Odor Control for the Perfect Storm of Sewer Sulfide Release

This paper chronicles the evolution of an odor control system at the particularly turbulent intersection of King County's Eastside Interceptor sewer and the Sweyolocken pump station's force main discharge. High energy wastewater flow resulting from a steeply sloped 60″ interceptor colliding at right angles with up to 26 MGD discharged through two 20″ force mains provides sufficient energy to liberate large quantities of hydrogen sulfide from the liquid phase into the sewer headspace. This paper will describe the original carbon adsorber odor control system, the use of a proprietary water-washable high hydrogen sulfide capacity carbon scrubber, addition of a second stage activated carbon scrubber and the eventual replacement of the proprietary scrubber with a biotrickling filter. The reasoning behind the installation of each technology will be described in the context of the time period of their selection. Hydrogen sulfide control efficiency and overall odor control will be discussed.