Tiwest has a progressive rehabilitation program in place for land disturbed during the mining process at Cooljarloo.
The company's rehabilitation objective is to return all farmland to an agricultural capability typical of the region and to establish stable, resilient, self perpetuating natural ecosystems compatible with surrounding undisturbed bushland areas.
All mining operations at Cooljarloo begin with the collection of native plant seeds from mature vegetation ahead of the mine path. In preparation for mining, the site is cleared and the topsoil removed and stored ready to be returned in rehabilitation activities, unless immediate respreading of topsoil is possible.
As mining operations move through the orebody, sand and clay are returned to fill the void and the surface is contoured to landforms similar to those that existed prior to mining.
Because less than five per cent of the total sands mined are removed during mining, the rehabilitation program can establish similar landforms and ecosystems to the original countryside.
In 2002 Tiwest introduced an innovative and sustainable slimes management strategy to resolve problems associated with disposing of wet clay slurry at Cooljarloo. The inability for the clay to settle and dry out when deposited in deep mine voids has previously made rehabilitation more difficult.
As part of its long term environmental focus, Tiwest now uses purpose-built cells to solar dry the clay slurry in areas of already disturbed land. Once the slurry cells are dry, the material is excavated and incorporated into the rehabilitation process.
Tiwest undertakes annual monitoring of rehabilitation areas at Cooljarloo to measure the evolution of mined land towards a steady state natural ecosystem.
Tiwest continues to develop and refine its rehabilitation standards, techniques and monitoring protocols in close consultation with the Department of Environment and Conservation (DEC) and other regulatory authorities.