SOIL AND MINERALS

DEGRADATION OF SOIL

• Population growth
• Overstocking
• Overgrazing
• Open mining
• Pollution on land
• Intensive Farming
• Deforestation

IMPACTS ON SOIL

• Land disturbances.
• Scarring of land.
• Disruption of the land surface.
• Spoil heaps and tailings.
• Sink holes.
• Dust.
• Toxic substances.
• Acid mine drainage.
• Water pollution

Soil Management

• Soil management is a fundamental part of any project
• Consideration must be given in the design stage, during development work and in completion to:
– Soil type;
– Structure; and
– Chemistry.

• This will ensure that:

– Environmental values are not compromised.
– Contaminated / reactive soils are not disturbed.
– Development features are not compromised by changes to soil characteristics.

• Manage soil during development activities by:

– Identifying soil types and potential impacts on development.
– Managing and remediation of contaminated soils.
– Avoiding of impacts from erosion and sedimentation as well as impacts to waterways and wetlands.

– Managing topsoil.

• Feasibility and planning.
• Design.
• Construction.
• Lot creation. Avoidance.
• Minimisation.
• Management.

MANAGING/REDUCING IMPACTS

AVOIDANCE:

• Investigate potential site issues during feasibility/planning stages.
• This will provide for appropriate identification of potentially complex soils which may impact on development.

Most simplistic method to manage these types of soils is to avoid their disturbance

MINIMISATION:

If total avoidance of complex soils is not possible:

• design the development to minimise the extent of soil disturbed, or
• minimise the types of development features in those areas which will result in extensive disturbance (e.g. significant excavation for construction/placement of infrastructure).

MANAGEMENT:

• Erosion and sediment control.
• Removal and disposal of contaminated soils.
• Onsite remediation.

BENEFITS OF SOIL MANAGEMENT:

• Avoidance/minimisation of environmental harm and costs associated with remediation.
• Costs for strategic remediation and reuse/reburial of complex or contaminated soil types.
• Retention and reuse of topsoil minimises costs

RISKS FROM MIS-MANAGEMENT OF SOIL:

• Environmental damage and remediation costs.
• Costs associated with regulatory action.
• Damage to buildings, structures, etc.
• Repair/remediation costs.
• Increase (hidden) costs.
• Loss of revenue.

SAVINGS FROM SOIL MANAGEMENT:

Savings from appropriate soil management during development activities may come in the form of financial and/or time savings. Savings will largely accrue through the avoidance of additional costs as a result of:

• thorough investigation and proper planning,
• appropriate management of soil according to results of feasibility investigations and development planning,
• application of appropriate environmental management methods and technologies,
• avoidance of additional costs for remedial actions in the event of an environmental incident arising from soil mobilisation,
• reduced potential for additional costs for remedial action, repairs, replacement of development features, etc.

COST OF SOIL MANAGEMENT

Direct costs associated with soil management in the development process include:

• Feasibility – preliminary soil mapping/investigation, contaminated land searches, etc.
• Planning and design – detailed soil investigation;
Construction – engineering costs, machinery operation costs, materials e.g. agricultural lime (AgLime) for ASS treatment, geotextiles, plant stock, etc

DEVELOPMENT PHASE ACTIONS:

• Feasibility.
• Design.
• Construction.
• Lot creation.
• Completion.

FEASIBILITY

Relevant tasks:

• Undertake site investigation.
• Obtain soil mapping.
• Investigation of likely soil contamination.
• Assessment of topography.
• Identification of environmental features, waterways and drainage.


DESIGN

• Engineering planning
• Development design to maximise avoidance of complex soils (where possible)
• Identification of appropriate management (mechanisms/approaches to dealing with soil issues e.g. dealing with acid sulfate soils and/or contaminated soils.)
• Prepare site management, construction management, environmental management plans as required.
• Establish training/site awareness mechanisms/protocols to be applicable during construction stages


CONSTRUCTION

• Site establishment.
• Soil and erosion control
• Appropriate management of particular soil types.
• Implement and maintain storm water management
• Undertake topsoil management
• Landscaping and site restoration.

LOT CREATION AND COMPLETION

Lot completion:

• Undertake site establishment for individual allotments.
• Provide appropriate site management, including stockpile management, storm water management, construction management, materials management - stockpiling and storage, and site stabilisation/landscaping.

Completion:

• Decommissioning of site management works.

REHABILITATION OF SOIL

• Not reactive but proactive.
• Conservation of topsoil.
• Prevention is better than cure.
• Part of environmental management programme.

HOW CAN YOU HELP TO PROTECT THE SOIL?

At work:

• Rehabilitation of land.
• Prevention of soil erosion.
• Protecting the topsoil.

At home:

• Planting trees.
• Planting vegetables.
• Planting grass.

Making your own compost.

• Prevent veldfires.
• Do not litter.
• Prevent soil erosion.