2022 Sasol Sustainability Report - Book - Page 54
SUSTAINABILITY PERFORMANCE AGAINST OUR FOCUS AREAS
INTRODUCTION
DATA AND ASSURANCE
MANAGING OUR ENVIRONMENTAL FOOTPRINT (CONTINUED)
Air quality management (continued)
WHAT WE ARE DOING (CONTINUED)
If a favourable postponement decision is received, the AEL will be updated
to reflect the extended compliance time frame for meeting the new plant
standard and the limits applying in the interim.
Air quality offsetting programme
In Secunda, phase one of the air quality offsetting programme focused
on the reduction of particulate matter (PM) and SO2 pollution in the
surrounding (fenceline) communities. In Sasolburg and Natref, the air
quality offsetting programme focused on the reduction of PM and SO2
pollution from non-industrial sources and included the continuation of
specific activities implemented since 2015. The activities for these
operations were detailed in Sasol’s 2021 SR on page 46 and have thus
far resulted in the avoidance of emissions of more than 207 tons of PM10,
194 tons of PM2,5 and 80 tons of SO2 in the surrounding community/
airshed. We remain committed to implement the second phase of our
offsetting implementation plan toward 2025 (aligned with the 1 April 2025
extended compliance date) which, among other initiatives, includes an
environmental air quality education and awareness programme which
was expanded to include campaigns on veld fire management and
prevention as well as the sorting and recycling of waste.
Source apportionment
We continue to contribute to achieving the goals set out in the
Vaal and Highveld priority area improvement plans and believe
that a holistic, integrated approach to air quality management is
required to achieve these goals and objectives. A fundamental
part to this is the concept of source apportionment which is
essentially an understanding and quantification of all sources
that contribute to the quality of the air we breathe (specific to
an airshed). Source apportionment, supported by accurate
emission inventories, is an effective air quality management
tool to identify and quantify the sources resulting in effective
strategy development to mitigate and reduce these emissions
to achieve an overall ambient benefit.
All our activities are regulated through licences issued by
the authorities in the different geographies where we operate.
These licences require that we report frequently on our
emissions to authorities as well as the timeous submission
of comprehensive annual air quality compliance reports in
South Africa. Refer to page 64 to 65 for more detail on our
environmental compliance.
Source apportionment
The schematic below attempts to explain the significance of source apportionment. It highlights the difference between point source
minimum emission standards (MES) and the National Ambient Air Quality Standards (NAAQS). The MES aim to control sources of pollution
so that the ambient air quality (essentially the air that we breathe) does not present risks to human health and the environment.
The NAAQS, published by DFFE, prescribe tolerable concentrations of pollution in ambient air. Sasol has various ambient air monitoring
stations around its facilities to measure the concentration from combined sources over a period of time for different pollutants which
include, but are not limited to, SO2, NOx and PMs. Industry is not the only contributor to the ambient air quality, there are other
contributors such as traffic emissions, veld fires and household air pollution from inefficient cooking practices. To understand and quantify
the contribution of the different sources per pollutant, analytical approaches and mathematical models are used. Once the additional
contributors, over and above industry’s contribution, are understood, it is easier to implement effective reduction mechanisms on ground
level, which will have a positive impact on the ambient air. Sasol’s offsetting programme, which attempts to address inefficient cooking
practices and veld fire management, among various other initiatives, has a positive impact on the ambient air quality. Source
apportionment not only considers the various contributors to the ambient air quality, but also considers that different sources have
different impacts no matter the quantity that is emitted. This means that tall stacks typically seen in industry and ground level emitters
(eg meteorological conditions, atmospheric chemistry) behave differently which result in different ambient impacts.
The air quality monitoring station
(AQMS) measures a concentration
(ug/m3) from combined sources
over a time period for different
pollutants ie SO2, PM, H2S etc.
Statistical and analytical
approaches and mathematical
models are then used to identify
and quantify the contribution of
different sources per pollutant.
Source A
Source B
Source C
Source D
Source E
Weather (wind, rain, sunshine)
Chemical transformation
Emissions
Emissions
MES
NAAQS
Ambient air quality
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