Her point is that water is part of an endless cycle, and she argues that because water is continuously renewable, you cannot sensibly use water footprints as an environmental measure. Water is only going to become totally unavailable if it is “irretrievably polluted” or becomes part of a glacier which will exist for thousands of years. The leather industry suffers problems with water calculations lazily thrown up in opposition to both, keeping livestock and making leather.  Where the water exists, how it is used – and fits within its mini system – and how much gets returned to the system are all relevant. When cattle were first blamed for using too much water, the figures used were inflated by including water used for irrigating feed crops in desert climates, and this figure generalised to all cattle. When people complain about livestock consuming water, they are almost exclusively talking about this grain irrigation. It is neither accurate science nor useful to use water footprints as an environmental measure, and even less so when those who are involved in animal rights and aggressive vegan promotions deliberately pick isolated elements to build into their narratives.

According to Thornton, we should instead watch to see whether specific abstraction is too high, so depleting an aquifer if irrigation is balanced for the system it is part of, and whether all users are properly considered in a water zone. Tension around the world is obvious here if we consider that some 1.4 billion people live in river systems, where more is being taken out than being replenished, and cities like Jakarta are quickly sinking as a result of groundwater exploitation.  

For tanneries, we need to think about water that we use and the water that we consume, as they are different things. Both figures are important. Water use is the water that we take from municipal supplies or natural sources for all purposes, including cooling and cleaning. Even if half this water gets returned to the original source, quite quickly the tannery still needs it to run and while using it is depriving someone else of it, which may be significant in certain locations. The water that is consumed is that which is not returned, and this is most obvious in irrigated agriculture that accounts for 70% of water use worldwide. Almost 50% of that irrigation water is lost, either evaporated into the atmosphere or transpired through plant leaves (World Resources Institute). In the tannery, finished leather at around 14% moisture content contains less water than hides and skins at the start, and evaporation normally occurs only when we reach effluent lagoons (this can be considerable in some climates), so most of the water we use should be available to return after suitable treatment. 

All this should happen with a full understanding of where a plant’s water originates and where the effluent ends up. Because of the problem removing common salt from the effluent, a significant proportion of tannery waste water ends up in the sea, so will only return after evaporation as rain or via expensive desalination. Using less water and managing it carefully is important for all tanners, but very much so if you are using large quantities that are ending up in the sea.

One of the issues we cannot ignore is that a tiny fraction of tanneries in the world consider cleaning this used water to acceptable levels to be someone else’s responsibility or choose to deliberately ignore the law. Hopefully our global industry can start to focus on this rogue element and bring it to a stop. We have worked hard as an industry over the last few decades, and to have our image tarnished by these few is intolerable, and quite unacceptable for the tannery workers and the environment who suffer.

Dr Mike Redwood

April 10, 2019


Follow Dr Mike Redwood on twitter: @michaelredwood

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