Cedarwood was contracted by the City of Cortland to complete design and permitting associated with a new Gravity Belt Thickener (GBT) for their existing wastewater treatment plant. The existing plant had “squircular” thickeners that were not used for nearly 20 years. The existing thickeners would stagnate sludge in their corners which would go septic and cause odors and allowing rising septic sludge to overflow into the recycle stream. The sludge thickening is important to improve the efficiency of the plants solids treatment plants. Cedarwood designed the GBT to treat the sludge with a long-chain polymer and then pass across a porous woven belt. The polymer counteracts the electrical charge of the sludge particles, allowing them to clump together and release water. The belt allows the released water to pass through into a collection pan to be returned to the facility influent while conveying the now thickened sludge to a pump for delivery to the digesters. The project has resulted in a much improved solids retention time which in turn leads to better digestion and methane production.

Project Cost: $4 million

Contractor(s): Cortland staff self-performed work & subcontracted assistance

Funding Agencies: NYS Clean Water Grant & SRF Loan

Project Status: Completed in 2013