Lithium and water sadness

Does anyone know how to dispose of water that has been made super basic from a lithium ion battery? My bum ass dad decided that since we were gonna take a bulging lithium battery to hazardous waste, he should instead be smart and take it from the container we put it in and take it apart to put its inner components in water so now we have this water that is super basic. He says he can just put vinegar in it to neutralize it and it’ll be environmentally safe. Which sure, it’s good not to have an insane base. But, I am just like- I don’t even know so bewildered with why would you do that? I’m trying to find information on safe disposal this because I don’t want to be putting any toxic bullshit in the environment. Can’t find a lot though. Anyone have anywhere to point me so I can know kinda what to do. Is such a thing drain safe?? Seems not ideal.