Waste
Findings
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Landfills are the main method of disposal of waste in the country. Emit methane and
carbon dioxide
Local governments can lead integrated waste management services and make a
significant impact in terms of GHG reduction. Can change a per capita net positive GHG
emissions to a net GHG negative emissions situation by replacing ff generated electricity
with renewable energy, avoiding manufacturing energy consumption for virgin materials
and reducing methane emissions from landfills.
Reduction of GHG emissions in the waste sector can be achieved in a variety of ways:
1. Recovering materials for recycling into new products, thus avoiding the energyconsuming beneficiation and primary manufacturing processes that is otherwise
necessary in the use of virgin materials.
2. Reducing emissions of landfill gas (an approximately 50:50 mixture of methane
(CH4) and carbon dioxide (CO2) by better landfill practice and by reducing the
organic wastes entering the site.
3. Utilising and/flaring off landfill gas for both heat and electricity generation.
4. Reducing methane emissions from wet anaerobic processes e.g. sludges.
5. Recovering energy and reducing carbon emissions from waste using Mechanical
Biological Treatment processes.
6. Utilising the carbon dioxide from combined heat and power plants as a carbon
dioxide fertiliser in greenhouses.
Current initiatives in municipality
1. Materials recovery for recycling – Materials Recovery Centre
 Separation at source with kerbside collection – orange bags
 Materials recovery facilities –drop off centres, buy-back centres, mixed
waste materials recovery facilities
 Recovery of reusable material through an MRF has the following
benefits:–
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Plastics recovery reduces emissions related to the refining of fossil
fuels, from which plastics are derived.
Production of any type of paper involves the capture of carbon
through the growth of trees used as raw material. Approximately 30%
less energy is required to produce good quality recycled paper than to
produce virgin paper.
Recovered metals, whether ferrous or non-ferrous, may be re-smelted
with substantial energy savings.
Glass re-smelted saves substantial energy.
Opportunities for job creation in the sorting system: the Mariannhill
MRF employs 100 previously unemployed workers.
Rejected material and biodegradable organic waste is either landfilled
or, better still, passed on to the next step in Mechanical Biological
Treatment, which could include the anaerobic digestion treatment
stage, where energy may be generated. This is already under
consideration at Mariannhill Landfill.
Challenges:
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Many people abuse the Mondi recycling service and use the orange bags
for other waste.
The population does not care about recycling
Glass is not currently being recycled due to the transportation costs of
getting the glass to the recyclers
Recycling must be considered not only from a materials recovery
perspective but also from the point of view of energy usage in
transportation, water consumption of rinsing soiled recyclable materials
It seemed unlikely to the DSW officials that incentives would work to
encourage people to dispose of waste
2. Composting
3. Energy recovery
 Landfill gas to electricity projects – CDM project installed at 3 landfills: La
Mercy (not continued), Mariannhill and Bisasar Rd. – 10MW potential.
Good learning experience
 Waste water to energy projects- aerobic waste water treatment processes
used at most WWTWs are energy intensive – consume large amounts of
energy to drive the activated sludge process. Move to return to anaerobic
digestion technology.
 Small scale anaerobic digesters –on site digesters are being promoted.
Small system is in operation at Cato Crest – produces 60kW of electricity
for use at community centre. Treated effluent is used for food garden.
 Urine diversion toilets – 90 000 been installed. Require no electricity and
little water.
4. Other planned projects
 Biodiesel project – transform algae from maturation ponds to biodiesel
 Sewage sludge disposal plan – trying to dispose of sludge at WWTWs.
Also investigating it for generate electricity
 Mariannhill Mechanical Biological Waste Treatment (MBT) to Energy
CDM project
 eThekwini Southern WWTW Anaerobic Digestion (AD) Biogas to Energy
project – treatment of raw sludge by anaerobic digestion biological
processes, generation to electricity using methane rich biogas and
production of compost and nutrient rich fertilizer.
Further opportunities to reduce GHG emissions
 Waste avoidance and recycling – Ewaste recovery, green procurement policies,
cleaner production processes, waste exchanges
 Mechanical Biological Treatment incorporating waste to energy
Draft Recommendations
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Expand kerbside collection of mixed paper and plastic through orange plastic bags to
additional residential areas (planned)
Improve and expand education programmes on recycling of materials to foster greater
awareness and use of kerbside collection of mixed paper and plastic and drop-off
centres (being done)
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Increase the number of Buy-Back Centre – provide carts/wagons to unemployed people
(collect from centre – pay deposit and return at the end of the day)
Expand (give more land) to Material Recovery Facility at Mariannhill landfill that is aimed
diverting (recovering) recyclable materials from mixed waste stream (currently only
handling domestic – could expand to industrial)
Make a plan for glass
Encourage small-scale composting of organic waste at household level – urban
agriculture
Promote the use of anaerobic digestion technology at municipal WWTWs and use
methane produce to generate electricity in gas engines and use waste heat to improve
rate of biodegradation
Promote the use of safe on-site sanitation (septic tanks??) in new development areas (to
avoid high elec requirement of WWTW with activated sludge units
Promote the disposal of e-waste (electronic hardware) to EWASA-accredited recyclers
Promote the education of the public on disposal of e-waste (include in education
programme)
Introduce clause in the procurement policy of the municipality that permits purchase of
hardware only from members of EWASA to ensure that recovery and recycling is
assured
Introduce a clause in the procurement policy of the municipality the only permits the use
of paper with a guaranteed recycled fibre content
Stimulate the formation of Waste Minimisation Clubs in industrial areas
Undertake (Encourage) a feasibility study for waste exchanges in industrial areas –
where wastes from one industrial process are used as feedstock for another process by
a different industry
Investigate dry anaerobic digestion options for reducing the amount of waste going to a
landfill
CDM
The AFD loan was probably a key factor that made the eThekwini Landfill Gas to
Electricity Project possible. Knowledge gained from this successful project is valuable for
informing other potential gas-to-electricity projects and building capacity to replicate
similar projects. The report found that there was a need for a practical follow-up
workshop with decision makers and implementers from other Municipalities and larger
cities that contemplate engaging in similar projects to assist them in moving forward.
Recommendations
There is a growing body of evidence based not only on Life Cycle Assessment but also on reallife studies that local government can lead integrated waste management activities and make a
significant difference in terms of GHG reduction
Reduction of GHG emissions in the waste sector can be achieved in a variety of ways:





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Recovering materials for recycling into new products, thus avoiding the energyconsuming beneficiation and primary manufacturing processes that is otherwise
necessary in the use of virgin materials.
Reducing emissions of landfill gas (an approximately 50:50 mixture of methane (CH4)
and carbon dioxide (CO2) by better landfill practice and by reducing the organic wastes
entering the site.
Utilising and/flaring off landfill gas for both heat and electricity generation.
Reducing methane emissions from wet anaerobic processes e.g. sludges.
Recovering energy and reducing carbon emissions from waste using Mechanical
Biological Treatment processes.
Utilising the carbon dioxide from combined heat and power plants as a carbon dioxide
fertiliser in greenhouses.
DROP-OFF CENTRES
Drop-off centres may become unsightly open dumps if strict supervision is not exercised over
the deposition of recycled material, but generally work well when placed under the direct control
of local authorities who can enforce by-laws that prevent littering. These centres also work
successfully when located at garden refuse transfer stations that are managed by local
authorities.
MRFS
a MRF such as this to remain viable, it needs to receive a share of the tipping fees recovered by
DSW through the weighbridge operation. This MRF remains viable because of the formal
commitment by DSW and Re- todiverting waste and recovering recyclables as part of the
eThekwini Metro carbon footprint reduction and metro greening effort.
COMPOSTING
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introduce shallow trench gardening as an option for organic waste management
The study further suggested that co-operatives of were the most effective organisational
arrangement when running composting schemes in communities.
WASTE WATER TO ENERGY
The aerobic waste water treatment processes used at most WWTWs are energy-intensive, in
that they consume large amounts of electricity to drive the activated sludge process. One
mitigation measure to avoid this is to revert to anaerobic digesters which have much lower
energy requirements.
Added benefits can be achieved by using this methane to generate electricity in gas engines.
The electricity generated can be used to drive the mixers within the anaerobic digesters which
are essential for efficient biodegradation.
Wastewater treatment plants with activated sludge units have very high-impact global warming
scores (carbon footprinting) due to their high electricity requirements. Wherever appropriate,
safe on-site sanitation should be promoted because of the environmental advantages
associated with lower energy requirements (collection and secondary treatment are not
necessary) and sustainability.
Waste avoidance and recycling
Significant progress can be made in reducing a municipality’s carbon footprint by increasing
waste avoidance and recycling in the following areas:
Ewaste recovery
Policy should state that hardware should be purchased only from members of EWASA to
ensure that its recovery and recycling is assured. Similarly electronic hardware should not be
disposed of except to EWASA-accredited recyclers.
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Green procurement policies
The use of paper with guaranteed recycled fibre content should be written into municipal
procurement policy and procedures, to stimulate demand and create a market for recycled
paper.
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Cleaner production processes
Cleaner production in industry, supported through the formation of Waste Minimisation Clubs,
will significantly reduce wastage and the quantities of waste going to landfill. This will need the
commitment of industry and will need to be driven by a champion, whether this is an
organisation or an individual, with strong support from the municipality. .
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Waste Exchanges
Industry and municipalities can implement waste exchanges. These initiatives have been
successfully set up in areas such as Cape Town but are highly dependent on there being an
active product champion, usually an individual with strong backing from the municipality.
Mechanical Biological Treatment incorporating Waste to Energy
MBT options must be considered if a low carbon footprint is a priority.
Pre-treatment of municipal solid wastes prior to disposal, to reduce the volumes of waste to be
transported and disposed of at landfills, as well as negative emissions from the organic contents
of municipal solid waste.