By Dr Don Williams MRSV

“Science gathers knowledge faster than society gathers wisdom” – Isaac Asimov (1988)

Bottled drinking water is widely consumed in Australia, despite safe and reliable drinking water being readily available from centralised urban water systems (‘tap water’). Bottled water remains immensely popular despite its significantly higher cost, and scientific advice that tap water is both healthier and far less environmentally damaging.^1,2

This article briefly compares the safety and environmental attributes of bottled water and tap water. It examines reasons for bottled water’s popularity and potential policy options to discourage bottled water consumption. The mass consumption of bottled water is identified as a specific example of a more general class of policy problem.

Impacts of bottled water vs. tap water

Australian tap water is reported to be very safe and cause far less environmental harm than bottled water.^1,2 But what does that mean, exactly? And how is the safety and environmental impact measured?

Safety

Victorian tap water is treated by proven technologies, including detention, filtration, and disinfection. Its quality is regulated by the Safe Drinking Water Act 2003, which adopts the risk management philosophy of the Australian drinking water guidelines.³ Monitoring and public reporting of water quality is also required.⁴ This comprehensive risk-management framework means safety risks associated with Victorian tap water are minimal. Victoria’s approach to managing drinking water quality typifies Australian practice.¹

Bottled water is deemed to be a packaged food and is regulated by national Food Safety standards, which are enforced by state food authorities. These standards include health-based limits for a range of substances and risk-management procedures. However, bottled water producers generally have less control over the catchments used to source their water than water utilities.1 Recent research has identified the presence of microplastics in bottled water in Australia.⁵

Both tap water and bottled water are subject to contemporary risk management frameworks. There is no evidence that bottled water is safer than Victorian tap water – if anything, the presence of microplastics in bottled water make it a less healthy product.

Environmental Impacts

Bottled water manufacturing impacts the environment throughout the product life cycle, including bottle production, water extraction, bottling, transport, and cooling. Impacts include resource depletion, consumption of energy and water, greenhouse gas emissions, and solid waste generation.

While studies on these impacts are limited and use different methods, a recent review found the environmental impacts of bottled water exceed those of tap water across all criteria.⁶ For example, the energy required to produce bottled water is up to 2,000 times more than tap water, and greenhouse gas emissions for a 500ml PET bottle are equivalent to 3.87 kg CO₂. Additionally, the estimated ‘water footprint’ values for bottled water (ratio of fresh water used in production per unit of product) range from 6 to 35, compared with 2.4 for tap water.⁶ While acknowledging the limitations of available studies, it is clear the environmental impacts of bottled water greatly exceed those of tap water.

Together, this means that bottled water is no safer than drinking water, and causes far greater environmental harm. The unit cost of bottled water is also hundreds of times that of tap water, further diminishing any potential benefits.^7,8

It is difficult to provide rational explanations for the success of bottled water. To understand why bottled water has triumphed in the marketplace, we must turn from the physical world to the less concrete realm of human behaviour.

Consumer behaviour

Australians purchased an average of 504 litres per person of bottled water in 2021, indicating it is a mainstream practice.⁷ Research suggests there are varied reasons why some consumers prefer bottled water. These include perceptions about relative safety, which may be influenced by previous incidents with the tap water supply system; claimed health benefits; and taste preferences and appearance.^9,10

Bottled water is supported by extensive advertising, which seeks to connect the product with buyers’ emotions.⁹ A distinct, commercially successful bottled water ‘brand’ has emerged.¹⁰ The success of bottled water is a striking example of the power of branding to transform a commodity into a meaningful part of daily life for many consumers.¹¹

An Australian analysis showed that even though consumers might express concerns about the impacts of disposable items such as plastic bottles, these concerns are not associated with major changes in purchasing behaviour.¹² In other words, knowing that plastic bottles pollute our environment isn’t enough to stop people buying water in plastic bottles.

In the absence of interventions, the popularity of bottled water seems unlikely to weaken.

Bottled water as a policy issue

The adverse consequences of bottled water represent a significant public policy issue. How can science be utilised to reduce the demand?

The intersection of science with public policy is often framed as using scientific knowledge to influence governments, encouraging them to mitigate harmful outcomes by adopting explicit policies and passing laws to mandate outcomes. Examples of this approach include the introduction of strong legal regimes to zone land for conservation purposes, regulate medicines, and control radioactive materials.

However, bottled water is an example of a different type of policy issue, which requires different interventions. Bottled water consumption is determined by individual consumer decisions. Similar public policy issues associated with consumer choices include consumption of unhealthy foods, purchase of ‘green’ electricity, and choices about transport modes. Potential policy responses to this type of issue must recognise that proposals for government intervention in markets currently encounter strong political opposition.¹³

How can science help to mitigate the impacts of bottled water in this seemingly unpromising context?

The role of science

An Approach Based on Regulatory Theory

Regulatory theory suggests governments can influence behaviour by interventions that extend beyond direct legal controls. These interventions can include:¹⁴

1. Legal regulation: direct control via laws
2. Authorisation: use of licences/approvals to regulate behaviour.
3. Economic regulation: governments create or influence markets.
4. Transactional regulation: governments carry out transactions in markets.
5. Structural regulation: alter the physical environment to direct behaviour.
6. Informational regulation: provide information to overcome information asymmetries, and to modify behaviour.

The last two measures are particularly relevant to bottled water. The introduction of refilling stations, where bottles are replenished with tap water, alters the physical environment to direct behaviour. Studies show this measure reduced bottled water consumption at specific sites.^2,15

Governments at all levels could ensure that refilling stations are readily available at the extensive range of public facilities under their control, such as airports, tertiary institutions, schools, libraries, hospitals, and land transport hubs. This intervention could also have the indirect benefit of normalising tap water consumption.

Another potential intervention would be to require producers to provide information about bottled water. This could include information such as the adverse environmental impacts identified above, and health data. This would reduce information asymmetries between bottled water producers and consumers, and allow consumers to make more informed purchasing decisions.¹⁶

Given the availability of these simple, unobtrusive regulatory interventions, the scientific community could encourage governments to adopt them. If the provision of information were mandated, scientists would have a key role in ensuring the information reflects sound, evidence-based knowledge.

Or a More Ambitious Role for Science?

A precedent for strong, science-informed intervention in a market is the introduction of controls on tobacco marketing. The Tobacco Act 1987 introduced measures such as restrictions on advertising and sponsorship, control of tobacco sales to minors, prohibiting the sale of small, cheap packets of cigarettes, and the establishment of VicHealth, funded by an increased levy on tobacco sales. A key factor in gaining the Victorian government’s support for the Act was a strong, science-based advocacy network, led by the Anti-Cancer Council of Victoria.¹⁷

A potential hurdle advocates of strong regulatory controls should recognise is that contemporary government practice usually requires quantitative economic assessment of these interventions, including cost-benefit analysis to show that regulation would provide net positive outcomes. These requirements are typified by the Victorian government’s Victorian Guide to Regulation.¹⁸

A complex case study

Bottled water consumption is an example of a more general type of policy issue associated with consumer behaviour. Advocates for intervention are faced with a general reluctance of governments to impose direct legal controls on consumers. However, measures such as installing refilling stations and providing comprehensive information to consumers could be used to discourage bottled water consumption. The scientific community could place pressure on governments to recognise the impacts caused by bottled water and could help to design, implement, and review appropriate interventions.

There is no absolute barrier to introducing a more ambitious approach to regulating bottled water consumption: the introduction of controls on tobacco in Victoria provides an example of what is possible under the correct circumstances. However, direct government intervention in retail markets would require a very strong scientific and economic case to justify regulatory controls. This is true for the bottled water issue and other policy issues related to consumer behaviour.

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Dr Don Williams MRSV worked for 30 years in the water quality management, wastewater regulation and water efficiency fields. Don then completed a PhD examining how planning laws influence the adoption of sustainable urban water practices. He has a long-standing interest in how scientific knowledge influences public policy.

References:

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2. Willis, K., et al. (2019). The Success of Water Refill Stations Reducing Single-Use Plastic Bottle Litter. Sustainability, 11(19), 5232. doi.org/10.3390/su11195232
3. Water Quality Drinking water guidelines. (2019, July 19). Water Quality Australia. waterquality.gov.au/guidelines/drinking-water
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6. Parag, Y., et al. (2023). Bottled Water: An Evidence-Based Overview of Economic Viability, Environmental Impact, and Social Equity. Sustainability, 15(12), 9760–9760. doi.org/10.3390/su15129760.
7. AAP. (2023, March 17). Australians are spending an average of $580 a year on bottled water, making us the second-biggest consumer globally. ABC News. abc.net.au/news/2023-03-17/australias-unquenched-thirst-for-costly-water/102110514
   
8. Average household water bills in Victoria. (2024). Essential Services Commission. esc.vic.gov.au/water/water-prices-tariffs-and-special-drainage/average-household-water-bills-victoria
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15. Becerra-Galicia, S. A. (2022). Refill, Reuse, Repeat: How Water Bottle Filling Stations Enhance Low-waste Drinking Water Consumption Through Nudging. Arizona State University. hdl.handle.net/2286/R.2.N.171674
16. Switzer, D. (2019). Getting off the (water) bottle: Constraining or embracing individual liberty in pursuit of the public interest. Ethics, Policy & Environment, 22(3), 331-348.
17. Winstanley, M., et al (2007). The Victorian Tobacco Act 1987: the untold story. Carlton South, Vic.: The Cancer Council Victoria: VicHealth; Carlton, VIC. vichealth.vic.gov.au/sites/default/files/VictorianTobaccoAct_1987.pdf
    
18. Victoria, Department of Treasury and Finance (2016). Victorian Guide to Better Regulation. Melbourne: Department of Treasury and Finance.