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BHP Olympic Dam tailings an "extreme risk" to workers and the environment

Olympic Dam tailings dam

David Noonan, a long time anti-nuclear activist, writes in Chain Reaction magazine about BHP's plans for its controversial Olympic Dam Mine in South Australia.

The world's largest miner BHP proposes a major new Tailings Storage Facility at the Olympic Dam copper-uranium mine in outback South Australia.1

Tailings Storage Facility (TSF) 6 is intended to be larger in area than the CBD of Adelaide ‒ at 285 hectares and up to 30 metres in height. BHP states the total footprint area of TSF6 is intended to be 416 hectares.

BHP is seeking federal government approval of TSF6 under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), prior to a comprehensive Tailings Safety Risk Assessment of all BHP tailings waste across the entire Olympic Dam operation.

This BHP application follows on from a BHP Tailings Facilities Disclosure stating that three Olympic Dam tailings facilities are at the highest "extreme risk" hazard category based on the consequences of a potential catastrophic failure of the radioactive tailings waste facilities.2

BHP and the mining industry are in serious trouble internationally over catastrophic mine tailings dam failures in South America at the BHP and Vale joint venture mine at Samarco in Brazil in 2015 and the nearby Vale Brumadinho tailings dam collapse in early 2019.

In response, the International Council on Mining and Metals (ICMM) has teamed with the United Nations Environment Program (UNEP) to conduct a comprehensive Independent Tailings Review to draw up a new international safety standard for the management of tailings storage facilities.3 This important report and new tailings storage safety standard are due at the end of 2019.

BHP's June 2019 'ESG Briefing: Tailings Dams' states that the "principal potential impact" of a "most significant failure" of Olympic Dam tailings waste facilities is that of "employee impacts", with the potential loss of life of 100 BHP employees.4

The Canadian Dam Safety Guidelines "extreme risk" consequences category shows impacts of a potential loss of life of more than 100; an extreme loss of infrastructure and economics; and a major permanent loss of environmental and cultural values ‒ with restoration stated to be impossible.

BHP is seeking federal environmental approval for TSF6 prior to availability of the new ICMM and UNEP international safety standard for the management of tailings storage facilities. With BHP stating a preferred schedule for TSF6 to start construction in November 2019 and to operate in early 2020.

BHP is also seeking federal approval for TSF6 to be held prior to and separate from a required federal and state assessment of a major proposed expansion in the scale of underground mining at Olympic Dam, with copper production to increase from 200,000 to 350,000 tonnes per year.

The SA "Olympic Dam Major Projects Declaration" (SA Government Gazette, 14 Feb. 2019, p.461-462) has already "excluded" the three "extreme risk" Olympic Dam tailings waste facilities, and the proposed major new TSF6 and associated Evaporation Pond 6, from the scope of a required public environmental impact assessment process on BHP's proposed Olympic Dam mine expansion.5

To exclude, or to fail to apply, environmental assessment and public consultation on fundamental environmental impacts of mining at Olympic Dam is contrary to the public interest, and works against transparency, scrutiny, public confidence and basic modern community expectations.

Environmental impact assessment process

The new Federal Environment Minister Sussan Ley should require a public environmental impact assessment process on BHP's EPBC Act Referral 2019/8465 Tailings Storage Facility 6 under federal responsibilities to protect Matters of National Environmental Significance (see NGO briefing Uranium Mining Triggers "Protection of the Environment" Under the EPBC Act6).

This EPBC Act public assessment should include a comprehensive Tailings Safety Risk Assessment of TSF6 and of all BHP tailings waste across the entire Olympic Dam operations, especially the three "extreme risk" tailings waste facilities, before any potential approval or advance of major new BHP radioactive tailings waste facilities or increase in tailings waste production output.

The Minister must not approve this major new Tailings Storage Facility on the basis of limited non-independent BHP Referral input. Significant safety and environment protection issues cannot be left to BHP to decide. BHP must be made accountable for the three "extreme risk" tailings waste facilities at Olympic Dam and made to apply the most stringent safety standards in this case.

BHP Olympic Dam radioactive tailings waste present a significant long-term risk to the environment (see Tailings Briefing Paper7). The tailings contain approximately 80% of the radioactivity associated with the original ore and characteristically also retain around one-third of the uranium from the original ore. Tailings wastes retain the radioactive decay chains of uranium, thorium and radium and should be isolated from the environment for over 10,000 years.

Since 1988, Olympic Dam has produced around 180 million tonnes of radioactive tailings, intended to be left in extensive above ground piles on-site, imposing ongoing risks ‒ effectively forever.

In October 2011, the federal government recognised BHP tailings risks are effectively perpetual with its Olympic Dam Approval Condition #32 seeking to require environmental outcomes "that will be achieved indefinitely post mine closure".8 However, these conditions were not applied to Olympic Dam as BHP abandoned a proposed open-pit mine expansion project in 2012.

Existing BHP radioactive tailings waste facilities at Olympic Dam are extensive, covering an area totalling 960 hectares (ha) or 9.6 sq km ‒ an area far larger than the Melbourne City Centre of 6.2 sq km.

One of two active "extreme risk" tailings waste facilities at Olympic Dam, TSF4, started tailings slurry waste operations in 1999 and is already over 30 metres in height, equal to the height of a ten-storey building at the centre of the tailings pile. TSF4 covers an area of 190 ha ‒ over 100 times the playing area of the Melbourne Cricket Ground.

In 2015 federal approval was granted to BHP to extend the period of operations of TSF4 into the mid-2020s and to increase the height of TSF4 to up to 40 metres. The federal government should now require BHP to decommission this "extreme risk" facility and not to extend its use.

TSF 1, 2 and 3 are now classified as a single "extreme risk" inactive facility, totalling 190 ha in area and up to 30 metres in height. These TSFs are from a 1980s design and no longer receive tailings slurry waste but BHP has failed to close or to cover these radioactive waste piles.

Olympic Dam is an out of date "extreme risk" mining operation in sore need of high standards.

Prudent approach

Federal environmental protection standards for the management of radioactive tailings waste have been set at the Ranger uranium mine in the NT "to ensure that:

  • The tailings are physically isolated from the environment for at least 10,000 years;
  • Any contaminants arising from the tailings will not result in any detrimental environmental impact for at least 10,000 years."

This prudent approach and public interest requirement must also now be applied at Olympic Dam.

Sussan Ley faces a key decision test on the consistency and integrity of EPBC Act powers and responsibilities in BHP's TSF6 referral and proposed mining expansion at Olympic Dam. The Minister's tests include acting consistently with important Department of Environment Recommendations in the September 2011 'Olympic Dam expansion assessment report EPBC 2005/2270' that: "conditions be applied to the existing operation so that the entire Olympic Dam operation (existing and expanded) is regulated by a single approval under the EPBC Act".9

The Minister's 2019 decision should adopt Olympic Dam Approval Condition 32 Mine Closure (Oct. 2011) as a requirement on BHP for a comprehensive Safety Risk Assessment covering all radioactive tailings at Olympic Dam, including that the tailings plan must "contain a comprehensive safety assessment to determine the long-term (from closure to in the order of 10 000 years) risk to the public and the environment from the tailings storage facility".10

Further, the Minister should enforce Fauna Approval Conditions 18‒21 (EPBC 2005/2270)11 to help protect Listed Bird Species and 21 Listed Migratory Bird Species found in the area from mortality caused by BHP's toxic acid liquor Evaporation Ponds ‒ that kill hundreds of protected birds each year (see NGOs Briefing Migratory Birds at Risk of Mortality if BHP Continues Use of Evaporation Ponds12). These strong federal EPBC Act conditions required that BHP "must not construct Evaporation Ponds (for the purpose of the expanded mine)" and to "phase out the use of Evaporation Ponds as soon as practical".

The Minister should also mandate a 100% non-negotiable bond on BHP to cover rehabilitation liabilities across the entire Olympic Dam operation ‒ including the three "extreme risk" radioactive tailings waste facilities. BHP has avoided paying this multi hundred million dollar bond since taking over the Olympic Dam mine in 2005 (see NGO Briefing BHP Must Lodge a Bond to Cover 100% of Rehabilitation Liabilities at Olympic Dam13).

More information about the proposed Olympic Dam mine expansion is posted on the Friends of the Earth website.

Published in Chain Reaction #136, August 2019, national magazine of Friends of the Earth Australia.




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