What is Your Water Footprint Color?

It is an indisputable fact that water is an indispensable part of our lives. But this is not just because we need to consume (2 liters per day) in order to sustain our life or use it for hygiene purposes.

From the computer you are reading this article, to the coffee you sip (apart from the water used during the brewing of the coffee), water is used during the production or cultivation of every product we use and consume. When we add the amount of water used during the production and cultivation of the products we use to the amount of water we use daily, we find our water footprint.

What is a water footprint?

The Water Footprint consists of 3 components: Blue water footprint, green water footprint, and gray water footprint. While the blue water footprint represents the surface and underground fresh waters used during the production or cultivation of the product, the green water footprint represents rainwater used during these processes, and the gray water footprint represents the amount of freshwater polluted during the production and cultivation process. For example; the amount of water required to obtain one kilogram of beef is about 15,400 liters, 94% of this water is green water footprint, 4% is blue water footprint, and 2% is gray water footprint.

In the average of the data collected between 1996 and 2005, it has been determined that the global water consumption, that is, the annual water footprint of the world, is 9,087 Gigametres (1 Gm3= 1,000,000,000,000,000,000,000,000,000 m3). Of this amount of water spent, 74% is green footprint, 11% is blue footprint, and 15% is gray water footprint 2. Agricultural production constitutes 92% of this huge pie.

Considering the change in consumption habits and population since those years, it is safe to deduce that the global annual water footprint has increased considerably. To support this thesis, we can present the information that the amount of water required for the production of each of the chips, which are the backbone of technological tools, is approximately 8300 liters.

Virtual Water

Now we know that water footprint is a concept that includes both the water we use directly in our daily lives and the water used in the production of the products we use, which we, as the end-user, do not see. This water consumption, which the end-user does not see, is called "Virtual water". The concept of virtual water includes the water used during all production stages of a product. E.g; if we consider coffee: The amount of virtual water used in the process from the beginning of the cultivation of the coffee plant to the preparation of a cup of coffee by the end-user is approximately 140 liters, while the direct water used throughout this process is only one cup (approximately 250ml).

John Anthony Allan, the inventor of the “virtual water” concept; wondered why the war or civil unrest, which was expected to break out due to water shortage in the Middle East, did not occur and he started research on this subject. As a result of his research, he discovered that despite the water scarcity of the countries in this region, they were able to survive with their large-scale food product trade. In the light of this discovery, he realized that these countries imported not only these products, but also the water used during the production of these products, and he coined the concept of virtual water.

Virtual water is included in trade not only in countries with water scarcity but also in all international trade. It has been calculated that the average annual virtual water flow during the trade of industrial and agricultural products between 1996 and 2005 was 2,320 Gm3. 68% of this virtual water is green, 13% is blue, and 19% is gray water footprint. Although virtual water flow is essential, especially for countries experiencing or in danger of experiencing water scarcity, when the figures between 1996 and 2005 are examined, a larger portion of the water footprint due to water flow consists of blue and gray water footprints. In other words, with international virtual water trade, surface and underground water resources are both used more and polluted more.

While our water resources are gradually decreasing, we will soon be faced with the danger of both production problems and scarcity of drinking water, as we are growing our water footprint together. Since it is obvious that international trade or the production of electronic goods cannot be stopped, it seems that there is not much that can be done to reduce our water footprint, but it is possible to reduce the global water footprint with the measures to be taken during the production phase and on an individual basis. 

Measures that can be taken individually are quite simple. First of all, it is essential to be sensitive about water saving. In addition, we need to avoid unnecessary shopping. To give an example to show how much difference this can make; the water used to produce a t-shirt is approximately 2,720 liters (54% green, 33% blue, 13% gray water footprint), while the water used to produce jeans is 10,850 liters (45% green, 41% blue, 14% gray).

Treatment technologies are at the forefront of the measures that can be taken during the production phase. By the use of purified water and sludge cake, obtained by dewatering the wastewater generated during the production phase, in different areas, sustainability can be achieved. Purified water can be used in irrigation. The obtained sludge cake can be burned after processing to obtain biogas. In addition, the ashes formed as a result of incineration can be used in the chemical industry.

Written by Ugurkan Bozkurt, Marketing Assistant Specialist | Polat Makina