Chances are, mainstream chemical industry is going to be shy of offloading mercury waste that way now, it'll get found out sooner or later, after there is an environmental disaster, they won't want to be supporting human vegetables for the rest of their existence, and people in general by now are pretty well aware of Hg being bad news in general.
I still see it happening though by some clandestine chemists, makes me SO fucking pissed when I hear something like 'yeah, I ditch industrial sized drums of my Al/Hg waste [sorry, shorthand for aluminium amalgam reduction, commonly just referred to as the Al/Hg, used for reducing phenylnitroalkenes direct to the aminoalkanes, especially in large-scale amphetamine manufacture. And used for reductive amination of ketones like P2P/phenylacetone, for the same purpose, basically it involves amalgamation of cut up thick aluminium foil (thinner types react faster, in potentially volcanic fashion) with a mercuric salt, mercuric chloride often as not. Very commonly used, often by those who can't figure out alternative routes, I don't use it myself, I've a hate-hate relationship with that particular reduction technique, I hate it, it hates me and I've never got it to work, it's unpredictable, exothermic as hell, and worse, it NEEDS that initial soyuz-esque blastoff of exothermia to get going, and then has to be put on external heating to maintain it over several hours at a downright alarming roiling reflux, that's a few inches of condenser height short of blowing itself all over the ceiling. Produces a load of toxic mercury wastes, and it's a complete wanker to workup the resultant thick slurry of digested aluminium waste, balled up Al foil and something that looks like grey phlegm, only with less attractive characteristics to it's name. Some times it'll take off like a rocket, other times even a blowtorch and external heating on a hotplate won't get it to kick.)
People have admitted to literally just dumping the waste in barrels buried in the woods, 70 gallon drums of the noxious toxic crap left behind, I have to confess, that is one of THE worst things I've ever heard, as far as clandestine chemistry goes, not counting a few accidents affecting people on a personal level. There's more than one 'bee' (not that I consider them worth the name, hence the quotation marks, intended to convey scathing sarcasm) who's been sent away with their ears burning after my giving them a real roasting for that this year. I hope it'll be the last time I see it, but somehow I doubt it.
Large companies these days wouldn't get away with it for long. And people would be PISSED when they find out who's responsible.
