No aliens - humans only. One ofthe themes of District 9 a movie that’s come out recently.

My university days were spent in Johannesburg. The slimes days are still there and in vast view in the movie. Here is a picture of the Driefontein gold mine slimes dam.

We never thought to call them anything but slimes dam. I still feel a little uneasy about the euphemisms inherent in the terms tailings impoundment or containment facility. But then the waves of political correctness engulf both politicians and slimes dam engineers alike.

Ileave it to movie critics more refined than me to evaluate the movie. All Ido is encourage you to go and see the movie so that you can see the big slimes dams in the heart of Johannesburg. Here is sustainable mining in all its glory. The town grew up around the mines and nobody even notices the slimes dams. Instead, they got on with fundamental human activities like prejudice, race hate, removals of those who are different, and the application ofthe rule of law to dubious purposes.

All I can do to capture the tenor and idiocy of those times is to write a sketch of the official attitude of those days to slimes dams. George Donaldson was a research engineer at the CSIR–the government-controlled research institute in Pretoria where they provided the scientific basis for apartheid. He had ginger hair and bushy eyebrows and he never liked me. Here is a perfect example of his attitude to slimes dams—he thought they were wonderful things. The following is an abstract of apaper he published in 1973.

Theoretical and engineering aspects of slimes-dam construction by G. W. DONALDSON, M.Sc. (Eng.)(U.C.T.), D.I.C. (Visitor) This paper reviews the recommendations made in 1959-60 as a result of research into slimes-dam construction and finds that these recommendations are still valid. The requirements for pollution control, vegetating, in situ leaching, and future development of slimes dams as building areas are considered as they affect the engineering aspects of slimes-dam construction, and it is found that these requirements can be met without any major changes to current recommended slimes-dam construction practice.

I particularly like this statement:

Even on badly drained sites, a dam can be built to a safe height of 40 m at an angle of 30 degrees at a rate of 3 m per year. As the rate of building increases, the safe height and/or angle of slope must be reduced.

And you must love his conclusion:

Although this is not true of the gold-mining industry, there are slimes dams where the seepage effluent contains harmful pollutants, such as the gypsum dams for the fertilizer industry.

He was so perfect a defender of the status quo that he was blind to scientific evidence. Thus it is fun to look at the situation today. Here are links to three papers on the topic:

There awaits a PhD for the student who can integrate the movie District 9 into the story of slimes dams, apartheid, and the blindness of professionals in research organizations. Go for it!