Black & Veatch Facilitates Technical Decision-Making for a Drinking Water Tunnel

Black & Veatch drew upon its vast resources to design a major water system in the suburbs of Washington, D.C. Assembling a team of experts for the Washington Suburban Sanitary Commission (WSSC), Black & Veatch helped WSSC address economic, environmental and community aspects of a major water conveyance system.

The final design consists of a 10-foot diameter deep rock tunnel, lined with an 84-inch diameter steel liner, which conveys drinking water for 5.6 miles along an interstate highway.

Black & Veatch performed a comprehensive evaluation, including technical requirements, alternative alignments, construction methods, environmental and community impacts, and cost and schedule requirements. The effort included collaboration with county policy stakeholders from Montgomery and Prince George’s counties in Maryland, and an extensive community outreach program.

Black & Veatch proceeded with an extensive geotechnical program and detailed design of the water tunnel. Black & Veatch also provided construction administrative services and rock mapping, and the Bi-County Tunnel project was officially completed and put into service in early 2015.

To address the client’s unique geotechnical situation, Black & Veatch assembled a group of its world-class tunneling experts to act as an independent technical advisory panel and sounding board to WSSC and the design team. This group was engaged in workshops at critical milestones of the project.

“With Black & Veatch’s help, we have installed a major transmission main designed to last at least 100 years, while minimizing community and environmental impacts as promised to the stakeholders during the design phase.”

John Mitchell, WSSC Project Manager