Perceived poor water quality and living with children influence our preference for drinking bottled water at home

Drinking water at home is something we do almost automatically as part of our daily lives. The water we consume may come straight from the tap, we may buy it bottled, or it may have been processed by a domestic filtration system. But what are the reasons behind our decision to opt for one or other of these sources for our drinking water?

A group of researchers from the Universitat Oberta de Catalunya (UOC), the Universitat Autònoma de Barcelona (UAB) and the Barcelona Institute of Regional and Metropolitan Studies (IERMB) have been investigating just that in a study that highlights a perception of poor-quality tap water, the lack of a domestic water filtration system and the presence of children in a household as the primary factors that lead consumers to drink bottled water.

In 2018, some 2.6 billion litres of bottled water were consumed nationwide in Spain, with the coastal and tourist regions of the Canary Islands and the Balearic Islands topping the charts for bottled water consumption, followed by the Valencian Community and Catalonia.

According to the study’s co-author, Hug March, who is also a researcher for the TURBA Lab group, part of the Internet Interdisciplinary Institute (IN3), and professor of the UOC’s Faculty of Economics and Business, “Our survey showed that our perception of water quality – encompassing everything from organoleptic considerations to health concerns related to water hardness – was the most influential variable in terms of prompting us to opt for bottled water or home filtration systems.”

The results of the research study, published in the journal, Water, and co-written by Xavier García and Elena Domene from the IERMB and David Sauri from the UAB, are based on phone interviews conducted with members of a total of 581 Catalan households in April 2015.

“The result we were most surprised by was the considerable amount of people that have some kind of water treatment system in their home, whether it’s an activated carbon filter jug or a more complex system, such as reverse osmosis,” highlighted March.

In fact, the study revealed that a third of the households (31.2%) surveyed possessed one of these systems, the most common being water softeners and reverse osmosis systems (both more expensive), followed by water filter jugs and bottles.

The importance of taste and smell

The survey results indicated that people were more concerned about using tap water for drinking than they were for cooking. While 80% of households rated their water as, at the very least, acceptable for cooking, that proportion dropped to 65% when it came to drinking it.

When asked to state their main reason for choosing to drink bottled water, improved taste and smell (51.3%) and health reasons (34.2%) were the most popular answers.

As the researcher pointed out, “In general, within our geographic context, tap water undergoes numerous, continuous sanitary controls that, in physicochemical and microbiological terms, ensure it is safe to consume.”

The perception of its quality is, however, a different and more subjective issue and, according to March, is linked to water hardness levels and the relative content of certain minerals in the supply source used: “It’s also true that, in the case of some specific conditions, the medical recommendation may be to avoid the consumption of very hard water, even though the levels may fall within legal limits, and drinking water with a low mineral content may be advised.”

Tap water, a safe and sustainable option

Given that a third of the households surveyed indicated that they bought bottled water as a result of health concerns, the authors predicted that public institutions and water suppliers may face an uphill struggle to convince consumers that it is safe to drink tap water. Another issue is its taste.

In terms of sustainability, March stressed the fact that, of all the options, tap water is the most environmentally friendly. When opting to consume bottled water, it is important to minimise waste wherever possible. To that end, the researcher recommends using large-capacity containers, such as jugs, instead of bottles, and recycling them once finished.

In relation to some treatment systems, such as osmosis, March pointed out that, “although packaging isn’t an issue, these systems may consume a lot of energy (in the case of reverse osmosis) and use more water than ends up being consumed, as a proportion of the water is also removed in the process of eliminating salts and by-products.”

This research was funded with the following grants: CICYT - CSO 2012 36996, 2017 SGR 1351 and 2017 SGR 130.

This research supports the following Sustainable Development Goals (SDGs): 6, clean water and sanitation; 11, sustainable cities and communities; 12, responsible consumption and production, and 13, climate action.

Reference article

March, H., García, X., Domene, E. y Sauri, D. “Tap Water, Bottled Water or In-Home Water Treatment Systems: Insights on Household Perceptions and Choices”. In: Water. doi: 10.3390/w12051310.

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