Lithium mining isn’t exactly “environmentally clean”. At 500,000 gallons of water per metric ton of lithium mined and ~10kg of lithium per car battery, that makes each electric car take up at least 5,000 gallons of water just from the extraction process of the lithium, to say nothing of refining, transportation, and other components that also use lithium.
Aaaand that’s all assuming there’s no localized pollution from the extraction process!