November 16, 2022
Although studies traditionally focus on carbon footprint and fossil fuel use, drinking water is a very scarce commodity that is receiving increasing attention.
Our planet contains 1,386 million cubic kilometers of water, not in vain we call ourselves the blue planet, but of this large amount only 35 million cubic kilometers (2.5%) is fresh water. However, not all fresh water is available for human use or potable, it is estimated that only 0.3% of the total water on planet Earth is available for use by humans and animals. There is official data stating that only 0.007% of the Earth's water is potable (a small figure of 97 thousand cubic kilometers) and the figure is decreasing year by year due to pollution.
Water sustainability is important to maintain the scarce resource of drinking water and we can assess our impact using the Water Footprint indicator.
The water footprint is defined as the "total volume of water used to produce the goods and services consumed by an individual, a group of people or a country, respectively". And here the key word is total, i.e. it includes production water, but also cleaning water, cooling water, or even water used to obtain the raw materials or energy we need.
If we think about it for a moment, that's a lot of water.
In Spain, the average water consumption is 132 liters per day. This is above the 50-100 liters of water that the World Health Organization (WHO) considers necessary to guarantee the coverage of the basic needs of any person. It is in the productive processes, especially in agriculture, which represents 80% of the total water expenditure.
As in everything, the first step is to propose it and become globally aware of our consumption. This is usually the first and most difficult step to take.
When we think of our products, the first thing that comes to mind is to make products without water in their composition, but we can do more.
For example, using washing methods that minimize water consumption, i.e., removing debris dry and recycling it properly. Absorbing grease with paper or sawdust before washing helps on the one hand to use less water and detergent, but also reduces the polluting potential of gray water (I will explain later what gray water is), since a single liter of oil is capable of polluting about 1000 liters of water, according to the most conservative estimates. The effect is amplified if solubilizing substances such as detergents and soaps are present in the water.
It is also advisable to use manufacturing methods that do not require a water circuit for cooling or that minimize water intervention , as well as water-independent energy sources, such as solar or wind energy, which help to reduce this impact.
We can go even further by choosing raw materials that have a low water footprint, i.e. that do not require large amounts of water to obtain. This is especially important in the case of vegetable products, where cultivation and irrigation techniques are key. As we have said, it is estimated that 80% of potable water use goes to agriculture and livestock, so improving irrigation techniques and performance is fundamental to reducing the water footprint.
As always, having a good supplier that shares our philosophy and values is key to achieving our objectives.
Once water is used, what happens to it, and is it a recyclable resource? Water is naturally recycled in what we call the water cycle. Even water used for drinking by animals returns to the environment and is "purified" by the action of the soil and geological agents. The water cycle in nature is a closed cycle.
Humans have opened this cycle, altering the water we use and not purifying it sufficiently before returning it to the cycle. This is why the percentage of available drinking water is decreasing every year.
Blue water is drinking water that comes from snowmelt (rivers) or from subway sources. Green water is water obtained from rainfall and used before it becomes part of wastewater. Gray water is water that has already been used in production or domestic processes.
The gray water footprint is one of the most important indicators, since it is the value resulting from calculating the amount of water needed to dilute the pollutants until the water is clean enough to pass the quality controls established by law.
Therefore, in our daily life we can use products that do not pollute the environment, so that when they are to be treated with greywater, the amount of water needed to return it to the cycle will be less. If we also use biodegradable products, the bacteria and enzymes used in the greywater processing plants will be able to do their job well and eliminate them from the environment.
Also use rainwater as much as possible before it goes into the wastewater system, whether for watering, cleaning or any other purpose.
We must be aware that water purification systems are not able to remove some synthetic substances such as medicines or some detergents used for laundry. But also natural products can eutrophicate the water (increasing the available carbon sources and causing algae to proliferate uncontrollably).
The way to know if the ingredients contaminate is to check their safety data sheet. There you will find all the information related to the ecotoxicity of each substance. ECHA also periodically reviews its reports and ecotoxicity is one of the pillars of its analysis.
With all this perspective, it really seems that we cannot completely eliminate our water footprint. It probably wouldn't be necessary either, as the planet has many mechanisms for controlling and buffering impacts. But we can try to reduce it so as not to saturate these systems and lend a hand to the planet in its efforts.
A future with clean drinking water is possible and it is everyone's business!
AQUAE Foundation (12/22/2021) How much potable water is there on Earth?
Find out more about Celia Campos, Technical Director and co-founder of MuttuLab, author of this article.
Learn how we work at MuttuLab.
