The anniversaries of three deadly mine waste disasters should have governments in all mining jurisdictions insisting on new audits of tailings dams and demanding sound assurances that such needless mine waste disasters never recur.

The Aberfan coal dump collapse on October 21, 1966, should have been enough to bring a halt to all future sludge slides, but even though the tragedy in that Welsh village killed 144 people, 116 of them children, it was not enough to stir the conscience of the mining sector.

Twenty-eight years later, on the night of February 22, 1994, Harmony mine’s gold tailings dam failed at Merriespruit, in Virginia, in South Africa’s Free State province, killing 17 people and destroying 80 homes.

Now, tomorrow marks the first anniversary of yet another dereliction of mine management duty, perpetrated by two of the world’s richest mining companies.

The world’s largest company, BHP Billiton, and the huge Vale, as the joint owners of Samarco, in Brazil, failed to manage the Bento Rodrigues iron-ore tailings dam, which resulted in another needless mine mud flood on November 5, 2015, which killed 19 people, left hundreds homeless and halted water supply to 260 000 in what was condemned as an “environmental catastrophe”.

The decision by BHP Billiton chairperson Jac Nasser and CEO Andrew Mackenzie to take the Samarco disaster to the top of the agenda at last week’s annual general meeting in London was right and fitting but is not going to go any of the way towards saving the company from intense lawsuits and hefty financial claims.

None of the many difficult issues faced by the two mining giants come anywhere close to being more serious than Samarco.

All other mining company directors and CEOs should take note of the trouble they will land themselves and their shareholders in if they allow another such tailings tragedy to occur.

Directors and CEOs should all take note that prevention is far easier than cure in these matters.

In the past year, more than 500 community meetings have had to take place, just to ensure those affected at Samarco are consulted on the recovery work.

In March of this year, BHP Billiton and Vale agreed to establish 41 programmes to compensate communities and restore the environment affected by the dam failure.

The benchmark used for dam safety reviews will now be the Canadian Dam Association processes, the most rigorous in the industry.

Nasser concedes that some issues are poised to take years to resolve and foresees setbacks along the way.

Regulators the world over should be putting dry processing on the agenda as a potential obligatory measure.

Dry stacking, which is often put forward as a way of mitigating disasters, removes water from processed ore using pressure filters and allowing the mine waste to be stacked in a more controlled fashion.

Those in favour of it say that dry stacking can also reduce waste seepage into groundwater that risks extending environmental liability after mine closure.

It sounds like a measure that should come in for serious consideration.