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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 of these studies 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. There were several important objectives relevant to the estimation of bioavailability and potential bioaccumulation of mercury from wastewater treatment plants and other sources in receiving waters. The first was to develop a working definition of bioavailability. For purposes of this project, this definition includes not only methylmercury, the form of mercury that readily bioaccumulates in aquatic food chains, but also bioavailable and potentially bioavailable inorganic mercury species that can be converted to methylmercury within a reasonable time frame. It is concluded that the strength of binding to solids and mercury-sulfur-organic matter associations are major factors in determining the bioavailability of inorganic Hg.A second major objective was to identify those factors or conditions in both the effluent and the receiving waters that enhance or mitigate the transformation of inorganic mercury to methylmercury and its subsequent bioaccumulation. Profiles were developed for various sources of mercury in watersheds, including wastewater treatment plants, with regard to bioavailable and potentially bioavailable mercury, and key factors in effluents and receiving waters that enhance or mitigate it. A procedure to assess the relative bioavailability of mercury from various watershed sources, including wastewater treatment plants was developed and tested using data from a US location. The project also features a literature review of conventional and emerging technologies for the removal of mercury from effluent streams and their effects on mercury bioavailability. A review of the salient aspects of mercury TMDLs completed by EPA and the states is also included.This 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, along with urban runoff and mining runoff. Atmospheric deposition and contaminated sediments tend to be among the highest sources with respect to mercury bioavailability.

Infectious diseases caused by pathogenic bacteria, viruses and protozoa, are the most common and widespread health risk associated with drinking water. Most waterborne pathogens are introduced into drinking water supplies by human or animal faeces (enteric pathogens) but they can also exist naturally in water environments as indigenous aquatic micro-organisms. Controlling the risks related to these pathogens is a permanent challenge for the water industry. In addition to the constantly evolving range of pathogens to consider, assessing and managing such risks requires the integration of information issued by a wide range of disciplines. The necessary knowledge is however still sketchy and incomplete for most pathogens, and research efforts are necessary to fill the remaining gaps of knowledge. The purpose of this study is to provide an updated, comprehensive review of current knowledge on a selection of pathogens of interest for the drinking water industry, and to identify the remaining gaps of knowledge and thus the necessary research to be conducted. Emphasis has been laid on the information needed to assess and manage the risks related to each of these pathogens in drinking water production and distribution.The pathogens considered in this review were selected on the basis of: Their recognized or highly suspected transmission by drinking water through ingestion, inhalation, or contactTheir recognized pathogenic character for humansThe severity of their health effects Each micro-organism in this study is described in a summary fact sheet composed of the following items: microbiology, human health effects, geographical distribution, epidemiology, ecology, inactivation/removal, surrogates, environmental detection and research needs. Since much remains unknown about many aspects that are common to viruses, the study features a general section on virus research needs. A special section summarizes the risk management research conducted on waterborne pathogens. Finally, the conclusion gives an overview of the main gaps in current knowledge on waterborne pathogens. Visit the IWA WaterWiki to read and share material related to this title:http://www.iwawaterwiki.org/xwiki/bin/view/Articles/WaterbornePathogens

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.

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 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.

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.

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.

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.

In order to facilitate more effective integration of monitoring data and technically sound assessment methodologies into the waterbody assessment and listing process, a critical evaluation of the current methodologies employed by the states was recognized by WERF. Funding was provided to document and evaluate current assessment and listing methodologies employed by the states during the development of their Integrated Reports. The findings from the review of current waterbody assessment methodologies presented herein provides a comprehensive overview of the current state of the science for the waterbody assessment and listing process. Using the strengths found in many of the states assessment methodologies and information found in other guidance, the Research Team developed recommendations which request the states to: 1) develop and publish minimum data quantity and quality requirements, 2) better integrate monitoring programs with waterbody assessment needs, 3) develop standardized assessment units that allow for better water quality extrapolation, 4) develop numeric water quality criteria by which to more reliably determine support or impairment of designated uses, 5) use statistically-based data evaluation techniques to more confidently determine attainment of water quality standards, and 6) include the public in the assessment and listing methodology development process.

Ciliated protozoa are one of the most relevant biological communities in the reactors of wastewater treatment plants. These organisms are excellent tools to assess the biological status of the reactor being used to monitor wastewater treatment plants performance. This book has been designed to simplify identification of ciliates, bearing in mind the difficulties on the manipulation and proper identification of these species. The specific role of ciliates in WWTP is discussed; methods for observation together with a glossary of scientific words and a simple and easy key to the taxonomic groups of ciliates are also provided. Illustrations, drawings, photographs and brief morphological descriptions of the species are included. Guidelines for the Identification of Ciliates in Wastewater Treatment Plants is the first book to use the new official classification proposed by the Society of Protozoologists (2005). It includes a complete chapter on methodology that is designed to be easy to follow and reproduce. A simple key to classify main taxonomic groups and genera is included, as are detailed descriptions to aid observation and identification of species of ciliates, in addition to drawings and photographs that accurately reproduce ciliate species.

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 "e;odor artists"e; 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.

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, po

The purpose of this User's Guide is to provide guidance on modeling watershed-scale problems associated with decentralized wastewater-treatment systems (DWTS), with a particular focus on onsite wastewater systems (OWS). The guide focuses on modeling transport and fate of the nutrients nitrogen (N) and phosphorus (P) because these are the most common OWS constituents of concern, and because these pollutants are regulated in surface waters (N and P) and in ground water (N). However, limited but useful information is also provided regarding the modeling of organic wastewater contaminants, such as pharmaceuticals, pesticides, and other household products. It provides some general information on modeling bacterial pollutants. The guide can be used by decision makers to determine whether relatively simple screening models (presented in Appendix A) are sufficient for use in the decision-making process, or if sophisticated models (presented in Appendix B) are more appropriate. The document provides guidance about the type of model that should be used for particular scenarios, and the data requirements for model implementation. The guide is also useful to modeling experts by providing guidance on important issues such as conceptual-model development, mathematical-model selection, modelsensitivity analyses, model uniqueness, and calibration. Finally, the guide provides some real-world and hypothetical case studies that can demonstrate the usefulness of using watershed-scale models, and provide templates for certain common scenarios relevant to the decentralized wastewater treatment community.

Concerns about water quality degradation resulting from land appliation of manures and biosolids have elicited a wide array of national and state regulations. The regulations focus on P as the limiting nutrient to eutrophication of most freshwater supplies and threaten to severly impact biosolids recycling. Critical data about biosolids-P phytoavailability and run-off potential, especially field data, needed to validate the regulations are scarce. The goal of this reseach was to supply such data. Conventionally treated biosolids exhibit both less agronomic and environmental impact, such as co-application with water treatment residuals (WTF).

Municipal wastewater treatment facilities were not specifically designed to remove xenobiotics such as endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs). European studies have described the need for a minimum critical SRT to achieve good removal of EDCs and pharmaceuticals. These studies have presented limited data on PPCPs from full-scale facilities. The objective of this study was to expand published findings to the removal of twenty PPCPs commonly found in the influent of full-scale treatment facilities operating in the United States.The six selected facilities cover operating SRT conditions ranging from 0.5 to 30 days and include facility capacities in excess of 300 mgd. The results demonstrate a wide distribution in both the occurrence of these compounds in the influent to secondary treatment processes and the percentage removal achieved through secondary treatment. The twenty PPCPs were categorized into nine bin combinations of occurrence and treatment reduction.While a large number of these compounds were well removed, one in particular (galaxolide) occurred frequently and was resistant to removal. A minimum critical SRT, defined in this study as the minimum time needed to consistently demonstrate greater than 80 percent removal (SRT80), was determined for the twenty target compounds.SRT80 was compound-dependent with most compounds consistently removed at 5 to 15 days.

This project evaluated the quality of data needed to determine relationships between chronic Whole Effluent Toxicity (WET) test results and in-stream biological condition. A data quality objectives approach was used, which included several proposed measurement quality objectives (MQOs) that specified desired precision, bias, and sensitivity of methods used. Six facilities (four eastern and two western U.S.) participated in this study, all having design effluent concentrations > 60% of the stream flow. In accordance with a Quality Assurance Project Plan most of the facilities completed four quarters of chronic <i>Ceriodaphnia dubia</i>, and <i>Pimephales promelas</i> (fathead minnow) WET tests, and three quarters of <i>Selenastrum capricornutum</i> (green algae) WET testing following the most recent USEPA methods. Several other WET tests were conducted to address MQOs including splits, duplicates, and blind positive and negative controls. Macroinvertebrate, fish, and periphyton bioassessments were conducted at multiple locations up and downstream of each facility following the most recent USEPA Office of Water bioassessment protocols. <div><br></div><div>Test acceptance criteria were met for most WET tests, however, this study demonstrated the need to incorporate other MQOs in a full study (such as minimum and maximum percent significant differences and performance on blind samples) to ensure accurate interpretation of effluent toxicity. More false positives, lower test endpoint (i.e., higher toxicity), and morefailed"e; (non-compliant) tests were observed using No Observed Effect Concentrations (NOEC) as compared to IC25s (concentration causing 25% decrease in organism response compared to controls). Algae tests often yielded the most effluent toxicity in this study, however, this test was most susceptible to false positives and high inter-laboratory variability. WET test results exhibited few relationships with bioassessment results, even when incorporating actual effluent dilution. Neither frequency of WET non-compliance nor magnitude of WET were clearly related to differences in biological condition up and downstream of a discharge for the most part. Macroinvertebrate assessments were most able to discriminate small changes downstream of the effluent, followed by periphyton and then fish. The sampling methods used were robust but a full study should collect more field replicates up and downstream of each discharge to increase detection power. Macroinvertebrate and periphyton assessments together appeared to be sufficient to address project objectives. Fish assessments could be useful as well but would entail more effort and cost per site than expended in this project, to be useful.</div>

Recent research has shown that the concentrations of microbial indicator organisms (e.g., fecal coliforms) in stormwater may be quite high. However, studies have not clearly established relationships between the concentrations of indicator organisms and microbial pathogens in stormwater, or between stormwater indicator organism concentrations and illness. Thus, it is difficult to interpret indicator data collected by local public agencies in the context of potential risk to human health. The primary objective of this investigation was to generate guidance to enable more accurate and defensible evaluations of stormwater microorganism data and the associated risks to human health from exposure to microbial pathogens in stormwater. The investigation consisted of three major tasks: reviewing and summarizing relevant published literature, conducting a web-based data questionnaire and developing a science-directed data collection plan. Topics discussed include: 1) waterborne pathogens that pose the greatest risk to human health, 2) concentrations of pathogens and indicator organisms observed in stormwater, 3) defensible relations between indicator organisms and pathogens of public health concern in stormwater, 4) the environmental fate of pathogens and indicator organisms in stormwater, 5) the use of microbial source tracking (MST) techniques to identify sources of fecal contamination, and 6) the effectiveness of stormwater microorganism control technologies and associated costs.Additionally, recommended next steps needed to enable defensible evaluations of stormwater microorganism data and the associated risk to human health from exposure to stormwater are presented. Next steps include the development of interim guidance for management prioritization, pathogens enumeration method development, and pilot and nation-wide data collection programs.

A key step in the development of Total Maximum Daily Load (TMDL) allocations for water bodies impaired due to sediment toxicity is the identification of chemicals responsible for toxicity. Sediment toxicity identification evaluation procedures (TIEs) are one of the primary tools used in this process. This project evaluated standardized and recently developed sediment TIE methods developed by the US EPA and others, to determine their utility for identifying chemicals responsible for toxicity. In this study, formulated sediments were spiked with five chemicals: copper, fluoranthene, tetrachlorobenzene, nonylphenol and ammonia. Experiments were conducted using sediments spiked with single chemicals and chemical mixtures. Toxicity tests used the estuarine amphipod Eohaustorius estuarius and the freshwater amphipod Hyalella azteca. TIEs were conducted using solid-phase (whole sediment) and sediment interstitial waters.Results indicate that the TIE methods are sufficient to characterize and identify toxicity due to single and multiple chemicals using spiked sediments. One key finding from the spiked sediment experiments is that methods to elute chemicals from extraction media used in solid-phase and interstitial water TIEs require further refinement to ensure complete and consistent elution of sorbed chemicals. An additional finding is that both solid-phase and interstitial water TIE procedures provide useful lines of evidence and that both approaches should be used in a weight-of-evidence approach in the sediment TIE process.In the final phase of this project, we evaluated the TIE procedures using ambient samples collected from three marine sites and three freshwater sites. Marine sediments were collected from Switzer Creek in San Diego Bay, Upper Newport Bay in Newport Beach, and Consolidated Slip, in Long Beach Harbor, all of which are sites in southern California. Freshwater sediments were collected from two additional sites in California: San Diego Creek, in Newport Beach, and Alisal Slough, in Salinas. The final freshwater sediment was collected from a site in Indiana Harbor. Multiple solid-phase and interstitial water TIEs were conducted on each sediment and results of these were combined with chemical analyses and other lines-of-evidence to evaluate the methods. The results indicate that sediment TIE methods are sufficiently developed to characterize toxicity due to general classes of chemicals such as cationic metals, organic chemicals, and ammonia.Methods to improve extraction and elution of metal and organic chemicals in highly toxic sediments require further refinement in order to allow identification of specific chemicals responsible for toxicity as part of the Phase II TIE process. These refinements include determining the appropriate masses of solid-phase extraction media to allow complete removal of toxic chemicals from sediments and interstitial waters. In addition, we recommend that additional studies be designed to determine optimal equilibration periods to maximize removal of toxic chemicals using resin amendments in solid-phase sediment TIEs. As in the spiked-sediment TIEs, we observed inconsistent elution of toxic chemicals from extraction media used in solid-phase and interstitial water Phase II TIEs with the ambient samples. These procedures require additional work to ensure that chemicals responsible for toxicity are completely eluted from extraction media. Improvement of the Phase II TIE elution and solvent handling steps should facilitate better identification of chemicals responsible for toxicity, particularly in situations where toxicity is due to highly insoluble chemicals. When these considerations are satisfactorily addressed, the methods evaluated are capable of providing useful lines of evidence that can be combined to successfully identify sediment toxicants.

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

Edited by the Water Policy Research Center of the Environment Department of Tsinghua University, this comprehensive report on the Chinese water sector is a collection of findings from recent research conducted by the Center and government consultancy reports. The report presents an overview and analysis of the current situation of the reform of the Chinese urban water sector. This is followed by case studies and appraisals on 17 water industry reform measures collected by the authors in 14 cities. The report then examines key problems of the current water industry reform. The comprehensive scope of this report, the level of detail, as well as the authors' insights together make this document a unique reference on China's water industry, as well as an important guide to the future of China's water management. The book will be extremely useful for public utility reform in China and in other countries. It will therefore be of particular value to government departments, policy advisors, consultants, financing bodies, and utility service providers. The report is part of the Water21 Market Briefing Series. Titles in the series provide more focused insight into aspects of the international water sector.About the authors: Dr Tao FU is Director of the Water Policy Research Center, Tsinghua University, Beijing, P.R. China. Dr Miao CHANG is Senior Research Fellow at the Water Policy Research Center, Tsinghua University. Dr Lijin ZHONG is with the Department of Environmental Science and Engineering, Tsinghua University.

The Adaptiveness of IWRM provides new insights and knowledge on the challenges and solutions that current water management faces in a situation of complexity and uncertainty. Drawing on the available results from a wide range of European research projects under several framework programmes, the book provides an overview of the state of the art in European research on Integrated Water Resources Management on the topics of Participation, Transboundary regimes, Economics, Vulnerability, Climate change, Advanced monitoring, Spatial planning, and the Social dimensions of water management. The achievements of EU research projects are considered in view of the extent to which IWRM responds to the current complexity and uncertainty water management is facing. These achievements are positioned in a wider context of worldwide developments in the respective topics which account for the future challenges. From this, the book concludes with the required focus of European research in the near future and promotes the concept of Adaptive Water Management as the preferred direction for the development of IWRM. The book presents the achievements of European IWRM research on a range of water management topics and offers conclusions and recommendations for research foci that will be invaluable to water managers, policy-makers and academic researchers working in the field of IWRM.

This book is focused on techniques, technologies and management approaches for optimising investment in infrastructure while achieving demanded customer service standards, and provides an opportunity to gain access to the latest discussion and developments at the leading-edge in this field.

This study explores the current state of knowledge with respect to the effects of wet weather flows from urban areas on the physical character of aquatic habitat. It identifies knowledge gaps with respect to our ability to define the cause-effect relationships, examines the comprehensiveness of the data used in support of the published literature in the subject area, and makes a qualitative determination of the usefulness of those data for further analysis to increase our knowledge in the subject area. Finally, it recommends further research studies that will increase our knowledge in the subject area, with emphasis on pilot-scale projects that can be used to develop practical protocols for preventing or mitigating the effects.Major findings and conclusions are: 1) we lack a solid conceptual framework for predicting the impact of large-scale watershed modifications and wet weather flows on ecological processes that influence stream communities; 2) there is a need for longer-term monitoring; 3) there is no widely accepted system for quantifying geomorphic instability and degradation of physical habitat; 4) there is a need for process-based stream classification; 5) specific links between urbanization characteristics and stream degradation are lacking; 6) there is a need for urban best management practice (BMP) assessment standards; and 7) developing a multi-scale understanding of habitat potential in human-dominated watersheds is needed. The report recommends a research program that first and foremost, includes comprehensive, long-term monitoring augmented with mathematical modeling of the linkages between development style/drainage system design, flow regime, and multi-scale changes in physical habitat and biotic response. Improved diagnosis and predictive understanding of future change require multifaceted, multiscale, and multidisciplinary studies based on a firm understanding of the history and processes operating in a drainage basin. Detailed long-term analyses of the influence of hydrologic regime and channel morphology on differences between communities in recruitment, immigration/emigration, mortality, and age structure are also needed. Finally, future research should directly examine tradeoffs between: 1) flood mitigation versus channel roughness, habitat heterogeneity, debris inputs, and riparian protection; 2) chemical water quality improvement through extended detention versus geomorphically-based flow regime controls; and, 3) rehabilitation of aquatic habitat using static features versus allowing the potential for dynamic adjustments in channel form and habitat structure. It is extremely important that the research be pragmatic, and focus on developing pilot/demonstration studies that will lead to design guidance that municipalities can use to design new systems, or improve existing systems, that will protect not only the safety and welfare of the citizenry that it serves, but also the aquatic ecosystems in the streams that receive the wet weather discharges from these urbanized sites.

A laboratory study was conducted to elucidate the source-effect relationships for seven chemicals (sources) that can cause activated sludge process upset (effect). These chemicals were studied over a range of concentrations using both nitrifying and non-nitrifying laboratory-scale activated sludge sequencing batch reactors. Effects were characterized according to traditional methods of evaluating process effluent and mixed liquor quality. A range of process effects were observed for both biomass sources. Overall impact was assessed and the degree to which a chemical caused an impact on process performance was considered to be more detrimental than if a chemical had multiple process effects that were moderate. The order in which chemicals caused adverse effects for the nitrifying biomass was: ammonium < octanol < DNP < cyanide < CDNB < cadmium - pH 11. For the non-nitrifying biomass, the order in which the chemicals caused adverse effects was: octanol < ammonia < DNP < cyanide < CDNB < cadmium < pH 11. Almost all chemicals caused multiple process effects, but the intensity and type of process effect was not always predictable based on the chemical applied. The findings show that there are multiple ways that chemicals can impact activated sludge plants, and suggest that corrective action practices need to be tailored based on the nature of the chemical causing the upset. This publication can be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below

The USEPA's ambient water quality criteria (AWQC) for cyanide were developed in 1984. Recently, however, concerns have arisen that the AWQC for cyanide have been problematic to implement and may not accurately reflect either the toxic forms or bioavailable concentrations of cyanide in water, sediments, and tissues of aquatic organisms. Also, the cyanide criteria typically have been implemented based on total cyanide concentrations rather than the free cyanide concentrations that formed the basis of the criteria calculations. New knowledge on cyanide toxicity, cyanide speciation and its measurement, and the relative toxicity of bioavailable cyanide species suggested that a re-evaluation of the aquatic toxicity data and chemistry that serve as the basis of the current national criteria is warranted. In response to these concerns, studies sponsored by the Water Environment Research Foundation (WERF) evaluated the formation and fate of cyanide in municipal wastewater effluents. Kavanaugh et al. (2003) evaluated the reliability of several analytical methods for measurement of cyanide species at low (ppb) concentrations, along with studies to evaluate the sources, transport, and fate of cyanide species in wastewater treatment plants (WWTPs) and receiving waters. Results indicated that potentially toxic forms of cyanide can be generated in WWTPs from several chemical processes, including dissociation of thiocyanate by chlorination or UV disinfection, chlorination in the presence of residual ammonia, nitrosation, and photolysis of ferrocyanate. Models were developed for predicting the fate of these compounds in surface waters downstream of WWTP effluents to establish where organisms might be most at risk from cyanide exposure. While implementation of these results could assist in the development of site-specific water quality standards for cyanide, a more thorough update to the National AWQC was warranted to apply our more current scientific understanding of cyanide toxicology to the derivation of aquatic life criteria.The present study was therefore undertaken to review and update knowledge of the aquatic toxicity of cyanide, and to develop recommended updates to the existing national AWQC to enhance the scientific basis of the concentrations and chemical forms of cyanide specified for protection of aquatic organisms. This update was conducted according to USEPA guidance for derivation of AWQC for protection of aquatic life, and is based both on an extensive literature review and on new toxicity studies that fill key data gaps. This re-evaluation of cyanide criteria also includes consideration of impacts on benthic (sediment) organisms, wildlife that consume aquatic biota, and possible effects to threatened and endangered species to ensure that revised criteria are adequately protective of the entire aquatic ecosystem.