My personal preference is I'd rather not be getting visits from EPA officials and newspaper folks. That's only my personal preference.
Also my personal opinion is that others would be nervous about living next door to someone with a 30 gallon tank of Chromic Acid in his basement. That's why you'll probably get more publicity than you want. I wouldn't want that.
My final personal opinion is that I wouldn't use chromic acid in the basement of a home. But I think with the proper fume hood and using Caswell's instructions it can be done safely in a LOCKED ventilated garage or out building. It needs to be locked to keep small children away. Why not a basement? If something goes wrong, the fumes have only one place to go...into the living area.
I think a few gallons (in the 5 gallon range) can be managed responsibly and straightforwardly by most do-it-yourselfers within the bounds of the EPA requirements. Beyond that it gets progressively risky, so you must be more and more careful, and be ready to prove to the authorities that you are. At some point as the size goes up there may be an expectation that you have the facilities to deal with on site waste treatment as well.
The cost of the risk as the tank size goes up (beyond the 10 gallon range) is something to cope with. If you can cope with it responsibly (including disposal), then great.
Check out the EPA website at
www.epa.gov. They lay out pretty clearly what the CESQG limits are. If you can stay within them, and meet their expectations for how you dispose of the waste, then you're at least clear on that count. My recollection is that with around a 5 gallon setup it's straightforward, but don't take my word for it. Check it out.
Always have the MSDS sheets available in a nice organized binder for EVERY hazardous substance you have around the plating shop. It's important for your own safety. The EPA will want to see these as well should they pay you a surprise visit.
Kind regards,
Ken