Revised Bronkhorstspruit Biogas Plant EMP Rev 2
Transcript of Revised Bronkhorstspruit Biogas Plant EMP Rev 2
BRONKHORSTSPRUIT BIOGAS PLANT (PTY) LTD
BIOMASS-TO-ELECTRICITY PLANT,
BRONKHORSTSPRUIT
ENVIRONMENTAL MANAGEMENT PROGRAMME
GDACE Reference No. Gaut 002/07-08/N1193
JUNE 2013
Prepared for:
BRONKHORSTSPRUIT BIOGAS PLANT (PTY) LTD
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TABLE OF CONTENTS
BRONKHORSTSPRUIT BIOGAS PLANT (PTY) LTD
1. Introduction ............................................................................................................ 5
1.1 Authors Details and Expertise ................................................................................. 5
1.2 Proponents’s Details .............................................................................................. 7
2 Legislative Framework ........................................................................................ 8
2.1 The Constitution of South Africa (No. 108 of 1996) .................................................... 8
2.2 The National Environmental Management Act (No. 107 of 1998) ................................. 8
2.3 Environmental Impact Assessment Regulations, 2009 .............................................. 11
2.4 National Heritage Resources Act (No. 25 of 1999) ................................................... 11
2.5 The National Water Act (No 36 of 1998) ................................................................. 11
2.5.1 Water use licensing ........................................................................................ 11
2.5.2 Pollution of water resources ............................................................................. 12
2.6 National Environmental Management: Air Quality Act (No. 39 of 2004): ..................... 12
2.7 The National Environmental Management: Waste Act (Act 59 of 2008)....................... 12
3 Project Location ............................................................................................... 14
4 Overview of Affected Environment...................................................................... 15
4.1 Biophysical Environment ...................................................................................... 15
4.1.1 Climate ......................................................................................................... 15
4.1.2 Topography ................................................................................................... 15
4.1.3 Geology ........................................................................................................ 15
4.1.4 Soils ............................................................................................................. 15
4.1.5 Land Use and Surface Infrastructure ................................................................. 15
4.1.6 Flora ............................................................................................................. 15
4.1.7 Fauna ........................................................................................................... 16
4.1.8 Surface Water ................................................................................................ 16
4.1.9 Ground Water ................................................................................................ 16
4.1.10 Air Quality ..................................................................................................... 16
4.1.11 Noise ............................................................................................................ 16
4.1.12 Traffic ........................................................................................................... 16
4.1.13 Archaeology and Heritage................................................................................ 17
4.2 Socio-economic Environment ................................................................................ 17
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5 Project Description ........................................................................................... 19
5.1 Simplified Microbiology of a Anaerobic Digester Plant ............................................... 19
5.2 Proposed Raw Material Waste Streams ................................................................... 20
5.2.1 Cattle Manure .................................................................................................. 20
5.2.2 Abattoir Waste ................................................................................................. 21
5.2.3 Organic food and beverage waste ...................................................................... 21
5.3 Project Infrastructure Components ........................................................................ 21
5.3.1 Slurry tank .................................................................................................... 24
5.3.2 Mixing tank ................................................................................................... 24
5.3.3 Continuous Stirred Tank Reactor- CSTR ............................................................ 24
5.3.4 Biogas Plant Storage structures........................................................................ 27
5.3.5 Solids Treatment for Fertiliser .......................................................................... 27
5.3.6 Aerobic Water Treatment System ..................................................................... 28
a) Sequenced Batch Reactor ..................................................................................... 28
b) Balance Pond ...................................................................................................... 28
5.3.7 Gas Cooling Plant ........................................................................................... 29
5.3.8 Flare ............................................................................................................. 29
5.3.9 Scrubber ....................................................................................................... 30
a) Effects of Hydrogen sulphide (H2S) in Biogas .......................................................... 30
b) Biotrickling Filter Biogas Desulphurisation (BRF-BGD) System ................................... 31
5.3.10 Gas Cooling Plant ........................................................................................... 32
5.3.11 Biogas Fired Power Generation ......................................................................... 32
5.3.12 Electricity connection and supply ...................................................................... 33
5.3.13 Stormwater Management ................................................................................ 33
5.3.14 Manure storage area ....................................................................................... 33
6 Project Phases and Proposed Activities ................................................................ 34
6.1 Construction ....................................................................................................... 34
6.2 Operation ........................................................................................................... 34
6.3 Decommissioning ................................................................................................ 35
7 Summary of Potential Impacts Identified ............................................................ 36
7.1 Ecological (Fauna and Flora) impacts ..................................................................... 36
7.2 Impact on Hygiene and Sanitation ......................................................................... 36
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7.3 Socio-economic impacts ....................................................................................... 36
7.4 Impact on Atmospheric emissions ......................................................................... 37
7.5 Impact on heritage resources................................................................................ 38
7.6 Impact on Groundwater ....................................................................................... 39
7.7 Impact on Surface Water ...................................................................................... 39
8 Proponents Commitments Regarding Environmental Management .......................... 41
8.1 Party Responsible for Environmental Management ................................................... 41
8.2 Incident Reporting and Record Keeping .................................................................. 41
8.2.1 Incident Reporting .......................................................................................... 41
8.3 Environmental Monitoring ..................................................................................... 41
8.3.1 Groundwater and Surface Water Monitoring ....................................................... 41
8.3.2 EMP Performance Assessment .......................................................................... 42
8.3.3 Health and Safety........................................................................................... 43
9 Environmental Mitigation Measures .................................................................... 44
10 References ................................................................................................... 82
List of Figures
Figure 1 Locality Plan of Proposed Biomass to Electricity Plant, from 1 in 50 000 topographical map
...................................................................................................................................... 14
Figure 3: Schematic diagram of Biogas Process ............................................................. 20
Figure 4. Process Schematic Diagram ........................................................................... 23
Figure 5. Different structures associated with horizontal, concrete silage pits. Walls are sealed
into the base to prevent leakage. The front remains open to allow front end loader access.
(Example taken from http://www.rebuildings.co.uk/concrete.html) Error! Bookmark not defined.
Figure 6. Continuous stirred-tank reactors (CSTRs) – Basic Flow Diagram ......................... 26
Figure 7. View of a typical flare stack ........................................................................... 30
Figure 7. Biotrickling Filter Biogas Desulphurisation System ............................................ 31
Figure 8: Simplified operational process for Biomass-to-Energy PlantError! Bookmark not
defined.
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1. INTRODUCTION
Integrated Environmental Management (IEM) comprises a set of procedures to be followed for any
project with the goal of achieving sustainable development1. The most widely recognised
procedure of IEM is the Environmental Impact Assessment (EIA) due to it’s inception as a
legislated process in South Africa since 19971,2. The goal of an EIA is to identify and assess any
possible impacts which a development may have on the surrounding environment, both at the
environmental and at the social/economical level. While the EIA focuses on the assessment phase
of the process of IEM2, the implementation of impact management and monitoring at all stages of
the project life-cycle, as identified in the EIA, is accomplished through the Environmental
Management Programme (EMP)1.
An EMP can be defined as “an environmental management tool used to ensure that undue or
reasonably avoidable adverse impacts of the construction, operation and decommissioning of a
project are prevented; and that the positive benefits of the projects are enhanced”1. This EMP is
thus to serve as a guideline for the owner, contractor and workforce involved with the
development, operation and decommissioning of the Bronkhorstspruit Biogas Plant (BBP) in
Bronkhorstspruit, Gauteng, of their responsibilities with regard to environmental management and
monitoring at the proposed site.
It is the purpose of this EMP to:
• Contribute towards environmental awareness of workforce2,
• Facilitate the prevention of environmental degradation2,
• Minimise impacts of unavoidable environmental degradation2,
• Demonstrate commitment to implementation of mitigation actions by adding value to decision-
making2,
• Facilitate progress towards environmental targets and objectives2 throughout the project-
lifecycle, i.e. at construction, operation and decommissioning1,
• Assist in the continual approval of the company’s environmental performance2,
• Ensure compliance with applicable local and national policies, legislation and guidelines1,
• Ensure that sufficient resources are allocated on the project budget to maintain the scope of
the environmental responsibilities regarding the project1,
• Responding to events and mitigating impacts as they occur even if not necessarily included in
the EIA1,
• Provide details of practical measures specific to the responsible people as well as the relevant
timeframe for reaching said objectives1,
• Clarify organisational roles within the project scope with regard to record keeping, reviewing,
auditing and updating of the EMP1.
1.1 Authors Details and Expertise
This Environmental Management Programme has been compiled by Karen-Dawn Koen and
Jonathan van de Wouw of Core Earth Resources and has been reviewed by Peter Theron for Core
Earth Resources. Core Earth Resources is an independent environmental consultancy that was
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established in 2006. The founding member Karen-Dawn Koen has over 13 years of experience in
the field of environmental management. Below are short Curriculum Vitas of the project team.
Karen-Dawn Koen (BA Hons Environmental Management and PGD: Sustainable Development -
Current)
Karen has over 13 years experience in undertaking environmental impact assessments, ISO 14001
compliant environmental management systems, environmental auditing and environmental
management plans for construction phase. Her project work has focused on undertaking
environmental impact assessments for linear developments such as roads, pipelines and
powerlines, land-use change applications, power generation facilities and telecommunication
towers as well as developing and implementing ISO 14001 compliant environmental management
systems for airports, industrial entities and the Chapmans Peak Toll Road. She has personally
project managed a number of environmental projects, managed specialists and have been involved
in a number of civil engineering projects since 2000 combining aspects of environmental
legislation, environmental management and project management. Key environmental impact
assessment undertaken includes the following:
• Dreamworld Film Studio and house Estate EIA, Cape Town
• Berg River Farm Mix-Use Development EIA, Paarl
• Mossel Bay Open Cycle Gas Turbine (OCGT) EIA, Cape Town
• Environmental Impact Assessment and Management Plans for a number of 132kV overhead
powerlines on behalf of Eskom Distribution, Western Cape
• Oudtshoorn Landfill site EIA, Western Cape
Peter Theron – (BSc Civil Engineering, GDE (Hons.) Environmental Engineering)
Peter has over 21 years of experience in environmental management, auditing, due-diligence and
impact assessments as well as civil engineering design, tailings, geotechnics and tunneling.
Recent focus of his project work has been related to project management of environmental
assessments, advising on environmental legislation and permitting, environmental due diligence
investigations and environmental risk assessments. His specialist skills are the integration of the
technical design into the environmental management process. Clients and projects have been
focused around the mining, industrial and government sectors. He has personally project
managed over 200 environmental projects since 1986, combining aspects of environmental
legislation, environmental management, civil engineering and project management. Key
environmental impact assessment undertaken includes the following:
• Uranium Mine EIA , Klerksdorp
• Gold Mine EIA, Springs
• EIA and Environmental contract implementation on behalf of Lebalelo Water Users Association.
• Project manager for the scoping study phase for the conversion of Sasol from coal-fired to
natural gas.
• Southern Era Voorspoed Project Manager for the environmental impact assessment and
subsequent EMPR.
• Potable and TSE water Basic Assessment, Klerksdorp
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Jonathan van de Vouw (BSc (Hons) Microbiology and Biotechnology)
Jonathan has working experience in the field of Environmental Microbiology and Biotechnology and
has recently shifted his area of focus to Environmental Science and Consulting at his current
position at Prime Resources (Pty) Ltd. He has received experience and training in Environmental
Management in the form of Scoping Reports and Environmental Management Plans and Impact
Assessments for companies in both the mining and industrial sector as well as environmental
auditing of industrial waste-fill sites. He has a working knowledge of the South African
environmental legislation. Key environmental impact assessments undertaken includes the
following:
• Barrick Waste Management Complex Basic Assessment, North West Province
• Johnson Matthey Waste Transfer Facility Basic Assessment, Germiston
• Anglo Platinum – Rustenburg Platinum Mines, Rustenburg Section – Chromite Recovery Facility,
North West Province
1.2 Proponents’s Details
Project Title Bronkhorstspruit Biogas Plant
Name of Applicant Bronkhorstspruit Biogas Plant (Pty) Ltd
Contact Person Sean Thomas
Postal Address
P O Box 1068
Lonehill
2062
Location of Project
Beefcor Cattle Feedlot,
Remaining Extent of Farm Boschkop 543
JR,
Boschkop Farm,
Bronkhorstspruit,
Gauteng
Contact Number 079 496 6725
Fax Number 0866485023
Email Address [email protected]
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2 Legislative Framework
In order to protect the environment and ensure that this development is undertaken in an
environmentally responsible manner, there are significant pieces of legislation which focus and
guide this scoping assessment. They are as follows:
2.1 The Constitution of South Africa (No. 108 of 1996)
The Constitution of South Africa took effect in 1997 and is considered the supreme law of South
Africa that cannot be superseded by any other law or government action. According to the
constitution, everyone has the right:
a) to an environment that is not harmful to their health or well-being; and
b) to have the environment protected, for the benefit of present and future generations,
through reasonable legislative and other measures that
i. prevent pollution and ecological degradation;
ii. promote conservation; and
iii. secure ecologically sustainable development and use of natural resources while
promoting justifiable economic and social development.
2.2 The National Environmental Management Act (No. 107 of 1998)
The National Environmental Management Act (No. 107 of 1998) also states that the principles of
Integrated Environmental Management (IEM) should be adhered to in order to ensure sustainable
development. A vital underpinning of the IEM procedure is accountability to the various parties
that may be interested in or affected by a proposed development. Public participation in the
formulation of development proposals is a requirement of the IEM procedure, in terms of the
identification of significant environmental impacts (scoping) by Interested and Affected Parties
(I&APs). The IEM procedure is designed to ensure that the environmental consequences of
development proposals are understood and adequately considered during the conceptual design
process, allowing negative aspects to be resolved or mitigated and positive aspects to be
enhanced. It is thus a code of practice for ensuring that environmental considerations are fully
integrated into all stages of development, by providing a procedural and regulatory mechanism for
EIAs.
Chapter 2 of NEMA provides a number of principles that decision makers and developers have to
consider when making decisions that may affect the environment. The proposed development as
well as the EIA process being followed takes into account the NEMA principles. The NEMA
principles are the following —
1. The principles set out in this section apply throughout the Republic to the actions of all
organs of state that may significantly affect the environment and —
a) shall apply alongside all other appropriate and relevant considerations, including
the State's responsibility to respect, protect, promote and fulfil the social and
economic rights in Chapter 2 of the Constitution and in particular the basic needs
of categories of persons disadvantaged by unfair discrimination;
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b) serve as the general framework within which environmental management and
implementation plans must be formulated;
c) serve as guidelines by reference to which any organ of state must exercise any
function when taking any decision in terms of this Act or any statutory provision
concerning the protection of the environment;
d) serve as principles by reference to which a conciliator appointed under this Act
must make recommendations; and
e) guide the interpretation, administration and implementation of this Act, and any
other law concerned with the protection or management of the environment.
2. Environmental management must place people and their needs at the forefront of its
concern, and serve their physical, psychological, developmental, cultural and social
interests equitably.
3. Development must be socially, environmentally and economically sustainable.
a. Sustainable development requires the consideration of all relevant factors including
the following:
i. That the disturbance of ecosystems and loss of biological diversity are
avoided, or, where they cannot be altogether avoided, are minimised and
remedied;
ii. that pollution and degradation of the environment are avoided, or, where
they cannot be altogether avoided, are minimised and remedied;
iii. that the disturbance of landscapes and sites that constitute the nation's
cultural heritage is avoided, or where it cannot be altogether avoided, is
minimised and remedied;
iv. that waste is avoided, or where it cannot be altogether avoided, minimised
and reused or recycled where possible and otherwise disposed of in a
responsible manner;
v. that the use and exploitation of non-renewable natural resources is
responsible and equitable, and takes into account the consequences of the
depletion of the resource;
vi. that the development, use and exploitation of renewable resources and the
ecosystems of which they are part do not exceed the level beyond which
their integrity is jeopardised;
vii. that a risk-averse and cautious approach is applied, which takes into
account the limits of current knowledge about the consequences of
decisions and actions; and
viii. that negative impacts on the environment and on people's environmental
rights be anticipated and prevented, and where they cannot be altogether
prevented, are minimised and remedied.
4. Environmental management must be integrated, acknowledging that all elements of the
environment are linked and interrelated, and it must take into account the effects of
decisions on all aspects of the environment and all people in the environment by pursuing
the selection of the best practicable environmental option.
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5. Environmental justice must be pursued so that adverse environmental impacts shall not be
distributed in such a manner as to unfairly discriminate against any person, particularly
vulnerable and disadvantaged persons.
6. Equitable access to environmental resources, benefits and services to meet basic human
needs and ensure human wellbeing must be pursued and special measures may be taken
to ensure access thereto by categories of persons disadvantaged by unfair discrimination.
7. Responsibility for the environmental health and safety consequences of a policy,
programme, project, product, process, service or activity exists throughout its life cycle.
8. The participation of all interested and affected parties in environmental governance must
be promoted, and all people must have the opportunity to develop the understanding,
skills and capacity necessary for achieving equitable and effective participation, and
participation by vulnerable and disadvantaged persons must be ensured.
9. Decisions must take into account the interests, needs and values of all interested and
affected parties, and this includes recognising all forms of knowledge, including traditional
and ordinary knowledge.
10. Community wellbeing and empowerment must be promoted through environmental
education, the raising of environmental awareness, the sharing of knowledge and
experience and other appropriate means.
11. The social, economic and environmental impacts of activities, including disadvantages and
benefits, must be considered, assessed and evaluated, and decisions must be appropriate
in the light of such consideration and assessment.
12. The right of workers to refuse work that is harmful to human health or the environment
and to be informed of dangers must be respected and protected.
13. Decisions must be taken in an open and transparent manner, and access to information
must be provided in accordance with the law.
14. There must be intergovernmental coordination and harmonisation of policies, legislation
and actions relating to the environment.
15. Actual or potential conflicts of interest between organs of state should be resolved through
conflict resolution procedures.
16. Global and international responsibilities relating to the environment must be discharged in
the national interest.
17. The environment is held in public trust for the people, the beneficial use of environmental
resources must serve the public interest and the environment must be protected as the
people's common heritage.
18. The costs of remedying pollution, environmental degradation and consequent adverse
health effects and of preventing, controlling or minimising further pollution, environmental
damage or adverse health effects must be paid for by those responsible for harming the
environment.
19. The vital role of women and youth in environmental management and development must
be recognised and their full participation therein must be promoted.
20. Sensitive, vulnerable, highly dynamic or stressed ecosystems, such as coastal shores,
estuaries, wetlands, and similar systems require specific attention in management and
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planning procedures, especially where they are subject to significant human resource
usage and development pressure.
2.3 Environmental Impact Assessment Regulations, 2009
According to the Environmental Impact Assessment (EIA) Regulations of 2009, the proposed
development evokes listed activities and requires that a Full Scoping and Environmental Impact
Assessment be undertaken and submitted to the Department of Environmental Affairs.
2.4 National Heritage Resources Act (No. 25 of 1999)
The proposed development comprises certain activities that require authorisation in terms of this
Section 38(1) of this Act:
• c) any development or other activity which will change the character of a
site—
o (i) exceeding 5 000 m2 in extent; or
o (ii) involving three or more existing erven or subdivisions thereof;
In addition the Act stipulates management and protection measures associated with heritage
resources such as graveyards, sites of archaeological and heritage significance. However it should
be noted that Section 38(8) of the Act states that if heritage considerations are taken into account
as part of an application process undertaken in terms of the Environmental Impact Assessment,
there is no need to undertake a separate application in terms of the National Heritage Resources
Act.
The designated authority administrating this act is the South African Heritage Resources Agency.
2.5 The National Water Act (No 36 of 1998)
The National Water Act plays a crucial in all water related activities, which require an appropriate
license from Department of Water Affairs (DWA). The Act recognises that water is a natural
resource that belongs to all people. The National Water Act regulates the manner in which persons
obtain the right to use water and provides for just and equitable utilisation of water resources.
The designated authority administrating the Water Act is the Department of Water Affairs.
2.5.1 Water use licensing
Under the requirements of the National Water Act, certain water uses requires a licence. For the
purposes of the National Water Act, ‘water use’ includes, among other things: taking water from a
water resource; storing water; impeding or diverting the flow of water in a watercourse; disposing
of waste in a manner that may detrimentally impact on a water resource; and altering the bed,
banks, course or characteristics of a watercourse. With reference to this proposed development,
the irrigation of treated wastewater a water use for which authorisation would be required. The
parameters of the proposed irrigation activity are however covered under a General Authorisation
GN 399. The General Authorisation which is provided for under section 39 of the National Water
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Act and a water use license is not required. The registration of the irrigation activities must
however be undertaken prior to any irrigtaion taking place.
2.5.2 Pollution of water resources
The National Water Act provides for situations where the pollution of a water resource occurs as a
result of activities on land. The person who owns, controls, occupies or uses the land in question
is responsible for taking all reasonable measures to prevent any pollution of a water resource from
occurring, continuing or recurring.
If these measures are not taken, the catchment management agency concerned may do whatever
is necessary to prevent the pollution or to remedy its effects. The catchment management agency
may then recover all the costs incurred as a result of it so acting from such person.
In recovering these costs, the catchment management agency may also claim from any person
who would have benefited from the measures taken by it.
2.6 National Environmental Management: Air Quality Act (No. 39 of 2004):
The Air Quality Act was promulgated on 24 February 2005. The majority of the provisions laid out
came into force on 11 September 2005. The objective of the Air Quality Act is to protect the
environment by providing reasonable measures for the protection and enhancement of the quality
of air in South Africa; the prevention of air pollution and ecological degradation; and securing
ecologically sustainable development while promoting justifiable economic and social development.
The Air Quality Act requires the establishment of a national framework for achieving the objective
of the Air Quality Act and the adoption of national, provincial and local standards for ambient air
quality. It further requires the formulation of air quality management plans and pollution
prevention plans, the declaration of priority areas, controlled emitters and controlled fuels, and the
preparation of atmospheric impact reports. It is envisaged that, in future, activities that result in
environmentally detrimental atmospheric emissions will be listed and anyone conducting any of the
listed activities will be required to have an emission licence. The Air Quality Act also addresses
issues of trans-boundary air pollution and control of dust, noise and offensive odours.
2.7 The National Environmental Management: Waste Act (Act 59 of 2008)
This Act serves to reform the laws regulating waste management in order to protect public and
environmental health by providing measures for the prevention of pollution and ecological
degradation and to provide defining requirements for the licensing and control of waste
management activities.
This Act succeeds Section 20 of the Environmental Conservation Act, no. 73 of 1989 and provides
measures for waste management covering the various aspects of activities which generate waste.
The schedules attached to the Act also provide definitions for activities which require a waste
management licence while also identifying the relevant environmental authorisations which are
further required for said activities.
In addition, the Waste Act (No 59 of 2008) allows for the development of a National Waste
Management Strategy. One of the key objectives of the National Waste Management Strategy is
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that municipalities will need to take responsibilities for the diversion of organic material for
composting or for biodigestion as a source of energy. The National Waste Management Strategy
further states target of 25% of recyclables needs to be diverted from landfill for re-use, recycling
or recovery by 2015.
In addition to the above the following legislation and guidelines inform the project:
• EIA Guideline and Information Series: Guide on Alternatives, DEA&DP, 2010
• EIA Guideline and Information Series: Guide on Needs and Desirability, DEA&DP, 2010
• EIA Guideline and Information Series: Guide on Public Participation, DEA&DP, 2010
• Guideline 3: General Guide to Environmental Impact Regulations, DEAT, 2006
• Guideline 4: Public Participation in support of the Environmental Impact Assessment
Regulations, DEAT, 2006
• Guideline 5: Assessment of alternatives and impacts in support of the Environmental Impact
Assessment Regulations, DEAT, 2006
• Integrated Environmental Management Information Series, DEAT, 2002- 2005;
• Land Use Planning Ordinance (Ordinance 15 of 1985);
• National Environmental Management: Biodiversity Act (NEM: BA) (Act 10 of 2004);
• Conservation of Agricultural Resources Act (CARA) (Act 43 of 1983); and
• Electricity Act (Act 41 of 1987).
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3 Project Location
The Biomass-to-electricity plant complex is approximately 2 hectares in extent and will be
located on the Beefcor Bayview farm named Boschkop in Bronkhorstspruit, Gauteng.
Figure 1 Locality Plan of Proposed Biomass to Electricity Plant, from 1 in 50 000 topographical
map
TO B
RONKHORSTSPRUI T
NORTH
TO B
RONKHORSTSPRUI T
NORTH
TO B
RONKHORSTSPRUI T
NORTH
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4 Overview of Affected Environment
The baseline information for the affected environment was fully studied and discussed as part
of the Scoping report for the project. Sections 2.1 and 2.2 below are merely summaries of that
information and should further details regarding the local environment for the project area be
required, please refer to the submitted Scoping and EIA reports, reference Gaut 002/07-
08/N1193.
4.1 Biophysical Environment
4.1.1 Climate
The Gauteng Highveld wherein the project is located is characterized by mild weather with cool
(9.80C), dry winters and warm (260C), wet (700mm) summers. The prevailing wind direction is
from the North-West.
4.1.2 Topography
The study area itself is flat and the local topography is best described as gently rolling
countryside with the Magaliesberg quartzite ridge to the north. The regional topography
comprises hills, ridges and undulating plains with low to moderate relief and rising up to 1600
m above sea-level.
4.1.3 Geology
The project location occurs upon shale layer between the quartzite of the Daspoort and
Magaliesberg Formations. Beneath this is a layer of slate and hornfel of the Silverton
Formation although these areas are stable in terms of seismic or tectonic movement.
4.1.4 Soils
The local soil profile comprises thin growing medium or topsoil underlain by a nodular or
hardpan ferricrete transition zone or pebble marker which is of a high quality and is well suited
to agriculture. Regionally, low permeability, yellowish-brown clayey silt to soft rock reside.
4.1.5 Land Use and Surface Infrastructure
The current land-use is zoned as agriculture and locally this is reflected locally by the presence
of grazing livestock and grain crops. The project area is comprised of broadly scattered
homesteads, sheds, silos, storage buildings, paddocks, composting heaps and feedlots and
regionally, single storey structures and gravel roads reside with powerlines to the North and a
national road to the North-West.
4.1.6 Flora
The local area for the proposed project comprises natural grassland of the Transvaal
Bankenveld. Naturally occurring grasses are sour and wiry comprise members of the Narrow
Heart Love Grass, Purple Finger Grass, Creeping Brittle Grass and Wire Grass species. The
vegetation withing the immediate study area has largely been cleared and flattened due to its
primary use as grazing land as well as for the Beefcor surface infrastructure and as such no
conservation areas near the site have been identified.
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4.1.7 Fauna
Aside from the cattle which occur upon the Beefcor feedlots, a number of smaller animals
typically associated with rural areas and land zoned for agriculture are also found on-site, such
rodents i.e. rats and field-mice, lizards, grasshoppers, various beetles and the associated
avifauna which prey upon these. A number of common birds were also noticed within the
vicinity of the stormwater dams.
4.1.8 Surface Water
Two surface water bodies lying within 2km of the proposed development serve to drain the
site, namely the Kleinspruit (which is non-perennial) and the Osspruit (which is perennial),
both of which fall in the catchment of the Bronkhorstspruit dam. This water is of a sufficient
quality for human consumption as defined by the SABS potable water quality standards.
4.1.9 Ground Water
The aquifer system underlying the proposed site for development of the biomass-to-electricity
plant is classified as minor, i.e. an aquifer system that is composed of fractured or potentially
fractured rocks not having a high primary permeability. The extent of the aquifer is limited and
the water quality variable, and yet they are usually important for local supplies and in
supplying base flow for rivers, although they seldom produce large quantities of water. The
groundwater flow is linked to regional topography and is thus to the north and northeast.
The groundwater quality of the site expressed elevated to high contents of manganese, iron,
nitrates, ammonia and chemical oxygen demand, all of which are indicative of contamination of
groundwater by feedlots and associated agricultural activities.
4.1.10 Air Quality
Air quality typical of the region occurs on-site, with poor quality winter air with smog and dust
occurring, while a general feature of the site is the odour associated with cattle and cattle
manure.
4.1.11 Noise
Ambient noise levels associated with large-scale farming operations are typical during daylight
hours i.e. engine noise, exhaust reports and reversing alarms from large trucks, tractors,
bulldozers and the like which are associated with agricultural activities like the transport of
animals, feed and stores, the shifting of earth and general upkeep of the operation.
4.1.12 Traffic
Minimal traffic is associated with the area and the nearest main road is the R25 which links to
the site via a 6km gravel road. This road is utilized for the transport of staff to and from
adjacent and surrounding farms as well as the transport of farmed produce or livestock. The
gravel road can become pitter with numerous potholes typically during the rainy season.
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4.1.13 Archaeology and Heritage
The closest heritage site is a monument commemorating the Battle of Bronkhorstspruit of
1886, which is located at the intersection of the R25 and R423. A small graveyard exists near
a smallholding on the gravel road approximately 2km from the site.
Cultural heritage also includes areas set aside for conservation, special or historical landscapes
and areas of archaeological significance, none of which occur upon the farm as well as within
the site where the proposed biomass-to-electricity plant is to be developed.
4.2 Socio-economic Environment
As of 2001, the total population for Kungwini Local Municipal Area was 107 875, and more
locally, the population of Bronkhorstspruit was 4121 with an annual growth rate of 5%. The
gender distribution for Kungwini was 67.4% female and 32.6% and the demographic
distribution for Bronkhorstspruit was 1014 black: 54 coloured: 81 indian/asian: 2973 white.
The level of education in Kungwini is low, with less than 31.6% of the population being in
possession of a Grade 12 or higher qualification, while 20.4% have no education at all. 79.6%
of the population is considered literate. The distribution of qualification in Kungwini is as
follows:
Table 1 Level of Education in Kungwini Local Municipality (Kungwini draft IDP)
The levels of education are directly reflected by employment statistics for the area, with the
majority (36.1%) of the population being employed in low to semi-skilled, elementary
occupations and approximately 12.5% of the working population in Kungwini are trained in a
trade or craft. Further reflecting the employment skills-pool is the distribution of income,
which shows that 15% of Kungwini residents are unemployed while the 64% majority earns
less than R1600 per month, even though 62.32% are formally employed.
Of the population of Kungwini Local Municipality, 7.4% suffer from some disability, while as of
2004, HIV/AIDS was prevalent in 11.9% of the population, which is increasing at an annual
rate of 22.8%.
The largest economic sectors presenting formal employment opportunities within the Kungwini
Local Municipality are, in descending order: Services (33%), manufacturing (19%), trade and
finances (14%) and agriculture (8.8%). Of these sectors, agriculture, tourism, manufacturing
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and mining have been earmarked for development opportunities within the Kungwini Municipal
area. The farms in and around Bronkhorstspruit, such as the one upon which the proposed
biomass-to-electricity plant is to be developed, accounts for the bulk of production in the
district agricultural sector and typically experiences a growth-rate of around 0.5%.
The Integrated Development Plan (IDP) for Kungwini has identified the need for poverty
alleviation through job creation. The IDP also recognizes the need for the upgrading of water,
sanitation, electricity, communication, roads and stormwater infrastructure.
As indicated previously, the project will take place adjacent to the Beefcor cattle feedlots,
Beefcor. Beefcor has over 20 thousand cattle in Bronkhorstspruit and a chicken farm with over
1 million chickens is located in close proximity.
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5 Project Description
The proponent proposes to erect a 3 MW Biogas Plant. The Biogas plant complex is
approximately 2 hectares in extent and is located on an existing cattle feedlot in
Bronkhorstspruit, Gauteng. The intention is to generate electricity through a process of
anaerobic digestion. The intention is to utilise cattle manure, abattoir chicken waste, organic
food and/or beverage waste in order to generate methane gas which in turn will be utilised to
generate electricity. In order to extract the methane gas from the waste products the biogas
plant will utilise a continuous stirred-tank reactor (CSTR). The gas produced, comprises of
around 60% methane and 40% carbon dioxide, is referred to as biogas. The biogas will then
go through an internal combustion where it will produce electricity and heat at 90ºC will be a
by-product of this process. The electricity will then be loaded onto the existing national grid
and will assist in alleviating Eskom’s load in this area and bringing further stability to the power
supply in the area. Once the waste has been circulated through the Biogas Plant it will be
recycled/ reused for composting purposes by an independent contractor.
From a sustainability l perspective the advantages of the CSTR system are as follows:
• The system is fully enclose, which reduces odour emissions;
• Has a higher gas yield;
• Relatively cheap and easy to construct;
• Fairly easy to maintain; and
• Has an automatic cleaning system.
The plant will be classified as a small industrial plant and would have a lifespan of
approximately 20 years.
5.1 Simplified Microbiology of a Anaerobic Digester Plant
Anaerobic digestion is a multi-stage biological process whereby bacteria, in the absence of
oxygen, decompose organic matter to carbon dioxide, methane and water. In this way the
sludge is stabilised and noxious odours are removed while the organic matter in the sludge is
converted into a combustible gas (Ross et al, 1992).
Ross et al (1992) describes the process as occurring in two stages:
First Stage:
The organic matter in the feed sludge is converted into organic acids (also called volatile fatty
acids) by acid forming bacteria.
Second Stage:
These organic acids serve as the substrate (food) for the strictly anaerobic, methane-
producing, bacteria, which convert the acids into methane and carbon dioxide.
The end result of the process is:
• A well-stabilised sludge in which 40 to 60 % of the volatile solids have been destroyed.
• A combustible gas consisting of 60 to 75 % methane with the remainder being largely
carbon dioxide and a little bit of water vapour.
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•
Figure 2: Schematic diagram of Biogas
5.2 Proposed Raw Material Waste Streams
The Biogas Plant project will entail the use of the following waste streams for energy
generation:
5.2.1 Cattle Manure
As indicated previously, Beefcor has approximately 20 000 heads of cattle on located within the
feedlots at any given time. Although the feedlots are not part of this application, the cattle
manure emanating from the feedlots will be utilised as a portion of the waste mixture required
to create the methane gas. The intention is to collect the manure
scrapping the manure to a central collection point. Approximately 360 tonnes (wet) of cattle
manure will be collected and utilised in the process per day.
The manure does not require a pasteurisation step and will be directly fed thro
hopper through a shaft-less screw conveyor into a concrete manure slurry tank. Considering
the capacity of this bin and the transfer rate to the slurry mixing tank cattle manure residence
time is approximately 9hrs allowing for a loading frequen
The manure is mixed with recycled water from the balance pond to form a manure slurry. The
manure slurry will then be channelled to the mixing pond and blended with the
and organic food and beverage waste
from the Biogas Plant.
Environmental Management Programme
Schematic diagram of Biogas Process
Proposed Raw Material Waste Streams
The Biogas Plant project will entail the use of the following waste streams for energy
As indicated previously, Beefcor has approximately 20 000 heads of cattle on located within the
eedlots at any given time. Although the feedlots are not part of this application, the cattle
manure emanating from the feedlots will be utilised as a portion of the waste mixture required
to create the methane gas. The intention is to collect the manure from the feedlot by
scrapping the manure to a central collection point. Approximately 360 tonnes (wet) of cattle
manure will be collected and utilised in the process per day.
The manure does not require a pasteurisation step and will be directly fed thro
less screw conveyor into a concrete manure slurry tank. Considering
the capacity of this bin and the transfer rate to the slurry mixing tank cattle manure residence
time is approximately 9hrs allowing for a loading frequency of 2-3 times each day.
The manure is mixed with recycled water from the balance pond to form a manure slurry. The
manure slurry will then be channelled to the mixing pond and blended with the
and organic food and beverage waste , mixed feed slurry, fresh water and the recycle streams
20
The Biogas Plant project will entail the use of the following waste streams for energy
As indicated previously, Beefcor has approximately 20 000 heads of cattle on located within the
eedlots at any given time. Although the feedlots are not part of this application, the cattle
manure emanating from the feedlots will be utilised as a portion of the waste mixture required
from the feedlot by
scrapping the manure to a central collection point. Approximately 360 tonnes (wet) of cattle
The manure does not require a pasteurisation step and will be directly fed through a feed
less screw conveyor into a concrete manure slurry tank. Considering
the capacity of this bin and the transfer rate to the slurry mixing tank cattle manure residence
3 times each day.
The manure is mixed with recycled water from the balance pond to form a manure slurry. The
manure slurry will then be channelled to the mixing pond and blended with the abattoir waste
ed slurry, fresh water and the recycle streams
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5.2.2 Abattoir Waste
The abattoir waste will consist of a combination of pasteurised chicken abattoir sludge and
general abattoir sludge (a mixture of beef and sheep waste). Approximately 7 tonnes of
chicken abattoir sludge and 7 tonnes of general abattoir sludge will be used in the digester per
day. Co-digestion of fat waste (chicken abattoir and abattoir sludge) with animal manure has
proven to serve as a “booster” for the methane production from agricultural wastes (CPG,
2011). The intention is to accumulate the chicken abattoir sludge, together with the general
abattoir sludge in a process reception tank, prior to it being fed into the pasteurisation process.
No abattoir waste will be stored for processing on site prior to it being included in the digester
(i.e. abattoir waste will be pumped directly into the digester).
5.2.3 Organic food and beverage waste
The organic food and beverage waste will largely consist of food waste including amongst other
waste streams yoghurt, ice cream, food sludge as well as vegetables and fruit. Approximately
200m3 of food waste will be required on a daily basis. The waste will be transported to the site
via 40 tonne trucks.
The mixed organic and beverage waste feed stream will be fed through a hopper into a
concrete maceration tank where the glycerol and fatty foods are broken down and diluted with
recycled water from the balance pond to form mixed food slurry. The maceration tank has an
effluent overflow to allow for heavy grit to settle out and be cleared during routine
maintenance.
Food and abattoir waste will mainly consist of large fragments. Biodigestion and subsequent
gas yield is enhanced by breaking of these fragments into smaller particles to increase the
available surface area.
The waste stream will then blended with the ; beef manure slurry, fresh water and the recycle
streams from the CSTR in the mixing pond.
A 75m3 concrete tank is to be erected on site to temporarily store ‘buffer’ food waste prior to it
entering the CSTR . It will also allow for continuous feed over weekends and public holidays
when waste companies are off duty.
5.3 Project Infrastructure Components
The fenced–off area of the Biogas plant encompasses approximately 5 hectares in extent. The
main components of the Biogas plant are as follows, although it should be noted that the
feedlots are considered to be part of the existing farming operation and are not located within
the 5 hectare site.
• Feed lot
• Collection storage areas
• Organic food and beverage waste storage facility
• Abattoir waste storage facility
• Slurry tank
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• Mixing tanks
• Continuous Stirred Tank Reactor (CSTR)
• Aerobic treatment system (SBR and balance pond)
• Gas Blower
• Scrubber
• Generator
• Flare
• Process water storage dam
Figure 3 below depicts the schematic process flow diagram and each of the components of the
Biogas Plant will be discussed thereafter.
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Figure 3. Process Schematic Diagram
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5.3.1 Slurry tank
The slurry tank is approximately 9m2 in extent and its purpose is to combine diluted cattle manure
from the collection sumps.
5.3.2 Mixing tank
The mixing tanks are approximately 32m2 in extent and their purpose is to thoroughly mix the
cattle manure and abattoir waste as well as the organic food and beverage waste which is then
pumped into the anaerobic reactor.
5.3.3 Continuous Stirred Tank Reactor- CSTR
The Biogas Plant will consist of four (4) CSTRs with an approximate surface area of less than 1ha.
A continuously stirred tank reactor or completely mixed reactor is the most common form of an
anaerobic digester. It is widely used sewage treatment plants and many industrial wastewater
treatment facilities. A completely mixed reactor is known as a low rate digester technology and it
is essentially a tank that is heated and mixed. The advantage of the CSTR is that it is a proven
technology with many biogas plants in Europe and wastewater treatment facilities in the United
States as reference. Another advantage is the ease of operation and its robustness towards solids
loads rating and solids concentration in the feed.
The CSTR is also more tolerant to variations in feed quality because the large hydraulic volume
serves as a buffer for changes in feed pH and temperature.
The stages of the CSTR process are:
• Feed receiving and preparation
All the feed materials are received and treated in this stage to enable optimum operation of the
digester. These include maceration of solids, sand, silt and plastic and wood removal. The mixing
of the feed into the desired ratio takes place in this stage as well.
• Anaerobic digestion (CSTR)
The feed is fed to the digester where the digestion process takes place and where the biogas in
produced.
• Digestate Treatment
After the digestation, the product, called digestate, is fed through a filter process where the
digestate is separated into solid and liquid digestate. The solids are available as compost for
fertilising, and the liquid effluent is available as liquid fertiliser.
• Gas purification
The biogas produced is taken through a gas purification plant which comprises a Sulphide scrubber
to remove sulphur from the gas, then through a dehumidifier and chilling stage to ensure the input
gas is at the right temperature and humidity for turbines.
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• Combined heat and power
The gas fed into the gas turbines are used in a Combined Heat and Power process to generate
electricity as well as heat from the jacket water of the turbines.
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Figure 4. Continuous stirred-tank reactors (CSTRs) – Basic Flow Diagram
FEED COMPOSITION • Cattle Manure Chicken
Manure
• Mixed Organic Waste
Mixing Vessel
Make-up water
supply
Anaerobic digester Vendor Package
Gas Handling
Gas treatment Gas
generators
Electrical power and heat water supply
Solids Treatment plant
Screen Filter or Screw
press Dryer
Fertiliser
Effluent Handling
Effluent Treatment
Recycled process water Clean water discharge to
environment
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5.3.4 Biogas Plant Storage structures
Hopper Foundations - A raft foundation set at 4.6 m long x 3.6 m wide shall be provided to support
the hoppers.
Beef Manure Hopper - A raft foundation set at 5 m long x 4 m wide shall be provided to support the
hopper.
Beef Manure Slurry Mixing Tank - Construct a reinforced concrete tank set at 5 m long x 5 m wide
x 2 m deep.
Mixing Pond - Construct a reinforced concrete pond set at 13.6 m long x 8.9 m wide separated by a
dividing wall along the length of the pond. The ponds foundation slab is set to slope towards the
dividing wall with the maximum depth set at 4.9 m.
Maceration Tank - Construct a reinforced concrete pond set at 6.6 m long x 3.6 m x wide. The
tanks foundation slab is set to slope towards hopper resulting in an overall tank depth of 3.05 m. A
perforated sheet metal 304 SS insert shall be provided by others.
SBR Pond - This area comprises of an earth pond, excavated into the existing ground. The pond size
is set at 50 m long x 20 m wide x 6 m deep at the bottom of the pond. Provision is made for the side
walls to slope including for an earth berm to be constructed along perimeter of the pond and a 6 mm
rubber membrane to cover the ponds surface.
Balance Pond - This area comprises of an earth pond, excavated into the existing ground. The pond
size is set at 50 m long x 20 m wide x 6 m deep at the bottom of the pond.
Provision is made for the side walls to slope including for an earth berm to be constructed along
perimeter of the pond and a 6 mm rubber membrane to cover the ponds surface
5.3.5 Solids Treatment for Fertiliser
The total solids and carbon content are reduced during anaerobic digestion in the CSTR , enhancing
the fertiliser value of the effluent compared to the original manures and wastes.
The sludge (liquid fertiliser) will be partially further treated by pumping a portion of this stream
through a dewatering unit to produce compostable fertiliser that contains approximately 35% solids
(w/w).
The sludge dewatering is achieved by using a 4.8m3/h Läckeby LSSP 260 shaftless screw press. This
application is used in various industries including dewatering of slaughterhouse waste; municipal and
industrial waste water; fruit and vegetable waste; and brewery waste dewatering.
The dewatering plant will receive sludge from the CSTR via the Biodigester Sludge Dewatering Pump.
Sludge enters the first stage of dewatering at ambient pressure. The first stage of dewatering is a
Rotating Sieve Drum consisting of a perforated drum with an internally fixed screw. The screw
transports separated particles out of the drum. The drum rotates on trunnion wheels and is driven by
a cog gear motor. Incoming liquid is fed into the drum through an inlet pipe configured to equally
distribute the sludge over a large area of the drum’s interior. As the sludge is transported through the
drum, water is screened through suitably sized perforations into a collection trough bellow.
Dewatering continues over the full length of the drum with dewatered solids exiting the unit via the
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screenings outlet. A rotating brush and spray header with nozzles continuously unclog any blocked
perforations thereby maintaining a consistent dewatering efficiency at all times. All the internal
components mentioned above are enclosed in a removable splash guard and equipped with a
ventilation exhaust to improve the working environment.
It is estimated that the rotating sieve drum will provide a low energy solution with a capability of
removing water from the sludge, resulting in a proportionate sludge mass reduction. Solids moisture
content can therefore be reduced even further by adding a second dewatering stage with a
proportionately lower throughput capacity.
The liquid effluent after dewatering (filtrate) will be recycled back to the mixing pond and also used for
irrigation.
5.3.6 Aerobic Water Treatment System
a) Sequenced Batch Reactor
Sequencing batch reactors (SBR) is an aerobic treatment process for the treatment of wastewater.
Oxygen is bubbled through the wastewater to reduce biochemical oxygen demand (BOD), nitrogen
and chemical oxygen demand (COD) to make suitable for irrigation purposes. It is likely that much of
the water recycled to slurry the incoming wastes will come from the SBR to help keep ammonia and
salts concentrations in the reactors to non-toxic levels.
The Aerobic Treatment system will have the capacity to treat up to 2,400 m3 effluent water per day.
The aerobic system will consist of two passive aeration ponds in series, treating liquid from the top of
the CSTR settling zones. The first pond is an aerated 6750m3 Sequencing Batch Reactor (SBR) pond
that overflows into the second balance pond (6750m3).
b) Balance Pond
The balance pond is approximately 1 000m2 in extent and the objective of the balance pond is to
remove any manure solids carried from the feedlot by stormwater. Solids settled in the balance pond
will be pumped to the anaerobic reactor, while the clarified water will either be discharged via
irrigation (20%) or recycled back to the biogas process plant (80%).
Excess water will be irrigated onto the adjacent lands.
According to the Government Notice No 339, prior to the use of effluent to irrigate agricultural land,
the effluent water needs to meet the standards indicated below:
(ii) irrigate up to 500 cubic metres of domestic or biodegradable industrial wastewater on any
given day, provided the-
(a) electrical conductivity does not exceed 200 milliSiemens per metre (mS/m);
(b) pH is not less than 6 or more than 9 pH units;
(c) Chemical Oxygen Demand (COD) does not exceed 400 mg/l after removal of algae;
(d) faecal coliforms do not exceed 100 000 per 100 ml; and
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(e) Sodium Adsorption Ratio (SAR) does not exceed 5 for biodegradable industrial
wastewater;
the irrigation of wastewater-
(aA) does not impact on a water resource or any other person’s water use, property or land; and
(aB) is not detrimental to the health and safety of the public in the vicinity of the activity.
It is anticipated that approximately 58 tons of effluent water will be irrigated daily.
5.3.7 Gas Cooling Plant
The off-gas system consists of a blower, flame arrestor, filter and enclosed flare to ensure maximal
carbon destruction in the event of biogas flaring during genset maintenance.
Biogas can exit the Sulphide Scrubber at elevated temperatures with proportionate amounts of
entrained vapour. Reducing the entrained vapour content by chilling the Biogas will enhance engine
performance. A 22kW electrically driven chiller coupled to a plate and shell heat exchanger will provide
sufficient cooling to a temperature suitable for condensation of entrained vapour as well as volumetric
reduction of the Biogas.
In the event that downstream equipment fails or gas production exceeds the maximum permissible
feed rate to the generator’s, it is an express requirement that emission levels are kept within current
environmental regulations. Environmental damage caused by vented Biogas is mitigated by
combusting it in a suitably designed and approved flare. This allows for a continuance of any benefits
associated with CDM agreements and also mitigates any fines that may be imposed by the local
authorities in upset conditions.
The flare will be connected in a bypass stream and isolated from the normal operation by means of a
manual butterfly valve. In the event of critical faults or alarms a pneumatically actuated slam shut
valve automatically isolates the flow of gas to the flare. A flame arrestor is positioned just prior to the
stack and burner to in the unlikely event of gas stream back ignition from the burner down the supply
pipeline. A pressure switch initiates all the relevant control and safety systems relevant to low
pressure conditions at the inlet manifold. An injector burner positioned at the stack base mixes biogas
and ambient air by means of a manually set natural draught created by gas flow. An ignition burner
(Pilot Flame) positioned above the injector burner consists of an electrical ignition device, manual and
solenoid valve piped to the inlet manifold between the manual isolation valve and slam shut valve. A
UV Probe and Thermocouple mounted in the side of the stack monitors the flame and stack
temperature continuously communicating with the field mounted control system. The control system
allows operators to control ignition and gas flow either manually or automatically and provides visual
alarm indication and identification provided by the monitoring devices described above.
5.3.8 Flare
Where there is more gas than can be used in the energy recovery system (through unusually high gas
production rate or through breakdown/maintenance of the energy recovery system) then flaring will
be necessary to eliminate the safety risks and protect the environment.
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The gas which would be emitted into the atmosphere via a flare would predominantly be carbon
dioxide, potentially with trace levels of carbon monoxide, nitrogen oxides and unburned hydrocarbons.
Flaring of the gas will only be undertaken in emergency situations as the methane gas is the product
required in order to generate electricity. Therefore the emission of methane gas into the atmosphere
would strictly monitored and only undertaken when required.
The height of the flare above ground level is approximately 15m, on a 64m2 concrete base.
Figure 5. View of a typical flare stack
5.3.9 Scrubber
A scrubber and dehumidifier are included to reduce the hydrogen sulphide content and the moisture
content of the biogas prior to the emission of any gas into the Gen Set.
a) Effects of Hydrogen sulphide (H2S) in Biogas
“Biogas” is formed by anaerobic fermentation in landfills, sewage sludge digesters, or anaerobic
bioreactors for high-strength wastewater. It typically consists of 50~65% CH4, 25~45% CO2, 5~6%
H2O, and up to 0.5% (5,000 ppmv) of H2S. The gas is saturated with water vapour at the operating
temperature of the source (typically around 35°C for digesters or bioreactors). H2S is formed by the
action of sulphate-reducing bacteria, so H2S levels will be higher if the wastewater or sludge being
treated contains more sulphates.
When biogas is burned as fuel, the H2S will be converted to SO2 that causes enhanced corrosion to
combustion equipment. If the combustion equipment does not have corrosion problems, it is normally
easier to scrub SO2 out of the combustion exhaust than to remove H2S from the fuel gas.
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H2S, mercaptans, and chlorinated mixtures will form acidic Sulphur Dioxide (SO2), Sulphuric acid
(H2SO4) and Hydrochloric acid (HCl) when the biogas is burned as fuel. High levels of hydrogen
sulphide are detrimental to genset performance and longevity.
b) Biotrickling Filter Biogas Desulphurisation (BRF-BGD) System
The BTF-BGD (See Figure 6 ) system consists of insulated Bio-tricking filters complete with HD QPAC®
structure packing. The air stream is introduced into the bio-trickling filter below the packing.
The gas pressure from the digester forms the feeding velocity of gas into the filter. As the biogas flows
through the packed section of the filter, the air stream comes into intimate contact with the biofilm.
The biofilm consists of anaerobic Thiobacillus bacteria that serve as H2S scavengers. As these
scavengers absorb the H2S from the air stream, H2SO4 is released. These scavengers usually function
in an environment with a pH of 1.5, but it is recommended that the pH in the sump should be
maintain above pH >2.5 so to ensure that the bacterial activity in the filter is not reduced. The pH
levels of the re-circulated sump water will therefore be monitored continuously.
Figure 6. Biotrickling Filter Biogas Desulphurisation System
When the pH set point is reached, a solenoid valve on the fresh water inlet will be opened to permit
fresh water into the sump. This valve will be opened for a set period of time, causing the sump liquor
to overflow and be removed from the sump. This addition and removal of water will raise the pH of the
re-circulated liquor in the sump. The removed liquor will be a mild acidic (max 3 % H2SO4) solution,
which may be collected and reused in another part of the plant or neutralised and disposed of.
Due to the live bacteria used in the filter, the biofilm will take a few days to stabilise in terms of
efficiency with a typical average efficiency of +94%. The design and construction of the HD QPac® is
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such that, as the biofilm grows and becomes too heavy, it sloughs off and new biofilm growth start.
This sloughing off maintains active growth on the packing and thus maintains an overall high
efficiency of H2S removal from the air stream.
5.3.10 Gas Cooling Plant
The off-gas system consists of a blower, flame arrestor, filter and enclosed flare to ensure maximal
carbon destruction in the event of biogas flaring during genset maintenance. Biogas can exit the
Sulphide Scrubber at elevated temperatures with proportionate amounts of entrained vapour.
Reducing the entrained vapour content by chilling the Biogas will enhance engine performance. A
22kW electrically driven chiller coupled to a plate and shell heat exchanger will provide sufficient
cooling to a temperature suitable for condensation of entrained vapour as well as volumetric reduction
of the Biogas.
In the event that downstream equipment fails or gas production exceeds the maximum permissible
feed rate to the generator’s, it is an express requirement that emission levels are kept within current
environmental regulations. Environmental damage caused by vented Biogas is mitigated by
combusting it in a suitably designed and approved flare. This allows for a continuance of any benefits
associated with CDM agreements and also mitigates any fines that may be imposed by the local
authorities in upset conditions.
The flare will be connected in a bypass stream and isolated from the normal operation by means of a
manual butterfly valve. In the event of critical faults or alarms a pneumatically actuated slam shut
valve automatically isolates the flow of gas to the flare. A flame arrestor is positioned just prior to the
stack and burner to in the unlikely event of gas stream back ignition from the burner down the supply
pipeline. A pressure switch initiates all the relevant control and safety systems relevant to low
pressure conditions at the inlet manifold. An injector burner positioned at the stack base mixes biogas
and ambient air by means of a manually set natural draught created by gas flow. An ignition burner
(Pilot Flame) positioned above the injector burner consists of an electrical ignition device, manual and
solenoid valve piped to the inlet manifold between the manual isolation valve and slam shut valve. A
UV Probe and Thermocouple mounted in the side of the stack monitors the flame and stack
temperature continuously communicating with the field mounted control system. The control system
allows operators to control ignition and gas flow either manually or automatically and provides visual
alarm indication and identification provided by the monitoring devices described above.
5.3.11 Biogas Fired Power Generation
A GE’s Jenbacher gas-fueled reciprocating engines, packaged generator set and cogeneration unit will
be used for power generation. The gen set is designed to run on biogas and the patented combustion
system, engine control, and monitoring enable power generation to meet stringent emission
standards, while offering high levels of efficiency, durability, and reliability.
3MW Electrical power at 11kV and 50Htz will be achieved by the conversion of biogas thermal energy
via internal combustion engines to mechanical energy, transferred to the rotor and stator coils of an
AC alternator, step up transformers and finally the output terminals of the plant medium voltage
circuit breaker.
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5.3.12 Electricity connection and supply
There will be a single OH line that will be utilised to draw power from the grid at start-up and then
once the plant is running to generate power to the grid. Once the methane gas has passed through
the Gen Set, the electricity will be placed on a newly built 22kV line connecting to the Tweedracht
Substation.
The Biogas Plant will utilise approximately 2250KWh electricity per day. The electricity will largely be
utilised at the following locations:
• Sumps
• Small office use
The Biogas plant will be able to source electricity off the newly built 22kV powerline which will be built
adjacent to the Biogas Plant site.
5.3.13 Stormwater Management
The intention is to keep clean stormwater separate from any effluent polluted stormwater. To this
end, the Biogas plant will be surrounded by a stormwater drainage channel that will ensure that all
clean stormwater does not come into contact with any effluent polluted stormwater. All effluent
polluted stormwater runoff (i.e. run-off water emanating from the Biogas Plant area) will be channeled
to a lined effluent retention dam. If there is “dirty” water available for use in the detention pond this
water will be recycled into the process. The stormwater berm, which will be located on the Biogas site
perimeter, will be approximately 1m high in extent.
Excess water emanating from the Biogas Plant (approximately 58tons per day) is to irrigate farming
land in summer and stored over rainy winter months.
5.3.14 Manure storage area
Once the methane gas has been extracted via the CSTR System, the water logged waste material
(consisting of cattle manure, abattoir chicken waste, organic food and/or beverage waste and) will be
drained/ dried out and water recovered from this process will be directed back into the Biogas Plant.
Prior to collection, the manure will be stored on an impermeable concrete slab. The manure storage
area will be located within the bermed-off area and all stormwater emanating from this site will be
channeled to the effluent contaminated lined retention dam.
The dried manure will then be collected by the property owner (Beefcor). Approximately 200m3 of
manure will be stored in this area prior to collection on a weekly basis.
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6 Project Phases and Proposed Activities
6.1 Construction
The construction phases will involve the erection of infrastructure directly related to the technological
process involved. This includes:
• Collection sumps,
• Silage pits,
• Slurry tanks,
• Mixing tanks,
• CSTR,
• Aerobic treatment systems,
• Blowers,
• Scrubbers,
• Generators,
• Flares,
• Settling Ponds, and
• Administration Offices
The development of this infrastructure will involve the removal off al topsoil, grading and flattening of
land, the establishment of foundations as well as the erection of structures.
6.2 Operation
During the operational phase, manure from the 20 000 cattle located on the Beefcor feedlots will be
flushed into one of seven 9m2 collection sumps, at a rate of 360 tonnes per day. Additionally organic
food and beverage waste as well as abattoir waste will be delivered to the Biogas for inclusion in the
plant. No abattoir waste will be stored on site but pumped directly into the biogas plant.
The mixed cattle manure, organic food and beverage waste and abattoir waste digested by bacteria in
an anaerobic environment where by-products in the form of biogas (60% methane and 40% CO2) and
heat at 90°C are generated. The Biogas produced will then be pumped to the GE Jenbacher gas-
fuelled reciprocating engine, package generator and cogeneration unit (Gen Set) at a rate of
1500m3/hour, where it will be converted into electricity and transferred to the existing electricity grid
via the existing 11kV Eskom powerline. A 15m gas flare based upon a 64m2 concrete slab will be
utilized for the flaring of any gas which may be unable to enter the Gen Set system, while a scrubber
and de-humidifier will be installed to reduce hydrogen-sulphide and moisture content of the biogas
before it enters the Gen Set.
Finally, water-logged manure which has passed through the Biogas system will be stored upon an
impermeable concrete block within a bermed-off stormwater control area where it will be dehydrated
with the excess water being returned to the plant and the manure residue being collected by a
contractor for treatment and utilization as compost off-site.
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A schematic diagram summarising the above process is depicted in Error! Reference source not
found. below.
6.3 Decommissioning
The decommissioning phase will entail the removal of the concrete and steel structures, which will
either be recycled or disposed of at a suitably landfill site. Thereafter the rehabilitation plan as
detailed in Section 9 will be implemented.
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7 Summary of Potential Impacts Identified
The following section is a summary of the potential impacts for the proposed Biomass to Energy
Plant as assessed in the Environmental Impact Assessment report associated with this project.
This report contains appendices with all specialist reports.
7.1 Ecological (Fauna and Flora) impacts
The site for the proposed development has been completely transformed by its use as a manure
and paper waste stockpiling area, and is therefore of no conservation significance. The habitats of
the entire area situated within a 500m radius of the site have either been completely transformed,
or heavily degraded by the establishment and operation of the Beefcor Feedlot infrastructure such
as cattle holding pens, manure stockpiles, manure dams (dams that capture runoff heavily
contaminated by organic waste), planted pastures, dirt roads, offices and residential dwellings. The
areas immediately adjacent to the study site (within a 500m radius) are therefore also of little or
no significance in terms of the conservation of threatened habitats or species, and no threatened
species were recorded or a considered likely to occur.
Although no potentially suitable breeding habitat for the Giant Bullfrog occurs within the 2ha site
for the proposed development or its immediate vicinity (within a 500m radius of the site), a
potentially suitable breeding habitat for this species does occur in the ‘channelled valley-bottom
wetland’ situated approximately 200m to the north of the study site (ie. 200 m away from the
proposed site and its 500m buffer area). In the event that Bullfrogs do indeed occur here, they
may utilise the areas situated between the 2ha study site and the wetland for foraging and
breeding purposes. The development of the 2ha proposed development site (study site) will,
however, not lead to any reduction in available foraging areas or the obstruction of any potential
migratory routes. The only concern with regards to the proposed development is that nutrient
laden runoff or seepage from the proposed plant may enter the wetland and lead to habitat
deterioration. The proposed development will not, however, lead to any significant impact on
potential Bullfrog habitat if the proposed ‘biomass-to-energy’ plant is designed and operated in
such a way as to ensure that no nutrient enriched surface water runoff or seepage enters this
wetland.
Based on the ecological screening undertaken the impact of the proposed development on the
ecology of the proposed site and the immediate surrounds is considered to be Low in significance
with the implementation of the management measures presented in Section 9.
7.2 Impact on Hygiene and Sanitation
The storage of the waste products, prior to being fed into the digester as well as after it exits the
plant could potentially have negative hygiene and sanitary impacts. This impact will however be
limited to the operational phase. With the implementation of the appropriate management
measures the impact is considered to be medium.
7.3 Socio-economic impacts
The proposed development would result in the creation of 10 permanent employment opportunities
during the operational phase. It is the Applicant’s intention to source labour from the immediate
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surrounding communities. With an average multiplier effect of 1:6 the potential beneficiaries of
the project would be 60 during the operational phase.
In addition, the proposed bio-energy plant will contribute to ensuring the efficient energy supply,
as the energy generated will be fed into the Eskom transmission grid.
The proposed development would thus evoke a positive socio-economic impact during the
construction, operation and decommissioning phases. The employment opportunities associated
with the proposed development is therefore considered to be Medium.
7.4 Impact on Atmospheric emissions
Cattle manure that is left on the surface which decomposes aerobically releases a complex cocktail
of gases into the atmosphere. Primary among these is carbon dioxide, mixed with a number of
organic odorants and ammonia. In the environment of a feedlot, the constantly disturbed surface
can also become a significant dust source.
Emission Likely emissions from feedlot manure management (US EPA,
2001)
Ammonia (NH3) Major contributor to regional levels but
has minor local impact
Atmospheric
deposition, haze
Nitrous oxide
(N2O)
Significant contributor to regional levels
but has insignificant local impact
Global climate
change
Nitric oxide (NOx) Significant contributor to regional levels
but has insignificant local impact
Atmospheric
deposition, haze,
smog
Methane (CH4) Significant contributor to global levels
but has insignificant local impact
Global climate
change
Volatile organic
compounds (VOCs) Minor local impacts
Quality of human
life
Hydrogen sulphide
(H2S) Significant local impacts
Quality of human
life
Particulate matter
(PM10, PM2.5) Significant local impacts Haze, health
Odour Major local impact Quality of human
life
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However with the collecting of the manure and storage thereof in the sealed digesters, a number
of changes are made to the emissions profile of this waste:
• Carbon dioxide emissions decrease as aerobic decomposition is replaced by anaerobic
processes which release methane,
• Odorants, dust and other pollutants are trapped by the high moisture content and are
unlikely to make as significant a contribution to future emissions, and
• Anaerobic decomposition results in a decrease in expected nitric oxide and dust emissions
and an increase in VOCs, methane and hydrogen sulphide.
With reference to the Biomass-to-electricity plant the following impacts have thus been identified:
• Dust and associated emissions during building and decommissioning phases.
• Fugitive dust emissions associated with the wind entrainment of large areas of exposed
earth and dry manure, particularly associated with the increased activity in clearing and
transporting manure from the pens to the digester
• Increased emissions of ammonia, VOCs, hydrogen sulphide and methane, associated with
anaerobic decomposition
• Increased odour impacts associated with anaerobic decomposition.
The impact on the ambient air emissions during the construction and decommissioning phases is
considered to be limited to the dust emissions from civil, demolishing and excavation activities.
The impact of the construction of the Biomass-to-electricity plant is therefore expected to be Very
Low in significance with the implementation of mitigation measures detailed in Section 9.
With reference to the operational phase, the impact of the Biomass-to-electricity plant on the
ambient the air quality is expected to be Low in significance with the implementation of mitigation
measures detailed in Section 9. This is largely due to the fact that the plant is considered to be a
very clean looking process. The modelling is assuming upset conditions where the scrubber and
the flares aren’t working and therefore stresses the importance of the equipment.
7.5 Impact on heritage resources
According to a heritage specialist study, the fieldwork undertaken revealed one feature of cultural
heritage significance on the area to be developed on the property. This feature consists of
remains of bottles, porcelain, bottle stoppers etc. These are typical of refuse middens from the
Late 19th to Early 20th Century. Maker’s marks that could be identified include SA Breweries and
Goldberg of Johannesburg. These are typical beer and soda water or mineral water bottles from
the time. The latter had a marble bottle stopper inside.
According to the Heritage Specialist, there are two possibilities in explaining this site. It may be a
midden dating to the time period indicated or it may be part of refuse brought in at some stage
during current activities on the site.
During the construction phase, the impact of the proposed development on heritage resources is
considered to be Low in significance with the implementation of the mitigation measures detailed
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in Section 9. As no heritage resources are located within the immediate study area other than the
potential middens, the impact on heritage resources during the operational phase is considered to
be Very low.
7.6 Impact on Groundwater
The storage and handling of waste poses a potential risk to the groundwater quality. The risk is
associated with the production and release of leachate into the groundwater system.
Based on the Waste-Aquifer Separation Principle (WASP) the appointed Groundwater Specialist
concluded that the site for the proposed Biomass-to-electricity plant has a marginal suitability
rating. What this implies is that although the site (from a groundwater perspective) is not
considered perfect, with the implementation of the mitigation and management measures detailed
in Section 9 below, the risks to the groundwater quality are greatly reduced.
The impact on groundwater during the construction and decommissioning phases are considered to
be Very Low in significance with the implementation of the management measures. The impact
on groundwater during the operational phase is considered to be Medium in significance with the
implementation of management measures as detailed in Chapter 9.
It should be noted that the storage of the cattle manure is currently taking place on unlined/
compacted surfaces and thus the implementation of the Biomass-to-electricity plant will therefore
reduce the potential for groundwater contamination through the lining of surfaces for storage.
7.7 Impact on Surface Water
Currently the removal of the cattle manure is based on a dry removal principle, the proposed
development would necessitate altering the collection of manure to a water borne system. The
additional water required for the Biomass-to-electricity plant would increase the potential for
accidental spillages. The Biogas Plant installation will be operated as a semi-closed circuit, i.e.
where possible water will be recycled and discharges will be avoided. However, ammonia and other
salts will eventually build up in the continuously recycled streams through the plant and for this
reason an amount of water will have to be wasted daily to counter this salt build-up.
According to a suface water specialist, it is not envisaged that the build-up of inorganic salts are
likely to pose a problem, as the intake water is of a high quality with low salt loads (rainwater and
borehole water from Pretoria Group aquifers). The greater problem would be related to the build-
up of organic products and by-products of anaerobic digestion.
It should be noted that the aerobic treatment plant layout is so that the treatment of the water
occurs prior to its discharge into the environment or its recycle back to the anaerobic section of
the plant. Many of the potential contaminants (such as COD, ammonia, H2S and a lower pH) can
be removed through aeration, either by physical removal (“blowing off” or “stripping”) or by
aerobic bacteriological action where harmful metabolic products are converted to less harmful
products.
In addition, it is the intention of BBP is to irrigate the treated water onto pastures in the area to
the north and northeast of the Biogas plant. This area locates in the catchment of the Kleinspruit
and surface run-off from this area has the potential to contaminate water in the Bronkhorstspruit
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Dam via the Kleinspruit, hence the inclusion of an aerobic treatment plant. The main contaminants
in this water would be of organic origin in the form of biodegradable matter (COD), while the
breakdown products of anaerobic digestion such as ammonia, hydrogen sulphide and a lowered pH
may also be present.
With reference to the operational phase, the accidental spillages from the plant is not expected to
have a significant impact on the surface water as the plant will have a detailed stormwater
management system which will separate the clean and dirty stormwater as well as contain any
spillages emanating from the plant. All stormwater that falls within the plant area will be directed
back to the plant process water.
With reference to the storage of waste on site, the intention is to store all waste on concrete
bases.
Based on the above the impact of the proposed plant on surface water during the operational
phase is considered Medium in significance with the implementation of mitigation measures
detailed in Section 9.
The impacts on surface water during the construction phase are considered to be Low in
significance with the implementation of the mitigation measures detailed in Section 9.
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8 Proponents Commitments Regarding Environmental Management
8.1 Party Responsible for Environmental Management
The designated person responsible for overseeing environmental control and management as a
whole on the site of the proposed project, from construction to operation and closure, will be the
Resident Engineer as appointed by Bronkhorstspruit Biogas Plant (Pty) Ltd (BBP). According to
Section 2 (h) and 2 (j) of NEMA, it will be the duty of the proponent to ensure that all parties
(including contractors and casual labour) involved throughout the project lifecycle are familiar with
BBP’s environmental policy from the onset as well as to negotiate specific roles of the various
parties in this regard and subsequent penalties for failure to comply.
As such, this EMP will be included as part of the terms of reference for all workers, contractors and
appointed parties related to planning and construction, operation and closure. It will then be the
responsibility of the appointed parties to ensure that all members of their staff are familiar with
the environmental policy and deal with issues which may arise in this regard.
8.2 Incident Reporting and Record Keeping
The community in the area surrounding the project and all interested and affected parties (IAPs)
and stakeholders (members of the local government and the various government agencies) have
been identified during compilation of both the scoping report and the EIA (refer to section 6 of the
EIA). Any complaints or concerns can be directed to the proponent who will ensure that these
issues are addressed within a period of a month. These concerns will be recorded in a register
which includes such information as date and time of receipt, person whom the query is directed to
and the necessary action taken.
8.2.1 Incident Reporting
• Any environmentally significant contamination and/or pollution must be reported to the
Department of Water Affairs within 24 hours.
• Should any condition of the NEMA: RoD be contravened, the Gauteng Department of
Agriculture and Rural Development (GDARD) needs to be notified within 24 hours. The
notification must include the reason for the non-conformance.
8.3 Environmental Monitoring
8.3.1 Groundwater and Surface Water Monitoring
In order to monitor the impact (or lack thereof) of the proposed Biomass to Energy plan during the
life of the project on the ground- and surface water resources, it is recommended that a
monitoring system be set up whereby sampling of the following monitoring points are undertaken
bi-annually:
Groundwater
• Boreholes BC1 and BC4, which are located up-gradient of the proposed Biogas Plant and
represents the receiving water quality. These boreholes can be used as reference
boreholes.
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• Borehole BC3 is located down-gradient and could monitor potential contamination from the
Biogas Plant.
• At least one additional borehole, but preferably two, is required between the pollution
control dams and the Kleinspruit.
• It is further recommended that this be a borehole pair consisting of a shallow borehole
(±10m) to monitor the weathered formation and a deep borehole (±30m) to monitor the
fractured formation.
• The northern boundary of the Biogas Plant is virtually on the contact between shale and
dolerite. Such a contact provides a conduit for contaminants to enter the aquifer. One
monitoring borehole is recommended on either side of the proposed Biogas Plant along this
contact.
Surface Water
The existing monitoring points can be utilised.
8.3.2 EMP Performance Assessment
During the construction phase of the development, BBP will monitor the contractors’ compliance
with the EMP during the construction phase on a daily basis by means of a checklist, and the
results fed back to the contractors at the monthly construction project meetings. In addition, an
independent Environmental Consultant will undertake compliance audits every second week. The
results there will be fed back to the contractors at the monthly construction project meetings.
BBP will compile an inspection checklist for the operational phase which will be modified as and
when required by the relevant government department. During the operational phase, inspections
will be undertaken every two weeks.
An annual EMP audit will also be undertaken, a report for which will be submitted to GDARD
detailing the plant’s compliance with the EMP. In addition, the audit report should include
conformance to the requirements associated with -
• The Occupational Heath and Safety Act
• Any addition environmental permits issued.
The annual audit is to include proof of the following:
• Emissions associated with the operation do not exceed occupational exposure limits.
• An emergency response plan has been approved by Kungwini.
• The relevant permits have been received from the Department of Water Affairs regarding
the project water uses.
• That the effluent quality is tested prior to discharge.
• Update of the emergency response plan and drills undertaken.
• All construction activities was undertaken as per the relevant SANS code
• Basic fire fighting equipment available on site.
• All permits applicable to the operations were obtrained.
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8.3.3 Health and Safety
Undertake monthly health and safety inspections. Any faults detected must be immediately
repaired.
Maintain an inspection register, which must be included in the annual audit to GDARD.
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9 Environmental Mitigation Measures
This section details the mitigation and management measures identified for the impacts associated
with the Biogas Plant.
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No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
Environmental Management Measures for –Design and Planning–
Air Quality
EM 1. Installation of the flare Air
Emissions Air Quality
Ensure that a scrubber is installed in
the plant prior to the emission on any
gases.
Design Phase BBP
Surface Water Management
EM 2. Stormwater management
Water
quality
deterioration
Surface and Ground
water quality
Ensure that a suitable stormwater
management system is deigned which
will ensure that dirty and clean
stormwater is kept separate.
The stormwater management system
should ensure that all dirty
stormwater is directed back to the
digesters.
Design Phase BBP
Environmental Management Measures for –Construction–
Land and Soil Capability
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No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
EM3.
Construction activities
related to development of
infrastructure for plant,
i.e. the sinking and/or
erection, construction and
installation of collection
sumps, silage pits, slurry
tanks, mixing tank, CSTR,
aerobic treatment
systems, blowers,
scrubbers, generators,
flares, settling ponds and
administration offices
Removal of
Topsoil1
Potential to impact
on fertility of topsoil
Potential loss of
topsoil
Potential for erosion
of topsoil
The topsoil will be removed as per the
Double strip method2, for the
preservation of seeds, nutrients and
micro-organisms that are found
within the top 15cm of topsoil.
Double strip method:
Remove the top 15cm of topsoil
(sandy and silty loams) and use to
create berms upslope of the plant.
Remove the remaining 15 to 30cm of
topsoil and place on a separate
stockpile close to areas intended for
revegetation. These will be available
for use as backfill materials prior to
the topdressing and vegetation of the
rehabilitated areas.
Soils should be stripped intact with all
vegetation other than large trees,
while grasslands and transitional zone
soils will be treated with sulphur
phosphate prior to stripping in order
to ensure proper soil-mixing and to
lower the requirement for fertiliser
during rehabilitation.
The
construction
phase is
projected to
begin and end
in 2009
Environmental
Control
Officer
(identified in
section 8.1
above)3
1 The term “topsoil” refers to the “A” horizon of the soil. It is usually darker than the underlying material owing to the accumulation of organic material and usually comprises the top 10 to 30 cm of soil. 2 Mitigation measures sourced from the Topsoil and Landscaping Sections of the Mine Rehabilitation for Environment and Health Protection Training Manual developed by the WHO and UNEP, 1998. 3 The Environmental Control Officer mentioned is Section 6.1 will hereafter be referred to as the “ECO”.
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No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
Soils should not be stripped when
they are wet. This can lead to
compaction and loss of the structure
of the soil.
Stockpiles should be re-vegetated
and slopes kept to less than 1:3 to
protect the topsoil from erosion, to
discourage weeds and to maintain the
active populations of the beneficial
micro organisms. The use of legumes
for this temporary vegetation is
recommended as they will maintain
the nitrogen content in the soil.
No stockpiles are to be placed within
20m of any drainage lines on site
The stockpiles will be located where
they will not be disturbed by future
activities or the development of
buildings or infrastructure, and where
possible, upstream of the area’s
natural stormwater flow path.
Disturbing the topsoil within the
stockpiles can further damage the soil
structure prior to final re-use.
Stockpiles will be no more than 1 to
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No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
2m high to ensure the best retention
of the organic components of the
topsoil.
If not previously fertilised, soils will
need to be treated with commercial
fertilisers (sulphur phosphate) prior
to the removal of large vegetation.
Regular re-inspection will be
necessary to ascertain whether
further fertilisation is required.
Any contaminated soil must be
removed to a suitable licensed landfill
site and the site rehabilitated to the
approval of the DWA.
The opportunity for onsite
rehabilitation and reuse of
contaminated soil must be
investigated prior to disposal. The
DWA should be notified of this regard.
Nuisance
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No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
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Proposed
Monitoring
EM4.
Construction activities
related to development of
infrastructure for plant4
Noise
nuisance
resulting
from
construction
activities
Disturbance of
neighbours and
surrounding
communities from
nuisance noise.
Construction activities will be
undertaken during working hours
(8am to 5pm).
Any change in the noise
characteristics of a particular piece of
equipment will serve as an indicator
of potential mechanical failure which
will immediately be investigated and
rectified by the ECO.
The
construction
phase is
projected to
begin and end
in 2009
ECO
A complaints
register will be kept
on-site which will
contain a section
specific to noise
issues. The EM will
maintain register
and address noise
complaints within
48 hours of them
being lodged.
Heritage
EM5.
Construction activities
related to development of
infrastructure for plant
Disturbance
of sub-
surface
heritage
resources
due to
construction
activities
Disturbance of sub-
surface heritage
resources.
If any unmarked archaeological
findings are discovered during
excavation activities, the excavation
must stop and the ECO must be
notified immediately. The ECO must
then contact the South African
Heritage Resources Agency (SAHRA)
to investigate the archeological
findings.
Should the site be identified as a
historical refuse midden, an
archaeologist should be called in to
collect a representative sample from
The
construction
phase is
projected to
begin and end
in 2009
ECO
BBP will monitor
the contractors’
compliance with the
EMP during the
construction phase
on a weekly basis
by means of a
checklist, and the
results fed back to
the contractors at
the monthly
construction project
meetings.
4 Construction activities refers to the development of infrastructure related to the proposed Biomass-to-Energy plant and includes the sinking and/or erection, construction and installation of collection
sumps, silage pits, slurry tanks, mixing tank, CSTR, aerobic treatment systems, blowers, scrubbers, generators, flares, settling ponds and administration offices
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No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
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Proposed
Monitoring
the site. This can then be studied in
order to obtain more information in
this regard.
Activities at the unmarked
archaeological sensitive area will be
allowed to recommence once SAHRA
has investigated the site and given
their permission to remove the
findings and/or to allow the
continuation of the proposed
operations.
Stormwater Management
EM6.
Construction activities
related to development of
infrastructure for plant
Storm water
arising
during
construction
phase
activities
Potential
deterioration in
surface water and
groundwater quality.
The plant site will have a storm water
berm of a minimum height of 0.5m
around it to separate the dirty storm
water within the site footprint from
the clean storm water outside of it.
The plant will ensure that there is a
storm water berm of a minimum
height of 0.5m around the topsoil
stockpile.
The plant will manage and maintain
the dirty water collection sumps
within the plant footprint so that they
do not overflow.
The
construction
phase is
projected to
begin and end
in 2009
ECO
BBP will monitor
the contractors’
compliance with the
EMP during the
construction phase
on a weekly basis
by means of a
checklist, and the
results fed back to
the contractors at
the monthly
construction project
meetings.
P070004 51
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
The waste storage areas and the
manure drying areas must be
designed with a stormwater system
which will utilise bunds for the
separation of the clean and dirty
stormwater.
Trenches are to be constructed
between the areas to be irrigated
with the treated effluent and the
Kleinspruit.
All hazardous waste are to be
disposed off at a suitably licensed
landfill site.
All hazardous substances to be stored
in SANS compliant bunding.
Fauna and Flora
EM7.
Construction activities
related to development of
infrastructure for plant
Loss of
faunal and
floral habitat
due to the
construction
phase
activities
Migration of fauna
from the area
Increase in animal
mortality
The construction site will be fenced to
prevent large fauna from accessing
the site.
The poaching of fauna by contracting
staff is illegal and will not be allowed.
The
construction
phase is
projected to
begin and end
in 2009
ECO
BBP will monitor
the contractors’
compliance with the
EMP during the
construction phase
on a weekly basis
by means of a
P070004 52
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
The site will be monitored for alien
invasive species and a weed
eradication program will be
implemented
The proposed biomass-to-electricity
plant should be designed in such a
way as to ensure that no nutrient
enriched surface water runoff or
seepage leaves the 2ha footprint of
the site, and that all polluted water is
treated to DWAF standards on site.
checklist, and the
results fed back to
the contractors at
the monthly
construction project
meetings.
Air Quality
EM8.
Construction activities
related to development of
infrastructure for plant
Creation and
dispersion of
dust during
construction
phase
activities
Deterioration in air
quality.
Deterioration in the
quality of
surrounding arable
land.
Potential impact on
human health due to
presence of
inhalable particles
All dirt access roads on the Beefcor
site will be adequately maintained to
minimise dust, erosion or undue
surface damage.
BBP will stabilize all surface areas,
which are exposed for longer than
two weeks, with dusticide or suppress
dust with water.
The speed of construction vehicles on
dirt roads will be restricted to a
maximum speed of 20-40 km/h to
avoid excessive dust being generated
or deterioration of the road surface.
The
construction
phase is
projected to
begin and end
in 2009
ECO
P070004 53
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
Wind breaks will be established
around soil stockpiles, taking into
account prevailing wind direction
Fire Hazards
EM9.
Smoking and open fires
on-site by contracting staff
during construction
activities related to
development of
infrastructure for plant
Increase risk
of fire
hazards from
smoking and
open fires.
Land degradation
Loss of vegetation
Deterioration in air
quality.
Fire breaks will be in place around the
construction site and will be
maintained for the life of the
operation.
No open fires will be permitted on
site.
No waste will be allowed to be burned
on site.
Induction sessions for employees and
visitors will include fire prevention/
safety precautions, actions and
contacts in the event of a fire.
The
construction
phase is
projected to
begin and end
in 2009
ECO
BBP will monitor
the contractors’
compliance with the
EMP during the
construction phase
on a weekly basis
by means of a
checklist, and the
results fed back to
the contractors at
the monthly
construction project
meetings.
Ablution Facilities
EM10.
Construction staff
ablutions during
construction activities
related to development of
infrastructure for plant
Utilisation of
non-
commissione
d,
unauthorised
or sensitive
Potential
deterioration of
surface water and
groundwater quality.
Potential
Contractors will provide construction
staff with chemical toilets during the
construction phase.
The chemical toilets will be serviced
and emptied weekly.
The
construction
phase is
projected to
begin and end
in 2009
ECO
BBP will monitor
the contractors’
compliance with the
EMP during the
construction phase
on a weekly basis
P070004 54
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
areas for
ablutions
deterioration of
surrounding soil and
land.
No sanitary facilities will be located
within 100 m of a watercourse
by means of a
checklist, and the
results fed back to
the contractors at
the monthly
construction project
meetings.
Concrete On-site
EM11.
Construction material used
in the development of
infrastructure for plant
Use and
mixing of
concrete on
site
Land degradation.
Potential
deterioration in
surface and ground
water quality.
BBP will ensure that the batching of
concrete will be undertaken on a hard
impermeable surface where possible,
or else inside a concrete mixer since
the cement used in making concrete
can potentially affect the pH of storm
water.
The cement will be delivered in bags
and will be stored on pallets in a dry
covered area within the bunded storm
water area.
No concrete mixing will take place
outside the stormwater bunded area.
Wash water from the mixing of
concrete will be allowed to settle or
evaporate from impermeable
concrete slabs with excess or waste
The
construction
phase is
projected to
begin and end
in 2009
ECO
BBP will monitor
the contractors’
compliance with the
EMP during the
construction phase
on a weekly basis
by means of a
checklist, and the
results fed back to
the contractors at
the monthly
construction project
meetings.
P070004 55
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
aggregate being disposed of at a
suitable landfill site.
Hydrocarbons
EM12.
Utilisation of hydrocarbon-
containing materials
during the development of
infrastructure for plant
Diesel and
oil spills from
equipment
Contamination of
topsoil and subsoil.
Potential
contamination of
surface water.
Potential
contamination of
groundwater.
All equipment will be kept in good
working condition and all leaks
repaired immediately.
All maintenance work will be done
over a plastic tarpaulin or steel drip
tray to catch all spills and leaks.
All operator and contractor-owned
generators will be placed on drip
trays to catch all spills and leaks.
Spilt oils and fuels will be stored in
210 ℓ drums within the service bay
area until the drums are collected by
a certified oil recycler.
In the event of an accidental spill
where the oil or transmission fluid is
spilled directly onto the ground, the
operator will either:
Treat the spill in situ using
bioremediation measures; or
Use a commercially available
hydrocarbon spill kit to absorb the
The
construction
phase is
projected to
begin and end
in 2009
ECO
BBP will monitor
the contractors’
compliance with the
EMP during the
construction phase
on a weekly basis
by means of a
checklist, and the
results fed back to
the contractors at
the monthly
construction project
meetings.
P070004 56
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
spilt hydrocarbons and then dispose
of the used spill kit and spoilt soil at a
certified landfill.
The ECO must keep copies of the
disposal certificates on-site.
Above surface diesel tanks and their
associated bund walls will be
constructed, operated and maintained
according to the South African
National Standards for the “storage
and distribution of petroleum
products in above ground bulk
installations” (SANS 10089-1:2003,
edition 4.1).
P070004 57
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
Environmental Management Measures for –Operation–
Access and Security
EM Site access Unauthorised
access Security
Erect appropriate access controls.
No waste not reflected on the Waste
License may be stored on site.
A weather proof durable sign in three
official language (appropriate to the
area) needs to be erected at the
entrance indicating – the hours of
operations, the name, address and
contact number of the license holder
and the Responsible Person on site.
On completion
of the
construction
phase
BBP
Hydrocarbons
EM13.
Pumping of manure from
feedlots to collection sump
Diesel and
oil spills
from
equipment,
pumping
mechanisms.
Contamination of
topsoil and subsoil.
Potential
contamination of
surface water.
Potential
contamination of
BBP will install storm water
management systems at the plant,
which include oil separators/ grease
traps.
Above surface diesel tanks and their
associated bund walls will be
constructed, operated and maintained
according to the South African
National Standards for the “storage
The Biogas
plant will
operate for as
long as is
required in
terms of
demand for
electricity or
supply of
waste
ECO
BBP will compile an
inspection checklist
for the operational
phase which will be
modified as and
when required by
the relevant
government
department.
Delivery of waste to the
plant
Transfer of waste from the
storage facilities to the
mixing tank.
Pumping of cattle manure
from storage silo to slurry
P070004 58
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
tank groundwater. and distribution of petroleum
products in above ground bulk
installations” (SANS 10089-1:2003,
edition 4.1).
The oil separator will be emptied by a
certified contractor and will not be
allowed to overflow.
The plant will store oils and other
lubricants in a bunded storeroom with
a capacity of 110%.
To prevent diesel and oil spills, all
equipment is to be kept in good
working condition and all leaks
repaired immediately.
All maintenance work will be done
over a plastic tarpaulin or steel drip
tray to catch all spills and leaks.
All plant and contractor-owned
generators will be placed on drip
material. Inspections during
the operational
phase will be
undertaken every
two weeks.
A bi-annual EMP
audit will be
undertaken, a
report for which
will be submitted
to GDACE detailing
the plant’s
compliance with
the EMP.
Mixing of contents of
slurry tank and pumping
to CSTR
Pumping of biogas
released from CSTR
through scrubber and
dehumidifier to Gen Set
Pumping of digested slurry
by-products from Biogas
Plant to storage area
Pumping of water to
digested solids storage
area and dehydration
Collection of dehydrated
slurry solids by contractor
P070004 59
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
trays to catch all spills and leaks.
Spoilt oils and fuels will be stored in
210 ℓ drums within the service bay
area until the drums are collected by
a certified oil recycler.
In the event of an accidental spill
where the oil or transmission fluid is
spilled directly onto the ground, the
plant will either:
Treat the spill in situ using
bioremediation measures; or
Use a commercially available
hydrocarbon spill kit to absorb the
spilt hydrocarbons and then dispose
of the used spill kit and spoilt soil at a
certified landfill.
The Environmental Control Officer
(ECO) must keep copies of the
disposal certificates on file at the
plant.
No waste will be buried or burned on
P070004 60
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
site.
The plant will ensure that all
transformers are surrounded by
reinforced concrete bunds.
The transformers will be serviced in
situ by a certified company.
Air-quality Management
EM14.
Delivery of waste material
to the plant Creation and
dispersion of
dust by
delivery and
collection
vehicles
Odour from
storage and
pumping of
chicken litter
and cattle
manure
Deterioration in air
quality (emissions,
odour).
Deterioration of
working conditions
of the plant staff.
Deterioration in the
quality of
surrounding arable
land.
All dirt access roads will be
adequately maintained to minimise
dust, erosion or undue surface
damage.
The speed of delivery/collection
vehicles on dirt roads will be
restricted to a maximum speed of 20-
40 km/h to avoid excessive dust
being generated or deterioration of
the road surface.
The gas flare will be maintained in
The Bio-2-
Watt Biomass
to Energy
plant will
operate for as
long as is
required in
terms of
demand for
electricity or
supply of
cattle manure
and chicken
litter
ECO
A inspection
checklist for the
operational phase
has been compiled
and will be
modified as and
when required by
the relevant
government
department.
Inspections during
the operational
phase will be
Storage of waste material
on site
Transfer of waste material
to the mixing tank
Storage of cattle manure
in storage silo
Anaerobic digestion of
slurry in CIGAR
Pumping of biogas
P070004 61
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
released from CIGAR
through scrubber and
dehumidifier to Gen Set
Emission of
methane gas
into air
following
breakdown
of
CSTR/flare
Carbon
emissions
from diesel-
driven
generating
and pumping
equipment
Storage of
slurry solids
post-
digestion
good working order
The pumping system will be fitted
with a pressure monitor to detect for
leaks from the Gen Set
All storage and silage pits will be
sealed with concrete covers whose
seals will be intermittently checked
for leaks to ensure that odours are
contained
Complaints from neighbours
regarding odours will be recorded in
the complaints register which will be
monitored by the ECO
The generating equipment will be
kept in good working order and will
be services regularly to minimise the
release of harmful carbon emissions
Windbreaks will be erected at
stockpiles
undertaken every
two weeks.
A bi-annual EMP
audit will be
undertaken, a
report for which
will be submitted
to GDACE detailing
the plant’s
compliance with
the EMP.
The complaints
register will be
monitored
Service records of
equipment will be
maintained
Flaring of excess gas
Storage of slurry solids
post-digestion
Pumping of water to
digested solids storage
area and dehydration
Collection of dehydrated
slurry solids by contractor
P070004 62
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
The functionality of the scrubber will
be monitored to ensure the gas
thresholds are maintained.
The pH of the manure will be
managed through balancing between
high ammonia (alkali) and high
hydrogen sulphide (acidic) emissions
through the addition of pH lowering
compounds such as base precipitating
salts.
Water Quality Management
EM15.
Pumping of liquid manure
from feedlots to collection
sump
Potential
stormwater
runoff which
has been in
contact with
litter or
manure
Breakdown
Potential
deterioration in
quality of ground
and surface water
Clean and dirty water will be
separated on-site
The plant footprint will have
stormwater berms of a minimum
height of 0.5m for the separation of
dirty stormwater (that which has
contacted manure) within the plant
footprint from the clean stormwater
The Biogas
plant will
operate for as
long as is
required in
terms of
demand for
electricity or
supply of
waste material
ECO
BBP will compile an
inspection checklist
for the operational
phase which will be
modified as and
when required by
the relevant
government
department.
Storage of waste material
P070004 63
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
Transfer of waste material
to the mixing tank
of system or
leakage of
liquids from
pipes
throughout
system
Potential
mixing of
clean and
dirty water
through
breaching of
bunds in
excessively
wet weather
Irrigation of
land with
excess
system
water
outside of the footprint.
The plant will ensure that there is
sufficient drainage and berms
surrounding manure storage areas
The applicant will obtain a permit
from the Department of Water Affairs
and Forestry in order to use treated
effluent stormwater for irrigation
purposes
Water will be treated in an aerobic
treatment system to ensure the
quality of effluent being used for
irrigation meets DWAF standards
The plant will monitor water quality in
the clean and dirty water systems
and the results will form part of the
EMP compliance checklist
The plant is to maintain at least 0.8m
freeboard of the effluent stormwater
Inspections during
the operational
phase will be
undertaken every
two weeks.
A bi-annual EMP
audit will be
undertaken, a
report for which
will be submitted to
GDACE detailing
the plant’s
compliance with
the EMP.
Bi-annual water
monitoring of the
groundwater
boreholes and
surface water on-
site will be
undertaken, with
the results being
Pumping of cattle manure
from storage silo to slurry
tank
Mixing of contents of slurry
tank and pumping to CSTR
Pumping of digested slurry
by-products from Biogas
Plant to storage area
Pumping of water to
digested solids storage
area and dehydration
P070004 64
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
Collection of stormwater
effluent in retention dam
retention dam.
The plant will fence and sign the
effluent stormwater dam.
The plant will be responsible for the
clearing of storm water culverts.
The stormwater control area will be
lined with impermeable concrete and
will be bermed-off
The effluent stormwater dam will be
able to retain a 1:50 year flood event
within 24 hours
No ablution facilities will be located
within 100 m of a borehole
Groundwater resources will be
protected through monthly
monitoring of the integrity of the
digester lining
submitted to DWAF
Use of treated effluent
stormwater for irrigation
P070004 65
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
A leakage detection system will be
installed
Collection trenches to be installed
between the land being irrigated and
the Kleinspruit must be regularly
maintained.
All hazardous material to be stored
on site in bunded areas as per the
relevant SANS requirements.
Waste Management
EM16.
Production of general,
domestic and industrial
waste during operation of
the plant.
Incorrect
disposal of
waste
Land degradation.
Surface water and
groundwater quality
deterioration.
Deterioration of
working conditions.
Adequate and covered waste drums
will be provided at the plant within
the stormwater control area.
No waste will be allowed to be buried
or burned.
Waste drums will be emptied
regularly at a suitably licensed landfill
The Biogas
plant will
operate for as
long as is
required in
terms of
demand for
electricity or
supply of
waste material
ECO
BBP will compile an
inspection checklist
for the operational
phase which will be
modified as and
when required by
the relevant
government
department.
P070004 66
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
site.
Copies of the certificate of safe
disposal of all waste must be retained
by BBP.
Industrial waste is to be handled at a
designated waste area.
All scrap metal should be sorted and
sold to scrap metal dealers.
Wastes such as paper and fluorescent
tubes should be sorted for recycling
at source.
The waste storage area will be
demarcated according to each waste
type (colour coded and labelled). The
design ensures environmental risks
are minimised by incorporating
impermeable surfaces and polluted
water separation systems.
The facility will also contain covered
hazardous waste storage area.
Inspections during
the operational
phase will be
undertaken every
two weeks.
A bi-annual EMP
audit will be
undertaken, a
report for which
will be submitted
to GDACE detailing
the plant’s
compliance with
the EMP.
Water and Energy Consumption
EM17. Pumping of manure from Consumption Conservation of The plant will investigate reducing The Biogas ECO Energy accounting
P070004 67
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
feedlots to collection sump of water and
energy
water and energy electricity consumption on an annual
basis as soon as full capacity is
reached
Where possible energy efficient light
bulbs will be used on site.
The mine will aim to reduce water
consumption on an annual basis as
soon as full capacity is reached, with
water from the system being recycled
wherever possible.
No washing of clothing, lunch dishes
or vehicles is permitted in natural
water systems.
It must be ensures that energy
production is always greater than
energy consumption
plant will
operate for as
long as is
required in
terms of
demand for
electricity or
supply of
waste material
will be done
annually according
to the GHG
protocol5 to
investigate
possible
reductions.
BBP will register
with the South
African Clean
Development
Mechanism in
order to register
for the selling of
carbon credits
Pumping of cattle manure
from storage silo to slurry
tank
Mixing of contents of
slurry tank and pumping
to CSTR
Anaerobic digestion of
slurry in CSTR
Pumping of biogas
released from Biogas Plant
through scrubber and
dehumidifier to Gen Set
Pumping of digested slurry
by-products from Biogas
Plant to storage area
Pumping of water to
digested solids storage
area and dehydration
5 The GHG Protocol is a Greenhouse Gas Accounting framework which was developed the World Resource Institute and the World Business Council for Sustainable Development and
which conforms to almost every international standard including the International Standards Organization (ISO). The GHG protocol provides a complete set of tools, guidelines and
worksheets for GHG accounting across sectors, thereby enabling the creation of a narrow scope by which to inventory GHG emissions.
P070004 68
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
Any leaks in the water system will be
attended to rapidly so as to avoid
excessive wasting of water
Non-essential machinery will be shut-
down when not in use.
Socio-economic impacts
EM18. Operation of plant
Staff
requirement
for running
and
maintenance
of plant
Employment
opportunities
(positive impact)
Increase in supplier
opportunities to the
plant (positive
impact)
Increase in the skills
in the local area
BBP will endeavour to employ
workers from the Bronkhorstspruit
area.
Procure material, goods and products
required for operations from local
companies where feasible
Promote workers horizontally to
become proficient in another type of
activity
Ensure that skill transfer takes place
should the required technical skills
not be available within the local
The Biogas
plant will
operate for as
long as is
required in
terms of
demand for
electricity or
supply of
waste material
ECO
P070004 69
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
community.
Increase opportunities for local
residents to be employed during the
life of the plant
Fauna
EM19. Operation of plant
Operation
phase
activities
resulting in
nuisance to
fauna and
flora and
potential
killing of
species
Migration of fauna
from the area.
Loss of conservation
important species
Increase in animal
mortality
Employees will be educated to
minimise the incidental killing and to
prevent intentional killing (hunting) of
animals.
The plant site will be fenced to
prevent large fauna from accessing
the site.
The killing of fauna by staff is illegal
and will not be allowed.
Movements of any animals intending
to flee the impacted area will not be
impeded
The Biogas
plant will
operate for as
long as is
required in
terms of
demand for
electricity or
supply of
waste material
ECO
BBP will compile an
inspection checklist
for the operational
phase which will be
modified as and
when required by
the relevant
government
department.
Inspections during
the operational
phase will be
undertaken every
two weeks.
A bi-annual EMP
P070004 70
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
The site will be monitored for alien
invasive species and a weed
eradication program will be
implemented
The proposed biomass-to-electricity
plant should be designed and
operated in such a way as to ensure
that no nutrient enriched surface
water runoff or seepage leaves the
2ha footprint of the site, and that all
polluted water is treated to DWAF
standards on site.
audit will be
undertaken, a
report for which
will be submitted
to GDACE detailing
the plant’s
compliance with
the EMP.
Hygiene and Sanitation
P070004 71
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
EM20.
Utilisation of manure
(bovine and fowl) for plant
operation
Pumping of
manure from
feedlots to
collection
sump
Storage of
waste
material
Potential
deterioration of
surface water and
groundwater quality.
Land contamination.
Ablutions at the plant will preferably
be connected to the municipal
sewage system
Should connection to municipal
sewage works not be feasible, septic
tanks will be provided for use by staff
The Biogas
plant will
operate for as
long as is
required in
terms of
demand for
electricity or
supply of
ECO
BBP will compile an
inspection checklist
for the operational
phase which will be
modified as and
when required by
the relevant
government
department.
P070004 72
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
Staff complement for
operating plant
Storage of
cattle
manure in
silos
Storage of
digested
manure
solids
Ablution
facilities for
staff
Handling of
manure
Nuisance odours
Potential for
diseases arising from
inherent
microorganisms in
manure
The ECO will check the pipes at the
ablution facilities monthly. If there
are blockages or leaks in the
ablutions, they will be repaired by
the plant within 24 hours.
The plant will perform proactive
monthly checks and will undertake
immediate action to prevent the
deterioration of the surface and
ground water quality.
The collection and storage pits will be
lined with concrete and will be
routinely cleaned with an
antimicrobial sanitizing agent.
Should any diseases amongst poultry
or cattle in surrounding areas arise,
all manure exposed to air will be
sterilised and disposed of.
Notification reminding staff to wear
PPE will be maintained at all time and
will be clearly visible.
Monitoring of exposure of employees
waste material
Inspections during
the operational
phase will be
undertaken every
two weeks.
A bi-annual EMP
audit will be
undertaken, a
report for which
will be submitted
to GDACE detailing
the plant’s
compliance with
the EMP.
P070004 73
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
to air pollutants must be undertaken
within one month of commissioning
the plant and thereafter as per the
requirements of the Occupational
Health and Safety Act.
Staff will be required to wash their
hands with sanitizing handwash
intermittently throughout the day,
while masks, gloves and overalls will
be worn at all times.
P070004 74
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
Environmental Management Measures for –Decommissioning–
Restoration of Land Post-closure
EM21.
Demolition/
Decommissioning
of plant
Removal of
concrete
foundations
Land restoration
The plant will dispose of
any concrete foundations
at a suitably licensed
landfill.
Prior to the resale or
scrapping of any concrete
from foundations, the
plant will undertake high
pressure washing and any
contamination testing
required prior to disposal /
sale.
Any potentially
contaminated concrete
(i.e. that which was in
The Biogas plant
decommissioning
phase is
estimated to last
for approximately
6 months
ECO
Weekly inspections
of
decommissioning
activities will be
undertaken to
ensure compliance
with the EMP
P070004 75
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
direct contact with
manure) will be sanitized
prior to resale, scrapping
or landfilling
The plant will ensure that
that no contaminated
concrete items are
released into the public
domain.
EM22.
Demolition/
Decommissioning
of plant
Removal and
disposal of steel Land restoration
The mine will dispose of all
steel with a certified
trader.
Prior to any resale or
scrapping of the plant
equipment, the plant will
undertake high pressure
washing and any
contamination testing
required prior to the
disposal / sale of the
equipment.
The Biogas plant
decommissioning
phase is
estimated to last
for approximately
6 months
ECO
Weekly inspections
of
decommissioning
activities will be
undertaken to
ensure compliance
with the EMP
P070004 76
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
All metal piping which has
been in direct contact with
manure will be sterilized
prior to scrapping or sale.
EM23.
Demolition/
Decommissioning
of plant
Removal of all
electrical cabling,
transformers and
power generating
equipment
Land restoration
Where possible,
infrastructure will be re-
used rather than
demolished.
Infrastructure can possibly
be sold to Eskom.
All copper cabling will be
stripped and sold to a
certified scrap dealer,
plastic coatings will be
recycled.
Oil filled transformers will
be re-used and where not
possible, oil will be bled
from the transformers for
disposal at a suitable
landfill site and the
transformers will be sold
The Biogas plant
decommissioning
phase is
estimated to last
for approximately
6 months
ECO
Weekly inspections
of
decommissioning
activities will be
undertaken to
ensure compliance
with the EMP
P070004 77
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
as scrap.
EM24.
Demolition/
Decommissioning
of plant
Ploughing,
compacting and
re-application of
topsoil
(Rehabilitation of
topsoil)
Reduction in
compaction of soils
Amelioration and
replacing topsoil on
disturbed areas for re-
vegetation
The plant will till all hard
standing areas
Before placing or re-
spreading topsoil two
factors must be
considered:
First, that the locations for
the spreading of the
available topsoil are
chemically compatible with
the available topsoil.
Second, that there is
sufficient topsoil to
complete the planned task.
The thickness of topsoil
placed will be sufficient for
grazing, 500mm
Where there are only
The Biogas plant
decommissioning
phase is
estimated to last
for approximately
6 months
ECO
Weekly inspections
of
decommissioning
activities will be
undertaken to
ensure compliance
with the EMP
P070004 78
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
limited supplies of topsoil
the following should be
considered:
Topsoil and the vegetation
should be laid in strips
alternating with areas on
which there has been no
placement of topsoil. This
will increase the coverage.
With limited supplies of
topsoil, an underlying layer
of subsoil will commonly
produce better results than
a thin layer of topsoil
alone. This will serve to
“stretch” the supply of
topsoil. Also, in the
application of topsoil, even
if there is very little
available, the smallest
quantities will commonly
introduce essential micro-
organisms and seeds into
the growth region.
P070004 79
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
The plant will carry out
testing of the topsoil prior
to replacing the topsoil.
The plant will test the
chemistry of the topsoil.
The plant will note the
results of the tests,
ameliorate, and seed the
topsoil accordingly.
It is recommended that
placing subsoil or topsoil
near a surface which
contains the following
constituents be avoided:
Soils that have sand or
gravel content of 70% or
more. However, where
soils are excessively
clayey, melding or mixing
granular material with the
P070004 80
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
clay material can produce
acceptable subsoil.
If material has a pH of less
than 5 or a pH of more
than 8.5, avoid or pre-
treat these areas.
The material should not
have a chloride content of
3% or more. If the soils
contain more they should
be treated in another
manner prior to the laying
of subsoil.
The plant will utilise the
recommended species list
for re-vegetation.
The plant will monitor the
re-vegetation process.
Vehicle access onto
rehabilitated land will be
P070004 81
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
No. Activity Aspect Impact Mitigation Measure Timeframe Responsible
Person
Proposed
Monitoring
limited
Soils will not be placed on
slopes with a gradient
greater than 6 % in order
to limit erosion- potential
Adequate sub-surface
drainage will be catered
for so as to limit the
potential for salinisation of
the soils and enhancement
of the arable potential of
the soils
Fauna
EM25.
Demolition/
Decommissioning
of plant
Preservation of
habitats
Re-integration of
fauna onto site
Boundary fences around
plant area will be removed
The Biogas plant
decommissioning
phase is
estimated to last
for approximately
6 months
ECO
Weekly inspections
of
decommissioning
activities will be
undertaken to
ensure compliance
with the EMP
P070004 82
Bronkhorstspruit Biogas Plant
Environmental Management Programme
July 2013
10 References
1Lochner, P. 2005. Guideline for Environmental Management Plans. CSIR Report No ENV-
S-C2005-053 H. Republic of South Africa, Provincial Government of the Western Cape,
Department of Environmental Affairs & Development Planning, Cape Town.
2DEAT (2004) Environmental Management Plans, Integrated Environmental Management,
Information Series 12, Department of Environmental Affairs and Tourism (DEAT), Pretoria.