What Is the Water Footprint? Why Should We Care?

In daily life, we usually think of water simply as what flows from the tap. When we talk about the water footprint, however, we consider the total amount of freshwater used throughout the entire life cycle of a product or service—from production to consumption. This includes not only the water we see and use directly, but also the “hidden” water embedded in the production chain.

If we look at it simply, the water footprint can be examined in three categories:

• Blue water: Water withdrawn from surface waters such as dams, lakes, and rivers, or from groundwater sources.

• Green water: Rainwater that infiltrates the soil and is used by plants; it plays a crucial role in agriculture.

• Grey water: The amount of clean water required to dilute pollutants generated during production to acceptable environmental standards.

To give a few examples:

• One cup of coffee: cultivation + processing + transportation of coffee beans ≈ 140 liters of water

• One T-shirt: cotton cultivation + dyeing + processing ≈ 2,500 liters of water

• One slice of bread: wheat cultivation + milling + baking ≈ 40 liters of water

• One pair of jeans: cotton cultivation + yarn and fabric production + dyeing and washing + transport and use ≈ 7,000–10,000 liters of water

The water footprint helps us understand the invisible water consumption that often goes unnoticed. This awareness, in turn, encourages more sustainable choices, starting from our individual consumption habits.

Water Footprint in Biotechnology

Laboratory

• Purified water production: Producing 1 liter of deionized water can generate 2–3 liters of wastewater.

• Sterilization and cleaning: Washing glassware, autoclaves, and fermenters consumes large amounts of water.

• Cooling: Especially in older systems, continuously running tap water is often used.

Industrial Production

• Fermentation: Carbon sources used to feed microorganisms (such as sugars and starches) come from agriculture and therefore carry a high water footprint.

• Cleaning processes: Industrial fermenters and pipelines are washed with thousands of liters of water after each production cycle.

• Cooling: Large-scale production requires vast amounts of water to reduce reactor temperatures.

• Wastewater (grey water): If biological and chemical wastes are discharged without proper treatment, they create an additional environmental burden.

How Can It Be Reduced?

In the Laboratory

• Using recycling technologies in purified water systems (reusing wastewater for technical cleaning).

• Switching to closed-loop cooling systems.

• Operating autoclaves and washing processes at full capacity to avoid unnecessary repetitions.

In Industrial Production

• Developing biocatalysts that operate at lower temperatures and with less water.

• Reusing cleaning water through filtration systems.

• Implementing dry or low-moisture fermentation technologies.

• Applying biological wastewater treatment methods.

Strategic Approach

• Identifying which stages have the highest water footprint.

• Shifting toward environmentally friendly solutions such as green chemistry and biosurfactants.

• Selecting agricultural raw materials from drought-resistant crop varieties.