Bi-County Water Tunnel Reaches Milestone
Tunnel Boring Machine "Holes Through" at Stoneybrook
A major milestone was reached this morning in the construction of the Bi-County Water Tunnel when Miss Colleen "holed through" the shaft at Stoneybrook and Beach Drive. The powerful and affectionately named Tunnel Boring Machine (TBM) began chewing through 4000 feet of rock on July 23 from the main access shaft near Connecticut Avenue, the first leg of a 5.3 mile tunnel.
The tunnel, which will contain an 84-inch in diameter water main, will run approximately 200 feet underground along I-270 and I-495. When completed in 2013, the water tunnel will connect two existing 96-inch mains and have a capacity of 100-million gallons of water per day.
The new line is being constructed to respond to increasing demands for water in Prince George's and Montgomery counties, as well as increase reserves in case of emergency.
The big cutter head will be detached from the TBM, lifted out of the Stoneybrook shaft and trucked back to the main access shaft. The rest of the machine will backup to the access shaft, and be re-united with the cutter head. This process is expected to take at least a month. "Miss Colleen" will then head toward the Tuckerman Lane shaft 4.5 miles to the west.
For video on this event, go to: http://www.wsscwater.com/home/jsp/content/bi-county-index.facesAbout Washington Suburban Sanitary Commission
Established in 1918, the Washington Suburban Sanitary Commission is the 8th largest water and wastewater utility in the nation, with a network of more than 5,500 miles of fresh water pipeline and nearly 5,400 miles of sewer pipeline. Serving 1.8 million residents in Prince George's and Montgomery Counties, our drinking water has always met or exceeded federal standards.
SOURCE: Washington Suburban Sanitary Commission