Bi-County Water Tunnel

Montgomery & Prince George Counties, Maryland

The Bi-County Water Tunnel project consists of approximately 5.3 miles of tunnel. The tunnel alignment was constructed beneath Rock Creek Park, I-270/I-495, and existing WSSC rights-of-way. The tunnel is located at depths ranging from 90 feet to 275 feet below ground surface in rock with tunnel access to the surface via three vertical shafts.

Brierley Associates provided pre-construction and construction phase engineering services to the Renda / Southland / SAK Joint Venture contractor (RSS JV).  Pre-construction engineering services included submittal preparation for: Geotechnical Instrumentation, Control of Water, Packaged Water Treatment Facilities, Drill and Blast Excavation, Tunneling, Rock Support, Tunnel Shafts, and Temporary Bridge.  Further engineering services prior to and during shaft and tunnel excavation included: blasting consulting and blast cover design, tunnel utility layout, rail and switch layout support equipment, dewatering design for shaft construction, rock stability analysis, and initial support design for shafts, TBM chamber, and tail tunnels.  Brierley Associates also provided full time engineering management for  RSS JV during the first year of construction.