Quarry Southern Africa September 2018 | Page 33

ENVIRONMENT IN FOCUS regulations , which prescribe how a mining / quarry operation is required to set money aside to rehabilitate the operations and to address any latent environmental risks post closure . It is an update to existing regulations , but there is no timeline yet as to when it will be implemented ,” says Hex .

Regulation 1147 addresses mining with closure in mind . “ With a quarry , specifically , one of the problems faced when assessing for closure , is to attempt to instate a free-draining land form by closure . There are several safety risks associated with a closed quarry — that of people falling into the quarry pit , and the risk of people drowning ( depending on the size , depth , and location of the quarry , as this equates to the potential for filling with water ). An effort must be made to return the area to its pre-mining state or an agreed upon sustainable state ; though , with a quarry , you ’ re removing a significant amount of material that cannot be replaced on closure , so there has to be a compromise .”

Quarries ’ other uses

For this reason , she explains , one common option on closure is to transform closed quarries into other uses such as residential estates with a dam feature . When undertaking the initial planning of the quarry , the desired end land use has to be assessed and costed so that money can be put aside throughout the operational lifespan of the quarry . One means of preparing for this is by having a planned matrix / grid throughout the life of the quarry / mine where overburden is placed in the optimal location , which can be easily reinstated to the pit with minimal doublehandling to achieve the final end state .

“ The DMR is increasingly policing the Financial Provisioning Regulations . This responsibility is something relatively new in quarrying and mining . Previously , mining with closure in mind was unheard of — mines used to simply remove the resource with profit in mind and walk away . There ’ s been a complete paradigm shift in people ’ s thinking , which has been guided by the legislation ,” says Hex .

“ From a surface water quality perspective , in terms of quarries , what people are most concerned about is an increase in the turbidity or suspended solids , as fine dust often lands in the water , as well as hydrocarbon spills from the heavy machinery on site . For this reason , it is often advised not to service vehicles on site . Depending on the depth of mining and other aspects , the applicant may be required to apply for a water use licence for dewatering . However , before undertaking that process , an investigation to determine whether the removal of that water will have an impact on the surrounding water table should be undertaken , and that ’ s normally where stakeholders are most concerned . The public perception is typically that when a quarry is dewatered , the water table will inevitably be lowered , to the detriment of surrounding landholders who may receive a lower water yield ,” says Hex .

“ In fact , it may be a different aquifer ,” says Jones & Wagener director and head of the environmental sciences department , John Glendinning , “ and each case is sitespecific and dependent upon what resource you are removing . On a quarry , the potential for contamination is much lower than for a mine — nonetheless , a small amount of hydrocarbon can pollute a large amount of water .”

It is not uncommon for a quarry or mine to be identified as a pollution culprit . In fact , it often has neighbours consisting of industries that pollute , or farmers who add chemical fertiliser onto their crops . As to why a quarry might become the target , Hex explains that the establishment of a quarry requires an EIA process , which gives a voice to people who previously never had a public platform to voice complaints about noise , dust , vibrations from blasting ,

1 . Jacqui Hex , head of the environmental management department at Jones & Wagener as well as a technical director and environmental practitioner .

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