Water is in many ways a poster child for circularity. For the last 3.8 billion years, the earth’s stock of water, a constant 1.4 billion km3, has continuously circulated through the many stages and processes of the hydrological cycle, powered by the energy of the sun. In the last hundred or so years, a blink of an eye in planetary time, human activities have started to disrupt this well-tuned circularity in ways that risk our future prosperity as well as the health of the planet.
Water is a remarkable substance. Its apparent simplicity belies its raft of peculiar properties, many of which are crucial to life on earth. These idiosyncrasies include the fact that its solid state – ice – floats on its own melt (insulating any life beneath it); its boiling point is much higher than similar hydrogen compounds (so it exists at a liquid within a temperature range ideal for life); and it dissolves more substances and stores more energy than any other liquid (making it an extremely useful medium for many of life’s processes). Water’s strangeness not only supports the processes of life, but is a major constituent of it – a new born child is 75% water. Perhaps oddest of all, water in its purest form (two atoms of hydrogen and one of oxygen) is hypertonic: if imbibed, it will strip the water out of your cells and could kill you.
“Water water everywhere, nor any drop to drink”
We live on a blue planet, but most water is not in a form or a place that can fulfil easily the basic needs of humankind. The great majority of it is seawater – only about 2.5% is freshwater and most of this is out of reach, locked up in icecaps, glaciers or deep underground. The actual percentage easily accessible to us is more like 0.007%. Luckily, this is a small fraction of a very large number, so there is in fact more than enough volume to meet the needs of the human population. The challenge lies in managing this water well.
In many areas of the world this challenge is not being sufficiently met, leading to a multiplicity of lost opportunities and negative impacts. These consequences inevitably become more severe as the level of economic development reduces.
In 2014, a drought in California led to the loss of 17, 000 part-time or seasonal jobs and $2.2billion in agricultural revenue. In the UK, leakages from the water network is equivalent to 20% of the nation’s water supply or 21.5 million people, thereby increasing the cost of providing water. During a recent dry period in Sao Paolo, low rainfall and polluted reservoirs meant daily shut-offs to urban water supply, electricity prices to rise by 80% and businesses to scale down or even close. In China, a major problem relates to the contamination of surface water and groundwater by industrial effluent, driving water scarcity and creating a significant public health risk. It is estimated that 11% of cases of cancer of the digestive system may be attributable to polluted water.
However it is the poor who suffer the most extreme consequences of inadequate water resources. In many African countries, people must walk for many hours each day to fetch water from sources that are often contaminated. This task often falls to women who are vulnerable to attack, or to children compromising their education. Poor quality water causes illness, leading to a loss of work productivity and requiring expensive treatment. Worse still, according to the UN, water or waterborne diseases lead to the deaths of over 3.4 million people per year, the majority of these deaths are children under the age of five. The rising severity of consequences as economic levels fall offers a good illustration of the paradox: the poorer you are the more you pay for things, relatively speaking.
Considering all of this it is easy to understand why the World Economic Forum cites “a global water” crisis as the biggest threat facing mankind in the next century.
Therefore we should ask whether the circular economy, a new framework for thinking about the economy that has already helped identify potential solutions to other big global resource challenges, could contribute to creating a better relationship between people and water: one that is resilient, regenerative, and works in the long term.
What is water exactly?
Before considering more deeply the application of circular economy thinking to water, it would be useful to first define what water is. As well as being a complicated substance, it can play several roles in a circular economy.
Firstly, water is of great significance from a natural capital standpoint, with the aquatic environment – lakes, rivers, wetlands, groundwater and seas – of real economic importance. So the circular economy link here is about preserving and enhancing this natural capital. Rather than continually degrading water sources, regenerative practices should be applied to the parts of the natural water cycle under human management.
Secondly, water is a resource. It’s a ‘catalytic good’, a critical requirement for energy production, industrial processes and agriculture. So we need to find a way to decouple economic growth and development from consumption. Essentially, we need to use water without using it up. This means that production processes should be designed to maintain effective water cycles.
Finally, water is sold as product. After undergoing high levels of refinement to become tap water or bottled water, it immediately becomes wastewater or sewage following its consumption. How could we circulate water at its highest value and eliminate the concept of ‘waste’? The answer could lie in extracting valuable materials, nutrients and energy from wastewater before it is cycled back into another use, or returned safely to the natural water cycle.
Drivers of change
The way we use water could be described as linear: we extract it upstream, apply expensive treatment processes to it, ‘use it’, then apply more expensive treatment processes before discharging it downstream. This system has numerous inefficiencies, leakages and malfunctions that have detrimental effects on the health of people and the environment. We should re-consider our current model and explore transitioning to a more circular one for several reasons:
Supply risks – a growing global population that is increasingly urban means demand for water is increasing at 2% a year. A quarter of cities already suffer water stress. By 2040 global demand could exceed supply by 50%.
Economic damage – the World Bank has identified many regions where water shortages could hold back economic growth. In India the cost to the economy of inadequate water and sanitation is estimated at 6.4% of GDP.
Structural waste – the way we currently use water is often ineffective. Agriculture accounts for 70% of global freshwater withdrawals, yet only 40% of this water reaches plants. The water that water-stressed Mexico City loses each year from leaky pipes is enough to supply the whole of Rome.
Degraded natural systems – 20% of the world’s rivers no longer reach the sea. In 2014, river levels were so low in California that 27 million young salmon had to be trucked to the sea. Half the world’s rivers and lakes are polluted by sewage. Dead zones caused by nutrient run-off are a common feature of coastal areas. Water pollution causes on average 250 million cases of disease each year.
Climate change risks – weather is set to become more unpredictable as global temperatures rise, leading to more intense rainfall in some areas and increased droughts elsewhere. The 1 in 100-year weather event will in future occur every 3 to 20 years.
Regulatory pressure – UN Sustainable Development Goal number 6 aims “to improve water quality and substantially increase safe recycling and re-use”; China’s Ten Year Plan aims to improve water management and safeguard the aquatic environment; Corporate Water Disclosure guidelines, increasingly adopted by large companies, evaluate the impact of corporate operations on global water resources.
Technological advances – smart sensors combined with big data analytics enable companies, building managers and city authorities to manage water more effectively. New resource recovery technology allows a wider range of useful materials to be extracted from wastewater.
New business models – in the future utilities could not just purify, deliver, collect and treat water, but could also extract and sell resources from wastewater. Wastewater plants could become bio-refineries accepting a wide variety of organic materials converting them to useful products. They could also sell ‘performance’ in the form of water conservation equipment and manage watersheds.
Looking at water through a circular economy lens
Although the vision for water in a circular economy needs further exploration, there seem to be a few obvious ideas that could immediately be applied to our relationship with water.
Apply systems thinking – water resource management should be approached with a holistic and systemic mindset. An example lies in the management of land in catchment areas for water sources that serve cities. It is estimated that improving farming practices on just 0.2% of such land around the world would improve the water quality of 600 million city dwellers. Such an approach is often cheaper than building expensive water treatment plants, but also improves the health and livelihoods of rural communities and habitats. Regenerative agriculture is another example of systemic thinking applied to water: between 1993 and 2013, the heavily degraded land on a 5,000-acre farm in Dakota showed a 30-fold increase in its water infiltration rate and a fourfold increase in its water storage capacity, as well as a plethora of other benefits, as a result of a farmer whose predominant focus was increasing the organic content of his soil. In Brazil, sugar cane farmers Leontino Balbo completely eliminated the need for irrigation by adopting ecosystem revitalising approach.
Move to closed loop systems – attempts to retain water resources in the system allowing it to be used again and again. Closing the loop invariably generates additional benefits beyond just reducing water consumption. An illustration of this is Mission Industry, one of the largest laundry companies in Las Vegas. A decade ago the company decided to address its huge water demand, equivalent to about two Olympic swimming pools per day, by installing an $800,000 in-house treatment system. The new plant recycles the water from the initial washing cycle and uses it in the subsequent rinse cycle, leading to a 30% reduction in overall water usage. A secondary benefit is that heat is retained in the recycled water, eliminating the need to raise the temperature of the rinse cycle water. Furthermore, the higher temperature of the rinse cycle opens up the pores of the sheets and towels, reducing the length of the final drying stage. By addressing its water usage, Mission has also significantly reduced its energy demand. This has enabled it to pay back the cost of the plant in two years and reduce its operational costs from 40 to 30 cents per room, helping it stay competitive in a volatile market.
Closed loop water systems can be full or partial and work at all scales:
- City scale – 30% of Singapore’s water demand is provided by recycled sewage
- Industry scale – the Pearl gas-to-liquid plant in Qatar recycles 450,000m3 of water a day, equivalent to 50% of the total demand of the country.
- Building scale – the Solaire building in New York recycles 750,000 litres per day of its wastewater. This reduces water demand by 50%, water discharge volume by 60% and significantly lowers the building’s energy demand.
- Product scale – Aquafresco, a Boston-based start-up has created an appendage to a washing machine that recycles 95% of its water and detergent
Extract cascaded value – if the resources in sewage could be valorised, then wastewater treatment could shift from a liability to a profit generating ‘resource factory’ creating a variety of useful end products. It would also have a positive impact on the future availability of freshwater resources, as even where water is not scarce it is often unusable due to pollution by untreated sewage. ‘Cascaded value’ is a concept used when referring to biological nutrients in the circular economy. When applied to wastewater, it refers to the process of extracting value at a series of stages beginning with high value products such as specialist chemicals, followed by fertilisers, energy, water and bio-solids. This final product is critical to closing the loop and contributing to regeneration of nutrients in the planet’s soils. Technologies for extracting high value materials are still being developed, but energy and nutrient recovery from wastewater is quite well-established. To illustrate the potential of energy recovery, VCS, a utility in Denmark, has built a wastewater plant that produces 110% of the electricity required to run its processes, with the excess electricity sold back to the grid.
Understand embedded value – millions of gallons of water go into the products we buy, use and throw away. A better understanding of ‘embedded water’ (also known as ‘virtual water’) would allow us to appreciate the true cost of products and materials. This in turn empowers us to make better decisions about how we make and use things, including the best locations to produce them. For example, a reusable cotton diaper requires 800litres of water to produce compared to 600litres for a disposable one. Assuming the reusable diaper is washed 30 times, using 20 litres of water for each wash, it would have a life cycle water consumption lower than the disposable diaper by a factor of 13. The retention of embedded water value is well-illustrated in Renault’s Choisy-Le-Roi remanufacturing plant near Paris. Rather than manufacturing injectors, gearboxes and turbo compressors from raw materials, the plant collects old automobile parts and re-manufactures them. This results in an overall water saving of 88%, high quality parts that are 30-50% less expensive for customers and a very profitable operation for Renault. At a country level, the hidden and vast movement of water in products and crops around the world is sometimes referred to as ‘virtual water’. It has been estimated that India, already water stressed in many regions, each year exports 38 billion cubic metres of virtual water just in its cotton exports. This is equivalent to 85% of the demand of its entire vast population. By modifying the way it produces the cotton, for example using more efficient irrigation techniques and being more targeted with the use of fertiliser and other inputs, this amount of virtual water could be decreased by a factor of three.
Moving to a circular economy of water is about synchronising with and then optimising natural water cycles rather than a shifting to new paradigm. Nature already circulates water effectively and has processes that regulate flow, maintain high quality and insure against drought. By using nature as a mentor and applying circular economy principles such as systems thinking, closed loop systems and retention of value, it should be possible to avert the water crisis that many predict and secure an abundant, resilient and regenerative water future for all.