Marine Cleveland Outfall


Durocher Marine installed 4,750 ft of 108” diameter concrete pipe to extend the City of Cleveland’s Westerly Treatment Plant’s sewer outfall into Lake Erie. 


The City of Cleveland upgraded their Westerly Sewage Treatment Plant.  This included a 4,750 ft pre-stressed concrete cylinder pipeline to convey treated effluent out into the open lake.  The pipeline project started near shore at the treatment plant that was demolished and rebuilt.  The project had several unique features.

At the start was a drop structure that housed the vertical component of the outfall.  This structure required sheeting the outside face of the dockwall to create a cofferbox, which required dredging the area to grade.  As the cofferbox was dredged, a series of internal braces were lowered and installed to prevent the structure from collapsing.  Once dredged, 40 vertical Hpile were driven into the base of the structure.  The Hpile were cut off below water, and a 4 ft thick reinforced cap was placed.  Once the concrete cured, the cofferbox could be dewatered and the internal piping was added.

The area from the cofferbox to the open lake required 900 ft of sheeted pipe trench with wales and bracing.  The top 6 ft of material was contaminated and required upland disposal.  The remaining material was dredged and reused as backfill.  Once dredged, the pipeline connected to the cofferbox and was installed to the end of the sheeted trench and backfilled.  The sheets were cut off at the elevation of the top of pipe and left in place.  

At the end of the sheeted trench, a temporary sheet pile structure was installed.  This allowed us to remove 300 ft of existing breakwall and install 300 ft of pipe, which got the pipe outside the breakwall.  Once this section of pipeline was complete, the breakwall was replaced and the temporary cells were removed.  This allowed for the remaining 3,500 ft of open lake trench to be excavated, the pipe installed, and backfilled.  


The existing outfall structure was undersized to handle the amount of effluent required.  By rebuilding the plant and expanding the outfall, they gained capacity for the future and made the byproduct cleaner.  


This was Durocher Marine’s first project as Kokosing.  It brought Durocher Dock and Dredge together with Kokosing.

  • Project Name:
    Cleveland Outfall