Optimization of waste reduction in the construction sector: the case study of the eThekwini Municipality in South Africa.
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Date
2021
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Abstract
Although South Africa is on the road to a greener future through the Act No. 26 of 2014: National
Environmental Management: Waste Amendment Act 2014, the South African Waste Report
(Department of Environmental Affairs, 2018b) states that in 2017, 48% of the overall construction
and demolition waste was landfilled. This percentage indicates that an extensive quantity of
valuable and recyclable construction and demolition (C&D) waste is disposed to landfills or
utilized in insignificant applications. The eThekwini Municipality, the third largest municipality in
South Africa, has diminishing airspace of its landfills. Construction and demolition waste
consumes approximately 40% of eThekwini Municipality’s landfill airspace. The Integrated Waste
Management Plan of Durban Solid Waste Unit (DSW) of the eThekwini Municipality does not
include a specific construction and demolition waste management strategy. Therefore the
eThekwini municipality was chosen as the case study for this research. The Waste and Resource
Optimisation Scenario Evaluation (WROSE) model is a decision-making tool that was developed
in South Africa by UKZN to enable municipalities to optimise their waste management strategies.
This study aims to establish the most economical, social, and environmentally feasible C&D waste
management scenario to be implemented in the eThekwini Municipality as well as to expand the
WROSE model to include different C&D waste management strategies. The literature review
showed the relevance of research, critically evaluating the waste management strategies that are
practiced internationally and nationally. This was followed by a waste stream analysis of DSW’s
weighbridge data. This data was utilized in the creation of valorisation scenarios for C&D waste,
which were inputted in the WROSE model. Various scenarios were investigated to determine
sustainable management of C&D waste that included landfilling, landfilling with recovery of rubble
for creation of access roads in landfills; 50% diversion from being landfilled and recycling of the
aggregates by DSW; as well as 65% diversion and recycling by a specialised company. Analysis
of the weighbridge data indicated that approximately 40% of the eThekwini municipality’s MSW
is C&D waste, with builders rubble increase rate of 1000 tons per year and Sand and Cover
material increase rate of 10 800 tons per year. The WROSE outputs included Landfill Space
Savings, Job Creation Potential and Economic Feasibility of the scenarios analysed. The analysis
conducted using the WROSE Model show that a total of 3 300 000 m3 of landfill airspace can be
saved, 59 jobs created, and R 108 000 000 generated at Buffelsdraai and Lovu landfills over the
next ten years. Implementing the scenarios and recommendations displayed in this study will aid
the eThekwini municipality in finding a solution to the diminishing landfill airspace problem and
overall improve society by saving valuable natural resources, creating jobs and uplifting the
community.
Description
Masters Degree. University of KwaZulu- Natal, Durban.