working on the issue.

Beth Daley can be reached at bdaley@globe.com.