Coca-Cola is the world’s most popular soft drink brand, selling 1.8 billion bottles of Coke sodas, waters, and fruit juices daily.

To produce all those drinks, Coke bottlers use more than 79 billion gallons of water a year—roughly the amount of water that pours over Niagara Falls in a 30-hour period. Water not only is the main ingredient in each bottle or can of drink produced but is also essential to their manufacturing processes, particularly in the cleaning and rinsing of equipment. “If we don’t have water, we don’t have a business. That’s pretty obvious,” says Paul Bowen, the Coca-Cola Co.’s director of sustainable operations.

Which helps explain why Coke has become a global leader in using a variety of proven, highly engineered technologies and efficient production techniques to drastically reduce its consumption of freshwater in a world where that commodity is scarce and getting scarcer. Advanced technology also allows Coke to be bottled and sold in parts of the world with substandard water purification systems.

The United Nations says an estimated 783 million people worldwide lack access to clean water. River basins are slowly drying up, and climate change, population growth, and pollution are depleting Earth’s groundwater sources, according to the World Bank. Coke lists water as a major ingredient under stress in its annual financial report to the Securities and Exchange Commission.

Wake-Up Call

Coke faced a consumer backlash in 2004 and had to close a plant in India over accusations (since rejected by a court) that the facility was siphoning water from a local community during a drought. The company made water management a priority and cut its consumption. In 2016, Coke announced that it was on track to meet its goal of reducing use of water in manufacturing by 25 percent by 2020, using 2010 as a baseline. It has already reduced the amount of water needed to make one liter of soda to 1.98 liters, which means 0.98 liters are used in the manufacturing process. By 2020, it expects to bring the total down to 1.7 liters. (View the company’s 2017 Sustainability Report and latest Sustainability Innovation initiatives.)

How is Coca-Cola accomplishing this? There is no secret formula involved. Rather, the company mainly relies on off-the-shelf technologies from outside suppliers—technologies that are also in wide use among other major beverage makers. There’s even a 20-member technology- and best-practices-sharing trade group, the Beverage Industry Environmental Roundtable (BIER), that Coke cofounded in 2006 “to advance environmental sustainability within the beverage sector.”

Nevertheless, Coke itself doesn’t have a one-size-fits-all approach to water conservation. That’s because it’s also a heavily franchised operation, wtih more than 250 bottling companies at more than 900 plants. The Atlanta-based parent company sets the water-use standards, and it’s up to each bottling franchise to determine how best to meet them in its plants.

Different strategies

Richard Crowther, a mechanical engineer who was Coke’s former director of environment and sustainability and is now a senior consultant for environmental consultants Antea Group USA, says aquifers are typically stacked, and communities in developing countries usually use the ones closest to the surface. That gives Coke space to drill more deeply, often thousands of feet, to find separate sources that don’t cross-feed into the community aquifers. For each of its plants, Coke does a Source Vulnerability Assessment every three to five years that looks at a number of issues, including susceptibility to drought, potential for contamination, pricing structure, and legal requirements. Each plant must then submit a Source Water Protection Plan that helps it devise efficiency, water treatment, and wastewater treatment programs.

Returning water

Those plans are also instrumental to Coke’s replenishment program. Last year, the company announced that in 2015 it not only met but exceeded its goal of returning to communities or nature an amount of water equal to the amount of product it produced. Between 2014 and 2015, it returned—either directly to sources used to manufacture drinks, or to areas outside those watersheds—some 50 billion gallons of water, or 115 percent of the water contained in its beverages that year, mainly via efforts like reforestation and reestablishing wetlands.

Dry wash

Efficiency can include a variety of things. Identifying and fixing leaks, for instance, can go a long way toward cutting water use. The conveyor belts in plants are metal, and many plants have switched from soap-and-water-based lubricants to dry lubes that are silicon-based and use no water. Some plants now use air instead of water for rinsing packaging. And Coke has worked with manufacturers of fillers, the machines that fill cans and bottles, to design them so they can be rinsed with less water. Bottlers often reclaim and reuse some of the water to clean mixing tanks.

Water treatment

Much of the technology used in plants is for treating water—both incoming water and wastewater. All water flowing into a plant is treated by the bottler, even potable water from dependable municipal sources. That’s because the water used to make drinks has to be as pure as possible to avoid altering the flavor. The rule of thumb for all beverage plants is that, after treating incoming water, 80 percent will be usable for products and 20 percent will be rejected because it’s full of concentrated contaminants. (That ratio can range from 90/10 for plants receiving highly treated water to 70/30 for plants whose sources haven’t been pretreated.) The rejected water, however, can be further treated for non-beverage uses, including cleaning, feeding cooling towers, and flushing toilets.

In the United Kingdom, a bottling plant in Wakefield, West Yorkshire, installed a membrane ultrafiltration system, a pressure-driven purification process that gave it a tenfold reduction in wastewater generation. It was developed by Norit Membrane Technology, a Dutch company. Some 250 Coke plants use a chemical-free water disinfection system that uses ultraviolet light, fiber optics, and hydraulics that was developed by Israeli company Atlantium Technologies. Fiber optics enable UV light to be sent long distances by reflecting it and using it over and over again. The system can be used to remove pesticides and bacteria, but also chlorine, which would make the beverage taste terrible.

The most complex—but important—step in cutting water use in beverage plants  is production process design, basically industrial engineering. For example, each beverage requires a separate line – which takes time and water to clean, rinse, sanitize, and cool down every piece of equipment whenever the bottler swaps flavors. By bottling all the Coca-Cola needed for the entire month on one line run, say, plants can raise productivity and save water.

This feature is excerpted from Thirsty Giant, by Thomas K. Grose, Prism’s chief correspondent, based in the U.K. It ran in the September 2017 issue of ASEE’s Prism magazine. Click HERE for the full article.

Filed under: Special Features

Tags: ASEE Prism magazine, Coca-Cola, Conservation, Environmental Engineering, Industrial engineering, Technology, Thomas K. Grose, Water Resources