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

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

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Description of impact:<br />

Construction phase:<br />

It should be noted that the mine is located in an area classified as a high yield area that needs to be conserved.<br />

During the construction phase, the catchment yield (mean annual runoff) will be affected as construction<br />

activities within the footprint of the mining area could cause pollution. This water needs to be retained in a<br />

pollution control or storm water dam which will result in a decrease in storm water runoff.<br />

Operational phase:<br />

Opencast and proposed underground mining activities will increase the surface water pollution threat. Water<br />

found or contained within the open pit to be used for re-cycling and for coal washing purposes is characterised<br />

by elevated levels of nitrate, sodium, sulphate, hardness and conductivity. Exposure of “fresh” weathered<br />

overburden materials to natural elements such as water and oxygen might have the potential to accelerate the<br />

acidification of pyritic material by the generation of Acid Rock Drainage (ARD) leachate with the concomitant<br />

decrease in pH and mobilization of metals such as Fe, Al and Mn.<br />

Significance:<br />

The impact on surface water quality will be negative, possible of medium term duration low magnitude, may<br />

extent from the site and is of low significance overall. Mitigation will be required.<br />

Mitigation:<br />

• Prevention of overspill of mining activities, and associated activities into the surrounding streams and<br />

rivers. Implementation of the necessary monitoring and management programmes to ensure the<br />

integrity of all water resources in the area during the construction, and operational lifespan of the mine;<br />

• Containment of return waters in a clay lined return water dam;<br />

• Re-cycling of contaminated runoff waters from lined settling and evaporation dams;<br />

• Sealing of process waters circuit and containment structures;<br />

• Separate clean and dirty water systems; and<br />

• Provide sufficient storage capacity to contain contaminated waters i.e. adopt a zero discharge policy.<br />

Table 22: Destruction of Wetland Habitat<br />

Activity Mining Activities and construction of an access road during the Operational Phase<br />

Nature of the<br />

Destruction of Wetland Habitat Status -<br />

impact<br />

Receiving<br />

environment<br />

Magnitude<br />

Weighting factor<br />

(WF)<br />

Mitigation<br />

Efficiency (ME)<br />

Significance<br />

<strong>EIA</strong>-<strong>REP</strong>-<strong>325d</strong>-11<br />

October 20<strong>12</strong><br />

Wetlands on the Usutu Site<br />

Extent (footprint; site; regional; national; international) SITE<br />

Intensity (low; medium; high) HIGH<br />

Duration (short; short-med; medium; long; permanent) PERMANENT<br />

Probability (Improbable; possible; likely; highly likely; definite) LIKELY<br />

WF (low; low-medium; medium; medium-high; high) HIGH<br />

ME (high; medium-high; medium; low-medium; low) MEDIUM<br />

Without<br />

mitigation<br />

(WOM)<br />

With<br />

mitigation<br />

(WM)<br />

(Extent + Intensity + Duration + Probability) x Weighting Factor<br />

(2 + 5+ 5+ 3) x 5 = 75<br />

Medium – High<br />

WOM x ME = WM<br />

75 x 0.6 = 45<br />

Medium<br />

<strong>12</strong>6

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