EIA-REP-325d-12 _BB_ - 201.09.14.pdf - SAHRA

Significance With
Mitigation (WM)
EIA-REP-325d-11
October 2012
With
mitigation
(WM)
MEDIUM
WOM x ME = WM
36 x 0.2 = 7.2
Medium
Source of impact:
The incorrect stripping and stockpiling of soil material during the initial phases of mining can cause the material
to decline in quality. This is mostly due to the soil material not being stockpiled in the identified layers.
Description of the impact:
Soil stockpiles are not clearly defined and separated and this results in the different identified soil layers being
stockpiled on one combined stockpile. Movement of individuals and vehicles over the stockpiled soil material
results in unnecessary pollution and decrease of the soil quality.
Significance of impact:
Soil is a fundamental and ultimately finite resource that fulfils a number of functions and services for society
which are central to sustainability. Some of the most significant impacts on this resource occur as a result of
activities associated with construction activity, yet it appears that there is a general lack of awareness and
understanding of this need within the mining industry.
The extent of the impact is on the site during the construction phase. The impact is given a high intensity rating
due to the potential thereof to contribute towards ground and surface water pollution of nearby water resources.
The duration would be over the short to medium term, since the potential for soil pollution will persist throughout
the construction period. The weighting factor attributed to this impact is low and significance of the impact with
mitigation is thus also low.
Mitigation:
Construction
• The Avalon and Glencoe soils are suitable for agricultural purposes; effort should be made to strip the
topsoil separate from the underlying plinthic material;
• The soils in the wetland should be kept undisturbed;
• The average soil depth ranges from 30-90 cm overall shallower then 70cm. If soil stripping is necessary,
it is recommended to strip only 40-60cm of the soil. These estimates take into consideration a possible
10% topsoil loss through compaction and allow the rehabilitated areas to be returned to the pre-mining
land capability, i.e. arable cropping land;
• During the construction phase it is recommended that the topsoil be stripped and stockpiled in advance
of construction activities that might contaminate the soil;
• The stripped soils should be stockpiled upslope of areas of disturbance to prevent contamination of
stockpiled soils by dirty runoff or seepage;
• All stockpiles should also be protected by a bund wall to prevent erosion of stockpiled material and
deflect water runoff.
Operational
149