For decades, the large ferries that plied the cobalt waters south of Cape Cod dumped tons of specially treated sewage as they made their runs back and forth to Nantucket and Martha’s Vineyard.
Environmentalists blamed the waste from those and other vessels for releasing toxic bacteria into the ocean and helping seed coastal waters with nitrogen, which has spawned vast tracts of algae that deplete oxygen and kill everything from eelgrass to shellfish. Over the past decade, state and federal officials have been steadily banning the release of sewage from Long Island Sound in New York to the waters off Mount Desert Island in Maine.
On Friday, Massachusetts officials announced that the US Environmental Protection Agency had approved extending the no-discharge zone to areas off all the state’s coast — the last of New England’s waters to come under the ban.
The new rules prohibit commercial and recreational vessels from dumping sewage in the most highly trafficked areas, extending the ban from Cape Ann to Scituate, between Woods Hole and Vineyard Haven, and south of Hyannis.
“Clean and healthy coastal waters are essential for the well-being of the Commonwealth’s economy and environment,” Governor Deval Patrick said in a statement. “The designation of the Commonwealth’s coastal waters as a no-discharge area means that we are protecting one of our most precious natural resources for generations to come.”
Administration officials said the delay in extending the ban to all waters off Massachusetts was the result of years of working with coastal towns, harbor masters, and the shipping and boating community to provide easy access to onshore sewage systems.
They said the ban had little opposition because the state subsidized the costs of more than 120 specially outfitted boats and onshore pumping facilities that are free to use for all local vessels.
“Massachusetts has worked hand-in-hand with our cities and towns, harbor masters, environmental groups, marinas and others, while also working closely with EPA to ensure a smooth approval process,” said Bruce Carlisle, director of the state’s Office of Coastal Zone Management.
State officials noted that commercial and recreational vessels in federal waters, which are generally 3 miles off the coast, are still allowed to dump sewage there. But they said they hope such discharges will no longer be necessary.
“We wanted to make this convenient, so that it would be far less likely that anyone would have to take advantage of discharging in federal water,” said Maeve Vallely Bartlett, secretary of energy and environmental affairs.
The ban is intended to improve water quality, reduce the risk of illness to swimmers and from local seafood, and protect fish and marine plants from the pathogens, nutrients, and other chemicals in discharged sewage. Officials hope it will also reduce the growth of the harmful algae that pollutes much of the Cape’s coastline.
Korrin Petersen, a senior attorney at the Buzzards Bay Coalition, called the ban a victory for everyone who lives near the coast.
“This is a great benefit for local water quality,” she said. “This has been a public health issue for a long time.”
Some private companies, such as the Island Queen ferry service, have paid to install their own pumping systems.
The Steamship Authority, an independently financed public entity that operates ferries to Martha’s Vineyard and Nantucket, has spent $3 million over the past several years retrofitting all nine of its ferries, with much of those costs passed on to passengers. The authority is likely to spend hundreds of thousands of additional dollars every year to operate its new system, which requires ferries to pump sewage between trips to its port towns in Falmouth, Barnstable, Nantucket, and Tisbury.
Officials said they did not fight the changes, even though some had proposed creating an exemption for the largest operators.
“From the beginning, we knew this was the right thing to do,” said Wayne Lamson, general manager of the Steamship Authority. “We knew it would cost money, and that we would pay for the cost of treatment, but we thought it was the right thing to do as an example for others.”
Before the ferries were updated, he said, they all carried equipment to treat their sewage with Coast Guard-approved systems that killed most of the bacteria, and the sewage was dumped as far from the coast as possible.
Lamson said he had no idea how much sewage had been released since the ferries began operating in 1960, but that it was a lot.David Abel can be reached at email@example.com. Follow him on Twitter @davabel.