Research is showing that these mixes of cyanide with other metals and chemicals can be just as toxic as cyanide itself, but that they are not routinely monitored or carefully regulated. Cyanide can be treated to become less toxic, but Trevino does not report that NMC is proposing any active destruction of the toxic chemical. Instead, it appears that NMC is simply expecting any leftover cyanide to break down naturally in the tailings dump. As much as 18-20 tons of cyanide per month is proposed to be transported and stored at the site. Cyanide is a powerful solvent that also further breaks down heavy metals such as mercury, cadmium, chromium, lead, and others that end up as waste products needing to be dumped.
Cold temperatures slow down the natural breakdown of cyanide into other less toxic compounds.
Cyanide recovery or destruction systems are available to mining companies, but NMC is not proposing to use a system currently. Cyanide is highly toxic and has been the cause of many environmental disasters-see additional examples cited the Mineral Policy Center below. The examples prove that disasters such as the Aurul mine waste spill in Romania are not unique. Cyanide spills are increasingly common. In Colorado, spills of cyanide and other contaminants from the Summitville gold mine, owned by Galactic Resources Ltd, contributed to severe environmental problems on a 17-mile stretch of the Alamosa River.