West of Johannesburg, Robinson Lake used to be enjoyed for recreational activities. It has now been abandoned due to its high sulphuric acid content. Robinson Lake is a graphic example, above ground, of what is happening below the ground to Johannesburg's water table as a result of acid mine drainage. There are thousands of deep abandoned mines in the wider Johannesburg region, each filled with rain water that reacts with exposed rock to create a poisonous blend of acid and heavy...