Yeah.

Besides finding lithium is one thing, confirming it’s a deposit worth mining is another.

It is destructive to the environment.

The real question is if it is worth the damage to the environment for the lithium? That lithium will make it possible to make more batteries for less money, which then less fossil fuels and more renewables can be used over the entire life of the battery. Further if we start recycling lithium batteries completely, then it is the improvement across the lives of all the batteries made from that lithium minus any damage to the environment caused be recycle each generation of batteries.

For Maine they probably will not see enough of an improvements directly. For the US we might see enough improvements elsewhere to make it worthwhile. For the world we probably would be a net gain of environmental improvement.

The longer the timeframe the lithium can be used to lessen climate change impacts (batteries for cars and renewables) the more likely even Maine would see a net positive versus the damage of mining the lithium to begin with. But that is very hard to quantify and even harder to predict the future (new battery tech might displace current lithium batteries).

Looks like there's three ways to mine Lithium:

1. Hard Rock mining (as mentioned in the article)
2. Natural Brine sources
3. De-salinated water brine

https://cen.acs.org/materials/inorganic-chemistry/Can-seawater-give-us-lithium-to-meet-our-battery-needs/99/i36

Maine has been burned in the past by previous mining operations closing up and leaving the state to clean up the remaining mess (also in the OP article). Definitely a tough situation all around.

Regarding how much Lithium can be recovered from desalination waste:

https://medium.com/prime-movers-lab/does-the-u-s-have-enough-lithium-to-support-the-growing-ev-market-d73a44a969e5

The US currently has one operating desalination plant, Carlsbad, that processes 50 million gallons of seawater per day. If it recovered 100% of the lithium in that water, it would produce… about 16 tonnes of lithium per year.

VS the amount needed/used per year:

https://www.statista.com/statistics/606481/estimated-lithium-consumption-in-the-united-states/

In 2022 the United States consumed an estimated 3000 metric tons of lithium.

https://www.neefusa.org/story/water/home-water-use-united-states

Each day in the United States, about 27.4 billion gallons of water are withdrawn and delivered from surface water and groundwater sources for residential use

So if we supplemented 10% of our needs from Desalinated water (2.74 Billion gallons a day) and recovered the same max amount of Lithium as the example a day (50 million gallons a day for 16T of Lithium a year) then we get:

(2.74B/50M)16T= 54.816T= 877T of Lithium a year

No doubt. But we do it when the benefit > cost(including environmental). If we never mined and destroyed land we would not have most modern things that we enjoy everyday.