Obstacles to wastewater reuse: an overview

ArticleinWiley Interdisciplinary Reviews: Water 2(3) · March 2015with 440 Reads
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.
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  • 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
    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.
  • Article
    The Water Environment Research Foundation in the United States funded an interdisciplinary and integrative social science study on public perception and participation in water reuse within the US. It employed a three-phased research protocol consisting of 1) literature review and three comprehensive case studies, including interpretive white papers from five different social science disciplines and public health and environmental engineering scientists, 2) a multi-stakeholder workshop to promote integrative, interdisciplinary analysis of the literature and case study findings, and 3) peer-review among twenty-one social science and water resource management experts. The case studies included examples of potable and non-potable reuse, with elements of success and failure. Five themes were identified as critical to building and maintaining public confidence in water resource management and water reuse decision-making: managing information for all stakeholders; maintaining individual motivation and demonstrating organizational commitment; promoting communication and public dialog; ensuring a fair and sound decision-making process and outcome; and building and maintaining trust. The study produced guidance for water resource professionals with a strategy for assessing the community context and developing a principle-based approach to public outreach, education and participation.
  • Article
    Full-text available
    In Europe the last two decades has witnessed growing water stress, both in terms of water scarcity and quality deterioration, which has prompted many municipalities to look for a more efficient use of water resources, including a more widespread acceptance of water reuse practices. This paper reviews European water reuse practices and sets out the map of the water reclamation technologies and reuse applications. The data are based on a conventional literature survey, on the preliminary evaluation of an in-depth survey of a large number of European water reuse projects and on the findings of a dedicated international workshop. The preliminary evaluation indicates that for an increased utilisation of reclaimed wastewater, clearer institutional arrangements, more dedicated economic instruments and the set-up of water reuse guidelines are needed. Technological innovation and the establishment of a best practice framework will help, but even more, a change is needed in the underlying stakeholders' perception of the water cycle.
  • Article
    Full-text available
    Zer0-M, short for “Sustainable Concepts Towards a Zero Outflow Municipality”, is a project financed by the MEDA Water programme of the European Union (EU). This project aims at concepts and technologies to achieve optimised close-loop usage of all water flows in small municipalities or settlements (e.g. tourism facilities).A key idea in Zer0-M is to integrate water supply, wastewater treatment and reuse. Actually it is about abandoning the concept of “waste” water, because on one hand there is no water to waste, and on the other disposal is a poor concept, which so far has proved very unsafe. From a disposal problem we should shift to an asset, which has to be developed.In order to encourage implementation of this concept in real systems Zer0-M is presently building so-called training and demonstration centres on one side, with a great variety of different techniques to be shown and tested, and pilot plants to implement and demonstrate the same techniques under real conditions.First results about greywater in MEDA countries will be discussed. Water demand and saving measures in rural areas of MEDA countries as well as simple potable water substitution techniques will be presented on the basis of studies and implementations of Zer0-M.
  • Article
    Increasing scarcity of freshwater resources and growing environmental awareness give rise to the use of reclaimed wastewater as an additional source of water supply. However, the amount of wastewater that can be reclaimed for reuse is subject to many factors, ranging from technical possibility to socio-economic and institutional conditions. Taking Beijing in China as a case study, this paper provides a systematic framework for the analysis of wastewater reuse potential under various driving forces and constraints. A linear programming model was used to analyse different reuse scenarios concerning alternative wastewater charges and reuse prices. The results suggest that the wastewater reuse potential is high at competitive prices. Wastewater treatment plants appear to be more economically efficient over on-site operation facilities in providing treated wastewater for reuse. The main users of the treated wastewater are agricultural irrigation and urban recreation sectors. The framework established in this study and the results of the Beijing case study help to better understand the complex systems and evaluate the effect of key factors influencing the potential of wastewater reuse. The study also provides a useful basis for the evaluation of wastewater reuse potential for other cities in China as well as cities in developing countries with similar conditions.
  • Article
    Many urban and regional areas of Australia have been facing severe drought over the past decade. This is particularly the case for most areas in the state of Victoria (located in the south east of the country). The management response to this situation has often been reactive with little thought about subsequent and long-term impacts. This paper reviews the water cartage industry in regional Victoria Australia which has developed in response to drought, suppling water in drought affected areas of the state. The review involved the survey of six water cartage businesses, and interviews with local government and water authority officers. The review found that the cost of the carted water is up to thirty-four times higher than the cost of the delivery of mains water in Australian cities and towns. Formal review of the water cartage industry and associated regulations is recommended to assess the environmental, social and economic impacts of water cartage. Secondly, and the paper benchmarks willingness to pay values for recycled water in a specific market segment of regional Victoria—Bendigo office workers (n = 305). The contingent valuation method was used to elicit maximum willingness to pay for recycled water. The study found that participants were willing to pay on average A$7.66/kL for recycled water delivered to their homes (on January 18 2009, A$1.00 = €0.50.US$0.68). This was an amount significantly greater than the A$1.33/kL charged to Bendigo residents for the delivery of potable mains water which is subject to water use restrictions. The results of this study indicate that individuals facing prolonged restrictions to the use of water may be willing to pay a higher price for recycled water than policy makers may anticipate. The established water cartage industry which services the Bendigo area may have influenced the high willingness to pay for recycled water which was evident in the particular segment of the population surveyed. Lessons learnt from this research will be beneficial for catchment (watershed) management globally. An important component of sustainable water management is consideration of impacts across catchments.
  • Article
    Full-text available
    China is facing severe water problems including scarcity and pollution which are now becoming key factors restricting developments. Creating an alternative water resource and reducing effluent discharges, water reuse has been recognized as an integral part of water and wastewater management scheme in China. The government has launched nationwide efforts to optimize the benefits of utilizing reclaimed water. This article reviewed the water reuse activities in China, including: (1) application history and current status; (2) potentials of reclaimed water reuse; (3) laws, policies and regulations governing reclaimed water reuse; (4) risks associated with reclaimed water reuse; (5) issues in reclaimed water reuse. Reclaimed water in Beijing and Tianjin were given as examples. Suggestions for improving the efficiencies of reusing urban wastewater were advanced. Being the largest user of reclaimed wastewater in the world, China's experience can benefit the development of water reuse in other regions.
  • Article
    Full-text available
    Nearly 3 billion additional urban dwellers are forecasted by 2050, an unprecedented wave of urban growth. While cities struggle to provide water to these new residents, they will also face equally unprecedented hydrologic changes due to global climate change. Here we use a detailed hydrologic model, demographic projections, and climate change scenarios to estimate per-capita water availability for major cities in the developing world, where urban growth is the fastest. We estimate the amount of water physically available near cities and do not account for problems with adequate water delivery or quality. Modeled results show that currently 150 million people live in cities with perennial water shortage, defined as having less than 100 L per person per day of sustainable surface and groundwater flow within their urban extent. By 2050, demographic growth will increase this figure to almost 1 billion people. Climate change will cause water shortage for an additional 100 million urbanites. Freshwater ecosystems in river basins with large populations of urbanites with insufficient water will likely experience flows insufficient to maintain ecological process. Freshwater fish populations will likely be impacted, an issue of special importance in regions such as India's Western Ghats, where there is both rapid urbanization and high levels of fish endemism. Cities in certain regions will struggle to find enough water for the needs of their residents and will need significant investment if they are to secure adequate water supplies and safeguard functioning freshwater ecosystems for future generations.
  • Article
    Urban water supplies are traditionally based on limited freshwater resources located outside the cities. However, a range of concepts and techniques to exploit alternative water resources has gained ground as water demands begin to exceed the freshwater available to cities. Based on 113 cases and 15 in-depth case studies, solutions used to increase water self-sufficiency in urban areas are analyzed. The main drivers for increased self-sufficiency were identified to be direct and indirect lack of water, constrained infrastructure, high quality water demands and commercial and institutional pressures. Case studies demonstrate increases in self-sufficiency ratios to as much as 80% with contributions from recycled water, seawater desalination and rainwater collection. The introduction of alternative water resources raises several challenges: energy requirements vary by more than a factor of ten amongst the alternative techniques, wastewater reclamation can lead to the appearance of trace contaminants in drinking water, and changes to the drinking water system can meet tough resistance from the public. Public water-supply managers aim to achieve a high level of reliability and stability. We conclude that despite the challenges, self-sufficiency concepts in combination with conventional water resources are already helping to reach this goal.
  • Article
    "Water rates are designed to meet multiple objectives, typically resulting in trade-offs among the objectives of economic efficiency, revenue sufficiency, and related revenue stability. Standard theory of natural monopoly is extended here to explain why long-run marginal cost (LMC) can be greater than both average cost and short-run marginal cost (SMC) for municipal water utilities. The distinctions between "benign monopoly rates" and "marginal cost rate design" favor LMC over SMC as the basis for economically efficient rate design. Taking into account conservation investments by consumers, SMC rates are economically inefficient, except during temporary shortages. The City of Los Angeles adopted economically efficient, revenue sufficient, and revenue-stable water rates at the end of a prolonged drought. After the drought ended, Los Angeles (LA) modified the rate design, making the design politically feasible during normal rainfall years. Unique features in the LA rate design determine the allocation of consumer surplus among ratepayers, making the rate design politically feasible by sharing efficiency gains among customer classes. Revenue sufficiency and stability features in the rate design minimize adverse job effects on water utility management, reducing the frequency of rate hearings with an increasing block design." ("JEL" L51, L95, Q25, Q51) Copyright (c) 2009 Western Economic Association International.