The Northeast Ohio Regional Sewer District Board of Trustees at its March 15 meeting awarded the Westerly Storage Tunnel contract to a joint venture of Jay Dee–Obayashi. Jay Dee-Obayashi’s bid was $135,000,000.
The project includes approximately 9,600 lf of 25-ft ID CSO storage tunnel excavated in rock and supported with a bolted, gasketed, one-pass steel fiber reinforced concrete segmental lining.
In addition to the tunnel, there are three deep shafts:
- WST-1: 46-ft diameter online access shaft at the TBM retrieval site.
- WST-2: 12-ft diameter baffle drop structure, connected to the main tunnel via a 5-ft diameter, 50-ft long adit in rock.
- WST-3: 40-ft diameter baffle drop structure at the TBM launch site.
Ancillary work includes Gate Structure and Gate Control Structure, at both the WST-2 and WST-3 sites, to regulate flow entering the tunnel, approximately 90 lf of 46-in. diameter sewer, and miscellaneous modifications to existing sewers.
The contract is part of NEORSD’s Project Clean Lake, a 25-year program that will reduce pollution in Lake Erie by 4 billion gallons per year. A combination of large tunnels, treatment plant improvements and expansion, and green infrastructure is reducing the volume of combined sewer overflow discharging to the lake.