“Water is vital to life and livelihoods. Without water, there is no wildlife, no economy, no food, no power, no health, and no society.” So begins the opening line of the National Framework for Water Resources 2025 published 17 June. The Environment Agency paper sets out the pressure on the country’s water supply. Rapid population growth, water hungry data centres, crumbling infrastructure and climate change mean the UK could run out of clean drinking water by the middle of the next decade. To quote the report: “The scale of the challenge is unprecedented.”
Drought risk is on the rise and with it the risk to food security. Rainfall across East Anglia in May was below average. With a dry start to the month, the soil moisture deficit increased across the region although the rains at the end of the month slightly improved the situation.
“Farmers can’t grow food without water,” says Andrew Blenkiron, managing director of Elveden Farms, “and too many are already seeing the effects of climate volatility year after year.”
Major infrastructure overhaul in the water sector is essential. Without investment, national water supplies will remain under threat and new homes simply cannot be built. For the first time in more than 30 years, the UK government has stepped in to fast-track the construction of new reservoirs, two in East Anglia, and has plans for new desalination plants. Currently the only major desalination plant in the UK is at Beckton, on the River Thames. A temporary desalination plant will facilitate the building of Sizewell C nuclear power station.
Anglian Water’s desalination plans
To augment water supplies from aquifers and reservoirs, eight desalination plants are proposed in the east and south of the UK by 2046. Anglian Water says it is “making progress” with plans to build the first of three desalination facilities in the East Anglia region by 2040. Bacton, on the north Norfolk coast is scheduled to be the first site.
A tender process has been conducted to find contractors for the scheme and for another in Lincolnshire. The contract would be worth £700mn for both projects.
Bacton’s desalination plant will be a flagship project. Anglian Water has promised to deliver it as part of a £103mn investment to improve north Norfolk’s infrastructure over the next five years.
However the plant will not be built “anytime soon”, says Gregg Tufts, regional engagement manager for Anglian Water. Speaking at a North Norfolk District Council (NNDC) overview and scrutiny committee meeting, Tufts warned it will be a “long-burn project”.
Desalination technology
Desalination is one the world’s oldest forms of water treatment, converting salt or brackish water to freshwater. Traditionally water is boiled and the condensation collected. But this is inefficient and expensive on a large scale.
The industrial process was developed at Glasgow University in 1960. Today there are many large-scale desalination processes. The most common system is reverse osmosis. Pressure is applied to the salt water in such a way that it passes through a semipermeable membrane. This separates the salt from the water.
Research continues into more innovative processes and especially mechanisms which use cheaper, renewable energy, such as photovoltaic energy.
The costs
“The flows from desalination are complementary but never substitutes for water from the aqueduct for economic and environmental reasons,” explains Joaquín Melgarejo, director of the Water Institute of the University of Alicante. He suggests that water from a desalination plant costs “five times more”.
And it is the cost that worries NNDC councillors. Councillor Nigel Housden, an independent representing Raynhams ward, says: “The [Bacton] desalination plant is going to take a considerable amount of money for its research, development and production.” Housden’s concern is that the project’s cost will diminish the £103mn funding pot that is also to pay for additional phosphorus removal from wastewater at 11 sewage works, extra ammonia removal and reducing the number of times storm overflows release sewage into local rivers and coastal waters.
“There are also the environmental costs, which are less talked about,” says Melgarejo. He calculates that production of one cubic meter of desalinated water at Spain’s Torrevieja (Alicante) plant, the largest in Europe, requires 3.8 kW. This compares with 1 kW per m3 for water drawn from aquifers and reservoirs. The source of the energy used determines whether the CO2 emissions are higher or lower. Hence the need for more research into desalination plants operating with renewable energy. But to convert the Torrevieja plant, covering 10 hectares (14.5 football fields), to photovoltaic would require a huge area of solar panels equivalent to the surface of the two lagoons in the area.
Another environmental issue is what to do with the salt. Returning it to the sea will affect the salinity of the marine ecosystem, causing harm to organisms and plants. Disposal on land will cause soil salinisation, affecting soil fertility and plant growth. It could potentially lead to land desertification with the consequential negative impact on local ecosystems and agricultural production. Appropriate measures must be in place to reduce the impact of salt emissions on the environment.
Across the world
Worldwide, many believe that water desalination is the solution to water scarcity.
According to the International Desalination Association, around 16,000 desalination plants are currently active in 177 countries. Over 90% of the daily water requirements in the Arabian Gulf come from desalination. Saudi Arabia has invested in the largest mobile floating desalination plant ever built on customised marine barges.
Europe is home to 2,352 desalination plants, though only 8% are large-scale facilities. Spain hosts 765 plants producing 5 million cubic metres of water per day, equivalent to 68% of Europe’s entire desalinated water production.
Cyprus is running out of water. By October, the country plans to add another four mobile desalination units to its four permanent desalination plants. Morocco is planning to add 13 desalination plants before 2030, adding to its 17 existing ones.
The UK’s reputation for delivery of large infrastructure projects in a speedy fashion, to time and to budget is chequered. But the clock is ticking. Desalination is no silver bullet – it’s expensive, energy-hungry and environmentally fraught. But without decisive action now, the UK risks watching its water security evaporate. The question isn’t whether we can afford to build these plants. It’s whether we can afford not to, before the taps run dry.
