As we all know leather production uses a vast amount of water. Our water footprint as an industry is big and is probably one of the largest if you take into consideration the husbandry of the animals. Knowing your water footprint is important for establishments so they can adapt their business models and improve resource efficiency. This can lead to the reduction of greenhouse gas emissions and lets policy makes better understand the relationship between economic activity and natural resource use. It happens time and time again that companies do not look at the full picture. They only focus on what they directly use, they need to look at the bigger picture. The whole supply chain affects you, everything amounts to your footprint even if it’s not directly in your tannery. This can include almost everything from packaging, transport to the final product. This is a message Stahl has been projecting across the industry for the last year.
Water footprint explained:
Water footprint definition: A calculation of all the direct and indirect use of water involved in the manufacture of products or services. The calculation can be done for a nation, a factory, or an individual.
Blue water footprint: The amount of surface water and groundwater required (evaporated or used directly) to make a product.
Green water footprint: The amount of rainwater required (evaporated or used directly) to make a product.
Grey water footprint: The amount of freshwater required to mix and dilute pollutants enough to maintain water quality according to certain standards (like the ones established in the US Clean Water Act) as a result of making a product.
The correct ISO calculation must be used. You need to measure the consumption and divide the total by the unit output, to get the consumption per unit of; blue, green and grey water. Indirect water is often referred to as virtual water and has to be factored into the footprint.
Virtual water: When services or goods are sold/moved the direct water use moves with it. Getting another country to process it for you means that the water is still used and needs to be included in the footprint calculation.
Correct procedures for effluent are key to overcoming water footprint. Recovery and reuse of water in your effluent can save you thousands of litres in your tannery. Water reduce and be done with lower floats and with the use of alternative chemicals; acetone, iso-propanol to name a few. There are also new technologies involving bead technology which help reduce floats.
“Will there one day be a way to tan leather without the use of water?”