In light of climate change and a growing population, water authorities around the world are looking at the treatment of recycled water to achieve water security and sustainability.

Recent authors on The Conversation have raised the possibility of expanding the use of water recycling in Australia, noting the potential benefits for domestic, agricultural and industrial water supply.

Some contributors have noted that the major roadblocks to water recycling, in places where it could be beneficial, are not technical issues, but public reluctance to use recycled water.


In the past, our aversion to recycled water has been explained by the “yuck factor”. Some people have an emotional response of disgust to using recycled water, even when they know it has been highly treated and is safe. There are large individual differences in the strength and type of different people’s disgust responses.

Psychologists have tried to understand why our thought processes can lead some people to think of recycled water as unclean. One explanation is contagion thinking, the idea that once water has been defiled it will always remain unclean, regardless of treatment, at least according to the mental models that underlie our emotional responses. What such approaches often neglect is that cognition does not occur in a cultural vacuum, but is affected by the associations and stigmas of society.

It is important to note that these emotional responses are often in conflict with our rational thinking. Some theorists, such as Nobel laureate Daniel Kahneman, have argued that we make judgements using two contrasting systems. One of these systems is slow and operates according to a formal risk calculus. The other is fast, based on positive or negative emotional responses.

Because of this, how we feel about someone or something (positively or negatively) is often as important as what they are being judged on. In other words, the fact that a person understands that a highly treated sample of recycled water is safe to drink may not be enough to stop the emotional response, as we often tend to think intuitively, drawing on our social and cultural values.

The most important question, however, is whether the emotional responses some people have to recycled water can be changed. And what role do stigmas associated with cultural norms play in shaping these?


In places where water recycling has been introduced, it has simply become a fact of life. In Singapore, citizens of the island nation have widely accepted NEWater (as the Public Utilities Board has branded it). It’s even celebrated at a visitors’ centre that has become a minor tourist attraction.

In Windhoek, the capital of Namibia, various forms of drinkable recycled water have been in use for almost 50 years, with no significant impact.

If these communities can accept recycled water, perhaps our aversion is simply a passing phase, which will disappear when people get used to it? If so, then cultural norms must also play a role, with acceptance building with increased familiarity.


Cultural cognition is an approach that suggests that our beliefs and judgements about risk and cleanliness are determined by social norms, as well as more innate processes of cognition. As cultural norms, peer pressure, stigmas and the public scientific consensus all affect our beliefs and judgements, then emotional responses to recycled water are strongly linked to our cultural classifications.

The anthropologist Mary Douglas coined the term “matter out of place” to refer to things that do not easily fit into our known systems of classification, and thus often come to be thought of as dangerous. Recycled water fits into this category, as it straddles our conceptions of both clean and polluted. As water recycling is a fairly new concept and most people have no direct experience with it, they revert to inferring from the categories that they do know about.

Thus our emotional responses to water recycling are associated with uncertainty, even though our rational scientific understanding tells us it is no different to any other treated water.

It is our cultural beliefs that determine whether we see recycled water as clean or dirty, and these categories are not fixed but are a reflection of our society at that point.


If we are to understand how to use new water technologies effectively for social and environmental benefit, we need not only to understand the scientific case for these technologies, but also to change the social and cultural values that inform our attitudes to them.

Culture is dynamic. Our acceptance of any particular new technology is based on norms that are current at a particular time. The “yuck factor”, which has been the focus of so much research over the years, may well change with increasing exposure to recycled water.

The Conversation

Daniel Ooi, Research Fellow, Institute for Sustainability and Innovation, Victoria University

This article was originally published on The Conversation. Read the original article.