A general review of literature published from 1990 to 2000 and unpublished (gray) literature on odors associated with municipal wastewater collection systems and treatment facilities, including biosolids handling. The literature review focused on several areas including odor characterization technology, odor sampling, analysis, measurement technology, and odor mitigation (control) technology. Odor literature from the agricultural industry and the industrial wastewater arena was also reviewed for technology transfer feasibility. Public perception of odors was also reviewed. Five databases searched yielded 5,155 abstracts of which 669 articles were retrieved. Gray literature (155 articles) was received by soliciting WEF, AMSA, and A&WMA memberships. All literature was reviewed to determine knowledge gaps and identify the most needy and promising areas for field research in Phase 2. The top priority research agenda selected for field research in Phase 2 was "Impacts of In-Plant Operational Parameters on Biosolids Odor Quality." This publication can also be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below