Phase 3 of the overall WERF project was developed to study eight Phase 2 hypotheses in more depth, beginning in the laboratory (bench-scale) studies and continuing on to targeted investigations where the WERF team manipulated plant parameters at full scale to identify the best means of reducing biosolids cake odors. The Phase 3 research specifically sought ways to enhance anaerobicly digested and dewatered biosolids to reduce the odor levels in the biosolids end product, thereby reducing negatively perceived impacts on the environment or to the public when beneficially used on land. The goal of the Phase 3 study was to provide a general application of findings to WERF subscribers who are seeking ways to reduce odors produced by anaerobicly-digested biosolids. The Phase 3 options summary presents a general roadmap for wastewater treatment plant operators seeking to optimize biosolids processing and reduce biosolids cake odors. Biosolids cakes with minimal odors lead to better public acceptance near biosolids management sites and in neighborhoods adjacent to WWTPs. Reduced odors also could open the WWTP dewatered biosolids cake to other recycling or disposal opportunities that are currently not used due to odor and other concerns (including on-plant site composting or storage). Additionally, significant cost savings could be realized by not requiring extensive odor control or other expensive options for containment and management of biosolids.

Wastewater collection system odors and corrosion issues continue to grow in importance to the community and to system owners and operators. Odor and corrosion prevention in collection systems has historically been as much art as science. Common control methods are selected based on practical experience as opposed to a fundamental understanding of why and when methods will be successful. Although much is known regarding the cause of odorous gases in the collection system, the underlying science and mechanisms of odor generation, sewer ventilation, odor characterization and monitoring, and corrosion mechanisms need further research. This WERF research activity helps odor-control specialists transition from "odor artists" to scientists and engineers, while also providing a useful tool both for designers to successfully prevent odor and corrosion events through proper design and for operators to mitigate and prevent odor excursions and corrosion impacts. This project transfers state-of-the-art technology and information gained from the literature survey to the collection system owner and designer on odor and corrosion assessment, measurement, characterization, monitoring, and prevention. The field studies identified in this Phase 1 effort will fill high-ranked knowledge needs. The resultant database and team-developed, web-based application tool will identify the best practices for the entire collection system and its associated facilities, infrastructure, equipment, and pipes. A plain-English guide providing a useful and easily understandable overview about odor and corrosion in collection systems including how odor and corrosion compounds are formed and what to do to control them is provided as an introduction to this document. This Phase 1 report then summarizes the state of the art in knowledge related to odor and corrosion in collection systems. This highlights the latest knowledge reported in the literature. These efforts to compile the literature database have included information-sharing partnerships with municipal utilities, the academic community, and the profession, all on a global basis. Our team included leading odor and corrosion control researchers in the academic, utility management, and consulting communities, and part of their role was to provide exhaustive literature research efforts through catalogue reference, gray literature review, and Internet search mechanisms. In this way we have accessed a broad spectrum of global resources tapping into the knowledge and experience of both WERF member and nonmember utilities.

This project was undertaken in response to needs by the wastewater treatment industry to better understand the generation of odors from biosolids produced by wastewater treatment plants (WWTPs). Its primary objective is to begin to establish relationships between WWTP process parameters and biosolids odors, so that more effective techniques for minimizing biosolids odors can be developed. The project consisted of a detailed field study involving extensive sampling and analyses at 11 WWTPs across North America with capacities from 13 to 350 million gallons per day (mgd). Biosolids samples were collected from the WWTPs at a number of sampling points, which were chosen to represent a complete snapshot of biosolids generation and handling at each WWTP. The sampling points started with influent wastewater, proceeded through primary and secondary clarification, and continued through digestion, dewatering, and onsite storage of dewatered biosolids cake. Laboratory-scale anaerobic storage tests were conducted to simulate odor development of biosolids in storage, prior to their beneficial reuse or disposal. A battery of analyses were performed on the biosolids samples by the participating utility laboratories, commercial laboratories, and specialized university laboratories. The analytical data were evaluated and compared with process and operation parameters at each participating WWTP.

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.

Although primarily concerned with the treatment of wastewater and water quality, publicly owned treatment works (POTWs) are required to be in compliance with the Federal Clean Air Act and an increasingly stringent series of Clean Air Act Amendments to control emissions of odors, criteria pollutants, and volatile organic compounds (VOCs). How POTWs demonstrate, document, or show compliance with federal and state or local quality laws and regulations can vary significantly from POTW to POTW and from state to state. VOC Emissions from Wastewater Treatment Plants: Characterization, Control, and Compliance provides the tools, concepts, policies, and information required to develop an air quality compliance plan and to assess the labor and capital requirements to maintain the plan's viability.

With contributions from a panel of experts and authoritative editorial guidance, the book reflects many viewpoints and approaches based on various air quality compliance and assessment conditions and experiences. The editors use this body of knowledge to develop a clear picture of how to design, set up, and maintain a successful air quality compliance program. Building on this foundation, VOC Emissions from Wastewater Treatment Plants: Characterization, Control, and Compliance shows you how to create a comprehensive, complete program that includes POTW-specific air emissions inventory information, measurement techniques, and viable control options.