Pulling the plug

Call it the world's longest tailpipe.

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.

The plugged diffusers are 100 feet below the ocean's surface. To fill the tunnel with water, and keep all the pressures equalized, the 70-pound plugs at the base of the risers have to be removed first. The accident occurred during the beginning of this plug removal.

First flush

When the project continues, the massive tunnel will be filled first with chlorinated sea water from the Deer Island end, forcing air from the tunnel out the diffusers. Some of the ports are equipped with one-way valves. Releasing the air could take a week or more.

The tunnel is the climax for this harbor-altering waste-management project. Historically, waste treatment in Boston has seldom been a subject of continued public interest. But the scale of the project - and the cost - has brought officials from around the world to tour Deer Island.

Equally as important as the tunnel are the huge settling tanks on the island, paired with a dozen, 15-story tall, egg-shaped digesters that break down the waste through anaerobic digestion by microorganisms. Both the tanks and digesters are now in operation, releasing treated waste into the harbor.

But such primary and secondary treatments do not remove nutrients from sewage effluent, a fact that opponents of the project say will damage the ecosystem of the bay. When nutrients amass, choking algae blooms can occur. Also, the effectiveness of the treatment depends on the length of time the waste is processed.

Ann Giblin, associate scientist at the Marine Biological Laboratory in Woods Hole, Mass., sees little risk of a nutrient overload in shifting the sewage outflow from the harbor to the bay via the tunnel. "From the data accumulated, most of the nitrogen currently leaving the Deer Island plant is already going into the bay," she says. "So, I don't see much change at all [from the tunnel] and perhaps even a lessening of the load."

Experts say, ideally, each town could have held costs down by treating its own waste. But squabbling and indecision went on for years until the tunnel became the solution.

"Boston really suffered from a not-in-my-backyard kind of attitude," says Richard Signell, an oceanographer for the United States Geologic Survey (USGS) at Woods Hole. "Hardly anybody wanted any kind of local treatment," he says. "Just send it down the pipe to the treatment plant in Boston Harbor. But this tunnel is a step in the right direction because the harbor was really a mess."

'Steady degradation,' detractors say

Some community activists continue to protest. "My concern is both Massachusetts Bay and Cape Cod," says Mary Loebig, one of the founders of Stop the Outfall Pipe in Cape Cod. "The worst possible thing is that we will see a slow, steady degradation that is undetectable," she says. "Who is to say the existing Boston Harbor situation has not been depressing the ecosystem for hundreds of years because nobody remembers what we had before all this started?"

Over the years, MWRA has nonetheless achieved an unusual consensus among a host of interested parties. Created by the legislature to replace a corrupt agency, MWRA has proceeded without scandal or strikes, but extracted a huge cost of $3.4 billion for the tunnel and total of $7.1 billion to be spent between 1986 and 2009 for all waste-water capital projects. Rate payers eventually will pay the full burden.

"Everybody is sharing the burden of cost equally," says Mr. Berman, "and that means water and sewer departments, municipalities, industry, and residential customers. We could have easily gotten into a situation where there were rate differentials. Whenever the will faltered, there was a federal judge to keep everybody focused."

To pay for the Boston Harbor Project, homeowners saw their annual water rates increase 329 percent between 1986 and 1999. By 2005, the annual cost for water per household in the 43 communities is estimated to reach $1,002.

"The ratepayers are making a major investment here," MacDonald says. "The plant, the salaries, chemicals, and operating costs run $40 million a year. The outfall monitoring program will be $4 million to track, analyze, and measure what is going on."

Most environmentalists and experts who express support for the tunnel, qualify their endorsement with a call for source reduction as part of the ideal answer to pollution. "But as long as people want to use household stuff like cleaners, bleaches, and laundry products," says MacDonald, "you are in a place where long-term source reduction has its limits."

(c) Copyright 1999. The Christian Science Publishing Society