Now, in a cosmic practical joke on environmentalists, researchers say they've found a lithium mother lode -- in Pennsylvania fracking wastewater. 

It turns out that the Marcellus Shale --  a long swath of sedimentary rock in the northeastern United States that holds huge amounts of frackable gas -- holds huge quantities of lithium too. Justin Mackey and other researchers at the National Energy Technology Laboratory in Pennsylvania were pleasantly surprise when they studied the contents of wastewater dredged up in the fracking process at 515 sites in the Keystone State, reports Science Alert.

Long before the frackers showed up, deep groundwater has been dissolving the lithium in the Marcellus Shale for eons. "It's been dissolving rocks for hundreds of millions of years—essentially, the water has been mining the subsurface," Mackey told the University of Pittsburgh's Brandie Jefferson. 

When they analyzed the wastewater data, they were stunned by the volume of lithium. The shale "has the capacity to provide significant lithium yields for the foreseeable future" he says. Their detailed findings were published in Scientific Reports. 

It's unclear if other fracking hotspots have abundant lithium too. However, even using conservative estimates of how much can be recovered from the wastewater suggests that Pennsylvania alone could cover more than 30% of America's 2024 demand. 

The US government is targeting lithium independence, with the Department of Energy specifically aiming for all of the country's lithium needs to be covered by domestic production by 2030. That's causing a mad rush -- and conflicts that pit green energy boosters against environmentalists and American Indians who are litigating to shut down promising sources. 

Case in point: the Thacker Pass mine in northern Nevada, which is supposed to be the nation's largest open-pit lithium mine. Indian tribes sued, claiming the mine is too close to the site of an 1865 massacre.  Environmentalists sued, saying the mining process will destroy animal habitats and harm groundwater. Now the federal Fish and Wildlife Service is doing a year-long study on the potential impact to a tiny snail.