IMM is proposing four separate stockpiles of gravel, "mined material", "development rock" for a total of 628, 300 square feet of stockpiled material. (ESA/205379, Oct. 2008, pgs. 2-13, 14) How will these be managed and controlled? How will drainage with toxic materials be prevented during rain events? How were these amounts estimated and what happens if more material needs to be stored?

Waste Rock

The project description now indicates that, in full production, 2,400 STPD of gold production would be engendered, with 1,200 STPD to be used in the manufacture of ceramic brick, tiles, and building materials. The other half would be returned to the underground as backfill, or trucked somewhere within a 100-mile radius. (ESA/205379, pg. 2-23) This raises a series of important questions:

  • What buildings would use this waste rock?
  • Where would any of this be returned underground? Will there be open shafts and tunnels no longer in use?
  • If trucked, has this additional load of trucks and diesel emissions and wear and tear on the roads been incorporated into the issues to be mitigated?
  • If trucked, where exactly would this go, and what proof is there that there is a waste site willing to take it?
  • If there is any glitch in the system, where would this waste rock be stored and how would it be protected from toxic runoff?

Hazardous Materials

Other hazardous materials to be used onsite include:

  • lime
  • Ca(OH2)
  • sodium hydroxide (NaOH)
  • dilute hydrochloric acid (HCl) for pH control
  • lead nitrate (PbNO3) to enhance gold leaching kinetics
  • hydrogen peroxide (H202) or sulfur dioxide gas (SO2) for cyanide destruction
  • sodium isobutyl xanthate as a flotation collector
  • methyl isobutyl carbinol (MIBC) as a flotation frother
  • soluble starch

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