Papers and Reports

A study was completed to evaluate odor concerns and control strategies for the Town of Cary, North Carolina (Town) Western Cary Collection System. A primary driver for this project was to be proactive in reducing odors in the collection system in advance of the 2015 start-up of the new Western Wake Water Reclamation Facility (WWWRF) and prior to the change in flow direction in the collection system from north to south. Sulfide and dynamic air modeling provided a methodology for the Town to plan odor control for capital projects by creating redundant solutions for future growth. The results consist of projected liquid-phase total sulfide concentrations in the collection system for years 2015 and 2030. A dynamic air analysis of the 120 centimeter (cm) (48 inch) diameter Green Level Interceptor gravity pipeline at year 2015 and 2030 wastewater flow rates and at buildout flow rates was also performed to project air movement and odor emissions (in the form of hydrogen sulfide [H2S]). Final recommendations included a “toolbox” of odor control solutions to adapt to changing conditions as the Western Cary Collection System service area continues to grow and flows increase. It was important to achieve the correct balance between operating chemical addition and/or gas-phase treatment to reduce operating costs and provide optimal odor control.