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To limit effluent impacts on eutrophication in receiving waterbodies, a small community water resource recovery facility (WRRF) upgraded its conventional activated sludge treatment process for biological nutrient removal, and considered enhanced primary settling and anaerobic digestion (AD) with co-digestion of high strength organic waste (HSOW). The community initiated the resource recovery hub concept with the intention of converting an energy-consuming wastewater treatment plant into a facility that generates energy and nutrients and reuses water. We applied life cycle assessment and life cycle cost assessment to evaluate the net impact of the potential conversion. The upgraded WRRF reduced eutrophication impacts by 40% compared to the legacy system. Other environmental impacts such as global climate change potential (GCCP) and cumulative energy demand (CED) were strongly affected by AD and composting assumptions. The scenario analysis showed that HSOW co-digestion with energy recovery can lead to reductions in GCCP and CED of 7% and 108%, respectively, for the upgraded WRRF (high feedstock-base AD performance scenarios) relative to the legacy system. The cost analysis showed that using the full digester capacity and achieving high digester performance can reduce the life cycle cost of WRRF upgrades by 15% over a 30-year period. deteriorating water quality in water bodies due to eutrophication and pollution from point-sources such as effluents from wastewater treatment facilities. In response, the U.S. Environmental Protection Agency (U.S. EPA) has implemented more stringent effluent quality standards [2]. In addition, much of the wastewater treatment infrastructure is in dire need of improvement due to age, wear, and tear. In 2013, the American Society of Civil Engineers' Infrastructure Report Card assigned both drinking water and wastewater infrastructures a grade of D + , indicating a considerable backlog of overdue maintenance and a pressing need for modernization [3]. With a growing population facing increased regulatory requirements, resource constraints, and financial challenges, communities are seeking more comprehensive and sustainable solutions to address multiple environmental challenges and maximize the recovery of water, energy, nutrients, and materials [1,4,5]. Municipal wastewater and other high strength organic wastes (HSOW) generated in cities are now regarded as a resource for water, energy, and nutrients [6-10].However, the environmental sustainability of wastewater systems goes beyond the treatment plants. It has been argued that many impacts occur at a larger watershed level or along upstream supply chains during energy, chemical, and material production [11,12]. These complex water issues are inherently intertwined and cannot be solved by traditional siloed water management approaches [1]. It is necessary to apply system-based tools or metrics and integrated assessment frameworks such as life cycle assessment (LCA) and life cycle cost assessment (LCCA) to measure trade-offs and develop op...

Collection systemwide methane (CH 4 ) emission estimates are being developed from field sampling in DeKalb County, Georgia as part of Water Environment Research Foundation (WERF) project U2R08 -entitled "Methane Evolution from Wastewater Treatment and Conveyance." This task has been implemented in several phases of field monitoring and data collection. This paper presents initial findings of the Phase 2 of this task.The goal of the first phase of the investigation was to determine if CH 4 could be detected in the wet wells and forebays of a sanitary wastewater collection system. Instantaneous CH 4 measurements at 65 pumping stations across the entire county were quantified during Phase 1. The results of that investigation documented that approximately 1,000 MT of carbon dioxide equivalents (CO 2 e) are emitted each year from CH 4 evolution at pumping stations. While 1,000 MT CO 2 e/yr were quantified, significant sources of under reporting are thought to exist. Specifically, during Phase 1, gravity sewers and manholes where force mains discharge were not monitored.During Phase 2, continuous monitoring for CH 4 was conducted at the discharge of a 16-inch, 3.3-mile-long force main from the Honey Creek Pumping Station (HCPS) and at the enclosed wet well of the Stone Mountain Park Lift Station (SMPLS) that exhibited high Phase 1 CH 4 measurements. Systems were monitored under normal operation for CH 4 and hydrogen sulfide (H 2 S) emissions. To study the effects of electron acceptor addition on the force main CH 4 evolution, Sodium Nitrate (NaNO 3 ) was also dosed at HCPS during Phase 2.Overall, the results form the continuous monitoring during Phase 2 suggest that the collection systemwide emissions are likely considerably higher than the 1,000 MT of CO 2 e/year identified during Phase 1. It also suggests that force main discharge locations warrant additional investigation.

The handling and disposal of wastewater sludge is an increasingly costly portion of the operation of a wastewater treatment plant and is developing into an even greater future risk given the trend of decreasing availability and increasing costs of ultimate disposal options. Recently several technologies and process innovations have been proposed to reduce or eliminate the waste activated sludge (WAS) fraction resulting from treatment, or to render it more amenable to anaerobic digestion, a common sludge stabilization step, in order to maximize biogas production and the corresponding potential for energy cogeneration. Several of these technologies are also claiming significant improvements in the dewatering characteristics of the stabilized biosolids as a result of these pre-conditioning steps. The above claims are especially relevant for industrial facilities and smaller municipal facilities which frequently have no primary sludge but generate large quantities of difficult-to-dewater waste biomass. WERF's 05-CTS-3 Evaluation of Processes to Reduce Activated Sludge Solids Generation andDisposal, which started in the Spring of 2007, seeks to establish a comprehensive evaluation methodology for WAS reduction processes based on the in-depth consideration of a select number of technologies considered to be representative of the many options currently available in the marketplace. These technologies will cover both those intended to reduce the generation of residual sludge from the liquid treatment process, as well as those designed to pre-condition whatever sludge is produced in order to make it more amenable to a subsequent stabilization process such as anaerobic digestion. This paper presents the results of a literature review task conducted in the initial stages of the project, and is intended to be the first one of a series of papers in which the results of this important project are presented to the Residuals and Biosolids community of practitioners. This literature review places into perspective the basic mechanism behind the different WAS Reduction technologies, finding applications worldwide, identifying their application point within the treatment facility (i.e., digestion pretreatment, treatment of activated sludge recycle streams), and defining its development status.

WERF's 05-CTS-3 Evaluation of Processes to Reduce Activated Solids Generation and Disposal aims to establish a comprehensive evaluation methodology for waste activated solids (WAS) reduction processes based on the in-depth consideration of a select number of technologies considered to be representative of the many options currently available in the marketplace. These technologies cover both those intended to reduce the generation of wastewater treatment residuals from the liquid process, as well as those designed to pre-condition solids in order to make it more susceptible to subsequent stabilization processes such as anaerobic digestion.In conjunction with the previous paper titled "CURRENT STATE OF THE PRACTICE OF SLUDGE REDUCTION TECHNOLOGIES" (Sandino et al, 2008), this paper is intended to focus on the evaluation of the performance data collected from full-scale facilities. Laboratory analyses conducted at Virginia Polytechnic Institute from samples collected from these same facilities are included. This paper will discuss the mechanisms behind the technologies, present performance data, and discuss the operational considerations influencing the observed performance (e.g. wastewater characteristics, activated solids operational practice, solids reduction technology design basis and operation).