BOSTON, Mass. -- Ten years ago, 50 tons of raw sewage sludge was being dumped into Boston Harbor on a daily basis, making Boston Harbor a national disgrace and an environmental nightmare.
Today, the dreams of many at the new Deer Island Treatment Plant are coming true as 120 million gallons of sewage each day receives secondary treatment, a process that removes 85% of the pollutants and produces an effluent almost as clear as drinking water.
During the interim, billions of dollars have been spent, porpoises and harbor seals now patrol the harbor's vast expanse, beaches have re-opened, bottom-dwelling fish have returned to health, thousands of construction workers and engineers have toiled, and Boston Harbor has become a source of great pride.
"We have arrived at a milestone in the history of Boston Harbor that many thought we never could or would achieve," said Massachusetts Water Resources Authority (MWRA) Executive Director Doug MacDonald. "But we did not arrive here on our own. The 2.5 million residents of 43 communities have made financial sacrifices to support the project, and the Weld and Cellucci Administrations, our Congressional delegation, and the Massachusetts Legislature, have come through with injections of funds vital to this effort. The environmental community, the federal court, and the U.S. Environmental Protection Agency can all take a bow for providing the impetus to complete this vital project."
MacDonald noted that by this fall another secondary treatment battery will go on line, as will the 4.8-mile, 14-feet-diameter Inter-Island Tunnel, permitting all 450 million gallons of sewage generated on a dry day to receive secondary treatment. "These additional improvements will significantly improve the environment of Boston Harbor and Quincy Bay." he said. "Ninety percent of the Boston Harbor Project has been completed and the new facilities are getting the job done."
While primary treatment is a settling process, secondary treatment is a biological process that accepts treated wastewater from the primary plant. The secondary process uses oxygen to promote the growth of microorganisms ("bugs") which consume solids in the wastewater. The "bugs" increase their density and then settle out to the bottom of the tank. The sludge is then transported to MWRA's Fore River Facility in Quincy where it is de-watered, baked, and converted to fertilizer.
MWRA has already started construction of a third secondary battery to be finished in 1999. When completed, Deer Island will be the second largest sewage treatment plant in the United States. The cost of the entire Boston Harbor Project is expected to be $3.7 billion.
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