Dumping mine tailings into the sea via a submerged pipe is a highly controversial practice. While it is effectively banned in Canada under provisions of the Fisheries Act and the Metal Mining Effluent Regulations, Canadian companies practice so-called Submarine Tailings Disposal (STD) overseas. Mining companies operating in island-rich nations in southeast Asia and the Pacific are particularly likely to seek permission to dump their waste into the sea. Papua New Guinea (PNG) has already hosted two STD mines (one of which, now closed, was Canadian). Many more companies are indicating an interest in piping their waste into the seas around Papua New Guinea. Fishing communities near the planned disposal sites of proposed STD mines in Papua New Guinea are expressing strong opposition to ocean dumping of mine waste.
The European Union has collaborated with Papua New Guinea’s Mining Sector Support Programme (MSSP) to fund an independent evaluation of so-called Deep-Sea Mine Tailings Placement in Papua New Guinea. The research is being carried out by the Scottish Association for Marine Science (SAMS). In November of this year, SAMS and MSSP hosted a conference in Madang, PNG, to present the preliminary findings of the research carried out by the SAMS team and to present Draft Guidelines for the use of STD in PNG.
MiningWatch Canada has worked on the issue of STD with partners in Indonesia, the Philippines and Papua New Guinea since 2000. In 2002 MiningWatch Canada and Project Underground published an STD Toolkit that details the scientific and technical concerns associated with STD. The Toolkit also provides six case studies from the Asia Pacific region.
MiningWatch’s Catherine Coumans was invited to present at the conference in Madang and to hear preliminary findings of research being conducted by SAMS. The SAMS research to date recognizes many of the scientific and technical concerns elaborated in the STD Toolkit – among others: the potential for wider than predicted dispersal of tailings along the sea bottom; shearing off of tailings at various sea levels as they make their way to the sea bottom; the problem of pipe breaks at sea; greater levels of dissolved oxygen at depth than predicted in industry consultants’ reports; the potential for metal leaching from tailings in the marine environment; the ecosystem significance of marine biota found in deep sea environments; the inadequacy of baseline data for some STD mines; the importance of vertical migration of species from the deep sea to higher levels for potential metal mobility; and lack of information on potential re-colonization of tailings as biological processes are very slow at 1000 metre depths. Scientific presenters noted that “less is known about the deep sea than about the back side of the moon” raising the need first and foremost for precaution when considering a massive anthropogenic impact on a fragile and not-well-understood ecosystem.
Although the Draft Guidelines SAMS presented are meant to apply to PNG, it is clear that they may potentially form the basis for international guidelines. MiningWatch Canada will continue to monitor the development of these guidelines.