North Dorchester Bay Combined Sewer Tunnel cited in national engineering competition

WASHINGTON, D.C. —The Westwood, Mass.-based joint venture of Hatch Mott MacDonald and Shaw is a finalist in the American Council of Engineering Companies’ 45th annual Engineering Excellence Awards competition for the North Dorchester Bay Combined Sewer Outfall (CSO) Tunnel Project in Boston.

Though largely invisible to the public, the innovative CSO storage tunnel has eliminated repeated discharges from combined sanitary and storm sewers that frequently closed south Boston’s popular beaches and compromised water quality in North Dorchester Bay. During storm events, the 10,830-foot-long tunnel and associated infrastructure will store 18.5 million gallons of combined sewer flow for subsequent channeling to a treatment facility.

Because of the area’s complex soil conditions, the project team used an earth pressure balance tunnel boring machine to carefully navigate the curved alignment along the coastline and around existing underground infrastructure. Along with minimizing disruptions to traffic and residents, the approach also protected several historic properties from excessive vibration.

The project is among 161 engineering projects from throughout the nation recognized by ACEC as preeminent engineering achievements for 2010. Judging for the Engineering Excellence Awards — known as the “Academy Awards of the engineering industry” — took place in February, conducted by a panel of more than 30 engineers, architects, government representatives, media members, and academics. Criteria for awards include uniqueness and originality, technical, social and economic value, complexity, and success of the projects in meeting goals.

All winners, including 16 Honor Awards, eight Grand Awards, and the “Grand Conceptor Award” for best overall engineering achievement, will be recognized at the Engineering Excellence Awards Gala, to be held Friday, April 1, 2011, at the Grand Hyatt Hotel in Washington, D.C.