2 Otjikoto Final EIA Report 5MB - Asecnam.com

SLR Namibia (Pty) Ltd
SLR Ref.733.01023.0002
Report No.1
Page ix
Air - The air quality assessment focused on airborne particulates (PM10 emissions and total suspended
particles). Gaseous pollutants (such as sulphur dioxide, oxides of nitrogen, carbon monoxide etc.)
deriving from mine vehicles and equipment and from the gold smelting operations could not be assessed
but were regarded by the specialist as potentially negligible in comparison to particulate emissions.
The main contributing sources to both the unmitigated and mitigated PM10 predicted impacts are firstly
the unpaved roads specifically between the open-pit and the waste rock dump, and secondly the
materials handling operations and over the short term windblown dust from the TDF. In the unmitigated
scenarios the PM10 ground level concentrations exceed the WHO-IT3 limit at all sensitive receptors.
With mitigation these exceedances can be reduced and the impact area becomes much smaller. Some
exceedances are still predicted, regarding the WHO-IT3 daily limit. The annualWHO-IT3 limits for PM10
ground level concentration are not exceeded at any potential receptor areas in the mitigated scenario.
A number of uncertainties are associated with the calculation and simulation of fugitive dust from
unpaved roads and windblown dust resulting in expected conservative ground level concentrations
(GLCs). This is in addition to the inherent model uncertainty of -50% to 200%. Therefore, with effective
mitigation the impacts reduce significantly and can be limited to on-site only as indicated by the annual
average GLCs.
The proposed mitigation measures therefore focus on the use of water sprays, vegetation cover at
relevant areas and suppressants to achieve certain control efficiencies and monitoring the effectiveness
of these measures.
Noise - Excluding one noise sensitive development (NSD01), the severity of the noise impact is
considered to be low for all potentially noise-sensitive developments. Considering a worse-case scenario
the severity of the potential noise impact could be a medium on NSD01. It should be noted that the
unmitigated medium severity is based on the fact that there is the potential that the operation of the mine
will increase the ambient sound levels at night by more than 7 dBA at this one property. As such, it is
possible that the receptor (NSD01) will detect the change in ambient sound level, yet is it is unlikely that
the receptor may complain, as the total cumulative night-time noise level is still predicted to be less than
35 dBA (a level determined to be the level where rural communities may start to complain about the
increased noise levels). NSD01 (farm house), however, belongs to the developer, hence the
implementation of mitigation measures can include no permanent occupation of the farm house during
operations.
Blasting - In the unmitigated scenario, the probability of blasting hazards resulting in either damage
and/or creating a nuisance is low due to the location of the project site and limited third party
infrastructure in the vicinity of the open pit. In addition, as the pit deepens, the blast will be contained
Otjikoto Gold Mine EIA Report July 2012