Lagoon Aeration Upgrade

Orwell, Vermont | Town of Orwell

Orwell’s wastewater treatment facility includes an aerated lagoon facility that provides secondary treatment and chlorine disinfection of wastewater. The facility’s aging lagoon aeration system was a submerged lateral system that had become inadequate and inefficient. D&K provided design, bid, construction management, and startup assistance services to upgrade the lagoon aeration system to meet current standards. Our project team coordinated dewatering and sludge removal from Lagoons 1 and 2, which was processed on site to render it suitable for landfill disposal. D&K also coordinated the installation of the new aeration system in both lagoons and the replacement of the existing compressors while maintaining the facility’s operation during construction.

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Project Elements

• The submerged lateral system was replaced with a floating lateral system consisting of two new regenerative blowers with VFDs.
• Mechanical design included improvements to the operations building’s HVAC system.
• Electrical design included the installation of new electric service to replace the 150-amp service.

Sustainable Elements

The new aeration system has improved dissolved oxygen levels in the lagoons from 0.5 milligrams per liter (mg/l) to 7 mg/l while using the same or less energy.