The Wafi Golpu Mining Project is a recent national economic impact development project in Papua New Guinea (PNG). The Wafi-Golpu mine is located in the Bulolo District in the Morobe Province, 65 kilometers south-west of Lae City. The K18 billion project is at its advanced exploration stage. The Mine will use an underground mining technology known as block-caving to extract ore body that is to be crushed on-site at the Watut Processing facility, the ore and the slurry waste will be transported though a pipeline to Chivasing and onto Lae Wharf Area where the Treatment facility will separate the ore and the waste. The ore will be loaded onto shipping vessels for export while the waste continues onto Wagang to be disposed into the Huon Gulf using the Deep-Sea Tailing Placement (DSTP) method. This mine will be dumping a 13 million tons of waste per year into Huon Gulf over a mine lifespan of 28+ years.
The Government has given the license to mine to a joint venture company between South Africa (Harmoney Gold) and Australia (Newcrest) called the Wafu Golpu Joint Venture (WGJV).
What is DSTP?
The DSTP is a mine waste disposal method where slurry containing ground waste rock and chemicals from ore extracting process is dumped into the sea. In designing a DSTP, the engineers and environmentalist aim to safely dispose the excess rock waste and secondly to prevent acid from the rocks and the processing chemicals from reacting with oxygen to cause Acid Rock Drainage (ARD) causing highly toxic blue water characteristic of Paguna.
DSTP is preferred based on assumptions. Some of these include: (1) the slurry will only smother the sessile and immobile creatures below the euphotic zone. Mobile creatures such as fishes and other creatures will move away (2) The thermocline will form a barrier against sediments plumes coming up water column (3) there is no upwelling so the waste rock will remain under the sea (4) there is no oxygen under the ocean to oxidize the acid from the ground rocks which would otherwise cause Acid Rock Drainage (ARD).
Even in the 21st century the DSTP is considered experimental and its impacts unpredictable. The method is held up by assumptions. Many nations refuse to use DSTP and choose to take the precautionary principle because impact of DSTP is unpredictable.
DSTP in PNG
There are 15 mining projects in the world, using DSTP. PNG boast of five. These projects in PNG include: Lihir, Simberi, Basamuk and Woodlark and Misima. The now decommissioned Misima and the Lihir are used as models of the DSTP method. Firstly, Misima and Lihir are high islands (also volcanic islands) that rise from deep waters and therefore have slopes that go straight onto the deep ocean (ie have no continental shelf). Secondly, Misima and Lihir are both rural and remote islands with an absence of deep water subsistence or commercial fisheries.
DSTP is not without problems. The Misima Mine Project was PNG’s first DSTP. The tailing was placed at 120 m depth for to 16 years. The DSTP pipe in Misima broke twice. The third time cyanide was poured down the pipe resulting in 100s of deep fish being kill. Furthermore, there was a spill from the Basamuk pipeline resulting in environmental damage and fish kill.
In 2018. The Scottish Marine Association for Marine Sciences (SAMS) surveyed the Misima and Lihir and Basamuk and presented evidence to show that the footprint of the DSTP is bigger than predicted. Furthermore, recovery rate of the sessile meio- and mircro fauna from smothering impacts is slow. It is too early to predict Bioaccumulation and bio magnification in fish and effect on humans. The mine waste in Basamuk is spreading along the continental shelf, aided by the ocean action on the bathymetry of the continental shelf.
Legislative Framework for DSTP
The primary laws governing mining projects is the Mining Act and the Environment Act 2000 from Mineral Resource Authority (MRA) and Conservation Environment Protection Authority (CEPA) respectively. The MRA is pro- development and responsible for giving out mine license and mine lease. The CEPA is effectively a safe-guard for environment protection and conservation according to goal 4 of constitution.
The logical process to safeguard the environment and the people is for the government to conduct an Environmental Impact Study (EIS) and based on this, charge the company the prescribed fees. In PNG, the opposite is done, the developer is required to undertake EIS. The Environmental Council (minimum quorum of 3) will only check the EIS and advise the government. Once the government accepts the EIS and hands over a permit, the developer can start the mine project.
The Environmental Act 2000 does not have specific sections for mine waste disposal including DSTP. The Environmental Act 2000 allows the developer to pay for an annual permit to continuously dump waste throughout the life of the mine.
SAMS DSTP guideline
The SAMS guideline is an attempt by the industry to improve the DSTP method. The SAMS framework for DSTP was developed after comparisons of disposal options around the world including Misima and Lihir and Basamuk. The SAM guideline is a risk assessment matrix. The matrix take into account engineering and geological, social and ecosystem considerations then evaluates the constraints, impacts, and risks across terrestrial and oceanic boundaries and ecosystem values to these systems. The SAMS guideline supposedly make DSTP safer, by addressing all relevant considerations.
Using the SAMS guideline, the WGJV identified DSTP as the option over a tailing dam which was deemed dangerous in a seismically active, high-rainfall country.
Why Huon Gulf is not a good site
The SAMS guideline is not government document giving license to DSTP it is a decision making framework. The SAM framework (still a draft document) is used by WGJV to justify the DSTP. The draft SAMS framework for DSTP does not have legal basis. For the Environmental council to accept the controversial method shows a government putting profits before people’s lives.
Below are other reasons that make Huon Gulf not suitable for a DSTP.
Firstly, unlike Misima and Lihir (case study from here on), Huon Gulf is part of the mainland and has a continental shelf. It is unpredictable what will happen after the tailings waste is placed at 200m. The outfall at 200m is still 300 m away from the Markham Canyon. (Buleka et al 1999). The DSTP is described as being “placed” in effect it is dumped and left to the mercy of waves and currents at the ocean bottom. Experience from Basamuk shows what will happen.
History shows that tailings pipe do break. The likelihood for this happening is high in Huon Gulf because the outfall pipeline into the oceans runs parallel to the active Markham fault. To further make the point of how dangerous this is, studies show that South Easterly that piles water against the Lae City as it seeks to push water through the Vitiaz straits into the Bismarck Sea. This has implications for waste movement in an event of an accident. On the other hand, the North Westerly will spread any impact into the Solomon Sea and as far as Oro and Milne Bay islands.
Secondly, unlike the case study, which are rural and remote locations, the city of Lae is PNG’s second city that has a population of 200,000 (estimated from 2011 census). The city is low lying with the highest point about 8 m above sea-level. In the face of accidents, the pipeline will pose more problems for the city and the businesses located in the city.
The case study shows project containing their outfall inside the mine lease. In the case of the WGJV, the outfall is about 65km from the mine, this begs the question – how will the pipeline be policed. So many things can go wrong including vandalism, which may put the lives of many people at risk.
Third, people maintain livelihood from fishing, both onshore and off-shore in deep waters. Commercial fisheries in Lae city. Tuna industry generates money into PNG, DSTP is threat to our world Tuna market.
Furthermore, unlike the case study , the outfall in Huon Gulf is between two big fresh water bodies – the Markham and Busu. The impact of fresh water on DSTP has not been addressed by the SAMs framework nor the EIS. Furthermore, the impact of increased sedimentation by the mine (13 mt.yr) on top of that by Busu (??) and Markham (12 mt/yr) may have an unpredictable impact on Lae city and surrounding area.
We say NO to DSTP in Huon Gulf because, DSTP does not have legal basis and SAMS draft guideline is just a decision making matrix. A DSTP cannot be used in Huon Gulf because of so many actors that make this location unsuitable. The impacts of the DSTP is still being studied and unpredictable therefore it is injustice to subject people to an unpredictable procedure. We urge the government to choose the precautionary principal in this case.