Obstacles to wastewater reuse: an overview

ArticleinWiley Interdisciplinary Reviews: Water 2(3) · March 2015with 652 Reads 
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
Cite this publication
Abstract
With growing water scarcity worldwide, reclaimed wastewater is an increasingly attractive option for meeting household water demand, especially in urban areas. However, reluctance by households to use treated wastewater persists. In this article, we discuss the ‘yuck factor,’ health risk concerns, and cost considerations, which are key obstacles to wastewater reuse by households. We then summarize successful and unsuccessful case studies of wastewater reuse around the world. Reasons for the success (or failure) of each case study draws upon unique contextual, historical, and cultural circumstances. Direct potable reuse—where purified wastewater is added to the potable water supply directly—is rare; most successful projects are nonpotable wastewater reuse schemes—where purified water is placed into an environmental buffer before entering a drinking water distribution system. Our review of experiences around the world suggests approaches for improving public acceptability of wastewater reuse schemes. The literature also suggests that there is an urgent need to collect more wastewater treatment and reuse data, to research ways of better assessing and reducing health risk associated with emerging pollutants in reclaimed wastewater, and to better price both drinking water and recycled wastewater.For further resources related to this article, please visit the WIREs website.Conflict of interest: The authors have declared no conflicts of interest for this article.

Do you want to read the rest of this article?

Request Full-text Paper PDF
  • ... Development of sustainable technologies for water desalination, water reuse and recovery of valuable chemicals from water, and wastewater and process streams is a major technological challenge [1][2][3][4]. Membrane technologies, mainly pressure driven and electrochemical, play a significant role in these processes. For example, nanofiltration was shown effective for the separation of Mg 2 + , Ca 2 + , and SO 4 2 − from seawater [5,6,7]. ...
    ... Membrane technologies, mainly pressure driven and electrochemical, play a significant role in these processes. For example, nanofiltration was shown effective for the separation of Mg 2 + , Ca 2 + , and SO 4 2 − from seawater [5,6,7]. Electrodialysis with monovalent-selective ion exchange membranes has been studied for selective separation of divalent ions from seawater [8], lithium from magnesium in salt lake brines [9], phosphate from synthetic municipal wastewater [10] and others. ...
    ... On the other hand, higher current efficiencies might be achieved by application of composite TFCM-IEM membranes. Fig. 5A, B, C and D show the ionic fluxes of Na + , Cl − , Mg 2 + and SO 4 2 − through the NF270 membrane obtained in 18 NF-FCDI experiments conducted at the operational parameters listed in Table 1. Fig. 5E and F list permselectivities (P di mono ) of ions at varied initial mono-to divalent ions concentrations and applied cell potentials of 0.6, 0.8 and 1.23 V. Permselectivities of monovalent to divalent cations were found independent of the applied potentials and proportional to the (M ± 1 / M ± 2 ) 0 ratio. ...
    Article
    We report on selective separation of monovalent and divalent cations (Na⁺ and Mg2 +) and anions (Cl⁻ and SO42 −) from aqueous solutions using the flow electrode capacitive deionization (FCDI) process, operated with ion-exchange and nanofiltration membranes (NF). For the selective separation of cations and anions the FCDI module was operated with an NF membrane (NF270) and an anion-exchange or cation-exchange membrane, respectively, at varying applied cell potentials (0.6, 0.8 and 1.23 V) and initial mono- to di-valent ions molar concentration ratios of 1, 10 and 20. The permselectivity of the NF270 membrane, calculated as a ratio between measured ionic fluxes, was found highly dependent on the initial molar concentration ratios of the mono- to the di-valent ions. Concentration-normalized Na⁺ to Mg2 + permselectivity was 0.69–1.04, indicating that the NF270 membrane does not pose selectivity for the separation of sodium and magnesium in the studied process. Conversely, the concentration-normalized permselectivity between Cl⁻ and SO42 − was found between 1.28 and 7.03 depending on the applied cell potential, indicating high potential for implementing the proposed NF-FCDI method for selective separation of anions.
  • ... For example, the World Health Organization (2017) recently stated that, given continued The lack of public acceptance can pose a serious constraint on potable water reuse planning. As a result, water managers consider public perception of water recycling an important area of social scientific research [9,14,16]. The relationship between public acceptance and socio-demographic variables (e.g., age, gender, education, income, religion, race/ethnicity, political affiliation) has been studied extensively. ...
    ... Given that water related risks emerge from a complex interaction between humans, environment, and technology, additional social factors have also been known to significantly impact public responses to reclaimed water. Potentially significant social factors include perceptions of fairness, trust in water institutions, cost concerns, and prior knowledge of (or experience with) reclaimed water [9,10,14,16]. Previous knowledge of reclaimed water use is uneven and it varies from one community to another. ...
    ... The primary debate in the literature is the degree to which the lack of public acceptance of recycled water is psychological disgust or social and cultural context [10]. Psychological disgust is typically explained as an emotional response prompted by the deeply ingrained "yuck factor" [9,20,29]. Social and cultural objections include influential factors, such as prior experience, perceptions of fairness, trust in water authorities, or the longstanding public health practice of separating sewage from drinking water [4,10,30]. Following in line with social and cultural approaches to understanding public perceptions, this study explores if the way people think about their residential identity-as urban, suburban, or rural-has any relationship with how they think about the appropriateness of reusing treated wastewater for potable and non-potable purposes. ...
    Article
    Full-text available
    Urban water managers are increasingly interested in incorporating reclaimed water into drinking supplies, particularly in rapidly growing arid and semi-arid urban areas, such as the western United States. Northern Nevada is one location that is considering augmenting drinking water supplies with reclaimed water, a practice that is known as planned potable water reuse. Potable water reuse can expand water supply and reduce wastewater disposal. However, past studies have shown that the introduction of potable reclaimed water can be controversial and requires an understanding of public perceptions of the resource prior to implementation. This study explores the factors that influence whether or not respondents in northern Nevada express willingness to drink reclaimed water. We pay specific attention to the degree to which self-identification as an urban, suburban, or rural resident influences how people consider using treated wastewater for both potable and non-potable purposes. To address this, we conducted a survey to assess community perceptions of reclaimed water use and applications in northern Nevada in the spring of 2018. We find that years spent living in the home and a respondent being female are negative and significant predictors of being willing to drink reclaimed water, while having heard of reclaimed water before and self-identification as a suburban resident are positive and significant predictors. As the region becomes more developed, particularly in its growing suburbs, it is essential to understand the nature of the interests and concerns regarding water resources and the expanded use of reclaimed water.
  • ... In order to enhance urban water sustainability, recycling wastewater for potable purposes is emerging as an attractive alternative, either for immediate or future use [2,3]. The success of potable water recycling projects varies between cities and increasingly requires public approval and political support [3,4]. While many potable reuse projects have been proposed, some have been halted due to public opposition and flat-out refusal to drink what was once sewage water, as was the case in San Diego County, California, United States (US). ...
    ... 45), however, proposals for potable water recycling projects can be-and often are-frustrated by lack of political support and public skepticism during the planning process [3,5]. Although potable reuse is not new, it is an adaptation that planners recognize requires rebranding, engagement, and demonstration projects, which are directed at elected officials, opinion leaders, as well as the general public [4,28]. ...
    ... For water planners, public opposition is a potential obstacle that must be overcome before initiating potable water reuse projects [4,23]. In order to facilitate project success, the OCWD invested heavily in public education and outreach to the community. ...
    Article
    Full-text available
    Water planners in water-strapped communities in the western United States and beyond increasingly consider potable water recycling an important water management strategy. Although potable water recycling can increase an otherwise limited urban water supply, the threat of public or political opposition often looms large. This paper examines newspaper coverage of the most widely celebrated potable water reuse project in the world-the Groundwater Replenishment System (GWRS) in Orange County, California, USA. The case study examines the coverage of GWRS contained in local, national, and international newspapers during an era of significant investment and repeated expansion. Despite the potential controversy associated with drinking recycled wastewater, there was no negative newspaper coverage of GWRS from 2000-2016. Much of the coverage was mundane, however several articles embraced infrastructure and technology as key to developing new water resources while protecting public and environmental health. Although potable water recycling is presented as an innovative solution capable of solving several problems at once, a close analysis reveals that recycled water may not fulfill the promise of an uninterruptible urban water supply.
  • ... According to Callaghan, Moloney and Blair (2012), the resistance to recycled water must be considered as psychological rather than technological, as water quality standards are applied in every greywater reuse project. In other words, there are no qualitative differences between regular tap water and treated greywater, except in terms of origin and label (Callaghan et al., 2012): risk perception issues are still largely responsible for community acceptance or rejection of water reuse (Duong & Saphores, 2015). It is commonly accepted in social psychology that risk perception by non-experts is subjective and will differ from experts' points of view (Slovic, 1987). ...
    ... In a context of uncertainty concerning the future of water resources, we chose to focus on people's perceptions of water management issues and droughts, which is likely to be a significant factor for acceptance of alternative water sources and could help to overcome the barriers to behavioral change, especially in Europe where there appears to be a lack of studies on this subject (Duong & Saphores, 2015). In particular, we focused on greywater reuse as it appears to be one of the main solutions to water shortages and droughts. ...
    ... However, the principal brakes to greywater reuse are related to the health risks associated with this water management solution. This confirms the main results observed in the literature (Duong & Saphores, 2015;Lujala et al., 2015). The higher the perceived probability of occurrence of some threats and diseases, the less positively an individual will consider engaging in greywater reuse as a solution. ...
    Article
    Full-text available
    Population growth and the unknown consequences of climate change emphasize the need for alternative water sources. Greywater reuse is one of the main options available but such alternatives are poorly accepted by the public. In this research, our aim is to understand how greywater reuse is accepted, with a major emphasis on risk and personal involvement. An online questionnaire was completed by 252 people. The participants lived in the city of Nantes (France). To determine the possible effect of personal involvement and risk perception on greywater acceptance, a Bayesian linear regression was realized in order to determine with certainty the most probable model. Results show that acceptance of greywater reuse is significantly predicted by perceived personal exposure to water shortages and droughts. It also appears that perceived health risks related to greywater reuse work as a brake to greywater reuse acceptance, as well as age and the possession of a rainwater recovery system. Results are discussed in terms of how to inform and involve the population in greywater reuse by reducing risk perception and promoting personal involvement.
  • ... Nevertheless, some examples exist of both direct and indirect potable reuse projects. Indirect potable reuse projects have been implemented in Australia, the United States and Singapore (Duong and Saphores, 2015, Leverenz et al., 2011, Dupont, 2013. In these projects, recycled water is used to recharge potable aquifers to supplement the existing potable water supply. ...
    ... In these projects, recycled water is used to recharge potable aquifers to supplement the existing potable water supply. A few examples of direct potable reuse projects exist in Namibia and the United States (Duong and Saphores, 2015, du Pisani, 2006, Leverenz et al., 2011, in which recycled water is added to the potable water supply directly, without first passing through an aquifer. ...
    ... Chen et al. (2017);Duong and Saphores (2015);Garcia and Pargament (2015); Hurlimann and McKay (2007); Lazarova et al. (2001); Lu and Leung (2003); Mainali et al. (2014); Schaefer et al. (2004); Tram Vo et al. (2014); Urkiaga et al. (2008); Wang (2011); Willis et al. and public health risks if water is not adequately treated for pathogens and pollutants Chen et al. (2017); Duong and Saphores (2015); Garcia and Pargament (2015); Lazarova et al. (2001); Tram Vo et al. (2014) Lu and Leung (2003); Schaefer et al. (2004); Urkiaga et al. ...
    Technical Report
    Full-text available
    This study explored the possible role of recycled water in transforming Subiaco Wastewater Treatment Plant (WWTP) into a Strategic Resource Precinct (SRP). Subiaco WWTP is one of the largest treatment plants in Western Australia, currently servicing a catchment of around 240,000 people that includes the Perth Central Business District. The SRP concept re-imagines WWTPs as water resource recovery plants (WRRPs) that generate valuable resources, as opposed to dealing with waste, and encourages a land use planning approach that recognises and facilitates linkages between the plant and land users around the precinct. Despite the benefits it could provide, the SRP concept has not yet been thoroughly tested, a knowledge gap that this case study seeks to address. We investigated the extent to which recycled water use by non-residential land users in the suburbs surrounding Subiaco WWTP could contribute to the creation of an SRP. Specifically, our objectives were to: 1. investigate current and future non-residential land use in the suburbs surrounding Subiaco WWTP’s potential Strategic Resource Precinct, and understand the relationship between land use and water availability 2. investigate current and future non-residential water use in the suburbs surrounding Subiaco WWTP’s potential Strategic Resource Precinct, and identify opportunities for substituting recycled water for other water sources 3. estimate current willingness-to-pay for recycled water for non-residential use in the suburbs surrounding Subiaco WWTP’s potential Strategic Resource Precinct 4. explore future demand for recycled water for non-residential use in the suburbs surrounding Subiaco WWTP’s potential Strategic Resource Precinct under three groundwater allocation reduction scenarios. To meet these objectives, we conducted a non-market valuation survey of existing and potential recycled water users located in or near the odour buffer zone surrounding the Subiaco WWTP. The survey used the contingent valuation and contingent behaviour methodologies, which are stated preference non-market valuation techniques. The survey collected qualitative and quantitative data. In total, we interviewed 20 non-residential organisations, each of whom holds a groundwater extraction licence. This sample included local councils, schools/educational institutions, golf courses and miscellaneous others. We found that both land and water use are well established in the suburbs surrounding the potential SRP, and unlikely to undergo substantial change in the foreseeable future, irrespective of recycled water availability. Further, there is currently little opportunity to substitute recycled water for existing sources, because it is not appropriate for the uses to which Scheme water is currently being applied. Nor can it offer a price advantage over groundwater (which costs $0.16 per kL, on average) unless subsidised. Not surprisingly, therefore, our results suggest current willingness-to-pay for recycled water by existing non-residential land users is low (no more than $0.08 per kL, on average), and unlikely to justify the development of additional treatment and distribution infrastructure. We established that willingness-to-pay is closely linked to both the price and availability of groundwater. We also found that in most cases, organisations do not differentiate between stormwater and treated wastewater in terms of willingness-to-pay, provided that quality and safety standards are met. Finally, it seems most organisations are currently operating comfortably within their existing groundwater allocations. Willingness-to-pay is likely to remain low unless these allocations are reduced quite substantially, and much more severely than the level of allocation cut that is currently being proposed for the next decade. So at present, there is insufficient demand for recycled water to use it as a lever to implement the SRP concept at Subiaco WWTP. This work gives rise to the following key policy recommendations for implementing an SRP surrounding the Subiaco WWTP: • Effort should be given to identifying new funding sources for water recycling infrastructure. The amount of funding that key stakeholders are currently willing to allocate to water recycling is typically minimal or non-existent, and certainly well below what is required to get schemes up and running. Demonstration of public benefits would be critical to any application for government funding. • Policymakers could consider compiling information from existing recycled water users about their experiences using it, although variability between locations might mean that some experiences might not be applicable at other sites. Providing this information to prospective buyers in an easily accessible and understandable format is likely to greatly enhance their willingness to consider using/paying for recycled water. One example could be organising workshops where current and potential users can interact directly, to grow their knowledge and form networks to share information and experience. • Recycled water policy can incorporate captured stormwater in addition to treated wastewater, given the evidence suggests organisations view the two sources as functionally equivalent. • Strategic planning is likely to be critical for creating SRPs, to ensure that: land availability is sufficient to facilitate co-location of adjacent suitable land uses that can use wastewater treatment by-products; and that such land uses are compatible with odour buffer zone requirements. These recommendations may be applicable to other locations, both in Australia and overseas.
  • ... Aujourd'hui, avec l'augmentation universelle de la demande en eau et les menaces liées aux changements climatiques, l'adoption de cette pratique s'accélère. Des programmes de réutilisation des eaux usées urbaines sont conçus partout dans le monde et des stratégies de valorisation des eaux usées se mettent progressivement en place (SiDan et al. 2016; HanSeok et al. 2016-a ; Duong and Saphores, 2015). La Tunisie est l'un des premiers pays méditerranéens qui ont élaboré et mis en oeuvre une politique nationale de réutilisation des eaux usées à des fins agricoles. ...
    ... Le 2 ème axe qui absorbe 16,07% de l'inertie totale est défini positivement par la concentration en SF (0,56) et négativement par la concentration en EC (-0,39).La projection des valeurs moyennes des régions sur le plan défini par les axes 1-2 de l'ACP (95,76% d'inertie totale) montre une dispersion des régions permettant leur structuration en 2 groupes(Figure 2). Le 1 er groupe contient les régions du NO et Sud avec des concentrations élevées en CT (7,28-7,47) et des concentrations "très proches" en EC (7,06-7,09) et en SF(6,9).Le 2ème groupe comporte les régions de Tunis, N-Est et Centre caractérisées par des eaux moins chargées en CT (7,04 -7,23) et EC(6,9 -7,01) que celles du 1 er groupe. Ce graphique permet également de voir que la région du centre se distingue des autres. ...
    Article
    Une évaluation de la qualité bactériologique des eaux usées a été réalisée aux niveaux de 22 stations de traitement situées dans différentes régions de la Tunisie durant trois années (2013-2015). Les résultats montrent que la concentration moyenne des indicateurs fécaux dans les EUB varie de 6.6 à 7,6 unités log/100ml. Cette concentration ne subit pas de variations importantes selon les régions par contre, elle augmente entre 2013 et 2015. Les EUT véhiculent un nombre moyen d'indicateurs fécaux sensiblement plus faible que celui enregistré dans les EUB. L'abattement des indicateurs fécaux varie de 0,56 à 3,11 unités log selon les stations. Les abattements les plus élevés correspondent aux stations de traitement par lagunage. Les EUT contiennent toujours plus de 10 4 E. coli/100 ml et ne sont pas conformes à la norme tunisienne de rejet d'effluent dans le milieu hydrique.La recherche des salmonelles dans des EUT réutilisées à des fins agricoles en saison estivale a révélé une présence très fréquente de ce pathogène. Il est donc nécessaire d'ajouter, aux niveaux de certaines stations, des filières de traitements complémentaires afin d'assurer un abattement suffisant de la pollution microbienne et garantir une meilleure protection de la santé publique et l'environnement.
  • ... successful projects for water reuse is NEWater in Singapore, where the quality of water produced by the Bedok Water Reclamation Plant was found to be better than the water supplied by Public Utility Board (PUB) of Singapore, and also met the water quality standards of the Environmental Protection Agency of the United States and the World Health Organization (Tortajada, 2006). Although wastewater treatment is available to achieve recycled water qualities often superior to current potable water standards, public perception of water recycling activities is negative (Duong and Saphores, 2015). Some of the problems linked to this negative perception are the lack of infrastructure to supply recycled water, a highly subsidized and very cheap potable water resource, and the lack of community awareness about the limitations of freshwater resources, in particular in urban areas (Dolnicar and Sch€ afer, 2006), as well as the very high quality water produced by the system. ...
    Article
    In recent years, forward osmosis (FO) hybrid membrane systems have been investigated as an alternative to conventional high-pressure membrane processes (i.e. reverse osmosis (RO)) for seawater desalination and wastewater treatment and recovery. Nevertheless, their economic advantage in comparison to conventional processes for seawater desalination and municipal wastewater treatment has not been clearly addressed. This work presents a detailed economic analysis on capital and operational expenses (CAPEX and OPEX) for: i) a hybrid forward osmosis – low-pressure reverse osmosis (FO-LPRO) process, ii) a conventional seawater reverse osmosis (SWRO) desalination process, and iii) a membrane bioreactor – reverse osmosis – advanced oxidation process (MBR-RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality characteristics (similar feed water and similar water produced), production capacity of 100,000 m3 d−1 of potable water, energy consumption, materials, maintenance, operation, RO and FO module costs, and chemicals. Compared to SWRO, the FO-LPRO systems have a 21% higher CAPEX and a 56% lower OPEX due to savings in energy consumption and fouling control. In terms of the total water cost per cubic meter of water produced, the hybrid FO-LPRO desalination system has a 16% cost reduction compared to the benchmark for desalination, mainly SWRO. Compared to the MBR-RO-AOP, the FO-LPRO systems have a 7% lower CAPEX and 9% higher OPEX, resulting in no significant cost reduction per m3 produced by FO-LPRO. Hybrid FO-LPRO membrane systems are shown to have an economic advantage compared to current available technology for desalination, and comparable costs with a wastewater treatment and recovery system. Based on development on FO membrane modules, packing density, and water permeability, the total water cost could be further reduced.
  • ... Health risk concerns and cost considerations are key obstacles to wastewater reuse. Reliable data of future wastewater supply and demand are needed for better planning and risk management (Duong and Saphores, 2015;Asano and Levine, 1996). ...
    Article
    Full-text available
    The Council of Ministers issued a Royal decree number M/6 1421 H, corresponding to 2000 AD. The decree stated that, in Saudi Arabia, all wastewater should be treated at the tertiary level, without any discrimination (in terms of the type of reuse and discharge locations). The aim of this article is to discuss and elaborate the royal decree (2000AD), showing its limitations and recommending several modifications. This paper is a review and analysis of treated wastewater reuse in Kingdom of Saudi Arabia (KSA) and impact of implementation of royal decree for the treatment of wastewater reuse in future. Moreover, a critical appraisal of the use of tertiary treatment was done by elaborating negative impact of tertiary treatment and comparing a review of treatment of wastewater reuse in USA. It is emphasized in the paper that degrees of wastewater treatment should depend on: (a) types of reuses/discharges, methods of irrigation and local environmental conditions, and (b) whether irrigation takes place in restricted or unrestricted agriculture and types of crops. Thus, the Saudi Royal Decree (2000AD) that requires wastewater treatment up to a tertiary level needs to be re-evaluated and modified. The article suggested correlating the degree of wastewater treatment with the intended reuse, discharge locations and the degree of exposure to the public.
  • ... 2,3 Water reuse via biological and/or physicochemical processes is yet another great source of water. 4 Capacitive deionization (CDI) is normally an electrochemical technique for water desalination. 5,6 CDI is based on electrosorption of ions in the electric double layer of highly porous electrodes. ...
    Article
    We report the design and analysis of a salt metathesis process using Flow-Electrode Capacitive Deionization (FCDI) for the generation of a concentrated valuable magnesium sulphate solution from dilute MgCl2 and Na2SO4 (or K2SO4) solutions. First, a batch mode decomposition and recombination of the MgCl2, Na2SO4 and K2SO4 solutions was studied with varying initial concentrations. Current efficiencies of ~100% were observed for each cycle. In a so-called decomposition step, two different salt solutions are decomposed into electrically charged slurries having the counter-ions adsorbed. Swapping the slurries with the stored counter ions during the recombination step results into new salt solutions upon discharge including the desired product. Both, purity of products and overall conversion of ions into the products, depend on operational parameters, while maximal achieved MgSO4 purity was as high as 93% with a concentration factor of 6.3 and a discharge current efficiency of ~85%. Finally, a semi-continuous FCDI metathesis system was investigated. Performing the recombination step at appropriate process conditions also allows the concentration of the resulting product solutions by a factor as high as 81.5 with MgSO4 purity of ~80% and current efficiencies of 96%. Future improvements in process configurations and membrane ion selectivity will render the process even more selective.
  • ... Although comparatively few in number, there do exist positive examples of potable reuse practices and all of them can demonstrate true and honest citizen involvement in the respective water reuse projects [57]. Analysing these examples, one understands the need to go beyond a pure science-based approach and to admit that not only science, but also art and culture are reasonbased and need to be used to reconnect the environmental function of water with its cultural dimension [1]. ...
    Article
    Full-text available
    Abstract The Urban Water Atlas for Europe constitutes an original overview of Urban Water Management in Europe, explaining and illustrating water in an unprecedented way and reflecting how water, the essence of life, flows through the arteries of our cities. Leading experts in water sciences and technologies, together with climate change researchers, have joined artists and children in order to show how thirsty our cities really are and how we can cope with their growing demand for the most precious resource of our planet. The result is the first major publication of the Science and Knowledge Service of the European Commission, the JRC, which within a movement stemming from its Sci-Art Programme seeks to explore the important opportunities arising from the cross-fertilisation between science and art. The Atlas itself establishes the benchmark for over 40 cities, both European and from farther afield, in 30 different countries, in a manner which permits a vast range of municipalities to confront one of the greatest global challenges by employing local solutions in order to ensure a supply of water for all. It contains 95 scientific indicators and parameters, over 700 graphs, original illustrations and never seen before photographs and combines the work of 40 contributors from 22 organisations. Yet, the true value of this publication lies in the process of ensuring that the underlying scientific knowledge is available for societal uptake. The resolving of conflicts which stem from an exclusive self-understanding of traditional natural sciences, the difficulty to communicate the purpose of technological solutions and the challenge to engage in peer-to-peer discussion between the sciences, politics and the citizen constitute worthy lessons for both environmental experts and their social science counterparts.
  • ... Furthermore, it must be acknowledged that many well-established reuse schemes were implemented before widespread public involvement became an imperative of water sector planning and management and they have therefore benefited. According to this, priority was given to obtaining a new water resource while both environmental and health risks and regulation issues were excluded from social debate (Duong and Saphores, 2015). However, for farmers and the public, risks and regulations are key issues to accept or refuse water reuse. ...
    Article
    Full-text available
    The narrative of reusing water for agricultural purposes is sometimes conceived as being one of the reasons versus emotions, which might not capture the complexity of the issue at hand, including the legitimate fear of risks, diffuse regulations and the visceral reactions from farmers and the public. By analysing recent peer-reviewed literature (2007–2017) from a holistic approach (technical and social issues), this review explores: 1) the main characteristics of the reviewed literature on this topic (geographical contexts, research areas, main topics and tools), 2) relevant driving factors to effectively reconcile farmers’ needs and public perceptions of water reuse, and 3) the current knowledge gaps and future challenges to be addressed by end users, managers and authorities. The article concludes by discussing the level of the knowledge in this area and advanced recommendations to further a better comprehension of technical and social driving factors of water reuse in agriculture.
  • ... In both countries, testing for unregulated contaminants such as pharmaceuticals can help policymakers establish priorities for future monitoring. Because the long-term effects of many compounds are unknown and not all chemicals-of-concern may have been identified, more data, analysis, and regulations are necessary to properly assess risk from unregulated contaminants and to develop mitigation strategies (Duong & Saphores, 2015). Finally, it would be useful to apply the concept of vinecology, described first by Viers et al. (2013) that promotes biodiversity conservation in winelands by engaging producers and consumers alike in cooperative solutions, by promoting sustainable practices at multiple scales over large areas, and by embracing the ecological, cultural, and economic values that make these places desirable. ...
    Article
    The use of untreated or partially treated wastewater for crops irrigation is common practice worldwide, espe- cially in countries that face hydric limitations such as Mexico and South Africa. Both are countries denominated new world producers of wine and its economic importance in both regions is evident. Recent droughts in both countries have made it imperative to look for new sources of water for irrigation purposes in order to maintain agricultural production. It was found that there are no scienti c or legal obstacles to implementing vineyard irrigation with reclaimed water. In particular, Mexico has de nite plans to use reclaimed water in its Guadalupe Valley at a owrate of 1000 litres per second, thus with the potential of becoming the largest place worldwide to use reclaimed water for the vineyards irrigation. South Africa, has faced recent severe water droughts that also call for unconventional sources of water for irrigation but as yet has no concrete plans despite having a reg- ulatory framework that promotes water reuse. More emphasis on wastewater irrigation during national resource planning, and inclusion of wastewater as a resource when undertaking water planning could reap rewards in terms of job creation, rural development and economic security in both countries.
  • Article
    Full-text available
    Wastewater reuse has gained attention as an alternative and sustainable water resource. Reverse osmosis has been widely applied for wastewater reuse; however, generation of concentrate stream is the main drawback. Concentrate stream contains high concentrations of contaminants, and therefore, it should be properly treated prior to being discharged into a water body. Several technologies have been suggested for concentrate management, but the most common option is returning this stream to a wastewater treatment plant where a wastewater reuse plant is located. In this study, we investigated the feasibility of concentrate management by returning the concentrate to a wastewater treatment facility as a part of influent. The characteristics of the concentrate were extensively monitored, and it was verified that it contained high concentrations of salt and hardly biodegradable organics, which impede their application in biological wastewater treatment processes. The effect of seeding sludge was investigated using two different types of seeding sludge, adapted and unadapted. The adapted sludge taken at the wastewater treatment plant located at the wastewater reuse facility showed much better performance in terms of organic and nutrients removal. Moreover, the performance was recovered by a few days of additional adaptation time. However, the seeding sludge taken from another wastewater treatment plant (unadapted) showed poor performance due to different influent characteristics, especially salt concentration. Therefore, it could be concluded that the microbial adaptation step is very important for effective concentrate treatment when it is being returned to a wastewater plant as influent.
  • Article
    Full-text available
    This study investigates ionic transport and selectivity in a thin-film composite nanofiltration membrane (NF270)operated in pressure-driven and electrodialysis processes. The perm-selectivity and permeabilities of anions (SO 4²⁻ and NO 3⁻ , SO 4²⁻ and Cl ⁻ , NO 3⁻ and Cl ⁻ )and cations (Mg ²⁺ and Na ⁺ )were studied in an electrodialysis cell operated with NF membrane (ED-NF)at varied trans-membrane potentials (0.5–2 V)and in conventional nanofiltration process. The permeabilities of all ions in the electrochemical process were one to four orders of magnitude lower than permeabilities reported for the pressure-driven NF operated with the same membrane. In the pressure-driven process, a high selectivity of mono-to di-valent ions was obtained, with anions selectivity higher than cations selectivity (highest Na ⁺ to Mg ²⁺ selectivity value of 4.0 vs. lowest Cl ⁻ to SO 4²⁻ selectivity value of 11.6). In contrast, in ED a low perm-selectivity of mono-to di-valent ions was obtained (1.1–1.2 for Na ⁺ /Mg ²⁺ , and 2.4–3.4 for Cl ⁻ /SO 4²⁻ ). Our findings show that: (1)ionic transport in thin film composite membranes operated in electrochemical processes cannot be described by conventional ion exclusion models applied to pressure-driven processes, such as Born or Donnan exclusion mechanisms; and (2)a different, currently unknown, mechanism dominates the ion separation.
  • Article
    Effluents before disinfection from four wastewater reclamation plants were treated with chlorine (Cl2), ozone (O3), chlorine dioxide (ClO2), medium-pressure ultraviolet (MPUV) and four different combinations of the above, to evaluate the effect of disinfection processes on the genotoxicity removal by the SOS/umu test. Results showed that the genotoxicity increased after MPUV irradiation (10-100 mJ/cm(2)), but declined when adopting other disinfection processes. The effectiveness of genotoxicity reduction by five chemical disinfectants was identified as: O3 > pre-ozonation with Cl2 ≈ ClO2 > combination of ClO2 and Cl2 > Cl2. The sequential combination of MPUV, Cl2 and O3 reduced the genotoxicity to a level similar to the source water. The influence of differential disinfection process varied on iodinated wastewater, which is closely related to the competitive reactions between disinfectants, iodine and dissolved organic matters. The removal of genotoxic pollutants and the formation of genotoxic disinfection by-products are the two major factors that lead to the change in genotoxicity during disinfection.
  • Article
    Full-text available
    p align="center"> El contexto geográfico del tratamiento y reutilización de aguas residuales: un análisis benchmarking para el litoral mediterráneo español Este artículo examina los tratamientos y la reutilización de las aguas residuales en Cataluña y Valencia a través de un análisis comparativo (benchmarking) de las intensidades energéticas de todas las plantas de tratamiento de aguas residuales (EDAR) ubicadas en los municipios costeros de ambas regiones, que también se comparan con los promedios europeos. La comparación de las EDAR mediterráneas europeas y españolas indica que la plantas mediterráneas más pequeñas son más eficientes energéticamente que sus equivalentes europeas, mientras que para las plantas grandes (más de 10 000 m<sup>3</sup>/día) se da el caso contrario. En cuanto a la comparación entre plantas catalanas y valencianas, estas últimas son generalmente más pequeñas que las primeras y un poco menos eficientes energéticamente. El contexto geográfico puede explicar estas diferencias en términos del destino final de los efluentes tratados en estas plantas. La gran presencia de la agricultura de regadío en Valencia es responsable de la reutilización del 45 % de las aguas residuales tratadas, mientras que Cataluña, al carecer de esta alternativa, reutiliza menos del 3 %, aunque se están explorando iniciativas de reutilización indirecta para usos potables.</p
  • Article
    A review of the literature published in 2015 on topics relating to water reclamation and reuse is presented. The review is divided into the following sections: (1) General: extent of reuse, research needs, guidelines and monitoring, health effects; (2) Treatment technologies: integrated process design, membrane treatment, membrane bioreactors, electrocoagulation, ion exchange and adsorption, disinfection, wetlands, managed aquifer recharge; (3) Planning and management: public acceptance and education, economics/pricing, water quality planning and management and project/case studies. Much of the water treatment research focuses on membrane treatment, integrated designs, and other innovative technologies.
  • Article
    Full-text available
    Given the scope of water and sanitation challenges posed by climate change and continued urbanization, potable water recycling is gaining traction as a means to expand urban water supply and decrease wastewater disposal into waterways. No longer regarded as a system by-product without value, planners increasingly consider wastewater a displaced resource in need of recirculation. The literature suggests that public perception and institutional barriers are the limiting factors to greater recapture and reuse of wastewater. Implicitly accepting water recycling as a sustainable alternative, much of the research is aimed at overcoming public opposition. However, the trend toward potable water recycling disrupts the normally hidden processes of urban water delivery, treatment, and disposal. In doing so, it provides a rare opportunity to contemplate taken-for-granted technologies of waterborne sanitation and to recognize alternative modes of managing human excrement, including composting toilets and dry sanitation.
  • Water availability is facing crisis throughout the world because of various factors viz., population growth, climate change, rapid urbanization, leading to the requirement of treated wastewater as an additional source of water supply. However, the actual amount of wastewater that may be reused depends on many factors such as water demand, availability, cost and social acceptability, etc. In this study, a linear programming model has been developed to identify the amount of treated wastewater that may be used for various applications subject to water availability and demand constraints taking Delhi city as a case study. The results suggest that the wastewater reuse has the maximum potential in agriculture and landscape irrigation use followed by domestic and industrial applications. The framework developed in the study provides useful information for integrated planning and management of the reuse of wastewater in order to augment the existing water supply. It may be modified and used for the estimation of wastewater reuse potential in other areas with similar conditions.
  • Book
    First published in 1985, Mary Douglas intended Risk and Acceptability as a review of the existing literature on the state of risk theory. Unsatisfied with the current studies of risk, which she found to be flawed by individualistic and psychologistic biases, she instead uses the book to argue risk analysis from an anthropological perspective. Douglas raises questions about rational choice, the provision of public good and the autonomy of the individual.
  • Article
    Reclaimed water has been safely and successfully used for more than 40 years in Florida and California. Reclaimed water in these states is regulated with restrictions more stringent than World Health Organization guidelines. In the United States, Florida is currently the largest producer and California is the second largest producer of reclaimed water. Reclaimed water is more highly tested than other sources of irrigation water, and the safety of this water has been demonstrated in these and other states. Very high application rates of reclaimed water to citrus on well-drained Florida sands increased tree growth and fruit production. Although reclaimed water contains some nutrient elements, there is usually insufficient macronutrient content to meet plant nutritional requirements. Most reclaimed waters do not have high salinity levels although they are slightly more salty than the potable waters from which they originated. With an adequate leaching fraction, salts in reclaimed water can be handled with appropriate irrigation management. Use of reclaimed water has steadily increased in Florida since 1992, but other entities besides agricultural irrigation are now competing for its use. Public acceptance of reclaimed water has also increased, and crops grown with reclaimed water in Florida and California have been marketed without a negative public reaction. Recent issues of food safety have caused some to question reclaimed water, but there is no evidence of food safety problems with its use. Although reclaimed water in Florida was initially promoted as a way to improve surface water quality, it has now become an important alternate source of water to help meet water shortages and urban demand. In California, reclaimed water has become a necessary part of statewide water management.
  • Article
    This book is based on a screening of 113 worldwide experiences in alternative urban water management. A range of alternative water management strategies have been reviewed and 15 cases from around the world were studied in detail. These are presented as examples of possible water management strategies that have reduced the cities' dependency on water imports. The strategies include implementation of potable and non-potable wastewater reuse, rainwater collection and desalination. Alternative Water Management and Self-Sufficient Water Supplies provides inspiration for water planners in cities with restrained water resources by highlighting actual technical opportunities and challenges. It represents a unique collection of state-of-the-art water management practices and the opportunities and challenges presented are from real-life case studies. The book is primarily aimed at urban water management professionals working across different technical and management disciplines. These include water supply engineers and environmental planners that can use it for professional reference. It will also be a useful introductory text for under-graduate level courses on water supply. ISBN: 9781843392279 (Print) ISBN: 9781780401751 (eBook)
  • Whilst the development of suitable technologies which provide opportunities for water recycling has moved on apace over the past decade, their practical application will not depend solely on effective and reliable engineering performance. Successful employment of preferred strategies and technologies will require an understanding of the social environment in which they are to be applied. The study reported below explores some of the attitudinal determinants of public acceptance of water recycling in the UK. Findings show that there is broad willingness to accept in-house water recycling as long as public health is not compromised.
  • Article
    Full-text available
    For stormwater harvesting to achieve its full potential in mitigating water scarcity problems and restoring stream health, it is necessary to evaluate the human and environmental health risks and benefits associated with it. Stormwater harbors large amounts of pollutants and has traditionally been viewed as a leading cause of water-quality degradation of receiving waters. Harvesting stormwater for household use raises questions of human exposure to pollutants, especially human pathogens, which have the potential to cause large-scale disease outbreaks. These issues are compounded by uncertainties relating to the performance of stormwater treatment technologies in pathogen removal. Quantitative microbial risk assessment provides an objective risk estimate based on scientific data and the best assumptions, which can be used to educate and instil confidence in stakeholders of the practice. Although limited, human health risk studies have positively supported the use of minimally treated rainwater and stormwater for some non-potable applications. In addition to the well-known benefit of preserving the stream hydrology and ecology, wetlands used for harvesting stormwater can also provide new habitats for wildlife that benefit environmental health. A fundamental change from viewing stormwater as waste to resource requires the coordinated efforts in research, education, and effective communication.For further resources related to this article, please visit the WIREs website.
  • Chapter
    Freshwater is unevenly distributed amongst the countries bordering the Mediterranean (MED) Sea. Accounting for almost 7 % of the global population, the MED region only has just over 2 % of the world's freshwater resources, with two-thirds of them concentrated within the northern Mediterranean countries. With agriculture being the main user of freshwater, the reuse of treated urban wastewater for agriculture could, at least, relieve current freshwater stress. However, the capabilities of treatment and the motivations for reuse of treated wastewater differ amongst the MED countries. Northern countries, which enjoy better economic status and have relatively less water stress condition, treat up to 90 % of their generated wastewater, but they are the lowest in reusing the treated wastewater in the region. Most southern and eastern MED countries treat lower percentages of wastewater but use significant volume of treated and even untreated (or poorly treated) wastewater for irrigation. There is an imperative need to consider water saving and recycling strategies as population grows and future climate predictions anticipate a significant decrease in available freshwater resources in the MED region. This chapter not only reviews current production, treatment and reuse of wastewater in each MED country but also analyses their main drivers and constrains for reuse. © 2012 Springer Science+Business Media Dordrecht. All rights are reserved.
  • Article
    Full-text available
    Water shortages brought on by the Millennium Drought in Southeast Australia forced greater Melbourne, a city of 4.3 million people, to find innovative ways of increasing water supply and decreasing water demand. This article explores how water managers in Melbourne reacted to the crisis and evaluates the short-and long-term impacts of their decisions. Reduced water demand occurred primarily through residential and industrial water conservation programs, restrictions , together with emergency reductions in the environmental release of water to streams. The city also experimented with using recycled water, in place of surface water, to support agriculture in the Werribee Irrigation District. Water pricing was not strengthened during the drought, and thus not regarded as a drought demand management tool, primarily because Melbourne water companies lacked independent price setting powers. Today, 5 years after the end of the Millennium Drought, gains in water conservation appear to be holding steady, but recycled water for irrigation has declined for various reasons. We contend that the Millennium Drought provided Melbourne with the opportunity to develop and implement a more integrated approach to water management. Many of the innovations it forged (e.g., distributed harvesting and use of stormwater) will continue to enhance the city's resilience to drought and reduce its vulnerability to climate variability for years to come. Nevertheless, a challenge going forward is how to sustain these achievements in light of anticipated population growth and continued climatic change. This challenge—coupled with Melbourne's successes—hold important lessons for water-stressed cities around the world.
  • Article
    In South East Queensland (SEQ), extended periods of drought and unprecedented population growth have resulted in a water strategy reliant on permanent water conservation measures. As a result, there has been increasing emphasis on the installation of decentralised water systems at the household level, in particular, rainwater tanks and greywater systems to ease the water shortage stress. Results from a survey of 590 households in SEQ reveal that willingness to pay (WTP) for rainwater tanks and greywater systems range from $800 to $7,400 and from $1,700 to $14,100, respectively. When compared to the actual market price, WTP is substantially lower and subsidies will be required to encourage adoption. Nonetheless, a subsidy of $500 can lead to 100 % uptake of greywater diversion devices. Hence, the policy implication is that not all devices are preferred and subsidising greywater diversion devices would lead to the highest level of uptake with the least amount of subsidy spending.
  • Article
    Full-text available
    Public perceptions of risk are a focal point of many debates about the management of hazardous technologies. Different views about what the public knows and wants often lead to quite different beliefs about what policies should be adopted and even about how society's policy-making processes should be structured. Often these views about the public are based on speculation or anecdotal observation. In the interests of having better informed debates, the present paper reviews existing empirical evidence about public risk perceptions. In doing so, it reaches a number of interim conclusions and draws forth their implications for the respective roles of technical experts and lay people in technology management.
  • Conference Paper
    The Groundwater Replenishment (GWR) System, in Orange County, CA, is an indirect potable reuse project that is initially producing up to 265,000 cubic meters per day (m³/d) of highly treated recycled water with an ultimate capacity of 492,000 m³/d for groundwater recharge and direct injection to protect the groundwater basin from seawater intrusion. The project is jointly sponsored by the Orange County Water District (OCWD) and the Orange County Sanitation District (OCSD) and consists of three major components: 1) the Advanced Water Purification Facility (AWPF) and pumping stations, 2) a 14-mile pipeline connecting the treatment facilities to existing recharge basins, and 3) an expansion of the existing seawater intrusion barrier. The AWPF treats clarified secondary effluent, currently discharged into the ocean, using microfiltration (MF), reverse osmosis (RO) and ultraviolet light/advanced oxidation (UV/AOP). The product water is then lime stabilized and pumped into injection wells and recharge basins, where it naturally passes through the ground blending with Orange County's groundwater supplies. This new source of water, which is of near distilled water quality, provides enough water for 500,000 people and lessens the demand on imported water supplies. The project has been in operation since January 2008 and the AWPF treatment processes operated satisfactorily during the year, producing high-quality water in compliance with all permit requirements. Concentrations of inorganic constituents, such as arsenic and chromium, were either non-detectable or far below the permit limits. All potentially toxic organics, such as volatile organic compounds, pesticides and other synthetic organic compounds, were also non-detectable or far below permit limits. Analyses of AWPF recycled water for unregulated compounds indicated that concentrations of endocrine disrupting chemicals and pharmaceuticals were at non-detectable levels. For the various other unregulated constituents, test results indicate that the levels of these chemicals are not present in the recycled water. The focus of this paper will be on presenting the first year MF, RO and UV/AOP effluent quality including emerging contaminant removal by the overall treatment processes.
  • Conference Paper
    Reclaimed water has been safely and successfully used for more than 20 years in Florida and California. Reclaimed water in these states is strictly regulated with restrictions more stringent than World Health Organization guidelines. The safety of this water has been demonstrated by studies in these and other states. Reclaimed water is more highly tested than other sources of irrigation water. When providing for appropriate leaching fraction, salts in reclaimed water can be handled with appropriate irrigation management. Use of reclaimed water has steadily increased in Florida since 1992, but other entities besides agricultural irrigation are now competing for use of reclaimed water. Purposely high application rates of reclaimed water to citrus on well-drained Florida sands have promoted better growth and yield. Reclaimed water can provide some micronutrients, but does not provide sufficient nitrogen for good crop growth. Public acceptance of reclaimed water has increased, and crops grown with reclaimed water have been marketed without negative public reaction. Recent issues of food safety have caused some to question reclaimed water, but there is yet no evidence of food safety problems with reclaimed water.
  • Article
    Full-text available
    Water reclamation implementation and management practices at municipal wastewater treatment plants throughout the world are reviewed and some implementation and operational issues are defined. The information is based on a conventional literature survey, on an in depth survey study of European, Israeli and Australian medium and large-scale water reclamation utilities and on the findings of a dedicated international workshop. The review identified over 3,300 water reclamation projects and designed the map of the main process technologies and their fields of product water application. The main conclusion of the enquiry is that the technological risks no longer represent a major concern for the development of water reclamation projects, rather issues such as the financing, failure management and social acceptance have become more critical.
  • Article
    Water is a scarce commodity in Kuwait. With rapid growth of population coupled with increasing urbanization and agriculture, the demand for water in Kuwait is continually on the increase. The main water source in the country is from desalination with small quantities from underground aquifers. Wastewater effluent at least for irrigation purposes, could be a valuable source to augment this dwindling water supply, and should not continue to be wasted. Reuse of wastewater effluent could both minimize the disposal of water to the environment and reduce the demand on fresh water supplies. This paper discusses the features of reuse, the processes used and standards adopted. Design data, operational results, and physical characteristics for the three wastewater treatment plants (Ardiya, Jahra, and Riqqa) in Kuwait are discussed. In addition, the paper reports on the results of a research study undertaken to determine the willingness, level of awareness and knowledge among the people of Kuwait in using wastewater effluent for different purposes. Cost and benefit analyses were conducted on wastewater effluent and reuse. The study concludes with useful recommendations to both the authorities and the citizens of Kuwait.
  • Article
    Many farmers in water-scarce regions of developing countries use wastewater to irrigate vegetables and other agricultural crops, a practice that may expand with climate change. There are a number of health risks associated with wastewater irrigation for human food crops, particularly with surface irrigation techniques common in the developing world. The World Health Organization (WHO) recommends using quantitative microbial risk assessment (QMRA) to determine if the irrigation scheme meets health standards. However, only a few vegetables have been studied for wastewater risk and little information is known about the disease burden of wastewater-irrigated vegetable consumption in China. To bridge this knowledge gap, an experiment was conducted to determine volume of water left on Asian vegetables and lettuce after irrigation. One hundred samples each of Chinese chard (Brassica rapa var. chinensis), Chinese broccoli (Brassica oleracea var. alboglabra), Chinese flowering cabbage (Brassica rapa var. parachinensis), and lettuce (Lactuca sativa) were harvested after overhead sprinkler irrigation. Chinese broccoli and flowering cabbage were found to capture the most water and lettuce the least. QMRAs were then constructed to estimate rotavirus disease burden from consumption of wastewater-irrigated Asian vegetables in Beijing. Results indicate that estimated risks from these reuse scenarios exceed WHO guideline thresholds for acceptable disease burden for wastewater use, signifying that reduction of pathogen concentration or stricter risk management is necessary for safe reuse. Considering the widespread practice of wastewater irrigation for food production, particularly in developing countries, incorporation of water retention factors in QMRAs can reduce uncertainty regarding health risks for consumers worldwide.
  • Article
    Canada is the envy of many countries due to its abundant water resources: 7% of renewable fresh water with 1% of the world's population. However, pressure on this resource is growing; it is exacerbated by predictions of increasing water shortages and reduced reliability of traditional water supplies due to climate change. Canada has begun to examine the potential for the use of reclaimed wastewater to augment water supplies. The literature on reclaimed wastewater reveals a general reluctance to accept its use but that there are some situations in which consumers perceive benefits and are willing to pay for them. This paper investigates one such situation: namely, whether people are willing to pay in order to avoid summer water use restrictions via water supplies augmented with reclaimed wastewater that can be used for toilet flushing. The paper presents the first effort to examine the degree of public acceptance in Canada of supplementing existing water supplies with reclaimed wastewater. Using results from a double bounded contingent valuation survey undertaken in 2009, the paper finds an average annual WTP per household that ranges between $142 and $155, depending upon the scale of the project and upon whether respondents are concerned that other members of their community will not comply with summer water use restrictions, thereby, free riding on others. These values fall within the range of previous estimates in the literature and are somewhat higher than values obtained from Australia where there has been more adaptation to low water supply circumstances.
  • Article
    In areas that are still not serviced by a wastewater treatment plant (WWTP), economic valuation of the benefits derived from its construction should focus not only on those attributes that are linked to the services provided by the plant, such as cleaner environment and the possibility of reuse, but also on those attributes that are linked to its existence such as possible landscape and odor effects. This paper presents a choice modeling (CM) application that elicits the value of the attributes of a WWTP, where the latter are given by odor and landscape effects, jobs created, water quality, irrigation applications of the produced recycled water, and the additional charging. The results show that for rural populations such as farmers' communities, the potential increase of irrigated agricultural land is the main driver of willingness to pay while concerns over possible odor effects are also important. In addition, ignoring possible correlations across subsets of alternatives and variance heterogeneity would lead to substantial overestimation of willingness to pay.
  • Article
    Discussion of public reactions to water recycling is now framed around the idea of a 'yuck factor': advocates tend to assume an emotional response is the primary determinant of people's attitudes to reuse and they despair of people accepting rational arguments on its merits. Academic and consultancy work in the area has been dominated by particular work from social psychology: theories of disgust, models of attitude causation, and psychometric methods for measuring attitudes and determining the influences on them. This paper questions the models, their assumptions, the methods used to apply and validate them, their implications for change, and the practical consequences of framing the problem this way. It suggests that more fruitful explanations and more effective public engagement both require a shift to a more sociological and cultural explanation, one that examines users' practices around the sociotechnical systems of providing water and handling waste. The paper concludes there are no compelling arguments or evidence that negative reactions to recycled water cannot change with opportunities to learn about the issues; indeed deliberative consultation mechanisms are essential if people are to reach an informed, reasoned and robust evaluation of the option. The 'yuck' discourse is of limited value in explaining public responses and counterproductive in formulating strategies for increasing public support.
  • Article
    Reuse of municipal effluent for cooling systems in a large refinery and petrochemical complex is described. Quality criteria for the cooling water were related to scale formers, corrosion, and biogrowth. After tertiary lime treatment using sludge blanket precipitator-clarifier was applied, phosphate removal, high reductions in alkalinity, calcium, COD, and suspended solids were obtained. A stripping tower reduced ammonia concentrations by 50%. Biological nitrification eliminated ammonia in the circulating cooling system. Acidity generated by nitrification neutralized excess lime in treated effluent. Reclamation of waste water for cooling saved millions of cubic meters of fresh water.
  • Article
    Full-text available
    The Canadian experience with water reuse and recycling is reviewed under five theme areas: technology; policy and regulation; research; public acceptance; and coordination. At present, water reuse and recycling in Canada is practiced on a relatively small scale and varies regionally depending on the availability of water supplies and regulatory flexibility. Typical examples include using treated municipal wastewater to irrigate agricultural non–food crops, urban parkland, landscaping and golf courses. Water recycling also exists in select industrial sectors and experimental greywater treatment and reuse for toilet flushing, irrigation or other nonpotable uses at the scale of individual buildings. Recommendations for further action are presented from a recent national experts workshop on water reuse. The interest in reuse will likely increase, driven to a large extent by steadily increasing water demands, conflict among users and opportunities to save on future expansion of water supply infrastructure.
  • Article
    A well-known passage in Homer’s Odyssey, probably based on an ancient ritual myth, tells the story of Demeter, the Greek corn-goddess and Iasion, the son of Zeus by Electra, daughter of Atlas. The latter was the guardian of the pillars of heaven (Odyssey, 1.53), the Titan who holds the sky up (Hesiod, Theogony, 517) and is, thereby, identified with water and rainfall.
  • Article
    This chapter gives an overview of the current situation of water recycling in the world. Starting from the history of wastewater recycling, the objectives for recycling in the 21st century are identified. Driving forces include water scarcity and drinking water supply, irrigation using reclaimed water, source protection, overpopulation, and environmental protection. An overview of existing projects will be given for different parts of the world: the USA, where many recycling applications can be found in particular in California and Florida; Asia, where Japan is the number one in water recycling, but where many other countries face water challenges due to water scarcity caused by climatological and demographic pressure; Europe, where some very interesting projects have been carried out; Australia, where wastewater recycling will be more a matter of survival; and finally, water recycling projects in other parts of the world such as the Goreangab plant in Namibia.
  • Article
    The Windhoek Goreangab reclamation plant has been a pioneer in direct potable reclamation and is still today, as far as known to the author, the only commercial-scale operation in existence. From a humble beginning in 1969 until the commissioning of a new high technology plant in 2002, Windhoek has managed to do applied research and the original plant had been upgraded on a number of occasions. In any discussion on water reclamation from wastewater, the name Windhoek and its Goreangab reclamation plant enjoy a fair amount of recognition. An article by I.B. Law, published in May 2003 in the publication Water of the Australian Water Association was titled, Advanced Re-use—from Windhoek to Singapore and Beyond. Windhoek in Namibia, was indeed the pioneer in direct potable reuse.
  • Article
    The reuse of domestic greywater has become common in Australia, especially during periods of extreme drought. Greywater is typically used in a raw, untreated form, primarily for landscape irrigation, but more than a quarter of greywater users irrigate vegetable gardens with the water, despite government advice against this practice. Greywater can be contaminated with enteric pathogens and may therefore pose a health risk if irrigated produce is consumed raw. A quantitative microbial risk assessment (QMRA) model was constructed to estimate the norovirus disease burden associated with consumption of greywater-irrigated lettuce. The annual disease burdens (95th percentile; DALYs per person) attributed to greywater irrigation ranged from 2 × 10(-8) to 5 × 10(-4), depending on the source of greywater and the existence of produce washing within households. Accounting for the prevalence of produce-washing behaviours across Melbourne, the model predicted annual disease burdens ranging from 4 × 10(-9) for bathroom water use only to 3 × 10(-6) for laundry water use only, and accounting for the proportionate use of each greywater type, the annual disease burden was 2 × 10(-6). We recommend the preferential use of bathroom water over laundry water where possible as this would reduce the annual burden of disease to align with the current Australian recycled water guidelines, which recommend a threshold of 10(-6) DALYs per person. It is also important to consider other exposure pathways, particularly considering the high secondary attack rate of norovirus, as it is highly likely that the estimated norovirus disease burden associated with greywater irrigation of vegetables is negligible relative to household contact with an infected individual.
  • Article
    Full-text available
    Humans create vast quantities of wastewater through inefficiencies and poor management of water systems. The wasting of water poses sustainability challenges, depletes energy reserves, and undermines human water security and ecosystem health. Here we review emerging approaches for reusing wastewater and minimizing its generation. These complementary options make the most of scarce freshwater resources, serve the varying water needs of both developed and developing countries, and confer a variety of environmental benefits. Their widespread adoption will require changing how freshwater is sourced, used, managed, and priced.
  • Article
    The growth in population and of the economy of Hong Kong has caused a significant increase in the demand for fresh water. To secure sufficient water supply and to reduce reliance on imported water from Dongjiang (East River) in Mainland China, the Hong Kong Special Administration Region (HKSAR) government has implemented a wide range of water conservation measures which include the use of seawater for toilet flushing, metering and a tiered water tariff, large-scale replacement and rehabilitation of ageing pipelines to reduce leakage, valve-type toilet flushing apparatus and education and publicity programmes. To ensure sustainable and safe water supply, the HKSAR government is actively exploring alternative water resources including the treated effluent from sewage treatment plant, desalination of seawater and the extension of water-gathering grounds in the territory.
  • Article
    Full-text available
    Local authorities in Australia face twogreat challenges when managing municipal waters: Meeting future demands for clean water; and Preserving and enhancing the health of waterways. Municipal water recycling provides a means to achieve these objectives by providing an alternative source of water as well as reducing sewage effluent discharges. This paper identifies the key factors impeding the rate of growth of water recycling in Australia. Such knowledge will be crucial to our effective allocation of efforts and resources required for a rapid and sustainable change in the way we manage our water. While Australia currently recycles around 11 per cent of effluents from sewage treatment plants, where is substantial scope for increase. The key impediments are identified as: Lack of financial or economic incentive. Concerns regarding the effective destruction of pathogenic micro-organisms. Concerns regarding the presence of some inorganic and organic chemical contaminants. Costs, limitations and a lack of knowledge regarding the effectiveness of advanced water recycling technologies. Complications and costs associated with water transport and distributions systems. The need to ensure community acceptance. Energy demand and associated greenhouse gas emissions. Issues with storage systems for large volumes of recycled water. Availability of suitable reuse applications. Issues regarding national guidelines and standards.
  • Article
    Gerringong and Gerroa are coastal towns with 3,500 permanent local residents. They are located 120 km from Sydney on the southeast coast of Australia. The region is a popular holiday destination and very well known for its diversified flora and fauna, as well as its beaches. The main local industries are dairy farming and tourism. The Gerringong Gerroa Sewerage Scheme, commissioned in 2002, and designed to meet the local community's needs up to the year 2022 for an estimated population of 11,000, has brought significant benefits to the area. For example, improved housing and commercial development due to sewer reticulation and a sustainable agricultural-based reuse system designed to use greater than 80% of the treated effluent and 100% reuse of the biosolids. The Gerringong Gerroa Sewerage Scheme is the culmination of an intensive environmental impact assessment process and community input to provide the area with a state-of-the-art wastewater treatment system.
  • Article
    Full-text available
    This study presents the environmental burdens for different processes in the urban water cycle and one particular terrestrial pathway is followed. This pathway is geographically situated in the eThekwini (Durban) municipality and includes the Inanda Dam, Wiggins Waterworks, Southern Wastewater Treatment Works and the Durban Recycling Plant. An overview of the environmental scores calculated for major processes (treatment of potable water, treatment and recycling of wastewater and disposal to sea) is given for all environmental impact categories considered (global warming, ozone depletion, acidification, nutrification and toxicity). Since ecotoxicity is one environmental impact category that has been developed most recently in the LCA methodology, more detail is provided and a case study with regard to the disposal to sea of effluents is presented. Results show that major environmental impacts in the urban waterway investigated are traced back to the production of energy used for different processes. This is valid for four of the impact categories investigated namely global warming, ozone depletion, acidification and nutrification. In the case of toxicity this conclusion is only partially valid and due to the specificity of complex effluents additional investigations were undertaken. Therefore, the toxicity of effluents is presented as a separate case study.
  • Article
    Full-text available
    Determining the change in welfare estimates from introducing measurement error in non-linear choice models, Working Paper 1110, School Abstract Observed and unobserved characteristics of an individual are often used by researchers to explain choices over the provision of environmental goods. One means for identifying what is typically an unobserved characteristic, such as an attitude, is through some data reduction technique, such as factor analysis. However, the resultant variable represents the true attitude with measurement error, and hence, when included into a non-linear choice model, introduces bias in the model. There are well established methods to overcome this issue, which are seldom implemented. In an application to preferences over two water source alternatives for Perth in Western Australia, we use structural equation modeling within a discrete choice model to determine whether welfare measures are significantly impacted by ignoring measurement error in latent attitudes, and the advantage to policy makers from understanding what drives certain attitudes.
  • Article
    Introducing reclaimed water as an alternative to the traditional mains water supply involves change in practices as well as technology. Therefore, the social effects of innovative solutions to sustainable water management need to be carefully considered. This paper will present findings from research undertaken in California and Florida, USA, and Australia. What is the community response to recycling reclaimed water? Are there ways of involving the public so that the change involved in introducing reclaimed water achieves sustainable outcomes? Results from a series of case studies where indirect potable reuse has been planned will be considered along with the findings from a range of industry surveys, mainly conducted in the USA. In relation to non potable reuse, this paper will cover acceptance of some of the main uses, and householder's experience of recycling water for residential use. The resulting analysis suggests that the shift from traditional, centrally controlled water supplies to innovative alternatives, requires a corresponding shift in resources to support what is essentially a social transformation in water service delivery and management.
  • Article
    Full-text available
    Water reuse is an efficient way of managing water resources in cities, but reuse policies have often been derailed by the 'yuck' factor. While yuck has often been thought of as a problem of public acceptance, this paper argues that there is a more profitable way to frame the issue — as a form of social construct by the media, forming the basis of new learning by the public. This is then illustrated by way of an analysis of newspaper articles in Australia and Singapore. Some preliminary implications for norm formation and possibilities for theory-building are discussed.
  • Book
    Throughout history water has confronted humanity with some of its greatest challenges. Water is a source of life and a natural resource that sustains our environments and supports livelihoods – but it is also a source of risk and vulnerability. In the early 21st Century, prospects for human development are threatened by a deepening global water crisis. Debunking the myth that the crisis is the result of scarcity, this report argues poverty, power and inequality are at the heart of the problem. In a world of unprecedented wealth, almost 2 million children die each year for want of a glass of clean water and adequate sanitation. Millions of women and young girls are forced to spend hours collecting and carrying water, restricting their opportunities and their choices. And water-borne infectious diseases are holding back poverty reduction and economic growth in some of the world’s poorest countries. Beyond the household, competition for water as a productive resource is intensifying. Symptoms of that competition include the collapse of water-based ecological systems, declining river flows and large-scale groundwater depletion. Conflicts over water are intensifying within countries, with the rural poor losing out. The potential for tensions between countries is also growing, though there are large potential human development gains from increased cooperation.
  • Three criticisms of the contingent valuation method (CVM) are considered in this article. One technique that would appear to answer such criticisms is choice modelling (CM). CM permits value estimates for different goods sharing a common set of attributes to be pieced together using the results of a single multinomial (conditional) logit model. The CM approach to environmental value assessment is illustrated in the context of a consumer‐based assessment of future water supply options in the Australian Capital Territory. CM is found to provide a flexible and cost‐effective method for estimating use and passive use values, particularly when several alternative proposals need to be considered.
  • Article
    Full-text available
    The Middle East and North Africa (MENA) region is the driest region of the world with only 1% of the world’s freshwater resources. The increasing competition for good-quality water has cut into agriculture’s water share but since the use of freshwater for domestic, industrial and municipal activities generates wastewater, the volume of wastewater used in agriculture has increased. About 43% of wastewater generated in the MENA region is treated; a relatively high percentage compared to other developing-country dominated regions. This is because of the perceived importance of wastewater as a water resource and several oil-rich countries with the resources to treat wastewater. The MENA region has an opportunity for beneficial reuse of wastewater but few countries in the region have been able to implement substantial wastewater treatment and reuse programs. The major constraints leading to seemingly slow and uneven reuse of wastewater are: inadequate information on the status of reuse or disposal of wastewater and associated environmental and health impacts; incomplete economic analysis of the wastewater treatment and reuse options, usually restricted to financial feasibility analysis; high costs and low returns of developing wastewater collection networks and wastewater treatment plants; lack of wastewater treatment and reuse cost-recovery mechanisms and lack of commitment to support comprehensive wastewater treatment programs; mismatch between water pricing and regional water scarcity; preference for freshwater over wastewater; and inefficient irrigation and water management schemes undermining the potential of wastewater reuse. However, some countries such as Tunisia, Jordan, and Israel have policies in place that address wastewater treatment through a range of instruments. Policymakers in these countries consider use of treated wastewater to be an essential aspect of strategic water and wastewater planning and management. With flexible policy frameworks addressing rapid demographic changes and increasing water scarcity in the MENA region, water reuse has great potential if integrated with resource planning, environmental management and financing arrangements. KeywordsWater reuse-Wastewater reclamation-MENA region-Water scarcity-Water quality
  • Chapter
    Reclamation and reuse of various types of wastewater, including stormwater, greywater, and domestic wastewater, represents an important component of the urban water cycle helping close the loop between water supply and wastewater disposal. Safe and scientifically-based water and wastewater reuse has been practised for about a century, and a great wealth of practical experience with such practices has been reported in the literature. Essential elements of water reuse plans include the selection of categories of reuse, selection of water quality criteria for such specific reuses (in accordance with the existing regulations and guidelines), design of the treatment train providing the effluent of the required quality, and examination of overall feasibility. In Canada, water reuse is generally conducted on a small-scale or experimental basis. While no national guidelines exist at this time, a number of provinces have developed guidelines for specific water reuse applications. The current stresses on water supply, caused by growing population and increasing water demands, depletion of water sources, reduced supply reliability caused by climate change, ageing infrastructure and limited funding for its expansion, as well as the promotion of environmental sustainability and needs to reduce wastewater discharges to sensitive receiving waters, will contribute to further growth and expansion of water and wastewater reclamation and reuse.
  • Article
    This article documents the general need to reuse water reclaimed from sewage effluents for beneficial purposes and then considers in detail which specific uses will be most beneficial. The analysis begins by describing five levels of wastewater treatment: primary, secondary, tertiary, advanced, and advanced plus complete treatment. Next, five major uses for reclaimed water are identified: groundwater recharge, industrial use, irrigation, recreational lakes, and direct municipal reuse. Subcategories of reuse falling under each of the five major reuse categories are also identified and discussed. The analysis then proceeds to review significant literature available on health and environmental effects, treatment and distribution costs, and public opinion concerns in relation to each of the five major uses and their related subcategories. The paper concludes with a cumulative numerical analysis of the disbenefits associated with each specific type of reuse summed over the health effects, environmental effects, treatment costs, distribution costs, and public opinion concerns. Uses of reclaimed water for industrial purposes and for irrigation of fodder and fiber crops are found to be most beneficial by the analysis here employed, and use for aquifer recharge and direct municipal reuse are found to be least beneficial.
  • Article
    Full-text available
    Background: Over the past 10–15 years, a substantial amount of work has been done by the scientific, regulatory, and business communities to elucidate the effects and risks of pharmaceuticals and personal care products (PPCPs) in the environment. Objective: This review was undertaken to identify key outstanding issues regarding the effects of PPCPs on human and ecological health in order to ensure that future resources will be focused on the most important areas. Data sources: To better understand and manage the risks of PPCPs in the environment, we used the “key question” approach to identify the principle issues that need to be addressed. Initially, questions were solicited from academic, government, and business communities around the world. A list of 101 questions was then discussed at an international expert workshop, and a top-20 list was developed. Following the workshop, workshop attendees ranked the 20 questions by importance. Data synthesis: The top 20 priority questions fell into seven categories: a) prioritization of substances for assessment, b) pathways of exposure, c) bioavailability and uptake, d) effects characterization, e) risk and relative risk, f ) antibiotic resistance, and g) risk management. Conclusions: A large body of information is now available on PPCPs in the environment. This exercise prioritized the most critical questions to aid in development of future research programs on the topic.
  • Article
    This paper investigates the Willingness to Use (WTU) and Willingness to Pay (WTP) for recycled water in agriculture. We report results from surveys of farmers and consumers on the island of Crete, Greece. Crete is suffering from an increasingly severe water shortage coupled with declining groundwater supplies, therefore the wider use of recycled water is an important policy priority. We have investigated WTU and WTP for two crops with two different levels of water treatment. The mean WTP for 1 cm3 of recycled water was 0.15€ for the irrigation of both olive trees and tomato crops, namely 55% of the fresh water price. The mean WTP for olive oil produced from olive trees irrigated with recycled water was 2.65€, namely 88% of its current market price. We have found that both attitudinal factors, such as environmental awareness and economic factors, such as freshwater prices and incomes, are significant in explaining the WTU and WTP for recycled water and products produced using it, but that important differences exist between farmers and consumers.
  • Article
    A model-based estimation of the wastewater reclamation and reuse potential in a European context is presented, and the effects of different water management scenarios on the appraisal are quantified. The impact of climate change on water availability and variation in the demand pattern and water use of considered countries is the modifying variable in these scenarios. The simulation demonstrates that there is a significant potential for an increased utilisation of reclaimed wastewater in many European countries, specifically in the Mediterranean region. Aspects related to the factors that will definitely drive or slow down the development are addressed.
  • Article
    This paper provides discussion of ways in which an interdisciplinary approach can be taken to produce an integrated assessment of water stress and scarcity, linking physical estimates of water availability with socioeconomic variables that reflect poverty, i.e., a Water Poverty Index. It is known that poor households often suffer from poor water provision, and this results in a significant loss of time and effort, especially for women. By linking the physical and social sciences to address this issue, a more equitable solution for water allocation may be found. For the purpose of initiating discussion, a summary of different approaches to establishing a Water Poverty Index is discussed.