The desalination plant would take 75 million litres of seawater per day from the Solent to convert into tap water during droughts. This is an energy-hungry and expensive process more commonly seen in dry and arid countries, such as Dubai and Australia.
Seawater removed from the Solent would be screened on a filter which could trap, injure and potentially kill marine species that can’t pass through. Smaller animals and plankton which can pass through the filters could be killed by the harsh treatment of the sea water which makes it drinkable and creates the concentrated waste brine. Plankton can include the young of larger marine animals, many of them commercially important, like oysters, clams and crabs. Plankton, juvenile invertebrates and small fish are food for many other species. Any declines in their populations will have an impact higher up the food chain, including important and protected species and habitats in the Solent.
After the sea water goes through treatment, what remains is a concentrated, highly saline brine (aka super salty), with chemicals and heavy metals concentrated within it. This waste solution is put back into the Solent. This super salty water can alter the chemistry of the surrounding water, and even reduce the amount of oxygen available in the water. This can lead to potentially lethal impacts on the diverse range of plant and animal species that live within the Solent. There is also a chance that the super salty brine discharge could stimulate algal blooms which can have devastating impacts on shallow coastal systems, such as the Solent, suffocating the life beneath the surface.
Dr Tim Ferrero, marine ecologist for the Trust, said:
“We shouldn’t need desalination to solve our water needs. Water is a valuable resource, and we should be managing the water we have more effectively. The Solent is a highly protected, narrow and shallow strait unsuited to receiving discharges of concentrated brine directly into a Special Protection Area (SPA) designated as feeding grounds for terns, and close to other Marine Protected Areas including Marine Conservation Zones (MCZs) and Sites of Special Scientific Interest (SSSI). If we are truly committed to reversing the harm we have already done to the marine environment, we have to change the way we exploit the sea and value the natural services and resources it provides, rather than putting them under further pressure.”
2,954 million litres of water are lost every day through leaky pipes and taps in England and Wales - equivalent to 1,182 Olympic swimming pools. Water companies must prioritise fixing leaks in their system, water recycling and reducing water consumption rather than looking to these expensive and harmful ‘silver bullet’ solutions.
Southern Water has said it aims to reduces leaks by 50% by 2050. We think that this target should be much more ambitious and be matched by commitments for better water treatment and recycling.
You can download below the Trust’s full statement which was sent to Southern Water in response to their ‘Water for Life’ consultation on the desalination proposals.