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Pulling the plug

As Boston harbor cleanup nears completion, the final hurdle is opening

By David HolmstromStaff writer of The Christian Science Monitor / September 9, 1999


Call it the world's longest tailpipe.

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And, with "mufflers" added, it also costs a cool $3.4 billion.

It begins 420 feet under Deer Island in Boston Harbor and tunnels exactly 9.5 miles to a point out in Massachusetts Bay. Of the 2.5 million people who own and will benefit from this pipe, most are flushed with pride.

The pun is intended. This concrete pipe - really a 24-foot-diameter tunnel bored through the earth by a monstrously efficient, 720 ton boring machine - is an effluent outfall built by the Massachusetts Water Resources Authority (MWRA). It will carry hundreds of millions of gallons of treated waste water sent by a network of 43 communities for dilution in the briny waters of the Atlantic.

When the first surge of treated water rolls through the tunnel in the coming months, the hope is that more than a century of environmental pollution and abuse of Boston Harbor will be completely reversed. No more raw sewage, industrial chemicals, or toxins dumped in the waters where the famed Boston Tea Party happened.

At one time, the harbor was considered the most polluted in the nation. To end the abuse, more than two decades ago a federal judge stepped in, as the result of a lawsuit, and mandated the independent MWRA to oversee an orderly recovery known as the Boston Harbor Project.

"Usually, when you build a sewage plant, your reward is not in this life, but you get it with this one," says Bruce Berman, Baywatch Director of Save the Harbor/Save the Bay, an advocacy group in Boston.

Though no one can predict the overall environmental impact of millions of gallons of effluent nutrients flowing into the sea, most marine scientists, after years of research, have concluded the sea environment will not be significantly degraded.

As a good indicator of what might happen, they point to the treated effluent that has been flowing into the harbor from Deer Island since changes began in 1989 and after a new primary treatment facility went on-line in l995. When the tunnel is operational, this effluent will be diverted 9.5 miles out into the bay.

Cutting toxic waste in the bay

Significant reductions have already been achieved in the amount of pathogens, toxic metals, and petroleum products in the bay. And bottom-dwelling communities such as shrimp-like amphipod have increased in abundance. Still, a few advocacy groups continue to call the tunnel an ill-advised "big experiment" destined to change the balance of the bay's sea life.

Doug MacDonald, executive director of MWRA, concedes there are "ifs" with the project. "But to acknowledge that there is a measure of uncertainty," he says, "is not to suggest that this is some willy-nilly grand experiment. The project has generally been accepted as independent, science-based, peer reviewed, and not a narrow-minded approach in figuring out what is happening."

As for monitoring ocean conditions once the tunnel is operative, John DeVillars, the Environmental Protection Agency's New England administrator, says, "As a package, the MWRA monitoring is a very tight and protective instrument. I think it will work extremely well." The EPA recently issued a permit for the tunnel to begin operation.

Originally scheduled to be opened in late September, completion is now on hold. In late July, during final preparations for opening the empty tunnel to the first flow of water, two workmen with sophisticated breathing apparatus died in the tunnel for reasons as yet unknown. The plan they followed is under investigation by the Occupational Safety and Health Administration to determine responsibility.

"A recklessly complicated plan," says Larry Davey, a former commercial diver who worked on a documentary film about the overall tunnel project. "Nothing quite like this had been done before," he says, contending that the use of liquid oxygen and liquid nitrogen for the workers added too much complexity to a risky job.

"After nine years of work," says Mr. MacDonald, "this has come at a terrible time, to say nothing of the traumatic implications. We may be many weeks away or months away from filling the tunnel."

An MWRA worker described the area at end of the empty tunnel as "a dangerous moon-like environment." To remove the plugs that have kept sea water out, workers travel to the end in HumVees connected back to back. All the boring and debris-removal equipment is gone. Little oxygen exists in a cold and wet environment.

Overhead, rising vertically from the last mile of the tunnel, are 55 risers (30-inch diameter round pipes) that will carry the waste water to diffusers. The diffusers are gum-drop shaped and weigh several tons, each with eight ports that are the final release point of waste water into the ocean.