Decision nears on Papua New Guinea coastal mine waste dumping
The photo was taken at a site not far from
the proposed dumping location.
Image: Amanda Reichelt-Brushett

The dumping of mine tailings waste into the shallow coastal marine environment is currently before the National Court of Papua New Guinea, in a case that will have far-reaching implications. At stake are the pristine waters of the Bismarck Sea and the livelihoods of thousands of coastal inhabitants on one hand, and the future of mine waste disposal on the other: a number of other mine operators are reportedly waiting on the result before announcing their own plans for waste disposal.
While a decision may come as early as 15 April, the issues raised make the information timely and important regardless.

The newly-constructed Chinese nickel cobalt mine, coastal treatment facility, and submarine waste pipeline are fully constructed. The only thing standing in the way of operation is a temporary injunction, brought on behalf of 1081 local landowners, who fear that the proposed dumping threatens their livelihoods. They seek a permanent injunction against dumping, which would require the mining company to use some form of on-land waste disposal. Specifically, they fear that the pipe will leak waste into the local reef lagoon; that upwelling will carry a suspended fraction back up into the upper mixed layer and thence into the lagoon; or that the local fishery will be impacted by the discharges.

The waste pipe runs 450 metres from the shoreline out to the 150 metre isobath. The bottom slopes are fairly gentle: about 12Ëš or less from the shore out to 1300 m, where the slope is less than 1Ëš. For part of the way, the path is constrained by the walls of a submarine canyon (Basamuk Canyon, located 40 km due SE of Madang, PNG, at the eastern side of Astrolabe Bay).

The dominant large scale oceanic features are: the strong New Guinea Coastal Undercurrent that flows west along the coast at about 200 metres depth; the New Guinea Coastal Current that reverses with the monsoons; and a wind-driven upwelling plume during the SE monsoon that spreads along the PNG coast (Cresswell, 2000). In the vicinity of the mine outfall, none of these appear to drive massive large-scale upwelling (Hasegawa et. al, 2010). However, progressive vector diagrams published in the Environmental Impact Assessments (EIA) (NSR, 1999 and Coffey enesar, 2007) show clear evidence of onshore drift near the seabed above the proposed outfall site at about 1 cm/s (750 metres/day). The drift is persistent; while it occasionally swings alongshore, it was seen most of the time and in all months of the year. If it continued onshore beyond the point of observation, it would advect a suspended fraction up into the base of the mixed layer and possibly beyond. The mixed layer is often as little as 30 metres vertically above the proposed outfall. Thus, the fears of the local landowners are well-founded.

Upwelling is not the only matter of concern in this case. The lateritic Ni and Co ore refinery solid tailings are predicted to form a sedimentary apron within the submarine canyon and seaward between the 500 and 1500 metre depth contours, over an area of at least 150 km2 of ocean floor, to a thickness of tens of meters. The area in which this occurs is within the “Coral Triangle”, an area described by marine biologists as having the highest diversity of corals, fish, crustaceans, molluscs and marine plant species in the world (Veron et al., 2009). SE Asian countries (including PNG) have vowed to protect and conserve this region of exceptional biodiversity. This region is also the location of one of the few healthy tuna fisheries in the ocean (Lehodey et al., 1997). Aside from a few scattered bottom samples, virtually nothing is known about the deep area that will be buried in Fe/Mn rich silty clay refinery tailings, that are enriched in a chemical soup of trace elements and refinery reagents. Submarine canyons are thought to be “hotspots” of poorly known biodiversity and biomass (DeLeo et al., 2010). It should be added that nearby larger mines are being developed; their owners are waiting on the outcome of this case before deciding on whether to use the same method of waste disposal, in the same submarine canyon. Finally, it has been suggested that the coastal treatment facility be expanded to process ore barged in from distant mines. Thus, quite a significant fraction of the continental slope of the Astrolabe Bay/Vitiaz Basin would be buried deeply in tailings waste. Regrettably, this method of deep sea tailing placement has already happened at Lihir and Misima Island, where significant areas of surface water and deep seafloor have been deleteriously impacted (SAMS 2010).

The mining company and its consultants have argued before the Court that, because the site is located in a seismically active and high rainfall zone with sharp topography, a conventional land-based tailings storage facility (TSF) is too expensive. This is due to the heavy engineering which is required for site investigations, design, construction, operations and then decommissioning a TSF in these conditions. The fact, however, that they readily acknowledge that TSFs have been built in similar contexts around the world - and safely - is proof that the primary driver for preferring marine waste dumping is cost - certainly not any alleged environmental risks of marine dumping versus land-based TSFs (which can be addressed by a good TSF engineer). With an above-ground, land-based TSF, the waste remains above ground and can be easily monitored - and, if deemed necessary, remedial action readily taken. If tailings are dumped into the marine environment, it is inconceivable that any remediation could ever be undertaken practically. Put simply, a land-based TSF would be close to a hundred times as expensive (or more) to build than marine dumping - yet marine tailings disposal has been approved without any understanding of its long-term costs.

The ecotoxicity testing upon which the EIA was based contained a number of flaws and deficiencies that seriously under-estimated risk.  Early toxicity tests were completed on temperate species using 0.45µm filtered tailings water.  Other tests completed after proposed changes to the ore processing included the use of some tropical marine species using 22µm filtered tailing water.  In the real world no organism will be exposed to filtered tailing waters. No tests exposed organisms to tailing filtrates for longer than 96 hours.  No tests were completed to investigate trophic transfer to contaminants. No mesocosm studies were completed. All toxicity tests were conducted in static water as opposed to flow through conditions. No tests were completed on whole tailing toxicity (i.e. equivalent to sediment toxicity tests) even though this was a recommendation made in a sub-consultants report. Furthermore consultants recommended safe dilution rates of tailings water to protect 95 per cent of species.  However these calculations had only 50 per cent confidence in their prediction – an  enormous uncertainty that does not give confidence in ensuring that species will not be harmed.

The PNG Department of Environment and Conservation, by their own admission are short on capacity, to either critically review Environmental Plans or to monitor the environmental performance of the mining industry.  Indeed the department has been treated somewhat as a ‘rubber-stamping’ agency by the small number of environmental consulting firms that monopolise the sector.  Despite warnings from both the Department of Fisheries and the Department of Mining about the problems in the miner’s EIA relating to adverse currents and the toxicity of tailings as far back as 1999, and despite several peer reviews and external assessments calling for substantial modifications and new data (mostly unheeded), the project remains essentially unchanged from that proposed a decade ago.  In a rather sad indictment of the parliamentary government response, the Environmental Act of Papua New Guinea was then revised implicitly to facilitate the dumping.

The case took a dramatic twist when Dr Tracy Shimmield, of the Scottish Academy of Marine Sciences (SAMS), took the stand on behalf of the mine owners, to testify that the best way to test for upwelling would be to start dumping as soon as instruments could be placed in the field to observe the effect. This, she suggested, would proceed for some months, after which instruments would be retrieved and upwelling and tailings dispersion assessed. It emerged that SAMS itself had been contracted to perform the fieldwork and analysis. Dr Shimmield’s affidavit further proposes that SAMS continue to monitor the behaviour of the tailings plume on the assumption that the tailings dumping continues indefinitely. The Shimmield affidavit strongly supports marine tailings dumping as an alternative to on-land storage, repeatedly stressing that the majority of the waste ends up in deep water. (This logic has an interesting history. About a decade ago, in the face of a series of submarine tailings pipe breakages resulting in ecological and human health catastrophes, the proponents of marine tailings dumping began insisting that the practice be referred to as “Deep Sea Tailings Placement” (DSTP) in order to emphasise the final “deep and still” resting place of the majority of the waste. While the new title may detract attention from the pipe breaks and upwelling issues, it ignores the fact that abundant, and almost completely unexplored, life exists on and within the deep sea bed that is destroyed by burial.)

Dr Shimmield revealed under cross-examination that SAMS will also be paid by the World Bank to produce a set of guidelines to assist governments in setting conditions for marine dumping of mine waste.

The timing of the proposed guidelines, and their announcement before the Court, also has an interesting history. In 2003, the World Bank produced the “Extractive Industries Review” (World Bank, 2003), which concluded that:

  • Submarine tailings disposal (STD) is currently the waste disposal procedure preferred by many mining companies planning large-scale operations in mountainous areas of active seismicity, particularly in Southeast Asia and the Pacific. If major projects proposed for the region receive permission to use STD, there could be a significant increase in its use in the next 10 years for already approved and proposed large-scale mining operations. This is also a critical region of maximum marine biodiversity and thus of global marine conservation significance. The effects of STD (if any) on tropical marine life, marine resource use, and ecosystem function are not well understood, and there is an urgent need to address the major gap in biological data on the possible effects of STD on tropical marine ecosystems, particularly in the Indo-Pacific deep sea. On the basis of the precautionary principle, since marine biodiversity has global conservation significance and since the possible effects of STD on the tropical marine ecosystem are not well understood, STD should be avoided especially in island regions where this method of disposal may not assure people’s sustainable livelihoods.

  • Almost all STD operations worldwide, whether disposing at shallow depths or in the deep sea, have had problems, including pipe breaks, wider than expected dispersal of tailings in the sea, smothering of the benthic organisms (although this is predicted) and loss of biodiversity, increased turbidity, introduction to the sea and marine biota of metals and milling agents (chemicals, such as cyanide, detergents, and frothing agents), and loss of potentially re-mine-able metals from tailings in the deep sea.

  • The EIR heard numerous other concerns about current as well as anticipated environmental and socioeconomic impacts of submarine tailings disposal in Southeast Asia. STD presents an inherent economic risk to local and export fisheries, for example, because of real or perceived contamination of marine resources. It may affect large and often endangered marine life, including whales, dolphins, and marine turtles, and it may raise the risks to human health through direct or indirect exposure to mining wastes. Mining procedures such as STD may have a negative impact on numerous other important socioeconomic and environmental factors, ranging from reduced marine tourism potential to additional, often illegal small-scale mining activities by opportunistic individuals. Environmental impact assessments of mining operations with STD as their main mechanism for waste management do not adequately assess any adverse effects in the deep sea and marine food web, and such potential impacts should be included in the scope and terms of reference for such studies.

The timing of the Shimmield guideline-drafting contract is concerning, because its announcement (before the Court) maximizes the degree to which it undermines the landowners’ case. While the Review does not completely reject the option of “Submarine Tailings Disposal” as they call it, there is a big leap between leaving a door open a crack (as in the Review) and flinging it open with an effective endorsement, which in a country like PNG, with very weak regulatory controls, is precisely the effect of a new set of guidelines issued by a world body. 

In response to queries from the authors, the World Bank has stated:

“This (support for the new guidelines) does not imply any form of approval (of  STD) by the World Bank, but demonstrates that should the Government go down this path, then the Bank supports the establishment of a regulatory framework which minimizes any potential environmental impacts from whatever tailings management system which is adopted by the Sovereign State of Papua New Guinea.  The Bank’s assistance is motivated by a desire to see that permits issued through that 'normal' process are then also subjected to further site-specific stringent requirements, to strengthen ability to hold industry accountable and responsible in discharging their permitted activities.”

It may be that in certain future circumstances the guidelines will have a positive impact. For example, in a developed country, in which there exists the capacity and political will to enforce them, they might make a useful framework to deny permission to dump wastes in coastal seas. However, nearly all developed countries have either explicitly or effectively banned the practice of shallow marine dumping of mine tailings waste (STD/DSTP). Even in countries like PNG, a generally-excellent set of laws exists. The only problem is that they are not enforced, or enforced poorly. So however lofty the stated goals of the World Bank, their effect will be to simply facilitate a practice that – like many early forms of industrial pollution  – should be consigned to the dustbin of history.

The situation, as it currently stands, is that a state-funded European institution is being paid by a foreign mining company and/or a foreign national government agency to not just monitor but to actively advocate in Court marine pollution on a massive scale (covering perhaps hundreds of square kilometres of seabed with potentially toxic waste), a practice which almost certainly would not be tolerated in their home country, while at the same time being paid by the World Bank to produce guidelines to govern when and how the dumping should be done – guidelines which (if followed) would have disallowed the particular mine outfall they hope to monitor.

While scientific institutions increasingly have to chase the dollar to survive, as scientists we have to be able to say no when profitable consultancies become ethically questionable, or when our actions in faraway places can leave a poisonous legacy for generations to come.

The authors of this report were called by the landowners to provide unpaid “expert witness” testimony in their case to get a permanent injunction against the shallow marine dumping at Astrolabe Bay.  

1South Australian Research and Development Institute, Adelaide, SA, Australia
284 Alligator Creek Road, Alligator Creek, QLD 4816, Australia
3Environmental Engineering, Monash University, Clayton, Australia
4School of Environmental Science and Management, Southern Cross University, Lismore, NSW, Australia
5Australian National University, Canberra, ACT, Australia and University of Papua New Guinea, Port Moresby, PNG


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Editor's Note: This story was provided by the authors. Please contact the ScienceAlert editors to republish it.