Saudi Arabia isn’t just the world’s top crude oil exporter. It’s also the biggest producer of a toxic effluent that’s the byproduct of slaking the desert kingdom’s thirst for water.
United Nations scientists warned Tuesday that desalination in Saudi Arabia and other countries is creating huge volumes of chemical-laced brine that risks contaminating food chains if left untreated. The problem is most acute in the Middle East and North Africa, which account for two-thirds of the world’s water contaminated by energy-intensive desalination plants.
“We have to address potentially severe downsides of desalination — the harm of brine and chemical pollution to the marine environment and human health,” said Vladimir Smakhtin, the director for the Hamilton, Canada-based UN Institute for Water Environment and Health.
Together, the world’s 16,000 desalination plants produce enough effluent every year to cover Florida with a foot of toxic brine, according to the peer-reviewed UN study, which was published by Elsevier Ltd’s journal Science of the Total Environment.
Desalination is an industrial process that uses heat and pressure to make mineral-laced seawater fit for human consumption. For every litre of potable water produced, the UN estimates about 1.5 liters of liquid polluted with chlorine and copper are created. When pumped back into the ocean, the toxic brine depletes oxygen and impacts organisms along the food chain.
Saudi Arabia’s desalination plants produce about 31.5 million cubic metres of contaminated water each day. That volume of liquid, most of which is pumped back into the ocean, is equivalent to about 20 million barrels of oil a day, or, double the amount of crude it currently produces. The Kingdom is tendering seven desalination and waste-water projects as it tries to alleviate the impacts of depleted aquifers.
While countries can treat the toxic brine to remove chemicals and heavy metals, those processes are expensive and require even more energy, according to the report.