Treading water

Given that we have just emerged from the wettest June on record since Met Office records began in 1905, it may seem ironic that the latest buzzword, “water footprint”, is forcing many companies to take a long, hard look in the water tank and take stock of their use of water.

Our carbon footprint has become solidly entrenched in our environmental consciousness, so much so that the term has now become ubiquitous in the fresh produce industry. But while companies are frantically calculating the extent of their carbon emissions, how many have stopped to consider the impact of their water usage?

The public is bombarded with environmental messages by the media, and has surely in the midst of these managed to glean some idea of how important it is to save water, whether the phrase “water footprint” is widely recognised or not. We all use water to drink, wash and clean our homes - but this volume is minimal compared to the water used to produce the food and goods we purchase.

Around 70 per cent of global water usage is employed for agricultural purposes, and the manufacturing and horticultural industries are also large-scale consumers of what many are starting to realise is a precious resource.

A global trend towards centralisation and a rapidly rising population are certainly not easing the problem. Some estimates suggest that the human population could leap from 6.8 billion in 2010 to 9.4bn in 2050, compared to 1.7bn in 1900.

“The global human water footprint increases as the population’s demand for food and goods increases, and there is a major global transition from traditional consumption patterns to those previously seen only in Europe and North America,” says Louise Manning, who was awarded a 2007 Nuffield Farming Scholarship to study water quality and quantity and its impact on food production. “This will increasingly impact on water usage and availability.”

Professor John Moverley OBE, chief executive of the Royal Agricultural Society of England, posed a pertinent question at the Chartered Institute of Marketing’s recent Food, Drink and Agriculture Group seminar: “Will water be the new oil? Globally, great changes are taking place in the supply and availability of clean water. The UK distribution infrastructure is in need of major improvement to ensure supply meets demand.”

Government statistics predict that the UK population will increase from 59.8 million in 2004 to 67m by 2031, predominantly in England. But the breakdown of UK water usage does not reflect that of global application at all, with 75 per cent pegged for industrial use, 22 per cent for domestic and three per cent for agricultural purposes. “As the human population rises, this could potentially put pressure on the agricultural industry in areas where water supply is limited compared to demand,” says Manning. “A nation’s water footprint can be internal, meaning within national boundaries, or external, as goods and services are imported. Some 70 per cent of the UK’s water footprint is external, demonstrating the great degree of dependence we have on the water resources of other nations to produce food, clothing and manufactured goods for us.”

According to www.waterfootprint.org, “the water footprint of an individual or community is defined as the total volume of fresh water that is used to produce the foods and services consumed by the individual or community. A water footprint can be calculated for any well-defined group of consumers, including a family, business, village, city, province, state or nation. A water footprint is generally expressed in terms of the volume of water use per year.”

The UK’s footprint per person per year is pegged at 1,245m3, according to the website. The Environment Agency, which determines water availability in England and Wales, highlights the South East and the Thames Valley as regions offering the lowest water availability per person in the country. “As the population rises, and if there is more amenity demand for leisure activities, availability will reduce even further, and in areas such as the South East this could become unsustainable in the long term,” says Manning. “If we were to manufacture all the goods and produce all the food we consume in the UK, we would barely have enough water available. Rainfall is not evenly distributedacross the UK and in areas such as the Thames Valley, the sheer number of people living in the region - something like 13m inside the M25 alone - means availability per person is significantly reduced.”

The virtual water content (all the water it takes to grow, process and pack something) of a bag of crisps stands at 32 litres, compared to 50l for an orange, 70l for an apple and 40l for a slice of bread.

“The key issue for fresh produce is whether the water being used and/or evaporated is rainwater (what we call green water - rainwater stored in the soil as moisture) or irrigation water (blue water - surface and ground water) which is abstracted. The volume of water that is used does not all get recycled back into the water system it came from, for example if food is then exported to other countries,” says Manning.

“The same produce being grown in different countries may have a very different blue/green ratio, and this ratio is environmentally relevant for the produce industry, because the impacts of blue and green water use are very different on the water cycle. Many people in the UK are only just beginning to talk about water footprint, and the stats available are quite general at the moment. However, we hope that we can hone this down as the industry starts to scrutinise its footprint a little more closely,” she adds.

While the water footprint may be a relatively alien concept in the UK, certain parts of the world are already taking action with regard to this issue. Drought-ridden Australia is a prime example. Here, water availability is being closely analysed, especially the differing requirements of rural and urban locations. “The Australianpopulation generally livesaround the coast, wherehistorically there has been more water available, but food tends to be grown further inland, where water supplies are much scarcer; so it is a question of determining how to manage scant supplies effectively,” says Manning.

One of the major controversies surrounding water as a valuable resource is the question of ownership. “Is it a public good, or a private one?” asks Manning. “In the US, this has been an issue for hundreds of years, and in Utah, for example, whilst the water is seen as a public good, the right to use water is regulated, i.e. a private good. At the moment, much of the mid-west of the US is suffering from severe water shortage, and in some areas this has led to increased water extraction from rivers. Around the globe, many rivers cross national boundaries, and one of the issues that can arise is that farmers upstream extract water, thereby posing problems for farmers downstream in their own, or indeed a different, country.” The World Wildlife Fund, in its report World’s Top Ten Rivers at Risk, highlighted the Rio Grande river as being subject to high levels of evaporation, extraction and damming at various points along its flow, as well as increased demand from urban areas and increased salination,and this has hada major impact on water quality.

In 2005, water was rationed for domestic use in over 50 per cent of Spain as a result of drought. Irrigation, which accounts for three-quarters of all water usage in Spain, was also heavily restricted in order to meet domestic demand.

“The recent UN report, entitled The State of World Population 2007: Unleashing the Potential of Urban Growth, stated that every week the number of people living in cities in Africa and Asia increases by approximately one million,” says Manning. “Asians and Africans are adapting their lifestyles, with more and more moving from rural to urban locations, sopeople who have been consuming food produced by themselves or their local communities have now relocated to urban areas and are becoming even more reliant on othersto produce their foodstuffs, which are becoming more western in nature. As people look to horticulturalists and farmers to provide their nutrition, farming often becomes more intensive and therefore localised water usage escalates.”

Globally, this results in regions where there is a huge imbalance between water demand andwater supplyin terms of both quantity and quality. “As we import moremanufactured goods and foodstuffs, we are reliant on those exporting countries managing their water availability and quality effectively,” says Manning.

With major parts of the UK still under water following the torrential rainfall of two weeks ago, it may seem that the prayers of some UK growers for an end to one of the driest winters on record have been answered. But Manning is quick to point out that this is not automatically the case. “Aside from the fact that some crops havebeen more or less completely washed away, and that some growers cannot get equipment onto the sodden fields, the rainwater will only be of future use to farmersif they have managed to capture it in reservoirs. But the likelihood is that the majority of itis eventually going straight back to the sea,” she explains.

“In response to the recent flooding, there has been a fair amount of talk about developing local agreements in the future to let farmland bear the brunt of the floods to save town centres further downstream - but this is only speculation at the moment and there would obviously have to be some kind of financial benefit for the farmer.”

But going forward, UK producers will undoubtedly be obliged to look at ways they can overcome the sporadic rainfall which has become the norm these days. “Although in a number of areas we are receiving the average rainfall per annum we would expect, it is not at all consistent - we seem to be going through very dry spells, followed by very wet patches,” says Manning. “Being unable to effectively manage irrigation systems is such a limiting factor for fresh produce firms, and fluctuations in rainfall need to be overcome.”

One way farmers are trying to combat this is by building reservoirs on their land, so they have a constant supply to hand. “As well as treating water as a valuable resource, there are benefits for farmers in identifying potential areas of water wastage, as if these can be addressed they can in some cases lead to significant cost savings,” says Manning. With mains water in some areas now costing over £1 per m3, water costs are escalating, but businesses can rarely pass on this cost to the price of the final product. “Businesses paying to dispose of waste water have to pay when the water comes in and also when it goes out.”

While some fresh produce farms in the UK are installing reservoirs, others are looking at water recycling systems, according to Manning, while many have also started collecting rainwater. “The water utilised in the packhouses has to meet defined microbiological standards, but rainwater can be used to fulfil domestic purposes, for example to flush toilets in packhouses and offices,” she says.

Retailers are also starting to see the benefits of a water-friendly policy, and back in March, Morrisons announced the implementation of a rainwater harvesting system at its new headquarters in Bradford. The high-durability, custom-made gutters from GutterMaster ­- more than 400 linear metres of aluminium gutters, soffitts and aerofoil fascias on the roofline - are set to boost the sustainability of the building, which spans three floors and provides a working area of 331,000sqft. The system constitutes one of the largest rainwater harvesting schemes in the UK.

Water from the roof is captured and transferred to tanks in the basement. After filtration to remove debris, the water is then made available for toilets and other domestic uses in the building, saving the needless use of metered, treated mains water. “Harvesting rainwater is a modest investment that has a rapid payback and continues to make savings long into the future,” says architect Michael Hellawell.

Manning explains that water footprint calculations are quite involved, but if a company wants to address water efficiency, the first thing to do is to identify current water usage and then monitor on an ongoing basis to see how muchwater is used and implement measures, where possible, to identify leaks and reduce any other wastage.“A firm looking to improve its efficiencies will ultimately always be looking at the bottom line, and water is a cost that needs to be considered,” says Manning.

Applying a wetting agent, or surfactant, to a soil bed or plant substratecan significantly reduce water usage for a fresh produce company, according to Daniel Wilkinson, managing director of plant nutrition firm Hortifeeds.

Wetting agents overcome water movement problems associated with water repellency, or hydrophobia. They are chemical compounds whose molecular structure is well suited to overcome both the water-repellent characteristics of hydrophobic soil profiles and poor infiltration of water.

Hortifeeds’ technical manager, Terry Grimshaw, says: “Horti-Wet ensures the whole of the soil profile is wetted, and that soil does not repel water application. When water is added through a dripper, it tends to go straight down, whereas with a wetting agent, the feed liquid moves sideways too, wetting the edge of the bed as well. Water is spread better to more catchment roots and the need for frequent watering sessions is reduced. The labour required to water fresh produce is also expensive, and Horti-Wet can help firms save on this kind of cost too. It effectively means growers are not over-watering areas or using too much water to flush out salts.”

Wilkinson adds: “Horti-Wet tackles these difficulties for a wide range of crops, but is especially beneficial for soft-fruit growers. Two years ago, Stuarts of Tayside applied the system, as the firm was having problems wetting its plant beds. Growers reported back to us that after just one application, they were easily able to wet up their whole farm.

“Horti-Wet has been available for a few years now - our original market was compost manufacturers who traditionally apply a wetting agent to their product, but then we also decided to start targeting growers, who are increasingly aware of the need to save water to help reduce costs. Water is a much larger input for the industry than it used to be.”

Grimshaw explains how a second Hortifeeds product, Fytocell, can also help reduce water usage for substrate growers. “Fytocell is a flaked foam substrate, frequently employed in UK greenhouses for tomatoes, cucumbers, peppers and strawberries,” he says. “At the moment it is produced in the Netherlands, but we are about to build a Fytocell factory here in the UK, and then we will target the domestic strawberry market in a big way.”

Fytocell enables an even wetness from top to bottom of a plant grow bag, meaning growers can irrigate accurately without expensive run-off. “Fytocell is made of an easily wetted cellularmaterial, ensuring very even levels of wetness,conductivity and pH throughout the whole bag root zone,” says Grimshaw. “It is pleasantly soft and light to handle, and plants root into the foam very easily. It can also save on fertiliser costs, as using it ensures fertilisers are not washed away through excessive watering.”

Growers are becoming steadily aware of the need to save on water usage, as new legislation has come into force and water costs are being pushed up, says Grimshaw. “Fresh produce growers no longer have the luxury of wasting water,” he adds.

Along with availability, the quality of water is a further pressure growers will be forced to address.And Manning warns that the quality of available water in the UK may also deteriorate in the future, if we begin to rely increasingly on ground water supplies pumped from boreholes, where salt levels may vary, or on river systems, where we need to consider upstream sources of pollution or contamination.

“Recent incidents with microbiological contamination of producemeans that the issue of water suitability will beon the radar more than ever now,” she says. Many fresh produce farm assurance standards already define standards for water supplies, and certifications such as the LEAF Marque standard also require farmers to conduct a water efficiency audit.

The EU has been typically quick off the mark and already implemented legislation to address water pollution. The Water Framework Directive addresses the management of river systems and basins and the pollution pumped into them. Member states are obliged to prepare river basin management plans by 2009.The directive also states that all inland waters within defined river basin districts must achieve good ecological status by 2015. “Farmers who are irrigating their land from rivers will increasingly be affected by this legislation, which requires that ‘overall principles should be laid down for control on abstraction…to ensure the environmental sustainability of the affected water systems’,” says Manning. “Water management planning is currently, and will continue to be, a key requirement for fresh produce companies, so that they ensure water is free from microbiological or chemical contamination, is used efficiently and maximises crop yields. Fresh produce organisations need to define a baseline, i.e. how much water they are using, which is currently a requirement of many farm quality assurance standards anyway, and determine if there is any potential for saving, conserving or recycling water and developing action plans accordingly.”

It is tough to assess right now if water footprint will become as pertinent an issue in the UK as carbon footprint, as in some ways that will depend on the media attention it receives, says Manning.

“Potentially it could become more of an issue, as a result of the unintended consequences of carbon footprint. If we start to grow significant amounts of our future fuel requirements, then there will be less land and water available, and less water for agriculture, industry and manufacturing. Ultimately, water rather than fuel could become the limiting factor to growth population and development. But for businesses, water footprint is a major issue right now, because water is a cost, and that cost is rising, and if a business depends on water and its availability then any shortage will end up impacting on its viability.

“In some areas of the world, the effects of not sustaining valuable water supplies are clearly already being felt,” adds Manning. “For fresh produce companies, in the UK or otherwise, forewarned is forearmed, and you must all pose yourselves two questions. Firstly, are you getting your water from a source that will be sustainable in the mid to long term? And, most importantly, could water availability ultimately limit the growth of your business?”

Food for thought as we look back on a year of fruit and vegetable production that has so far fallen foul of some very unusual behaviour from this valuable element.

ISRAELI PROCESS DEWY-EYED

A low-tech method to turn dew into fresh, useable water has been developed by two architects at the Technion-Israel Institute of Technology in Haif.

Inspired by the dew-collecting properties of leaves, the invention can extract a minimum of 48 litres of fresh water from the air each day.

“Depending on the number of collectors, an unlimited supply of water could be produced even in remote and polluted places,” the inventors claim. Their invention recently won an international competition seeking to make clean, safe water available to millions around the world. As noted in The Jerusalem Post, the invention, called WatAir, is the brainchild of Technion’s architecture and building planning graduate student Joseph Cory, and his colleague Eyal Malka.

WatAir is an inverted pyramid array of panels that collect dew from the air and turn it into fresh water in almost any climate.

According to Cory, WatAir can be easily incorporated into both rural and urban landscapes because it has a relatively small base. Its vertical and diagonal design utilises gravity to increase the collection area. The panels are flexible and easy to collapse when not in use, and provide shelter from rain and heat.

The project was selected from 100 entries from North America, Europe, Africa and Asia as the winner of the ‘drawing water challenge’, sponsored by Arup - a global firm of designers, engineers, planners and business consultants specialising in innovative and sustainable design.

“WatAir is a wonderful, simple concept which draws its inspiration from nature,” says judge José da Silva. “This is a simple and effective idea using tried and tested technology.”

HERBS GO POTTY FOR CELCOTE

Reducing a plant’s actual demand for moisture has benefits for fresh produce growers that go further than just preserving water, including reducing disease risk and improving shelf life of plants. But the benefits also stretch to supermarkets and to the end user.

Growing fresh herb pots for supermarkets under 21 acres of glass, Humber VHB began a trial with dry water management additive Celcote, from Certis, with the main objective of improving shelf life.

Celcote works by coating the fibres of the compost, improving the ability to absorb and retain water, and just as importantly, allowing it to be released when required.

Simon Budge of Humber VHB, pictured, oversaw the trials, and discovered herb pots were more able to cope with dry conditions. “Although we haven’t had a major problem of pots drying out, where Celcote has been added it has meant the problem has been avoided altogether, and pots are able to withstand less frequent watering,” he says.

“We have also been able to maintain the growth rate and quality of the plants while using Celcote, because watering is more controlled,” explains Budge.

“We have seen that it has the potential to increase the shelf life of our produce,” he adds, commenting that Humber VHB would like to carry out further trials with Celcote.

Alan Horgan, technical adviser for Certis, explains the knock-on benefits to supermarkets and consumers. “Growers have found that they have the ability to grow bigger, stronger plants with reduced watering and watering frequency, and provide the end user with a better quality product,” he says.

“Because growers can also hold back growth by manipulating the watering regime, they can tailor production to suit the needs of the customer,” he adds. “But the real benefit is the improved shelf life that using Celcote offers. If herbs grown in Celcote-treated compost are watered just before they leave the nursery, they will remain in top condition for longer, meaning that shelf life in the supermarket will be improved, leading to increased selling opportunities and less wastage.”