The Westerly Storage Tunnel Project is part of Project Clean Lake, the North East Ohio Regional Sewer District’s program designed to reduce pollution in Lake Erie by 4 billion gallons over the next 25 years.

When it's finished in 2020, the tunnel will be between 200 and 250 feet underground, 25 feet in diameter and almost 2 miles long! It will manage higher flow volumes, keeping stormwater out of the combined sewer system and reducing overflow occurrences.

Working under general contractor JayDee-Obayashi JV, Nicholson’s value-engineered proposal and eventual $7 million contract included installing three diaphragm wall shafts that act as support of excavation systems (SOE) for the tunnel boring machine’s entry and retrieval shafts and a vent shaft, plus the SOE system for an attached gate structure at the launch shaft.