Desalinated versus recycled water: Public perceptions and profiles of the accepters
Introduction
Many countries have increasingly limited water resources in both quantity and quality. Human water consumption has increased beyond sustainable levels in many regions, resulting in extended periods of man made drought, depletion of environmental flows in natural water systems and the decrease in the quality of drinking water reservoirs, including groundwater systems. High stress regions have traditionally included California, Australia, the Middle East and the Mediterranean (International Water Management Institute (IWMI), 2006).
The global water cycle is a closed system, with water molecules continuously taken in and excreted by living organisms (Suzuki, 1997). Debate is escalating about the acceptance and suitability of human-engineered water recycling within this continuum. Water recycling involves the treatment of municipal wastewater for the replenishment of available freshwater resources. It closes the water cycle on a local level, and enables the closure of water cycles for individual households, buildings, factories, towns, or regions. A range of wastewater treatment technologies is available to achieve recycled water of a quality that is often superior to existing potable water standards (Bixio et al., 2005, Wintgens et al., 2005). Despite this, the concept of drinking wastewater does not have wide public support. Several public consultation studies explore reasons for this resistance, and how to gain community support (for example, Marks, 2003, Marks, 2006, Baggett et al., 2006). In some instances cultural issues or even spiritual or religious relationships to water are important (Strang, 2004). Recycled water is now available in countries with severe water restrictions, but clients for the product often cannot be found. Several factors combine to hinder recycled water uptake, including inadequate distribution infrastructure for supply, existing highly subsidized and cheap potable water resources, and a low level of community awareness of the limitations of freshwater resources, particularly in urban areas. New problem solving approaches to water supply are needed (Weber, 2006).
Dual reticulation systems are one approach used in Australia (Wintgens et al., 2005, van Roon, 2007), where new developments are fitted with one set of pipes for potable water (conventional tap water) and another for reused water (treated with various technologies, depending on the scheme). Other approaches to promote recycled water acceptance include many countries’ implementation of (or plans to implement) seawater desalination to meet the shortfall in drinking water supplies and avoid public acceptance problems (IDA, 2006). Desalination is well established in some countries, and reuse is considered to be an alternative (Côté et al., 2005). The growth of desalinated water production worldwide is near exponential (Dawoud, 2005), which might be explained by the declining costs of desalination technology, even though it produces water more expensively than does traditional supply (Dawoud, 2005).
Key issues in the desalination and reuse debate concern energy consumption, water quality, and environmental impacts. Introducing alternative water schemes (such as recycled, desalinated, storm or grey water), while objectively necessary, indispensable and technically possible, is complicated, because contributions from three sides are required:
- (1)
Professional knowledge provides the technical foundation to provide safe, reliable, and affordable alternative water source schemes.
- (2)
The community needs to accept or desire alternative water schemes.
- (3)
Because public acceptance is typically slow to emerge, it requires an issue management approach to introducing alternative water schemes, which may extend well beyond a specific location and public consultation at that location. Hartley (2006) mentions five crucial dimensions of issues management in the context of water reuse decision making: “managing information; maintaining 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.” National social marketing campaigns may be necessary to educate the population about the importance (necessity) and possible risks (and opportunities) associated with adopting (and not adopting) alternative water schemes.
This paper discusses all these aspects. A brief background on the professional knowledge on recycling and desalinating water provides the technical knowledge base. Management implications are discussed in the conclusion. However, this paper mainly focuses on evaluating public acceptance of recycled and desalinated water. For this purpose it is necessary to determine: (1) what the main concerns are regarding household use of recycled and desalinated water; (2) how the community currently perceives recycled and desalinated water; (3) the level of factual knowledge; and (4) the stated likelihood of residents to use each of these alternative water sources.
Where some people state to be more likely to use recycled and desalinated water, it is also valuable to ascertain: (5) what the characteristics of those people are, because they could potentially serve as a market segment for early stages of the introduction of alternative water schemes. We henceforth refer to them as the “strong accepter segment.”
Although previous studies extensively examine concerns and levels of public acceptance, very little research investigates the actual knowledge of the population about alternative water sources, as well as people's perceptions of them. Comparisons of knowledge and perceptions of different alterative water sources are rare, and no comparisons of strong accepter segments for different water sources yet exist.
Section snippets
Review of prior research into public perceptions
The issue of public acceptance of desalinated water has received scant attention. This contrasts with work on acceptance of recycled water, which has taken several directions. The majority of work investigates people's willingness to adopt recycled water (Bruvold and Ward, 1970, Bruvold, 1972, Kasperson et al., 1974, Sims and Baumann, 1974, Stone and Kahle, 1974, Olson et al., 1979, Bruvold et al., 1981, Milliken and Lohman, 1985, Po et al., 2004). Most studies find that the most-opposed use of
Water quality issues: recycled versus desalinated water
The primary source of recycled water is municipal wastewater, and this has prompted community concerns about water quality. Seawater is seen as a more pristine source. Wastewater carries what humans excrete and discharge to the drain from sources such as toilet, bathroom, kitchen, and laundry, or miscellaneous dumps of household or garden toxins or pharmaceuticals.
Toze (2006) summarizes the primary concerns as being microorganisms including bacteria, viruses, protozoa, and helminthes, which are
Energy consumption and cost: recycled versus desalinated water
Energy constitutes a large portion of the cost of water provision, and is a prime driver of decisions about water and wastewater treatment technology. Generally, the more advanced the treatment and the further it is transported, the more energy is required to supply water. Other cost factors include pre-treatment, chemical addition, cleaning, maintenance, and capital works.
Almost identical technology—reverse osmosis—is commonly applied in large-scale facilities for both water recycling and
Environmental issues: recycled versus desalinated water
The most obvious consequences of unsustainable water consumption include energy and associated CO2 emissions, variation of environmental flows and wastewater discharge, with associated impacts on habitats and biodiversity. Natural water bodies, such as rivers, lakes, groundwater and wetlands, are often affected. While water recycling produces clean water, it also often involves cleaning up wastewater which might be discharged into the environment without adequate treatment, causing a range of
Data and methodology
The fieldwork for this study was conducted using an Australian permission-based Internet panel. This panel maintains a respondent database that is representative of the Australian population based on the Australian Bureau of Statistic's (ABS) census information. Respondents were randomly selected from this panel, were invited to complete a 30-minute questionnaire online, and received a monetary compensation for completing it. Such compensation is a standard payment that is prescribed by the
Main concerns raised by respondents
The open-ended question in which respondents were asked to state their main concerns with recycled and desalinated water centred on three main themes: health concerns, environmental concerns, and cost. Recycled water was perceived as more risky from a health perspective (55 percent of respondents listed health-related concerns in the open-ended question). Desalinated water was primarily perceived as bad for the environment (12 percent, and only 23 percent mentioned health-related concerns), but
Conclusions
The Australian population discriminates between recycled and desalinated water. Although responses to the knowledge questions reveal gaps in the population's general level of knowledge, respondents understand that recycled water is the more environmentally friendly option, whereas desalinated water is perceived as less risky from a public health point of view. Responses to emotional items such as “is disgusting” indicate that Australians currently have fewer reservations about desalinated water
Acknowledgments
This project was supported by the Australian Research Council under Discovery Grant DP0557769 and the International Science Linkages program established under the Australian Government's innovation statement Backing Australia's Ability. It is funded by the Commonwealth Department of Education Science and Training for the project OzAquarec: Integrated Concepts for Reuse of Upgraded Wastewater in Australia (CG030025).
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