Acid mine drainage (AMD) resulting from the oxidation of base metal tailings represents a substantial environmental liability for the Mining Industry.
A reduction in the rate of acid generation is suggested through the establishment of an oxygen consuming bacterial population. Heterotrophs, which decompose organic matter provided by a vegetation cover, would outcompete oxidizing bacteria for oxygen consumption.
Experiments have been carried out to test for the presence of heterotrophs in fresh tailings. Methods have been developed which allow for germination of grass seeds on fresh tailings. Roughening of the tailings surface and an organic supplement were found to greatly assist in vegetation establishment.
The experiments have demonstrated that it is possible to vegetate fresh tailings. Heterotrophic bacteria are numerous in the root zone. Further work is now required to establish the quantities of nutrients supplied to the heterotrophs in the root zone and to produce a moisture containing and acid neutralizing layer for acid water generated in the deeper parts of the tailings.