Improving the water quality in Lake Erie

Westerly Tunnel and Pump Station

Driven by a Consent Decree, the Northeast Ohio Regional Sewer District’s Project Clean Lake is a 25-year program to dramatically reduce pollution in Lake Erie. One part of the solution is using large storage tunnels to capture and temporarily store combined sewer overflows (CSO) that will then be pumped to upgraded treatment plants once the storm has passed.

In one area of Cleveland, approximately 300 million gallons of CSOs enter the Cuyahoga River in a typical year, and eventually flow to the lake. Stantec, as the lead partner of the MWH/HMM Westerly Joint Venture, is working with the District to significantly reduce this volume with the Westerly Storage Tunnel and Tunnel Dewatering Pump Station Project.

The tunnel will provide 36 million gallons of storage and capture 98 percent of the annual combined sewage in the Westerly District. It is two miles long and 21 feet in diameter serviced by a 36 MGD pump station. The tunnel will be built beneath the Ohio City neighborhood west of Downtown Cleveland, requiring consideration of impacts to historic structures. When completed, the estimated project costs for the improvements will be about $220 million.