Psychological aspects of the rejection of recycled water: Contamination, purification and disgust

There is a worldwide and increasing shortage of potable fresh water. Modern water reclamation technologies can alleviate much of the problem by converting wastewater directly into drinking water, but there is public resistance to these approaches that has its basis largely in psychology. A psychological problem is encapsulated in the saying of those opposing recycled water: “toilet to tap.” We report the results of two surveys, one on a sample of over 2,000 Americans from five metropolitan areas and the second on a smaller sample of American undergraduates, both assessing attitudes to water and water purification. Approximately 13% of our adult American sample definitely refuses to try recycled water, while 49% are willing to try it, with 38% uncertain. Both disgust and contamination sensitivity predict resistance to consumption of recycled water. For a minority of individuals, no overt treatment of wastewater will make it acceptable for drinking (“spiritual contagion”), even if the resultant water is purer than drinking or bottled water. Tap water is reliably rated as significantly more desirable than wastewater that has undergone substantially greater purification than occurs with normal tap water. Framing and contagion are two basic psychological processes that influence recycled water rejection.