Water and Wastewater companies operating all around the world have faced rising asset management and replacement costs, often to levels that are financially unsustainable. Management of investment needs, while meeting regulatory and other goals, has required: A better understanding of what customers demand from the services they pay for, and the extent to which they are willing to pay for improvements or be compensated for a reduction in performance Development of models to predict asset failure and to identify and concentrate investment on critical assets Improved management systems Improved accounting for costs and benefits and their incorporation within an appropriate cost-benefit framework Incorporation of risk management techniques Utilisation of advanced maintenance techniques including new rehabilitation failure detection technologies Enhancements in pipeline materials, technologies and laying techniques. These papers developed from LESAM 2007 for inclusion in Strategic Asset Management of Water Supply and Wastewater Infrastructures are focused on the techniques, technologies and management approaches aiming at optimising the investment in infrastructure while achieving demanded customer service standards, and they provide an opportunity to gain access to the latest discussion and developments at the leading-edge in this field. This book will be essential reading for utility operators and managers, regulators and consultants.

Understand the effects of climate change on urban water and wastewater utilities with this collection of international scientific papers. Case studies and practical planning, mitigating and adapting information provided on greenhouse gases, energy use, and water supply and quality issues. This title is co-published with the American Water Works Association.

The literature review described in this report is part of a larger research project to assess STU performance with respect to treatment of important wastewater constituents. The overall goal of the project is to provide a toolkit and tool-use protocol that is easy to implement and available to a wide range of users to assess STU performance. This literature review is not a preview of tools that we will develop and propose, but rather an analysis of the information and data and the literature, to help guide our tool development. All tools developed will be based on rigorous experimental data and quantitative models verified with field data from operating systems. In some cases, more sophisticated tools (e.g., complex mathematical models) may be warranted depending on the relative complexity of the problem and the relative risk associated with a poor design. This literature review focused on STU performance, key conditions or factors potentially affecting STU performance, and the current best practices for using models and other available tools to predict expected STU performance. The information gained during this literature review will guide the future direction of the project. Constituents of interest include nitrogen (N), phosphorus (P), microbial pollutants, and emerging organic wastewater contaminants (OWCs). Based on this literature review, it is clear that due to the variability of data collected at field sites, simple binary relationships (e.g., C/Co versus depth for various soil types) for statistical predictions of the attenuation of N, P, microorganisms or OWCs cannot be justified. Specific to N, hydraulic loading rate appears to be more important than soil texture or soil depth within the first 30-60 cm, although both soil depth and texture remain important variables. Most of the reported results related to the interaction of P with soil appear to be from laboratory batch tests. Similarly, field-scale evaluations of pathogen removal are limited. Finally, most of the existing OWC work has focused on the occurrence and concentrations of selected compounds in streams, lakes, and groundwater impacted by wastewater treatment plant effluents. Currently very few models have been developed for movement and treatment processes of N or P in OWTS. However, adapting the CW2D model for STUs that will predict the effect of different soil types (texture, structure, and drainage class) appears promising. CW2D is a module of the well known HYDRUS model designed to simulate nitrogen treatment in a sand filter. This model incorporates most of the features one might consider, including a comprehensive treatment of microbial growth, the impact of oxygen mass transfer on nitrogen transformation, and variable rates of denitrification due to changes in dissolved oxygen concentrations, dissolved organic matter, and microbial growth. The review of existing models demonstrates that simulation of microbial characteristics in OWTS is still largely uncharted territory.

This project was initiated in response to the establishment of mercury TMDLs around the country and issues raised by this process, specifically concerning the issue of mercury bioavailability. While many TMDLs recognize that point sources constitute a small fraction of the mercury load to a water body, a question has been raised concerning the relative bioavailability of mercury coming from various sources. For instance, is the mercury discharged from a wastewater treatment plant more or less bioavailable than mercury in precipitation, mercury in urban stormwater, or mercury in sediments? This project seeks to address this question by developing a reliable definition and approach to estimating bioavailability, by profiling various sources of mercury in a watershed with regard to the species of mercury present and by profiling those factors or conditions in either the effluent or the receiving water that enhance or mitigate the bioavailability of those forms. The report consists of two volumes. Volume I is a background document for evaluating the biovailability of mercury in wastewater effluents and receiving waters and establishes relevant project objectives. Volume II is a guidance document for wastewater treatment professionals interested in assessing the bioavailability of mercury in their wastewater, comparing it to other sources, and assessing changes in bioavailability in their effluent when it is mixed in a receiving water body. The project concludes that, based on available data and bioavailability as defined in this report, wastewater effluent is one of the lowest among the sources evaluated with respect to mercury bioavailability due to its typically low levels of methylmercury. Due to their typically low levels of suspended solids, wastewater treatment plants employing post-secondary treatment should not contribute appreciably to local sediment mercury burdens.

The best papers from the three-day conference on Safe Drinking Water from Source to Tap June 2009 in Maastricht are published in this book covering the themes of challenges of the water sector and adaptive strategies, treatment, distribution, risk assessment and risk management, sensors and monitoring, small scale systems, simulation, alternative water supply & sources, consumer involvement, and future drinking water. Worldwide, the water supply sector is facing tremendous challenges. Every new emerging contaminants and pathogens and aging infrastructures that are vulnerable for deliberate contamination pose a threat to the quality of water supplies. Shortage of good quality and readily treatable resources is increasing due to global warming, urbanisation and pollution from agriculture and industry. Regulators and consumers are becoming more demanding. Techneau - the largest European project on drinking water - addresses these challenges by developing adaptive supply system options and new and improved treatment and monitoring technologies. Future system options to be studied are flexible, small scale and multi-source supplies, utilising non conventional resources like brackish ground water, treated wastewater and urban groundwater.

The objective of this research was to develop guidance for collecting samples of biosolids for microbial analysis to ensure representative samples are tested. The types of biosolids products studied included liquid, cake and compost. To accomplish the research objective, three phases of research and development of a suite of communications documents were undertaken. The first Phase involved information gathering and establishing the status of sampling guidance and practices for biosolids. Phase II involved conducting sampling and microbial analysis of biosolids products from four target facilities utilizing different biosolids treatment technologies to determine which of a series of sample collection and handling parameters most affects sample integrity and representativeness. Phase III of the project involved field testing at nine utilities. Microbial monitoring results were compared and utility protocols were examined to determine the suitability of their sampling approach. Finally, a series of communications documents were prepared. These communications tools were designed to convey the importance of sampling and handling details at multiple stakeholder levels. This research demonstrated that analysis of multiple, discrete, grab samples provides insight into product variability. In addition, proper handling and adherence to sample size and storage protocols provides a reliable measurement of biosolids microbial content from the biosolids production process being sampled

The Zambezi river is the fourth longest in Africa, crossing or bordering Zambia, Angola, Namibia, Botswana, Zimbabwe and Mozambique. The river basin is widely recognised as one of the most important basins in southern Africa and is the focus of contested development, including water for hydropower and for agriculture and the environment. This book provides a thorough review of water and sustainable development in the Zambezi, in order to identify critical issues and propose constructive ways forward. The book first reviews the availability and use of water resources in the basin, outlines the basin's economic potential and highlights key concerns related to climate vulnerability and risk. Focus is then devoted to hydropower and the water-energy-food (WEF) nexus, sustainable agricultural water management, and threats and opportunities related to provision of ecosystem services. The impact of urbanisation and water quality is also examined, as well as ways to enhance transboundary water cooperation. Last, the book assesses the level of water security in the basin, and provides suggestions for achieving Sustainable Development Goal (SDG) 6. Throughout, emphasis is placed on entry points for basin-level management to foster improved paths forward.

Environmental Technologies to Treat Nitrogen Pollution will provide a thorough understanding of the principles and applications of environmental technologies to treat nitrogen contamination. The main focus will be on water and wastewater treatment, with additional coverage of leachates and off-gasses. The book will bring together an up-to-date compilation of the main physical, chemical and biological processes demanded for the removal of nitrogenous contaminants from water, wastewater, leachates and off-gasses. It will include a series of chapters providing a deep and broad knowledge of the principles and applications required for the treatment of nitrogen pollution. Each chapter will be prepared by recognized specialists across the range of different aspects involved in the removal of nitrogenous contaminants from industrial discharges. Environmental Technologies to Treat Nitrogen Pollution will be the first book to provide a complete review of all the different processes used for the global management of nitrogen pollution. It will also contain updated information about strategies to achieve nitrogen recovery and reuse in different industrial sectors. Several case studies will document the application of different environmental technologies to manage nitrogen pollution. This book will be of interest to lecturers and graduate students in the following subject areas: environmental engineering, environmental biotechnology, wastewater treatment plant design, water pollution control, contaminants recovery and reuse. The book will also be an attractive reference for environmental engineering consultants.

BOILER WATER TREATMENT, PRINCIPLES AND PRACTICE VOLUME 2 of Two Volumes by COLIN FRAYNE. Vol. II: Treatments, Program Design, and Management, ISBN:0-8206-0400-3 This comprehensive reference is the most practical field guide ever written on steam and boiler water treatment. In this two-volume handbook, Colin Frayne (Cooling Water Treatment, Principles and Practice, also by Chemical Publishing) analyzes the whole spectrum of boiler systems, including those used in residential complexes, commercial and institutional buildings, and industrial facilities. The breadth of the book covers: All types of boilers plants, from small cast iron units to large utility and nuclear power plants. Boiler subsystems, appurtenances, and auxiliaries Boiler maintenance and troubleshooting, fuel treatments, combustion gas analysis, pre-treatment processes, chemicals, and operational management Historical and modern program design and control in accordance with international standards Introduction; The Function of Boiler Water; Treatment and Its Marketing Steam Generation; Boiler Types and Applications; Boiler Plant Subsystems, Appurtenances, and Auxiliaries; Waterside and Steamside Problems: The Basics; Waterside and Steamside Problems: Hot Water Heating and Low-Pressure Steam Boiler; Waterside and Steamside Problems: Pre-Boiler Section Specifics; Waterside and Steamside Problems: Boiler Section Specifics; Waterside and Steamside Problems: Post-Boiler Section Specifics; Pre-Boiler and Post-Boiler Treatment Processes; Internal Treatment Programs; Adjuncts and Conjuctional Treatments; Control of Boiler Water Chemistry; Operational Control of Waterside Surfaces; Control of Fireside Conditions and Surfaces. Appendix I Useful Data; Appendix II Glossary; Bibliography. Index. This book is Volume 2 of a 2 Volume set. Other titles by author Colin Frayne: Cooling Water Treatment: Principles and Practice ISBN 978-0-8206-0370-4; Cooling Water Treatment Principles and Practices: Charts and Notes For Field Use ISBN 978-0-8206-0003-1

The Southeast Asian environment has been degraded by the release of industrial and domestic wastes, agricultural and aquacultural chemicals, and pollutants from automobiles. It suffers from water-related disasters, such as tsunamis, floods, typhoons, etc. In order to deal with these issues an integrated approach from the inhabitants, governments and researchers is essential. The environmental threats arising from the increasing population, overuse of natural resources, industrialization, urbanization, and natural disasters present ever increasing challenges to pursuing sustainable development of the region. Many developed countries such as Japan have experiences of dealing with severe environmental pollution and this publication is the result of building an academic network among researchers of related fields from different regions to exchange information. The most important articles presented at the Fourth and Fifth International Symposiums on Southeast Asian Water Environment have been selected for this book. This book will be an invaluable source of information for all those concerned with achieving global sustainability within the water environment in developing regions, including researchers, policy makers, NGOs and NPOs.

Phase 1 of this project demonstrated the technical feasibility of using decentralized stormwater controls in urban areas for retrofits and controlling combined sewer overflows. This technical feasibility was illustrated by a number of early adopters using decentralized controls to complement their existing municipal stormwater and wastewater infrastructure. However, institutional and programmatic issues required further study to broaden the use of a distributed, decentralized stormwater approach. This research evaluates implementation strategies for incorporating decentralized controls into an infrastructure management system. The distributed nature and multiple environmental benefits of decentralized controls necessitate an integrated and inter-departmental management approach. The results of this research identify various implementation strategies for incorporating decentralized controls into urban infrastructure management programs. Case studies and programmatic and regulatory examples detail alternatives to expedite the adoption of decentralized controls. Managing infrastructure by limiting demand is explored in the context of distributed controls. In addition, an evaluation of economic methods appropriate for assessing environmental costs and benefits is included to more fully capture the financial consideration of decentralized controls. Guidance for modeling decentralized controls with commonly used stormwater models is also provided.

This book presents select proceedings of the International Virtual Conference on Trends in Hydrological and Environmental Systems (ITHES 2021). Various topics covered in this book include urban hydrology, hydrological extremes, statistical analysis of hydro-meteorological data, impacts of climate change, hydrological modelling, groundwater studies, water resource management and applications of RS & GIS in hydrology. The book also discusses various topics on applications of CFD in water resources and environmental engineering, water and wastewater treatment, solid waste management and air quality. The book will be a valuable reference for beginners, researchers, and professionals interested in environmental civil engineering, especially hydrological and environmental systems.

Public and Private Participation in the Water and Wastewater Sector provides practical guidance on applying Public Private Partnership structures within the constraints of European legislation, with examples on how to ensure consistency with EU procurement, competition law and the Water Framework Directive. It reconciles the need for adequate regulation within the context of a monopoly provision of service - a major concern of the European competition policy. The purpose of this book is to provide practical guidance on how to introduce a Public Private Partnership (PPP) as a strategy towards helping meet the demands for massive capital investments and improved management and performance in the water and wastewater sector. The introduction of PPPs within a European context needs to be assessed against compliance with basic EU law principles related to Competition and the Water Framework Directive. International legal structures in the management, distribution and treatment of water are discussed. There is a brief overview of the present realities of European integration, the political and legal aspects involved in the water sector and two cases in which a viable solution was reached and which form the basis of this research. The book examines the general principles of EU law in terms of competition and procurement and how other directives have an impact on PPP. It then assesses the specific rules applicable to PPP in the EU context, and their implications in designing water PPPs. The book concludes with a review of two case studies (the City of Sofia, Bulgaria and the City of Tallinn, Estonia) that show how the Public Private Partnership structure chosen provides a sound legal basis and a viable way to achieve compliance with Community law and the Water Framework Directive, thus assisting the process of accession to the EU for each country. Public and Private Participation in the Water and Wastewater Sector: Developing Sustainable Legal Mechanisms is principally aimed at supporting municipal, provincial, and central governments and other policy makers seeking to improve water services. It is a must read for policymakers and practitioners seeking to navigate through the intricacies of EU legislation and the complexities of public private partnerships. The principles addressed in this book will also be useful outside the European context. See also: Private Sector Participation in Water Infrastructure, Organisation for Economic Co-Operation and Development (OECD), 2009; Public Private Partnerships in the Water Sector, Innovation and Financial Sustainability, Cledan Mandri-Perrott and David Stiggers, 2012

Industrial pollution is still a major concern and despite its significance, sound and systematic pollution control efforts are very poorly documented. The character and treatability of industrial wastewaters is highly variable and specific for each industrial activity. Biological treatment with activated sludge is the appropriate technology for industrial wastewaters from several major industrial sectors. Industrial Wastewater Treatment by Activated Sludge deals with the activated sludge treatment of industrial wastewaters by considering conceptual frameworks, methodologies and case studies, in a stepwise manner. The issues related to activated sludge treatment, such as biodegradability based characterization, modeling, assessment of stoichiometric and kinetic parameters and design, as well as the issues of industrial pollution control, e.g. in-plant control, effect of pretreatment, etc. are combined in a way to provide a comprehensive and information-rich view to the reader. By doing so, the book supplies an up-to-date reference for industrial wastewater experts and both graduate and undergraduate students. Industrial Wastewater Treatment by Activated Sludge provides a roadmap, describing the methodologies for the treatment of industrial wastewaters from several major sectors, based on a solid theoretical background. Up to now although valuable separate efforts both on activated sludge and industrial wastewater treatment have been presented, an integrated approach that is crucial to practice has not been available. This gap is filled by this book.

The biotic ligand model (BLM) is a computational tool that may be used to predict toxic effect levels of metals, including Ag. The BLM considers the effect of site-specific water quality characteristics on Ag speciation and bioavailability. This provides a basis for extrapolating from laboratory waters, used for most Ag toxicity tests, to natural waters, where the bioavailability and toxicity of Ag may differ. The original version of the BLM for the acute toxicity of Ag was reviewed by the USEPA Science Advisory Board (SAB) in 1999 and they recommended the completion of additional Ag chemistry and toxicity studies to provide data to test and refine the model. This project was completed to satisfy these recommendations. A chemistry component was completed to improve the representation of Ag speciation in natural waters and to characterize the important effect of sulfide on Ag bioavailability. These investigations added to the information that was available to characterize Ag chemistry and provided a basis for updating the earlier version of the Ag BLM. The BLM was also calibrated to laboratory toxicity data that were generated for a Ag-sensitive invertebrate, Ceriodaphnia dubia, a cladoceran that had previously been tested to only a limited degree. The studies were carried out in laboratory waters in which the chemistry was systematically varied to provide a basis for calibration of the BLM to the toxicity data for C. dubia. Toxicity tests were also performed with both Pimephales promelas and C. dubia in natural water samples that were well characterized chemically, with the data then used to test the model. While the C. dubia BLM results were relatively successful at simulating the observed effect levels the P. promelas results highlighted the need for further testing and refinement of the Ag BLM as it was applied to this fish species. Physiological tests were performed to explore the apparent increase in sensitivity of P. promelas in some of the test waters that were relatively low in ionic strength. It was determined that acclimation to such low ionic strength waters, in the absence of Ag, did not significantly reduce their sensitivity to Ag. Rather, it appeared that any benefit that may have been realized by acclimation, such as an enhanced ability to upregulate ion uptake rates in low ionic strength waters, was apparently offset by a concomitant increase in the rate at which Ag was accumulated. The Ag BLM was modified to account for the effect of low ionic strength water on the sensitivity to Ag of > 4-day old P. promelas. This led to an improved ability of the BLM to predict P. promelas effect levels in the natural waters. Physiological tests were also performed to investigate the apparent species-specific protection against Ag toxicity that is provided by chloride. Investigations with P. promelas suggested that the differences in degree of protection may be related to differences in how Ag affects the ionoregulation of Na+ and Cl- by different fish species. Although questions remain with regard to chloride, it appears that the BLM is able to predict this response reasonably well, particularly for the relatively sensitive <4 day old P. promelas. In summary, the WERF program yielded an improved chemistry and toxicity database, including data over an extended range of water quality characteristics and for an additional Ag-sensitive invertebrate, thereby providing a basis for refining the acute Ag BLM and improving its overall predictive ability.

This is the second of two volumes that together provide a comprehensive overview of the current sustainable and low-cost wastewater treatment technologies applied in communities that lack the financial and technical resources needed for an environmental, disease prevention and health nexus. This book reviews engineered wastewater treatment technologies and discusses their application in regard to greenhouse gas emissions, natural resource utilization, land-use, and energy and water savings. The chapters from expert contributors cover topics such as aerobic and anaerobic biological treatments, chemical treatments and precipitation, and disinfection. Readers will also learn about simplified and low-energy wastewater treatment plants, strategies for wastewater reuse, and nanotechnologies for wastewater environmental management. The feasibility regarding time and cost of implementing such technologies is also discussed in this book, and particular attention is given to the removal of conventional and emerging pollutants, toxicants, and heavy metals. Given the breadth and depth of its coverage, the book offers an invaluable source of information for researchers, students and environmental managers alike.

There is a tremendous amount of literature on and experience with wastewater disinfection alternative. However, it is difficult for wastewater professionals to sift through all of the available information, especially for relatively newer technologies. In addition, there are many factors, some of them site-specific, that influence whether a facility changes disinfection practice, and which alternative it chooses. There are few resources that provide a comprehensive discussion of decision factors with a direct comparison of the disinfection alternatives. This project developed a singular document that presents the pros and cons and costs of the various technical options for wastewater disinfection. The resulting report is intended to be utilized by wastewater professionals to help evaluate and select the appropriate technology for their application. This report presents a review of the existing literature, a survey of disinfection practice by major POTWs, and surveys of facilities with UV and ozone systems. The known advantages and disadvantages of the mature technologies (chlorine, UV, and ozone), other technologies, and combinations of multiple disinfection alternatives are summarized. The report synthesizes this information and presents a coherent method for selecting a disinfection technology, based on individual priorities and criteria. Finally, the report identifies data gaps that would benefit from additional research.

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.

Globalization of Water is a first-of-its-kind review of the critical relationship between globalization and sustainable water management. It explores the impact of international trade on local water depletion and pollution and identifies "water dependent" nations. Examines the critical link between water management and international trade, considering how local water depletion and pollution are often closely tied to the structure of the global economy Offers a consumer-based indicator of each nation's water use: the water footprint Questions whether trade can enhance global water use efficiency, or whether it simply shifts the environmental burden to a distant location Highlights the hidden link between national consumption and the use of water resources across the globe, identifying the threats facing 'water dependent' countries worldwide Provides a state-of-the-art review and in-depth data source for a new field of knowledge

Combining background knowledge and practical tools, Handbook of Inland Aquatic Ecosystem Management gives you an overview of how to manage inland waters in a holistic manner. It examines the problems that threaten aquatic inland water ecosystems and presents a set of toolboxes for solving them. The book focuses on lakes, reservoirs, ponds, rivers, wetlands, lagoons, and estuaries, including the predominant freshwater ecosystems as well as saline and brackish ecosystems. Understand Ecosystem Properties and Ecological Processes The book consists of two parts. The first part reviews the basic scientific knowledge needed in the environmental and ecological management of aquatic ecosystems, from limnology and ecology of inland water ecosystems to environmental physics and chemistry. It emphasizes the interacting processes that characterize all inland aquatic ecosystems and explains the scientific considerations behind the conservation principles and their applications. Define the Problems and Quantify Their Sources The second part of the book presents toolboxes that you can apply to achieve more holistic environmental and ecological management. After an overview of the environmental problems of inland aquatic ecosystems and their sources, the book examines toolboxes to help you identify the problem, namely mass balances, ecological indicators, and ecological models. It also discusses toolboxes that can be used to find an environmental management solution to the problem: environmental technology, cleaner technology, and ecotechnology. Integrate Science and Practical Toolboxes to Manage Inland Waters More Effectively This book shows you how to integrate biology, ecology, limnology, and chemistry with the toolboxes in an up-to-date, multidisciplinary approach to environmental management. It provides a powerful framework for ident

This book is an unique integrated treatise, on the concepts of fractional calculus as models with applications in hydrology, soil science and geomechanics. The models are primarily fractional partial differential equations (fPDEs), and in limited cases, fractional differential equations (fDEs). It develops and applies relevant fPDEs and fDEs mainly to water flow and solute transport in porous media and overland, and in some cases, to concurrent flow and energy transfer. It is an integrated resource with theory and applications for those interested in hydrology, hydraulics and fluid mechanics. The self-contained book summaries the fundamentals for porous media and essential mathematics with extensive references supporting the development of the model and applications.

The World Health Organization estimates that globally one billion people are without access to safe water and two billion people without adequate sanitation. The health consequence of such a situation is very serious and demands urgent appropriate action. The centralised system, which is still promoted all over the world, will not help in providing water and sanitation for all as it depends on huge financial and technological resources that are often not available. The International Conference on Decentralised Water and Wastewater Systems held in Fremantle, Western Australia in July 2006 (organised by the Environmental Technology Centre at Murdoch University) promoted decentralised systems as a means of solving this problem. All the papers submitted at the conference underwent a review process. This book brings together a selection of papers presented at the conference. The papers selected for inclusion in WEMS 13: Decentralised Water and Wastewater Systems promote the concept of decentralised systems, focusing on the design, operation, maintenance and management of small water and wastewater treatment plants and the uptake of decentralized systems. This book will be a valuable resource to industry practitioners, consultants and academics.

The problem of reservoir eutrophication and resulting increase of algal activity is common for seven Dutch waterworks. In this context, the text investigates dissolved air flotation (DAF) as an alternative for algae removal, compared to conventionally applied sedimentation.

Approximately 23 percent of the estimated 115 million occupied homes in the United States are served by onsite wastewater systems. The vast majority of onsite wastewater treatment systems include a septic tank, grease trap, or both for primary treatment. These units are efficient, simple, low-energy treatment units whose performance is critically important to the overall functioning of onsite wastewater systems. Regulations, industry standards, guidance materials and engineering texts vary widely and are often incomplete in their consideration of the factors that may influence primary unit performance in onsite systems. The objective of this research was therefore to identify, compile, analyze, and report on the existing body of work addressing the performance of primary treatment units in onsite wastewater systems and the factors impacting performance. Design, construction/installation, and maintenance issues were considered, with a goal of establishing what is known, what is not known and what future research is needed in this area. Over 700 sources of information were collected, with most reviewed and presented in this document - the white paper. A bibliographic database, which can continue to be updated into the future, was developed as a companion piece to the white paper, as a tool for researchers and practitioners.

The sudden increase in indicator bacteria, including fecal coliforms (FCs) and E. coli, was evaluated at several full-scale facilities, in addition to the increase measured during cake storage. The results showed that the sudden increase was a statistically verifiable occurrence at some facilities, but not all, as was the additional increases measured during cake storage. The sudden increase and growth were much more prevalent in processes that utilized centrifuge dewatering compared to belt filter press dewatering. The sudden increase appears to be a result of the reactivation of indicator bacteria that become reversibly non-culturable (RNC) during digestion. Although other hypotheses, such as contamination and presence of inhibitors, cannot be ruled out in all cases. Only one plant that was sampled with high solids centrifugation did not show reactivation and/or regrowth and this plant was different from others in that it utilized thermophilic reactors in series. The results showed a good correlation between the digestion temperature and the reactivation potential and amount of reactivation measured after dewatering. As temperature of digestion increased, the amount of reactivation increased (for plants with reactivation). Similarly, this was generally true, on average for the extent of regrowth. The digestion SRT and VS reduction did not correlate well with reactivation or regrowth.