03 April 2018

Could you taste the difference between toilet water and tap water?

It is important to make the idea of recycled water less scary to people, as it is becoming an important source of water in many parts of the world.

On 13 March 2018, Cooperative Governance and Traditional Affairs Minister Zweli Mkhize declared the prevailing water crisis affecting multiple provinces a national state of disaster.

As the water crisis in South Africa continues, recycling waste water could be the answer – but people are wondering if it will taste different. 

Results of a blind taste test suggest that it's unlikely

Alternative sources of water like desalinisation, recycling and groundwater will be employed.  

Disgust reactions

Although research has shown that recycled wastewater is safe, people are often repulsed by the taste.

"It seems that this term [wastewater], and the idea of recycled water in general, evokes disgust reactions," said study author Daniel Harmon, a graduate student in psychology from the University of California, Riverside.

"It is important to make recycled water less scary to people who are concerned about it, as it is an important source of water now and in the future," Harmon said in a university news release.

He and his colleagues asked 143 people to compare the taste of IDR tap water, conventional groundwater tap water and bottled water.

Years of drought in California have given momentum to household use of recycled wastewater. Six water agencies in the state already use wastewater that's produced through a technology called indirect potable reuse (IDR), the University of California, Riverside, researchers noted.

"The groundwater was not as well liked as IDR or bottled water," said study co-author Mary Gauvain, a professor of psychology.

The study was recently published in the journal Appetite.

"We think that happened because IDR and bottled water go through remarkably similar treatment processes, so they have low levels of the types of tastes people tend to dislike," she said.

Women prefer bottled water

Looking at personality types, the researchers found that nervous and insecure people tended to prefer IDR and bottled water.

Also, people who were more open to new experiences rated the three types of water about the same. And women were two times more likely to prefer bottled water than men.

"We think this research will help us find out what factors people pay attention to in their water decisions, and what populations need to be persuaded to drink IDR water and how to persuade them," Harmon said.

Image credit: iStock


Live healthier

Lifestyle »

E-cigarettes: Here are five things to know

E-cigarettes have become hugely popular in the past decade, but a rash of vaping-linked deaths and illnesses in the US is feeding caution about a product that's already banned in some places.

Allergy »

Ditch the itch: Researchers find new drug to fight hives

A new drug works by targeting an immune system antibody called immunoglobulin E, which is responsible for the allergic reaction that causes hives.