for aluminum, you can use denaturated spirit, wd40, or simply kerosene.. anyone can buy any quantity..
these coolants, simply disposed with the chip you taking to the recycling..
I can run in my garage all day long a compressor, inflating my car tire.. no one can shut down my compressor..
and trust me a compressor can be very noisy.. more than a milling machine
you need to realize, your client... least I can say, not a straight one..
and again, that haas mill can be said hobby machine due to workenvelope what it actually capable..