Environmental campaigner Hemantha Withanage is adamant that the purchase of plastic-bottled water should be discouraged.
“Damage from plastics is irreversible,” the chair of Friends of the Earth International tells the BBC.
“Once fragmented into microplastics, it pollutes all of the ecosystem including the oceans and the air we breathe, with no way to recover them.”
The bottled water industry raises strong emotions from its opponents, who like Mr. Withanage point to the environmental impact of all the waste plastic.
And, with only 2.3% of bottled water coming in glass bottles, there is a lot of plastic.
In the US alone, 50 billion plastic water bottles are purchased every year, according to one report. The study adds that only 9% of plastic bottles sold globally are currently recycled.
The industry counters that today’s bottles, made from polyethylene terephthalate (PET), are 100% recyclable. And increasingly they are made from already recycled PET in the first place.
Others point to bottled water being healthier than sugary soft drinks. And then there were the recent scandals about contaminated tap water in the US.
What is certain is that the global bottled water sector continues to boom. The industry is expected to enjoy revenues of $324.4bn (£266bn) this year. And that number is tipped to jump to $419.9bn by 2029.
This growth is being led by sparkling water, sales of which are more than doubling.
More from the BBC’s series taking an international perspective on trade.
Simon Oldham, joint managing director of Scottish bottled water brand Highland Spring, confirms the increased demand for the fizzy version.
“During the pandemic, sparkling water in particular saw strong growth, as consumers sought out low/no alcohol drinks that kept them hydrated and offered versatility,” he says.
Mr Oldham adds that the overall increase in sales of bottled water “has been driven by an increased health and wellbeing awareness… with consumers seeking healthy choices and alternatives to both sugary soft drinks and alcoholic beverages”.
Jill Culora, vice president of communications for the US-based International Bottled Water Association, says that for many people bottled water is a health necessity.
“For many economically developing countries, bottled water serves as a partial solution when safe drinking water is not available,” she says. “Many countries have not built the necessary public water distribution systems. For those countries, bottled water is often their only source of safe water.
“Bottled water is also available in times of emergencies and natural disasters because the bottled water market is strong and viable throughout the year. Sometimes, water from tap water systems can be compromised after emergency situations or natural disasters.”
But in the developed world, what is wrong with tap water for the vast majority of people? “Nothing,” says water expert Cristina Villanueva.
An associate research professor at the Barcelona-based Institute for Global Health, she has spent years researching water. Ms. Villanueva thinks that there is likely one significant factor behind the continuing boom in bottled water sales.
“The publicity and marketing of the bottled water industry, and [by contrast]a lack of publicity for public water supplies, probably has a main role, at least in countries like Spain,” she says.
She adds that while health authorities have a duty to ensure that mains water is safe, they would do well to be more transparent. More information about water quality would help ease people’s concerns, she says.
Regarding bottled water specifically, Ms. Villanueva says with much coming from natural springs, she is concerned that these sources “are prone to overexploitation” – that too much water is being extracted.
Simon Oldham says that is definitely not the case at Highland Spring, which comes from the Ochil Hills in Perthshire. “We extract no more than 3% of the rain that falls on our catchment, ensuring the long-term sustainability of one of the planet’s most valuable resources for generations to come,” he says.
“We are also very fortunate that Scotland’s climate has high levels of rainfall throughout the year.”
For anyone concerned about the quality of their tap water, an alternative to buying bottled water is to use a home water purification system, such as one fitted under your sink, or the filters that slot into dedicated water jugs.
This is also a booming global sector, with one recent report predicting that it will more than double from $22.6bn last year to $50.7bn in 2029.
In Israel more than three quarters of the country’s drinking water now comes from desalinated plants on the Mediterranean coast. Other countries such as Saudi Arabia and the United Arab Emirates are also heavily reliant on desalinated water, which tastes very flat and lifeless.
To improve the flavor of this water, and to help remove the chlorine, the Israeli firm Mayu makes a water jug system called “Swirl”. This includes a 1.5 liter glass carafe that sits on top of a porcelain base unit.
The latter is battery-powered, and when turned on it creates an oxygenating spiral motion in the water in the carafe, which is said to improve its taste.
Mayu users can also buy a mineral blend to add to the water to mimic the flavor of their favorite bottled water, and to return the nutritional value.
Shay Eden, a co-founder at the company, says that the technology also improves tap water in Europe and the US. “In some European cities, the average age of the pipes [in the last mile to people’s homes] is over 75 years old,” she says.
“Unfortunately, this means that many contaminants are dissolved into the water during its journey before reaching the glass.”
Back in Barcelona, Cristina Villanueva says “there is no one solution that fits all”. “You have to consider the options whether it’s bottled, tap, or filtered water, taking into account the specific issues where you live and decide your personal choice.”