Monontsha - A success story in holisticenvironmental management.

When Impala Platinum encountered waste management and environmentalissues at their Rustenburg mine complex they resorted to an original, holisticapproach to the problems. The mine had a number of waste streams thatneeded to be managed and they also wanted to attend to the rehabilitation ofthe slopes of their tailings dams. Monontsha was an innovative answer to thissituation.

Established in 2004 as an empowerment project between Impala and the localLuka community, Monontsha enjoys an ongoing contract with the mine currentlyvalued in excess of R6 million per year and provides employment for over 50people across its’ process, transport and vegetation divisions.

The Process

Timber wastes in the form of redundant shaft supports and wood fibre from themineral extraction process are brought into the Monontsha complex. Here thesolid timber is shredded in a powerful chipper.

Sewage sludge is brought in from both the mines own treatment plant and fromplants operated by the local municipality. The materials are mixed together inequal proportions and formed into windrows. Over a period of approximately12 weeks the windrows are regularly turned and watered promoting the creationof a quality organic compost.

The company currently produces around 900m3 of compost per month.

The raw materials for the Monontshacomposting process. From top, shreddedtimber from waste mine supports, woodfibre from the mineral extraction processand treated sewage sludge.

The windrows are regularly turned andwatered to encourage the naturalcomposting process.

The company operates its own transportdivision of trucks, plant and equipment.

The RehabilitationWhen ready for application the compost is transported to the slopes of thetailings dams. After the slopes have been manually cleared of alien vegetationthe compost is applied at a rate of about 100m3 per hectare. It is worked intothe ground which is then seeded with a mixture of selected grass species.This process not only stabilises the slopes, preventing erosion by wind andrain, but also beautifies the area and encourages the return of insect andeventually bird and animal life.

When the material is fully composted it istransported to the slopes and worked intothe ground before seeding can take place.

An extension of the companies’composting efforts, the vermicultureproject is showing encouraging results.

The Way ForwardTrials are underway to also utilise the compost in the growing of indigenousshrubs and small trees which will be transplanted onto the slopes to further theaim of returning the areas to a natural state.A new vermiculture project is intended to eventually supply the company withhigh quality vermi-compost which will be blended with the standard product.The resulting premium organic compost will be marketed to local farmers andgrowers providing additional income for the community.

Rehabilitated slope after a single winterseason shown against levels still to beattended to. Summer rains will quicklypromote healthy growth.

Tailings dam slope showing completedrehabilitation work. The next level will becomposted and seeded when it reachesa height of approximately 3 metres.

Fully composted material ready to beutilised for rehabilitation.

Compost not used for slope rehabilitationis screened to a fine consistency andmarketed to local growers.

Indigenous trees andshrubs grown withMonontsha compostwill eventually bereplanted as part of theslope rehabilitation.

Telephone 014 569 1145