PART TWO: OUTRAGE GROWS AND A "NEW" METHOD OF "CONTAINMENT" EVOLVES

In 1989 spokespeople for the mining industry had begun to publicly acknowledge at least some of the deleterious impacts of tailings disposal in rivers, streams, creeks and lakes and in "containment" lakes, dams and ponds [R Moody "The decade of betrayal", paper presented to the Conference on Mining, Environment and Social Conflicts, Third World Network-Africa, Accra, November 1999]. They were partly responding to the late 1988 Bougainville "revolt" provoked by the rejection of massive compensation demands made by landowners for the tailings devastation of the Jaba river and delta. A year later, additional wrath was sparked by BHP, when it persuaded the Papua New Guinea government to allow the company to break its original agreement, and continue throwing tailings from Ok Tedi directly into the river [MPI BHP Company Profile, Sydney, October 1997].

It was also at this time that Placer Dome, partnered by MIM of Australia, became the first mining outfit to use what, for the Pacific, was a new method of tailings disposal (Submarine Tailings Disposal or STD) at the Misima gold mine.

Meanwhile outrage had been growing over the lack of adequate tailings containment on Luzon island and elsewhere in the Philippines: two copper mines were discharging tailings which ended up in the sea. As a result, the United Nations Environment Programme (UNEP) commissioned consultancy firm, Dames and Moore, with the assistance of US AID (Agency for International Development) to compare the three main methods of tailings disposal (land, river and marine-oceanic). Dames & Moore came out in favour of "marine tailings discharge" for the Philippines, while acknowledging that it may be inappropriate for other countries, such as the USA. However Dames & Moore also identified disadvantages or limitations to the methodology which both it and some of its clients appear to have downplayed or ignored over the ten years since.

Out of site - out of mine? The theory of STD - and its liabilities

No-one in the industry claims that STD can, or should, be used at all mine-mill sites, even if they are within practical reach of marine waters. Nor has any informed advocate claimed that it is the best available technology for all high mountain, island environments. Nonetheless in regions where rainfall exceeds evaporation and/or high seismic activity contributes to ground instability, it is now being promoted as a tested and preferred option in "much of the Philippines", Papua New Guinea, Indonesia and Fiji [S Jones op. cit.].
In 1996, GESAMP (The Group of Experts on the Scientific Aspects of Marine Environmental Protection) concluded there was general agreement that, "re-mobilising" muds and sands [as from tailings] in coastal waters can be physically detrimental to survival, growth, abundance and net productivity of marine biota - and that's without accounting for other chemical or nutrient discharges .The prime danger in this zone is that of turbidity maximum, - where discharges and sediments occlude sunlight and prohibit photosynthesis - the key to growth [W C Dennison and R S Alberte "Photosynthetic response of Zostera mainra L. (eelgrass) to in situ manipulations of light intensity," Oceologica 55, 1982].

The bottom or base of this "euphotic zone" is defined as the depth reached by only 1% of the light transmitted from the surface; the zone itself is situated below the "thermocline" (break between upper warm waters and deeper colder ones) which, in the industry literature is generally set at depths of 80-100 metres. STD promises to shift the toxic/smothering burden of tailings below the euphotic zone - into parts of the ocean where life and reproductivity are not terminally threatened. The breakdown and dispersal of potentially toxic tailings does not need to be taken into account, since "...they will eventually be buried either by sediment eroded from land, and/or slow but continuous settlement of organic debris (marine snow) through the ocean water column" [S G Jones "Managing Mine Waste and Tailing - the Deep Sea Tailing Placement Process", paper delivered at Mining Philippines'99 - Moving into the Next Millenium, Manila, 1999].
Tailings must be kept permanently sunk well below the surface mixed layer - that area of the ocean where wind and waves create a zone of more or less uniform temperature, salinity and density, in order to prevent wastes rising upwards ("upwelling"). However, the "best practice" in STD also demands (rather confusingly) the human creation of a "mixing zone" near or offshore, which is intended to dilute potential contaminants not diluted prior to discharge, so they don't prove harmful to marine life in the upper layers of water.

Since the diffusion of oxygen in water is very slow, any acid formed by oxidisation of the tailings should be absorbed into the overlying water column, while the predominantly alkaline nature of sea-water should "inhibit" consequent solubilisation of the metals [S Jones op. cit.]. Golder Associates, in its 1996 study of STD, concluded that, where tailings are relatively inert, the ocean floor could actually become a "sink" rather than a source of metals. The key question here, of course, is what is meant by "inert" - a problem to which we will soon return.

The rate and gradient of tailings discharge are crucial factors - both in maintaining the integrity of the pipeline itself (as illustrated graphically by the Minahasa incident - see Figure 1) and in ensuring settlement of the wastes in a "coherent density current" (continual flow) between the receiving seabed and greater oceanic depths [see "Natural Systems Research Ramu Nickel Project Environmental Plan Inception Report", Victoria, Australia 1997]. It seems generally accepted that gradients less than 12% will impede this process.

Numerous "buts" and "ifs"

Even if gradient, mixing and the detoxification of mine effluent are satisfactory (a big "if"), substantial quantities of tailings may separate from the primary outflow at the point of discharge. This is due to "discontinuities" (differences in attributes within water bodies, such as temperature, density or salinity), thus causing turbulence - characterised by "plumes" visible across the surface of the sea [Mineral Policy Institute "Environmental Risk associated with Submarine Tailings Discharge in Astrolabe Bay, Madang Province, Papua New Guinea, a discussion paper" Sydney, February 1999]. (See also Lihir study in Figure 2).

In its 1991 study of tailings options, Dames & Moore defended STD as reducing many of the risks to surface waters, posed by heavy metals, changes in pH and large quantities of suspended solids typified by riverine disposal. It also argued that "when discharge [by STD] ceases, it is possible to have a …. marine environment in which adverse impact rapidly ceases. This is never the case on land." The company downplayed the toxicity of tailings on benthic (bottom feeding) fauna, or interactions and interdependence between biota at depth and that closer to the surface.

However, Dames & Moore acknowledged that, simply flushing out wastes below 100 metres is not sufficient. As tailings are discharged, so seawater is "entrained" (carried along with the tailings) and a plume containing fine particulates and dissolved heavy metal ions can rise into an upper plume, presenting the "significant risk of adverse effects on fisheries." [Dames & Moore op. cit.]. The action of wind and waves on the upper stratification layer can result in suspended particles entering the water column and "potentially have adverse effect on fisheries and shallow water organisms such as corals." (At the 2000 International Coral Reef Symposium, held in Bali, it was noted that mercury-contaminated dust from a mine in Algeria had apparently been carried by winds 3,000 miles to contribute to contamination of Caribbean coral reefs [FT November25/25 2000]).

Critically - and this point is ignored by some mining companies - Dames & Moore stipulated that "fishermen from the project area should be interviewed for their knowledge of choice fishing grounds and ... fishery stocks."[Dames & Moore ibid.]. In another observation, highlighted by recent failures in STD pipeline operation (see Minahasa case study, Figure 1) Dames & Moore pointed out that "...a marine outfall entails a substantial challenge to maintenance and repair, and excessive depth is undesirable from that standpoint". This means that there is an unpalatable "play off" between discharging tailings from the outfall well below the euphotic zone on the one hand, and being able to quickly identify and attend to any failure of the pipeline on the other. (Nonetheless, although the Minahasa pipeline breach occurred close to the surface, it reportedly took some days before it was properly attended to).

Dames & Moore summarised the essential data required before permitting marine discharge as:

• expected grain size distribution of tailings
• expected density of slurry at point of discharge
• proposed percent solids by weight and volume in the discharge
• predicted concentration of reagents in the tailings
• predicted concentration of dissolved metals in tailings
  

Five years later, in its own study of STD, Golder Associates, another consultancy long associated with mine construction including tailings dams, was considerably more cautious about endorsing STD. "...[O]ur knowledge of the physics governing solids [in tailings] transport is relatively poor. Many models exist for predicting sediment movement in the marine environment. However most of those are usually understated (sic) and are indeed based on inappropriate (sic) parameterization derived from empirical studies of sediment movement in rivers...".

Golder found that fine tailings may remain in suspension in shallow waters for some time and that wave-induced re-suspension of these "can be significant in water depths exceeding 100 metres" [Golder Associates Report for EnviroCanada, April 4 1996] It recommends that (in addition to Dames & Moore's list of essential data) baseline oceanographic studies should be made on the bathymetry (ocean depths), local winds, fresh water inflows and tidal range in the area of concern, along with their seasonal variations and what Golder calls "infrequent events" (But what advocates of STD do not appear to have properly considered is that, in recent years, global as well as regional changes in the natural phenomena just mentioned have created unprecedented and unpredictable, rather than "infrequent" occurrences).

Tucked away near the end of its study, Golder delivered a disturbingly negative verdict on STD as currently practised: "...[T]here is a lack of data to suggest that a stable and homogeneous [marine] community has been achieved at any of the contemporary STD operations (although the presence of key species suggest succession is occurring). This is, in part, due to insufficient time for recovery to proceed, and lack of comprehensive data from all sites" [Golder op. cit.].

No man is an Island

The best known industry advocate of STD is a noted marine biologist, D V Ellis (Professor Emeritus, Department of Biology, University of Victoria, British Columbia, Canada; chairman of the scientific and ethical board of the US-Canada Sea Use Council). Some of Ellis' early work (up to 1990) has been cited approvingly by critics of mining's past and present damage. But he has long been a quasi- evangelical advocate of submarine tailings discharge. Buoyed up by his 1980's field work in Canada, he has travelled in the south Pacific, employed in an advisory capacity by Placer Dome - a company notoriously committed to STD. Indeed one commentator claims that Ellis was brought by Placer Dome to the Philippines in 1998, to persuade the government to accept STD as a "solution" to the massive environmental degradation at Marinduque, caused by the 1996 collapse of a "plug" in a mined-out pit used to store tailings [Catherine Coumans "Should tailings be pumped out to sea?" Institute on Church and Social Issues, Canada, December 1998].

On Placer's behalf, in 1994 Ellis organised a conference in Fiji, where scenarios for the proposed Namosi copper-gold mine's tailings disposal were played out, while subtly being directed towards tolerance of STD ["Report on EIA workshop", University of the South Pacific, Suva May 9-13th 1994]. He is also a founder of Rescan Environmental Services - the consultants who became notorious, not only for their involvement in design of the notorious Omai tailings dam, but also of facilities at the fateful Marinduque site [Coumans ibid.]. In addition, Rescan helped design the Minahasa mine of Newmont, the first to employ STD in Indonesia (see Figure 1).

Ellis' defence of STD has been consistent, despite apparently carrying out field tests at only two mines - both in north America and both now closed - Island Copper and Kitsault. His Island Copper data seems to derive from observations made six years after the mine opened, without the benefit of baseline studies. [see I L Littlepage, D V Ellis, I Mcinerney "Marine Disposal of Mine Tailings", Marine Pollution Bulletin, volume 15, no 7, Britain 1984]. Two years following closure, Ellis was claiming that Island Copper had "proven" the technology of STD, and that "the prototype system developed here has been used successfully elsewhere" [Derek Ellis "Address to the 1997 Mining Philippines conference", quoted in Businessworld, October 16 1997].

Rupert Inlet

Rupert Inlet, on the west coast of Canada, received around 50,000 tonnes a day of mill tailings from the Island Copper mine between 1971 and 1995 - a total of 400 million tonnes in its 24 years period of operation. The tailings were released at only 50m depth to a fjord, and were supposed to flow as a density current into the deep sea "placement" zone. However, an unexpected "remobilisation" of the tailings resulted in a proportion of them (0.3%, or well over one million tonnes) spilling over a sill into the adjoining fjord, Quatsino Sound [Jones ibid.].

Grab samples and "submersible surveys" between 1981 and 1984 purportedly allowed an estimate of the presence of a large number of benthic and faunal organisms which might be affected by solids settling out from the tailings. But the results of these surveys were in many respects, manifestly inconclusive: they showed a certain resilience by benthic fauna in some areas, but not in others [see D V Ellis and C Heim "Submersible surveys of Benthos near turbidity cloud", Marine Pollution Bulletin, vol. 16 no. 5, Britain 1985]. These - and similar - results have been used to propose that, while tailings deposition below the turbidity plume can have short-term catastrophic effects on some biota, the recovery - or replacement - rate is better than might have been expected.

Ellis' qualified endorsement of Island Copper encapsulates what is not only palpably unscientific, but also morally questionable, about the practice of STD. First, he endorses a significant degree of environmental degradation, and indeed destruction, of marine life, without being able to define in advance just what, when, and how much, the biota will suffer. Second, the favourable comparisons he makes with alternative (primarily land-based) disposal methods are based upon worst, rather than best, case experience of the latter. Third - and most important - he seems to accept that, whatever goes on under the sea as a result of the use of STD, can be legitimately and indefinitely obscured from what the industry likes calling its "stakeholders " - and the most important ones at that, namely those dependent on the affected marine resources.

Island Copper has now been closed for more than five years. Shortly after closure, Golder Associates studied data from Ellis and others in its 1996 assessment on STD for EnviroCanada, exposing numerous flaws in methodology, monitoring and sampling procedures, along with failures to anticipate the behaviour of deep sea currents [Golder op. cit.]. EnviroCanada continues to monitor the mine's tailings impacts and, in 1999, one of its scientists concluded that, although the mine's land surface area has been reclaimed, strong tidal currents continue to re-mobilise fine tailings on parts of the ocean floor at Rupert Inlet, indicating that they have far from stabilised. While biota has "recovered" (a term Golder deliberately uses in preference to "recolonization") species are neither the same nor of such diversity as existed before, and the "hard bottom" species have been completely eliminated [Robert McCandless email to Minewatch Asia Pacific and Down to Earth, London June 7 1999].

More disasters...

The Kitsault mine looked like being a model for safe STD, although aspects of the initial plan were vigorously opposed by Native Canadians pursuing their land claims [Derek Ellis "Kitsault, BC - Technical Communciation in a Non-technical world", Marine Pollution Bulletin, vol 13 no 3, Britain 1982]. When Kitsault opened, both the Polaris mine in Canada and Black Angel in Greenland were undergoing some form of impact assessment of their tailings disposal procedures (Black Angel's was later shown to have been almost calamitous - see Figure 2). More important at this juncture, however, was the intention of Rio Tinto's wholly owned-subsidiary, US Borax, to exploit one of the world's biggest molybdenum deposits, which sat right at the centre of the recently-declared Alaska National Wilderness area. The company had successfully manoeuvred to get Quartz Hill - site of the main deposit - excised from this vast area, by pulling senatorial and congressional strings in Washington [see Plunder! Partizans and CAFCA London 1991].

By 1982, this ruthless mining company was strongly lobbying for STD as the best economic option to off-load the vast amounts of toxic wastes which the mine would have produced [see D V Ellis "Marine Tailings Disposal", Ann Arbour Science, Ann Arbour, 1982]. The project was knocked back and is not likely to proceed.
Initial surveys of the Kitsault STD system claimed to show that "no suspended tailings [were generated] within the photic zone and generally less than 5ppm above 150m water depth...even close to the discharge outfall" [Littlepage, Ellis and McInerney, op. cit.]. However, even before the mine was closed on cost grounds just over a year later in 1982, conflict had arisen between government scientists on the one hand and industry on the other, as to the meaning of the monitored results [D V Ellis in Salmons and Forster, op cit].

The Misima gold mine in Papua New Ginea has been claimed as "the best studied operating mine [using STD] in the world" [S Jones op cit] and the first where the technology was properly examined from concept through to operation [see S G Jones and D V Ellis, "Deep water STD at the Misima gold and silver mine, Papua New Guinea", Marine Georesources and Geotechnology, volume 13, 1995]. The mine's design outfall level is 112m, with the tailings intended to settle at between 1,000 and 1,500 metres depth. Cyanide from the milling process is washed three times, thickened to 50% to permit its recycling, with dilution by seawater before disposal [S Jones 1999]. It is claimed that tailings have never risen to the surface of the ocean and that, by 1997, "microscopic organisms" were already "colonising" the dumped material [NSR Environmental Consultants "Review of Submarine Tailing Disposal, Misima Mine PNG"]. (But see also recent report quoted in fig.2.).