png court allows marine dumping of mine waste, page-58

Ellis (1994) is a very old study of a cold water environment where there was no upwelling. Ellis is not a marine biologist, yet he mining industry always quotes that one document on the marine impacts of STD.

The thinking that the deep sea is a desert might remain in some sectors of the mining community, but was dispelled a decade ago with findings of extremely rich biodiversity. Here is just one paper on that subject alone: http://www.archive.org/stream/deepseabiodivers07vand#page/n1/mode/2up.

Google anything by Dr Crag Smith on deep sea ecosystems for mroe.

Tailings storage failure is the largest risk facing the global mining industry. Tailings are generally comprised of 30-to-50 percent solids by weight (clay, silt, and sand-sized particles) and 50-to-70 percent water containing chemical reagents used in the beneficiation processes, together with potentially high concentrations of heavy metals and oils. Leakage from tailings dams is the priority ongoing environmental management issue of mining companies.

Uncontrolled leakage can lead to catastrophic dam failure, contaminating downstream water resources, fisheries, wildlife, vegetation, food gardens and human health. It is for these reasons ‘best practice’ tailings disposal requires treatment and storage; not release into the environment.

The trial judge in the Ramu court case made findings of fact that serious environmental harm would come from the use of STD, based largely upon the testimony of expert witnesses - all of which I heard, as I was in court in Madang for the hearing.

Dr Gavin Mudd, whom I interviewed last year, is adamant that tailings treatment and storage facilities can and should be built in PNG.

However substantial the impact on marine ecosystems STD may have, some in the industry still believe it to be the best option. Most tailings dam failures elsewhere were not in environments as challenging. But the study, Tailings Dams Risk of Dangerous Occurrences, Lessons learnt from practical experiences, shows the the key physical causalities of impoundment failures are (in order):

Inadequate management
Lack of control of hydrological system
Error in site selection and investigation
Unsatisfactory foundation, lack of stability of downstream slope
Seepage
Over-toping
Earthquake

The study found major differences between embankment dams built to retain water reservoirs, and tailings dams, and that tailings dam failure has little to do with physical challenges and everything to do with a lack of appropriate risk analysis and management of the storage facility.

Tailings impoundment failure is not an engineering issue, but a management issue.

To say "It will be very irresponsible for MGO to go for the land-based dams solution JUST BECAUSE the PNG uneducated villagers/fishermen want it" is precisely the thinking that led to a civil war on Bougainville. It is precisely the thinking that led to two years of court cases at Ramu, which is now facing civil unrest (just this week a landowner death, police burning villages).

It can be done, it should be done, and it should be done properly.