Bottled Water: An Evidence-Based Overview of Economic Viability, Environmental Impact, and Social Equity

Abstract

This paper considers bottled water with respect to the three pillars of sustainability: economic viability, environmental impacts, and social equity. Per-capita consumption of bottled water has been growing steadily and is the fastest-growing sector of the packaged beverages industry, with expected annual growth of 10% until 2026. Most bottled water is sold in PET containers, and various impacts are evident along all phases of the product lifecycle. This paper reviews market trends and forecasts, lifecycle estimates of energy consumption, associated air pollution and GHG emissions, water footprint, and waste generation. Concerns around human and ecosystem health due to pollution, land use changes, storage conditions, microplastics, and leaching from containers are described, as well as local environmental benefits from companies’ efforts to preserve the quality of their source water. Growing awareness of the cumulative negative impacts of bottled water have pushed the industry to voluntarily improve its performance. Yet, as growth continues, further actions should focus on stricter regulation and on the provision of more sustainable, affordable, available, and trusted alternatives. Gaps remain in knowledge of the effects of bottled water over its full life cycle.

1. Introduction

Bottled water is often seen as one of capitalism’s greatest mysteries, “the packaging and selling of something that is already freely available” [1]. In its massive marketing campaigns and advertisements, the industry positions bottled water as the ultimate beverage for a healthy lifestyle and associates its consumption with personal success and a connection to wild nature [2]. Influenced by this messaging, the reasons consumers provide for preferring bottled water over tap water vary: some see it as the only option for clean water; for some it is a symbol of status and the modern lifestyle; for others it is simply more convenient, handier, or tastier than tap water [3,4,5]. In many countries bottled water consumption is common in all segments of society. In the USA, for example, consumption is spread nearly evenly between age groups and income groups, with perhaps slightly more women (54%) drinking it than men [6]. Considering the billions of bottles that are sold every year, the rate of industry growth, and the consumer price of bottled water often being thousands of times that of tap water, it seems that the public is convinced that bottled water is superior. This is surprising, given that most bottled water sold globally (nearly 60% in 2018) is purified tap water, not spring water or natural mineral water [7].

As a commodity, bottled water is a unique combination of natural resource and industrial product. In recent decades, the social practice of drinking bottled water has engendered cultural and social shifts with economic, environmental, and social implications [8]. Bottled water as a socio-techno-economic phenomenon has been widely studied from various perspectives and angles. Interest in bottled water manufacturing, consumption, and environmental impacts is reflected in the growing number of academic publications on the topic. A Web of Science database search returned 537 publications with the term “bottled water” in the title or keywords between 1997 and 2020 (Figure 1). The most common aspects of the bottled water issue to be addressed are health and environment (in terms of the impacts of bottled water on consumer health and the environmental impacts of single-use bottles), economics (global and local industry; market trends), psychology (why consumers prefer bottled water to tap water), and chemical and engineering aspects of the manufacturing and industrial processes. While many publications cover more than one aspect, no article provides a broad overview of bottled water as a socio-techno-economic phenomenon.

In 2011, the economics, environmental impact, and social implications of the bottled water industry and consumption trends of the product were reviewed in the Encyclopedia of Life Support Systems [9]. Subsequently, despite the changes in production technologies and consumption patterns, no article has provided a broad up-to-date multi-perspective overview of the phenomenon based on data and evidence from various disciplines. Our paper aims to fill this gap by using the prism of the three pillars of sustainability—economic viability, environmental impact, and social equity—to examine the bottled water phenomenon. As this phenomenon is wide in scope, we apply a semi-systemic review methodology, allowing us to include a broad range of topics and different types of studies [10]. Using evidence from these three realms, we observe the multifaceted reality of bottled water production and consumption. Herein, we present some of the complexities and tensions inherent to consumer society, in which short-term revenues and economic considerations often come at the expense of long-term environmental and health ones. Evidence and facts should be the foundation in the search for a feasible balance between protection of the environment and human health on the one hand, and fair economic growth and social prosperity on the other.

The paper begins with a short history of the bottled water market and its evolution, followed by an overview of the regulatory and policy frameworks that govern bottled water. It continues by examining bottled water from economic (market and consumption trends), environmental (energy consumption, air pollution, water footprint, waste, and ecosystem degradation), and societal (human health, equity, and justice) perspectives. The article concludes with a discussion of the future outlook and notes on the need for unbiased and updated data.

2. Development of the Bottled Water Market

According to Chapelle [11], the origins of the bottled water industry are in the early 1800s; it started to grow significantly in the United States when mass production of glass bottles became economically viable. In the early 20th century clean water was not widely available, and the bottled water industry thrived in both the US and Europe. Among the early distributors were brands that remain in the market today, such as Evian, San Pellegrino, Perrier, and Vittel. The improvement of tap water quality in developed countries during the first half of the 20th century led to a decline in the need for bottled water for drinking.

Bottled water markets re-emerged in response to several key factors [12]: changes in consumer drinking habits; strategies on the part of beverage producers; the development of polyethylene terephthalate (PET) bottles; the intensification of sophisticated branding techniques; and incidents of drinking water pollution.

Holt [13] identifies three “health constructs” that gave the bottled water market a substantial push: the hydration trend, starting around 1988, stimulated the demand for convenient portable water; the 1993 cryptosporidium outbreak in Milwaukee, which took a heavy toll and highlighted bottled water as a contaminant-free choice; and public health studies published in the early 2000s that identified sugar consumption as a cause of several chronic health problems and drove middle-class Americans to replace sweetened soft drinks with bottled water. Opel [14] describes a climate of distrust of public water supplies driven by several water contamination incidents. The industry took advantage of these events to spread doubt about public water safety while stressing the purity of its bottled products. During the first decade of bottled water advertising, water-bottling companies did not even have to advertise this safety advantage, as NGOs and the media were already legitimizing and amplifying the tap-water scare [13].

Brei [15] argues that while the concept of health is strongly embedded in the development of the French bottled water market, infrastructure and technical innovations brought about by the Industrial Revolution, such as drilling for new sources and faster bottling processes, improved the possibilities for commercial exploration of mineral waters. A major milestone in the growth of the bottled water market in France occurred in the mid-1950s, when new laws that eased the production process were introduced. These laws eliminated the requirement for bottling at the source, lifted a prohibition on the sale of a mixture of two or more different mineral waters, and allowed certain treatments of mineral water [15].

3. Governance, Regulations, and Policies

The governing structure of bottled water varies from place to place, and is somewhat different from that of drinking water because it covers both the water and its package. Drinking water, or potable water, is water intended for human consumption. Bottled water is drinking water sealed in any sort of packaging (plastic or glass bottles, cans, cartons, etc.) with no added ingredients except that like tap water, it may contain certain antimicrobial agents [16].

Regulations and standards are in place in most countries to ensure that drinking water is clean and to protect consumers’ health from any hazards arising from poor-quality water. Unlike tap water, bottled water is often regarded as a food product and regulated as such. Commercial foodstuffs are subject to less restrictive regulations and enforcement methods than tap water; emphasis is mostly put on truthful labeling, sanitary processing, and transport conditions. Nonetheless, bottled water regulations have become stricter over the years [17].

At least four levels of regulation apply to the bottled water industry: international, national, local, and trade association. As a result, the capacity and scope of regulations vary widely from place to place [18,19]. In the US, for example, drinking water is regulated by the EPA, whereas bottled water is regulated by the FDA, under Section 410(b)(1) of the Federal Food, Drug, and Cosmetic Act. The act requires the FDA to update its standards of quality for bottled water with every change in the National Primary Drinking Water Regulations issued by the EPA.

The FDA requires bottled water to come from sources that have been approved by government agencies with the appropriate jurisdiction (for example, municipal drinking water systems, wells, or springs). The source water must be tested at least every four years for radiological contaminants, at least once a year for chemical contaminants, and once a week for microbiological contaminants (unless the water comes from a municipal source, as these are subject to EPA regulation) [20]. The actual testing is conducted by the bottlers themselves and is subject to FDA inspection. Maximum contaminant levels have to be no less stringent than those set by the EPA for tap water. In certain cases, however, FDA regulation is more restrictive than EPA regulation. For example, the EPA standard for lead in tap water is 15 parts per billion (in more than 10% of collected samples), while the FDA standard for bottled water is 5 parts per billion (metal contaminants such as lead may be present in tap water due to its exposure to household plumbing pipes, and are less likely to be found in bottled water). At the same time, various potentially harmful contaminants such as bisphenol A (BPA) and microplastics, which are likely to be present in bottled water, are not regulated by FDA. In addition, unlike municipal water utilities, which must report to the public on contaminants found in their water, bottlers are not required to report contaminants or order recalls, nor are they subject to adequate oversight of their operations [20]. Certain states may require licensing, certification, or additional labeling not specified in the federal regulations.

EU legislation covers natural mineral water, spring water, and “other water”, including exploitation, treatment, microbiological criteria, chemical contaminants, sales description, labeling, and packaging. Spring waters and “other waters” must also comply with European Union (Drinking water) (No. 2) Regulations (S.I. No. 282/2016: Natural mineral waters, spring waters and other waters in bottles or containers).

As a food item, bottled water is subject to any legislation concerning food production, manufacture, packaging, labeling, storage, etc. [19,21]. For example, in the EU, containers are subject to safety regulations for all “food contact materials” defined under Commission Regulation (EC) No. 1935/2004.

4. Sustainability

The evolution of bottled water from health necessity (i.e., a way to ensure good water quality) to a lifestyle and cultural choice has environmental and social implications, as well as industrial and commercial ones [22,23,24]. In the following sections, we outline existing evidence of the current status of the main impacts in each of the three realms of sustainability: economy, environment, and society. Figure 2 highlights the various impacts along the life cycle of bottled water (excluding equity and justice, which are discussed below but are not related to any specific phase of the life cycle).

To begin, we should note three important things: first, only a few academic (non-industry) studies have quantified the various impacts of bottled water, and many industry publications do not explain their methodology in detail; second, several studies use figures from articles published more than a decade ago (for example, figures on energy consumption from Gleick and Cooley [25] are cited in many recent studies, although they are probably inaccurate today because manufacturing processes have become more efficient and bottles much lighter); third, comparison between studies is often difficult, as calculations are conducted for containers of different sizes and impacts depend nonlinearly on bottle volume (e.g., the impact of a one-liter bottle is not twice the impact of a half-liter bottle).

4.1. Economic Viability

Rising interest in healthy living along with government regulations aimed at tackling rising obesity rates has led to increased demand for sugar-free and healthy drinks, contributing to the growth of the packaged water market [26]. Today, millions of people around the world in both developed and developing countries consume bottled water regularly. It is now by far the most popular type of packaged beverage. In 2020, total consumption of bottled water (including still, carbonated, flavored, and functional bottled water was 336 billion liters according to Euromonitor International [27], or 443 billion liters according to Statista [28]. (Note that Euromonitor International includes additional products under the bottled water category, beyond those defined by the regulator; see Section 3 for a comparison.) This is compared to 346 billion liters of all other types of soft drinks combined, including carbonated beverages, juices, sport drinks, energy drinks, and ready-to-drink coffee and tea [29]. The vast majority of bottled water is sold in plastic packages, and nearly 90% is off-trade (that is, sold for consumption off the premises, as opposed to on-trade, which refers to bottled water bought and consumed in premises such as restaurants) [27,30].

The global bottled water industry, which involves many of the largest food brands in the world, has registered strong growth in recent decades. In 2020 its revenues were USD 285 billion globally, and it is expected to grow annually by 10.1% between 2020 and 2026 (CAGR) [28]. In 2010, approximately 206 billion liters of bottled water were consumed globally; in 2020, this was 335 billion liters [27,31] (Figure 3). Between 1999 and 2018, annual per capita consumption of bottled water (carbonated or still in plastic or glass bottles) in the US rose from 61 L to 160 L. In comparison, the figure was 274 L in Mexico, 274 L in Thailand, 190 L in Italy, 144 in Germany, and 132 in the United Arab Emirates [31,32].

Emerging markets such as India, China, Indonesia, and South Korea have recorded substantial growth thanks to their growing middle-class population, increasing disposable personal income, and rapid urbanization [26]. These processes have brought a monumental surge in the consumption of many consumer goods, bottled water among them. For example, in 2010, 20.3 billion liters of bottled water were purchased in China; in 2020, this was 50.8 billion liters [27].

With growth in consumption, the bottled water packaging market has been growing as well. In 2019 it was valued at USD 182 billion, and it is expected to reach USD 278 billion by 2025 at a CAGR of 6.86% over the forecasting period of 2020 to 2025 [33,34].

The growing consumption of bottled water may be simply explained by (and correlated with) changes in GDP per capita. However, a more critical view suggests that it should be understood in the context of the wide variation in the quality of public tap water, the extent of municipal water coverage, the public (lack of) trust in tap water in each country, and the industry’s implicit and explicit efforts to position bottled water as a desirable healthy lifestyle choice and as superior to tap water [12,22,23,24,35].

COVID-19 Market Impact

The COVID-19 pandemic brought lockdown restrictions and social distancing regulations which led to dramatic changes in the patterns of bottled water consumption and sales. According to a report by Euromonitor [36], in the US, on-trade sales of bottled water declined by 42% in 2020, while the long-term rise in off-trade sales was significantly intensified, with sales increasing by 7%. The off-trade increase did not offset the on-trade decline, and the overall impact of the COVID-19 pandemic on the bottled water industry in 2020 was a 2% decline in total volume. The high ratio between on-trade and off-trade prices made the industry very vulnerable to on-trade decline. As lockdowns eased and restrictions lifted, on-trade sales bounced back (Figure 3). Different figures are presented by BWR [37], indicating that total consumption of bottled water in the US increased from 54,300 million liters in 2019 to 56,700 in 2020, a 4.2% increase.

4.2. Environmental Impacts: Resource Use and Externalities

Post-consumer non-degradable bottle waste has attracted great media and public attention. However, it is only one of many negative impacts linked to the life cycle of bottled water. These include the depletion of resources and materials, consumption of energy and water, and emission of greenhouse gases and toxic substances. These arise from all stages of the life cycle, including bottle manufacturing, water extraction, bottling, packaging, and transport of the product to consumers. Comparing the resource usage for the production of potable tap water versus bottled water, the environmental impact of the latter is seen to be greater per all the criteria examined [38,39]. At the same time, the environmental impact of bottled water is the lowest among all packaged beverages, [40], and the commitment to the environment declared by the bottled water industry is much higher [41].

Today, the vast majority of bottled water is sold in plastic packages and most of the existing studies and data are about PET bottles, with only a few comparing different container types. Recent research suggests that PET bottles have the lowest environmental impact compared with alternative packaging options. Compared with glass packaging, the most significant aspects that determine the environmental impact are the number of reuses of a single glass bottle and the distribution distance [42] On average (i.e., varying conditions of recycling rate, energy mix, etc.) and for most impact categories, the life cycle impacts of an aluminum can are higher than those of a PET bottle of the same volume [43].

4.2.1. Energy and Fuels

In contrast to tap water, which is distributed through a relatively energy-efficient infrastructure, the manufacturing of plastic or glass containers and their filling, packaging, and long-distance transport involves burning large quantities of fossil fuels.

A life-cycle assessment conducted for the International Bottled Water Association [40] found that the manufacturing of a 500 mL PET bottle (weighting 8.3 g) requires 0.96 MJ. According to this analysis, PET bottles have the lowest energy consumption compared to other 500 mL beverage containers, i.e., aluminum can—1.34 MJ (19.7 g), beverage carton—1.06 MJ (21.8 g), and glass bottle—4.32 MJ (300.6 g). An earlier study [25] estimated that the total energy used to manufacture a typical one-liter plastic bottle (weighing 38 g) is 5.6–10.2 MJ, of which approximately 4 MJ/L goes to making the PET resin, turning it into bottles, and transporting the bottles to the filling location. The large difference between the figures from these two studies is explained by the reduced weight of the bottles and improvements in the production processes that took place during the twelve years that separated the studies. According to Antea Group [7], between 2013 and 2017 energy use for PET bottle manufacturing decreased by more than 9%.

After the PET bottles have been manufactured, more energy is used to fill them with water at the factory, transport them, and refrigerate them in stores or homes. Calculations from 2009 [25] of the energy used to transport bottles to market show great variation from 1.4 MJ/L to 5.8 MJ/L. Significantly less energy is needed for filling, cleaning, labeling, sealing, and cooling. In 2009, the embodied energy of bottled water (the total energy consumed in the life-cycle stages from extraction to consumption) was as much as 2000 times that of tap water [25]. At the product’s end of life, more energy is consumed during all processes involved in waste management, such as landfilling, sorting, recovering, or recycling (see Section 4.2.4 on solid waste). It is reasonable to assume that these figures have changed in the last decade; however, we could not find a more recent analysis or published estimates.

4.2.2. Air Pollution and Greenhouse Gas Emissions

As with any activity involving combustion of fossil fuels, the production of bottles, whether plastic, glass, or cardboard, emits greenhouse gases (GHG) and other pollutants to the atmosphere in amounts that depend on the type of fuel and the efficiency of the processes. A study from 2012 estimated that 1 kg of PET results in the emission of 40 g of hydrocarbons, 25 g of sulfur oxides, 18 g of carbon monoxide, 20 g of nitrogen oxide, and 2.3 kg of CO₂ [1]. The IBWA [40] estimates the GHG emissions associated with the manufacturing phase of 500 mL PET bottles to be 0.05 kg CO₂ eq per bottle (compared to other 500 mL beverage containers, i.e., aluminum can—0.15 kg, beverage carton—0.075 kg, and glass bottle—0.38 kg). However, the IBWA report provides insufficient information on the system boundaries (for example, whether emissions embodied in raw material and transport are included). According to Horowitz et al. [44], total GHG emissions for the full life cycle of a 500 mL PET water bottle are 3.87 kg CO₂ eq.

4.2.3. Water Footprint

A product’s water footprint (WF) is the amount of fresh water consumed along the complete life cycle, including direct (operational) and indirect (supply chain) consumption. In addition to the water contained in the bottle, water is used at the bottling plant (e.g., to wash the bottles), in the production of fuels that are used for transport, and in the manufacturing of packaging materials, such as PET or glass for the bottles and corrugated cardboard and low-density polyethylene (LDPE) for mass packaging [45].

The WF of bottled water varies significantly depending on local industry practices, fuel type, and study parameters [46]. An Italian study [47] estimated the WF of a 1.5 L PET water bottle from six different local manufacturers as 8.1 L on average. Results show an inverse correlation with the size of the manufacturing facility, which is plausible according to economies of scale. The WF of bottled water in India was estimated as 17.4 L per one-liter bottle of water, of which 61% is attributed to packaging materials (PET and cardboard) [48]. The IBWA [40] estimates the WF associated with the packaging material (PET) at 17.4 L for a 500 mL bottle (compared to other 500 mL beverage containers, i.e., aluminum can—28.4 L, beverage carton—51.8 L, and glass bottle—109.4 L). In other words, the amount of water that goes into the production and supply of PET bottled water may be 17 to 35 times greater than the water delivered to consumers in each bottle. Mainardi-Remis et al. [45] estimated the direct and indirect WF of water in 20-L reusable plastic bottles at six times the amount directly consumed, with electricity and raw materials being the most significant factors. By comparison, the WF of tap water has been reported as 2.4 L per liter of water delivered [47].

4.2.4. Solid Waste

Technological developments over the past decades have considerably reduced the mass of manufactured PET water bottles. The average weight of a 500 mL bottle declined by 51% between 2000 and 2014 to a mere 9.25 g [49], and further to 8.3 g in 2021 [40]. Nonetheless, because consumption is continuously increasing, plastic water bottles continue to produce enormous amounts of waste. Unfortunately, we could not find any data which differentiate between plastic waste more generally and PET bottles specifically, let alone PET water bottles; thus, we cannot quantify the specific contribution of bottled water to the growing global problem of plastic waste.

Post-consumer plastic waste is predicted to reach 230 million tonnes a year globally by 2025 [50]. Plastic waste is managed according to varying national waste regulations and various kinds of infrastructure. It is mostly collected and transported to a treatment facility (recycling, waste-to-energy, or landfill), although a significant portion is mismanaged or inadequately contained (for example, disposed of in open dumps). Part of this fraction is then transported by runoff or wind, inflicting mechanical and chemical damage on surrounding ecosystems. Lebreton and Andrady [50] estimated that 60 million to 99 million tonnes of plastic waste, representing 47% of global annual municipal plastic waste generation, was mismanaged in 2015. In developed countries most plastic waste is managed, while in developing countries waste collection and disposal are often of low quality or completely lacking, with indiscriminate dumping the most common disposal method [51].

In Europe, where landfilling restrictions are implemented in most countries, plastic packaging recycling rates reached 41% in 2016 [52]. In the US, the recycling rate of PET and high-density polyethylene (HDPE) bottles reached 29% in 2018; the remaining 71% was landfilled [53]. In most parts of the world the recycled percentage is even smaller, and managed plastic waste is mostly landfilled or incinerated for energy recovery, often after having been transported over long distances [54].

Recycling is perceived by many as the preferred solution for PET bottles, though in terms of environmental impact it is not necessarily preferable to incineration or landfilling. Which treatment method is best depends on local conditions such as the transport distance to the receiving facility and the electricity fuel mix. Plastic waste created in America or Europe is often not treated locally, instead being transported across the globe to the far east [55]. Microplastics pollution, a subcategory of plastic waste, is discussed in section Contamination from the Package.

4.2.5. Ecosystems

The bottled water industry puts a strain on ecosystems through pollution and waste production. Other environmental impacts of the value chain of bottled water include damage to ecosystems and reduction in biodiversity brought about by land use changes and the presence of microplastics and other pollutant emissions [56,57,58,59]. Compared to municipal water supply, water extraction for bottled water is relatively small, though it is increasing with the rapid growth of the industry, accelerating the drop in water reservoir levels [60]. We did not find any study that evaluates the actual impact of removing water for bottling on the health of ecosystems. While further research is needed to fill this knowledge gap, a recent modeling study that compared different strategies for meeting the drinking water needs of the city of Barcelona estimated that using entirely bottled water would result in approximately 1400 times more species lost per year compared to using tap water [56].

On the other hand, the activities of the bottled water industry can provide local environmental benefits, as seen in a comprehensive study in France that analyzed bottled water samples representing 70% of the local market. The rarity of contaminants indicates that aquifers exploited for bottling are better preserved compared to less protected groundwater reservoirs [61]. This is because companies that bottle natural water have an interest in protecting these reservoirs from pollution at their own expense, even if government legislation does not require them to take any action. However, these positive effects are only local, benefitting individual catchment areas, and do not extend to other water resources.

4.3. Societal Impacts

4.3.1. Human Health

Health concerns associated with bottled water consumption are related to the quality of the source water, the type of container, and the storage conditions.

Various recent studies have investigated the transformation of contaminants of emerging concern (CECs) in water [62,63,64,65]. CECs are newly identified anthropogenic-source contaminants, including pharmaceuticals and personal care products (PPCPs), bisphenol A (BPA), phthalates, alkylphenols, perfluoroalkyl and polyfluoroalkyl substances, and microplastics [62]. CECs may enter the environment through industrial, domestic, and agricultural runoff waters or through the overflow of wastewater treatment facilities.

While the impact of most of these substances on human health is not entirely clear at this point, evidence suggests that they are potentially harmful, with possible carcinogenic, teratogenic, and mutagenic effects and reproductive developmental toxicity [66]; in addition, they may disrupt the normal functioning of gut microbiota [67] and the endocrine system [68].

Human exposure to such substances is widespread, as a significant share of industrial food and beverages is delivered, stored, and consumed in various types of plastic containers. Differentiating between substances that enter the body via drinking of bottled water and those that were consumed with food, let alone attributing a specific pathology to bottled water consumption, is nearly impossible.

Contaminants from Source Water

Roughly 98% of all bottled water sold in Europe is either natural mineral water or spring water [69]. However, as mentioned earlier, in 2020 nearly 60% of all bottled water sold globally was purified tap water, not spring or natural mineral water [27]. Therefore, bottled water may contain any of the contaminants occasionally found in public drinking water. These include organic contaminants of natural origin in aquifers or surface water (such as, geosmin, methylisoborneol, isopropyl, methoxypyrazine isobutyl, and methoxypyrazine) or of anthropogenic origin (such as from pipelines, municipal sewage treatment plants, agriculture, or transport, including microbiological contaminants, pesticides, aromatic hydrocarbons, and amino acids) [70].

A recent study that tested for the presence of 187 pharmaceuticals and personal care products (PPCPs) in various brands of bottled water worldwide identified 44 compounds belonging to 14 PPCP categories in 56 of the 68 bottled water samples [66].

A 2008 study compared the bacteriological quality of Brazilian municipal tap water to bottled water in 20-L bottles for water dispensers. The municipal tap water was superior to water samples collected from the water dispensers, and even to samples collected from new bottles before installation in the dispensers. Of the tested bottles, 77% were contaminated with at least one type of coliform or indicator bacterium and/or at least one pathogenic bacterium, compared to 36% of municipal tap water samples [71]. In similar research performed in Nepal in 2016, all municipal tap water samples and most of the bottled drinking water samples tested were contaminated with one or more types of indicator organisms. In the Nepalese case, however, the bottled drinking water was found to be safer to drink than the tap water [72].

Contamination from Packaging

Contaminants originating in the chemical composition of plastic bottles are often found in bottled water. Contamination type and concentration depend on the container type [62] and storage conditions, which affect the rate at which the chemicals leach into the water [73,74,75]. A Chinese study analyzing the ten most popular bottled water brands in Beijing for the presence of phthalate esters concluded that their release from PET bottles into water could be mitigated by avoiding high temperatures, long storage times, and UV radiation during storage [76]. Unfortunately, most consumers are unaware of the conditions in which water bottles are stored prior to purchase, and cannot estimate the cleanliness of the water.

Various substances are added to plastic in the process of bottle manufacturing. For example, synthetic organic chemicals (the phthalates BBP and BPA) improve flexibility, transparency, and durability. These substances are known to disrupt normal human hormonal activity. Another example is Sb₂O₃, a catalyst used in PET manufacturing, from which antimony (Sb) leaches into the water [73,75,77].

With glass bottles, the main source of contaminants is the cap, which is either plastic or metal. Guart et al. [78] found that glass bottles with metallic crown caps caused migration of alkylphenols into the water. A German study that tested three bottled water brands found lead concentrations 26 to 57 times higher in water packaged in glass bottles compared to water packaged in PET bottles [79]. Santana et al. [80] suggested that phthalates may migrate into water from the PVC seals of glass bottles. Overall, however, water in plastic bottles tends to be more heavily contaminated than water in glass bottles [62].

A Greek study that tested six different bottled water brands for the presence of endocrine-disrupting compounds (BPA, nonylphenol, tert-octylphenol, and others) found low levels (below the maximum safe dose) in all brands [81].

In a Chilean study, 30% of bottled water samples were found to contain arsenic in amounts exceeding those permitted by Chilean, WHO, and US EPA regulations [82]. In Turkey, arsenic was found in certain bottled water samples at levels exceeding EC and WHO standards, in certain cases up to three times higher [83]. In Iran, certain samples of bottled water had levels of nitrates exceeding national and US EPA standards [84], and in Germany almost 5% of samples exceeded German and/or European limits for one or more of the following elements: arsenic, nitrate, nitrite, manganese, nickel, and barium [85].

Microplastics

Microplastics are contaminants of which awareness has been growing in recent years. They appear to be ubiquitous in both aquatic and terrestrial ecosystems [86] and in the body organs of humans and wildlife [87]. Though there is no internationally recognized definition, we take them to be “a heterogeneous mixture of differently shaped materials referred to as fragments, fibers, spheroids, granules, pellets, flakes or beads, in the range of 0.1–5000 μm” [88]. Most microplastics in the environment are derived from the degradation of larger plastic debris.

Microplastics have been identified in all aquatic environments, both marine and fresh water (lakes, rivers, reservoirs, groundwater); however, investigations focusing on drinking water are rare [89,90]. Microplastics have entered the food web, and are becoming an emerging food safety issue [90]. Human exposure pathways include ingestion and inhalation, and the presence of microplastics in human stool samples [91] and human blood [92] has recently been verified. Numerous studies in recent years have examined the presence of microplastics in various food products, including beer [93,94], table salt [95], and seafood [88]. Total human exposure to microplastics through food, drink, and inhalation ranges from 74,000 to 121,000 particles per year, depending on age and sex [96].

Drinking water is one possible medium of exposure to microplastics [97]. A recent systematic review reports that in all reviewed studies between 92% and 100% of bottled water samples tested positive for microplastics. The most common polymers identified in drinking water samples (both tap and bottled water) were PET and polypropylene [90].

According to Cox et al. [96], “individuals who meet their recommended water intake through only bottled sources may be ingesting an additional 90,000 microplastics annually, compared to 4000 microplastics for those who consume only tap water”. In 2018, researchers from the State University of New York examined 259 samples of bottled water; 93% showed signs of microplastic contamination, roughly twice as many as in tap water [98,99].

When comparing microplastic contamination in water sold in different types of packaging, wide variance was found between water sold in plastic bottles (single-use and returnable), beverage cartons, and glass bottles. While all the examined water contained microplastics of 5 to 100 µm, the composition varied by the type of container [89]. Water from single-use plastic bottles contained a mean of 14 particles per liter, while water from glass bottles contained 50 particles per liter. There were eight times as many plastic particles in water from returnable plastic bottles compared to water from single-use plastic bottles. Smaller particles (<5 μm) were found in much greater numbers: 2650 particles per liter in single-use PET bottles and up to 6290 particles per liter in glass bottles [100]. Schymanski et al. [89] suggested that the high number of microplastic particles in glass bottles could be due to the production, cleaning, and refilling of reusable bottles.

The impact on human health of the consumption of microplastics and nanoplastics is somewhat unclear as of yet [101]; the literature presents inconclusive and contradictory findings. For example, based on exposure estimates and the total mass transfer of small molecules (such as additives and oligomers), Welle and Franz [102] concluded that the reported microplastics amounts found in mineral water did not present a safety concern for people of any age. Hwang et al. [103] came to a different conclusion when considering that direct contact between polypropylene microparticles and cells might cause health problems by inducing the production of cytokines by immune cells. Prata et al. [104] maintained that with the predicted increase of microplastics in the environment, more studies are needed to fully understand the risk to human health, which requires knowledge of human exposure, pathogenesis, and other effects.

4.3.2. Equity and Justice

Related to the health and environmental impacts discussed in the previous sections are questions of equity and social injustice. These questions concern the contrast between the people who benefit from the bottled water industry (‘winners’) and those who suffer or pay for its negative impacts without gaining any benefit (‘losers’). Beneficiaries include the shareholders in the industry, the manufacturers, and other organizations, such as communities and people who are involved in the businesses of bottling and selling bottled water to consumers and who earn money from it. Other beneficiaries include those who choose to buy and consume bottled water. A relatively small group of affluent people can afford bottled water, while the environmental impacts of the industry, such as waste, pollution, and GHG emissions, as well as the costs of dealing with these externalities, are shared by all.

The losers are those who are not interested in or cannot afford bottled water, who nonetheless bear the negative impacts (for example, paying higher municipal fees for waste management), along with those who are exposed to the health impacts without consuming bottled water themselves. Other losers include the local communities living near the water resources, who sometimes experience environmental damage that harms their livelihoods, and those who do not live near the spring or water source but whose access to it (as either an income source or a recreational destination) is compromised, such as in the Siprianos case in Texas (Supreme Court of Texas, 1999; Thompson et al., 2018). Ethical dilemmas come into play in cases where bottled water companies are interested in water sources located near towns suffering from economic decline, and the residents are torn between the employment opportunities offered by the company and the need to preserve their local environment and maintain water access, such as in the case of a small town close to Mount Shasta in Siskiyou County, California [20].

When disputes arise between environmental advocacy groups or local residents and a bottling company over the pumping of water, often (and depending on the state’s legislation) the plaintiff has no standing in court [20]. One example is the lawsuit against Nestle Waters North America submitted by residents of Mecosta County, Michigan, in an attempt to prevent Nestle from constructing a new bottling facility and to limit the amount of groundwater that could be extracted. The suit was denied by the Supreme Court of Michigan, as the residents did not have riparian rights and could not prove that their aesthetic or recreational enjoyment of the waters were harmed as a result of the pumping [20,105]. When it comes to disputes, the inequality between global bottled water corporations and local communities or environmental groups is evident in the amount of resources each party has available. Large and often multinational commercial companies have substantially more financial resources and more sophisticated legal teams [20].

In certain situations, bottled water is the only way to provide people with the basic human right of healthy drinking water, for example, in places where the quality of tap water is bad due to poor infrastructure [35] or contamination, such as the case of lead contamination in Flint, Michigan, in 2014 to 2019 [106]. Notably, in 2015, nearly 21 million people in the US relied on community water systems that violated health-based quality standards [107], and approximately 25% of US residents (77 million people) were served by water utilities that violated at least one of the Safe Drinking Water Act (SDWA) requirements [108]. Racial, ethnic, and language vulnerability had the strongest relationships with most indicators of weak compliance and enforcement of the SDWA, including length of time out of compliance [109,110].

However, the practice of relying on bottled water for clean water supplies over long periods of time has been criticized as reducing the pressure on the government to fix its water infrastructure by treating the symptoms rather than solving the problem [2,111].

Bottled water is significantly more expensive than tap water. In Israel, for example, the average cost of 1 m³ of tap water is around USD 2.44, which is roughly the on-trade price of 500 mL of bottled water (around USD 2.38). Thus, bottled water costs roughly 2000 times as much as tap water. The high price consumers are willing to pay for bottled water drives many of the big bottled water companies around the world to engage in a constant search for new water supplies and the purchase of water rights from farmers in rural communities [111]. In South America, for example, foreign water corporations have bought vast wilderness tracts and even whole water systems to hold for future development. In a few places, bottled water companies have dried up whole ecosystems far beyond the boundaries of their own land [112]. The appropriation of public water supplies by private entities raises social justice concerns when local users are displaced and public resources are commoditized [113]. These concerns are even more salient in cases of water exported from less affluent areas, which may be deprived of vital water resources for the ‘convenience’ of affluent consumers elsewhere [112].

A widely researched and reported example is FIJI Water. Established in 1997, FIJI bottled water is extracted, bottled, and shipped from Fiji. The water comes from an artesian aquifer in the Yaqara Valley on Fiji’s main island, Viti Levu. FIJI Water has promoted its water with the slogans ‘untouched’ and ‘every drop is green’, and has won international success, especially in the US market, with numerous celebrity endorsements. All this stands in contrast to frequent claims of environmental, social, or political harm to the local surroundings and communities due to the company’s operations [114].

5. Conclusions

In his 2009 book Shopping Our Way to Safety: How We Changed from Protecting the Environment to Protecting Ourselves, Andrew Szasz argues that the use of bottled water by those who can afford it is an example of “inverted quarantine”, wherein by purchasing what they perceive as “healthy” products people attempt to isolate themselves from a dangerous environment all around them. Concerns over tap water quality are often implicitly promoted by the bottled water industry [24,111]. According to Szasz [2], one implication of inverted quarantine is that by switching to bottled water people feel protected from risk, and can stop worrying about the quality of tap water. This “political anesthesia” reduces the public pressure on policymakers to spend more resources on tap water infrastructure and treatment. The result is often weaker enforcement of public water regulations, which in turn further pushes people to consume bottled water in cyclical fashion. It seems, however, that in recent years the political anesthesia surrounding environmental problems in general and plastic pollution in particular may be gradually wearing off.

The growing awareness of the cumulative negative impacts of bottled water has pushed the industry to voluntarily improve its standards. As mentioned, it has improved significantly in terms of material consumption, energy efficiency, GHG emissions, water footprint, ecosystem protection, and more [40]. However, these voluntary steps are not enough to adequately protect the environment.

Challenges remain in regulating the industry to ensure that its various negative environmental and social impacts are minimized, externalities are internalized, and the “polluter pays” principle is implemented throughout the value chain. There is a need for stricter regulations along the different stages of the product life cycle of bottled water, from stricter protection of water sources and their surrounding ecosystems to tighter regulation of material consumption, production, storage, and waste management. Efforts to promote stricter regulation of a powerful multi-billion-worth industry such as that of bottled water often face strong opposition from the industry as well as its beneficiaries, stakeholders, and lobbyists.

Regulating the industry is not enough. In places where tap water is of good quality, trust in the public water supply must be improved. Guidance through education, nudges, and social marketing could influence consumer water consumption patterns and promote a shift to more sustainable options such as tap water and reusable bottles.

Several local and regional governments have in fact begun initiatives to reduce bottled water consumption in their jurisdictions. These actions include limits on the purchase of bottled water by public funds, bans on bottled water at public events, and taxes on the sale of bottled water. In the last few years more than 100 American cities have adopted measures to restrict government spending on bottled water, and bans have spread to national parks and universities [115]. San Francisco has been leading the way, for example with a 2014 city ordinance banning the sale of single-use plastic water bottles on properties owned by the city. Although San Francisco often “takes the limelight”, Concord, Massachusetts, was the first place in the United States to ban the sale of bottled water completely, which it did in 2010 [116]. Such regulations, which are opposed by a powerful industry sector with a strong lobby, can only work if they are supported by the public.

It has been suggested that banning bottled water might backfire. A study at a university campus examined the effect of banning bottled water on the consumption of other bottled beverages [117]. The unintended consequence was a significant increase in sales of sugar-free and sugar-sweetened beverages. This outcome is worrisome because bottled water is better in terms of its health and environmental impacts than these other bottled beverages.

Mainstreaming the norm of free tap-water provision in restaurants and bars is another strategy for reducing bottled water consumption. A 2017 survey in England by the environmental nonprofit Keep Britain Tidy asked people about their habits regarding water consumption in restaurants and bars; 71% of respondents felt uncomfortable asking for free tap water without buying something else, and more than a third (37%) felt awkward asking for it in a reusable bottle even if they were making a separate purchase [118]. Thus, consuming tap water in public places is not yet the prevailing or socially accepted norm. This might change in EU countries with the amended Water Directive EU 2020/2184 [119], which encourages the free provision of water in public administrations and buildings and allows the charging of a small serving fee in restaurants, canteens, and catering services. Not all countries have such legislation.

These observations suggest that in order to be effective, any initiatives to reduce bottled water consumption need to offer free and easily accessible alternatives and be bolstered by an informational campaign. To illustrate this, in the summer of 2019 San Francisco banned bottled water in SFO, the city’s international airport. The new policy prohibits the sale of single-use plastic bottles by shops, restaurants, lounges, and other retailers, including vending machines. Instead, passengers are encouraged to bring their own containers and refill them with filtered water at roughly 100 “hydration stations” around the facility [120].

This overview has presented the most current research available on various aspects of bottled water, underscoring the complexity of bottled water as a multidimensional phenomenon that carries long-term environmental implications and potential health risks. Despite this industry’s drawbacks, its growth is driven by powerful economic motivations, meaning that bottled water is unlikely to disappear in the coming decades. Therefore, we conclude that actions to reduce its impacts should focus on stricter regulation and on the provision of sustainable, affordable, available, and trusted alternatives. Technological innovation and the development of new environmentally friendly processes and materials is another promising path, and funding should be allocated towards research and upscaling of such initiatives. Finally, our knowledge about health impacts is insufficient, and many gaps remain in our knowledge of the full life cycle of bottled water as a product. Most recent studies have been carried out by or for industry. Transparent research conducted by impartial organizations or academia would permit a more comprehensive understanding of the interplay between economy, environment, and society in the bottled water industry.