Colossal quantities of lithium – a metal that’s vital for the world of tomorrow – could be sourced from wastewater that’s been pumped out of a Pennsylvania fracking site. 

In a new study, scientists at the National Energy Technology Laboratory and the University of Pittsburgh worked out that 38 to 40 percent of the country's demand for lithium could be obtained from wastewater that’s produced by the hydraulic fracturing of rocks in the Marcellus Shale of Pennsylvania.

Hydraulic fracturing, or fracking, is a technique for recovering gas and oil from shale rock by blasting it with a mixture of water, sand, and other chemicals. The process is highly controversial, not least because it can disperse a huge amount of tainted wastewater into the surrounding water table if not managed properly. 

This research suggests the wastewater might hold some benefits, however. The researchers took samples of the water back to the lab and found they were able to extract lithium from water with more than 90 percent efficiency.

“We just didn't know how much was in there," Justin Mackey, lead study author and researcher at the National Energy Technology Laboratory, said in a statement.

"It's been dissolving rocks for hundreds of millions of years – essentially, the water has been mining the subsurface," explained Mackey.

The world needs more lithium. In a future powered by batteries, from electric cars to smartphones, the silvery metal has became one of the most sought-after commodities on the planet. Obtaining it isn’t always easy, however. Mining lithium can have a damaging impact of the surrounding environment, as well as the people and wildlife that live there. 

The vital resource raises a bunch of political issues too. Currently, most of the world’s lithium is extracted from brine ponds in Chile, before being shipped to China where it's processed. 

China has placed itself as a fundamental node in the global supply chain of lithium – a position that the US isn’t too pleased about. The US is striving to become self-sufficient in lithium by 2030 so it doesn’t have to rely on importing it from elsewhere. Paired with this, the Biden Administration hopes to challenge China’s command over the global market for electric cars, which are typically powered with lithium-ion batteries.

If the technology explored in this latest study is implemented, it could help to make these goals a little bit closer to reality. 

The study is published in the journal Scientific Reports.