Why can't Ghana stop illegal mining?

Illegal mining is poisoning Ghana's water supply and degrading the environment. It involves both foreign and local artisanal miners and has become a national problem. Who's behind it and why is it so difficult to stop? Josey Mahachi talks to Enoch Randy Aikins, a researcher at the Institute for Security Studies, investigative journalist Erastus Donkor and DW's Nontokozo Mchunu in South Africa.