Owner
DC Water
Client
Frontier Kemper / Aldea
Cost
$500-550 million USD
Timeframe
May 2022
— July 2023
Services performed
Tender design of four adits, starter tunnel/launch chamber for TBM, and SEM tunnel connection to an existing shaft.
Description
The Potomac River Tunnel is a Combined sewer overflow (CSO) tunnel spanning approximately 5.5 miles as part of the DC Clean Rivers Project. This project consists of a large-diameter bored tunnel, with multiple diversion facilities, drop shafts, and adits. The tunnel will eventually connect to an existing CSO tunnel, in order to reduce the number of sewer overflows into the Potomac River.
Geology
Quartz mica schist, actinolite schist, and Potomac Group soils (primarily clayey sand, fat clay, and silt).
Location
Washington, DC, USA
Highlights
- 5.5 mile long CSO tunnel.
- Tunnelling in soft ground and rock.
- 18-foot diameter bored tunnel.
Starter Tunnel/Launch Chamber
JBAB Connection