This research was motivated by the need to control odor emission from the District of Columbia Water and Sewer Authority. Ever-increasing urbanization has created a situation where residential communities exist in close proximity to wastewater treatment plants. Offensive odor emissions associated with the treatment process causes a nuisance to the public. Odor mitigation has become a priority for many wastewater treatment authorities. The purpose of this study is to quantify the odorous compounds associated with the secondary treatment system of an advanced wastewater treatment plant. Determine the significant odor source locations in the secondary treatment system. Identify significant parameters which affect both the formation and release of odorants/odors from the secondary system and provide useful baseline information for the selection of appropriate treatment technologies for odor reduction.