Plant & Works Engineering
Water reduction in manufacturing - a commercial no-brainer
Published:  18 January, 2021

Ian Hart* sets out the many benefits – commercial and otherwise – of reducing water consumption in manufacturing and argues that businesses should adopt an altogether different approach to a precious resource that will come under increased pressure in the years ahead.

When we talk about the environment, we tend to limit the conversation to climate. The planet is warming and, unless we change our ways drastically, we’re going to have to get used to more extreme weather events, melting icecaps and rising sea levels.

Water issues, at least as far as the discourse in the UK goes, are more concerned with the prospect of it gushing through our homes than with any sense that the taps might ever run dry. But, while that outlook is understandable in a country so resigned to interminable rain as the UK, demand for the elixir of life could well outstrip supply inside 25 years, according to the Environment Agency.

In averting such an outcome, it is fair to say that we all have to do our bit. But, looking at things purely from a commercial manufacturing perspective, it strikes me that radically reducing and recycling the water we use in our processes and cleaning regimes is the obvious choice.

So obvious that I’m not sure why we discuss it so little or, indeed, why the idea didn’t gain more traction here a very long time ago.

Surmountable problem

Climate change is not the only or even main threat to the UK’s water supply. Our population has grown year-on-year from 56 million in 1982 and is projected by the Office for National Statistics to increase from today’s 66.4 million to over 70 million by the end of the decade.

Combine the dynamics of our population with the fact that our individual usage has risen from around 85 litres per day in the 1960s to 143 litres each today and you get an idea of the experts’ concerns around water scarcity. It is clear we have a problem to resolve but the good news is there are ways and means.

And, while the public would do well to limit their consumption too, there is a strong commercial case for manufacturers, particularly those in a food and drink industry that uses so much water, to reduce, recover and reuse.

Multiple benefits

Imagine for one moment that you were able to reduce the aggregate amount of water used in production processes at your facility by 25%, for the sake of argument. Not only does your bill for bringing it in reduce commensurately but so do the costs you face under the Mogden Formula for getting rid of it.

Think about further cost reductions, when you do the same with your cleaning regimes and then begin to recycle 50% of the water used for production and incorporate it into youwashdowns and other services. The savings alone would soon more than justify any investment in getting you to that point but it doesn’t end there.

It’s a big potential PR win, you find it easier to comply with intake and discharge regulations, your supply and, therefore, your production is more secure, you reduce your effluent stream, and you’re helping safeguard the nation from a looming water security crisis.

Changing attitudes

Such a broad set of benefits begs a question – why aren’t all UK manufacturing businesses taking serious steps to conserve water already, when they are well ahead of us in a number of other countries? Elsewhere, there are places that are much more water-stressed and, as a result, they are much more conscious of how precious a resource water really is.

In parts of Africa and India, for example, many manufacturers treat their wastewater and inject it back into the ground in a process known as ‘managed aquifer recharge’. Instead of depleting local water tables and damaging local harvests, they bank the water to ensure the farmer down the road using a borehole has everything he needs to irrigate his crops.

In Britain, however, where we usually experience rain all year round, we seem to think water is free and unlimited. It just falls out of the sky, so, if we pour our wastewater down the drain, who cares? It’s no longer our problem. Wastewater isn’t technically an externality, as companies bear costs in dealing with it, but they don’t seem to want the hassle of treating it. So, I’d argue, we need a change in mindset, whereby we understand that water is scarce and start treating it that way. The benefits to us all of doing so are plain to see.

Cyclical thinking

If a manufacturer is committed to water conservation and to securing the cost, regulatory and reputational wins I described earlier, the first step is to engage an expert partner to conduct a water audit that has two parts.

First, they come in and establish how much is being used, whether it’s being used effectively and to identify any opportunities to reduce consumption. And second, they then determine how you can integrate any further processes that enable you to recover and reuse a significant proportion of the water you do use.

While we’re not restricted by law in this country and there’s no technical reason it cannot be perfectly safe, the guidance is that you shouldn’t reuse recovered water in food production – imagine the headlines if a soft drink manufacturer, say, was revealed to be using wastewater to make their fizzy pop.

But there are plenty of other uses wastewater can be put to, including putting it through an anaerobic digester to clean it up and to harvest the biogas by-product to feed back into your boilers and other processes for further energysaving benefits. That way, you begin to create a cycle of reuse and of benefit. And that’s how we need to change our thought process about water. It is not a throughput. It is as integral to our operations as it is to the future of humanity.

Water is everything. As the central ingredient in the cycle of life, it sustains us in every way, so we should treat it with more care. And, if we do, we can all be winners in the end.

*Ian Hart is business development director at adi Projects, a division of the multidisciplinary engineering company, adi Group