2.3.4 Groundwater/Seepage management · The hydraulic design for the clean storm water diversion system was undertaken by Ilanda Water Services cc. (Ilanda) in June 2014 (refer to

Kangra Coal (Pty) Ltd Maquasa East Discard Dump

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2.3.4 Groundwater/Seepage management

In order to protect the groundwater resource below and within the vicinity of the Discard

Dump, two mechanisms will be employed to manage seepage from the facility, i.e. an

under-drainage system and a liner.

2.3.4.1 Under-drainage system

The under drainage system is designed to collect seepage on top of the liner and to achieve

phreatic surface drawdown at the toe of the Discard Dump. As such, the under-drainage

system is strategically placed along the critical downstream toe line of the Discard Dump

and includes the following:

• A filter drain (6 m wide toe drain);

• Non-perforated (High Density Polyethylene) HDPE drainage outlet pipes reporting to

manholes; and

• A collector pipe (linking the manholes) that diverts the drainage flows to a

downstream collection sump from where the seepage is diverted to the PCD.

2.3.4.2 Discard Dump Liner

The proposed liner system for the Discard Dump generally complies with the Class C liner

type in the waste classification regulations published in Government Notice R. 634 in

Government Gazette No. 36784, dated 23 August 2013 (GNR634), in terms of the NEMWA.

The liner therefore comprises four layers, as shown in Figure 2.2:

• Layer D: This is a 150mm compacted layer of reworked in-situ soils with a minimum

thickness. The layer must be compacted to a minimum density of 95% Standard

Proctor maximum dry density at a moisture content of 0 to +2% of the optimum

moisture. The permeability of this layer should be lower than 1 x 10-9m/s;

• Layer C: This is a 150mm thick compacted clay layer. The layer must be compacted

to a minimum density of 95% Standard Proctor maximum dry density at a moisture

content of 0 to +2% of the optimum moisture content in layers not exceeding

200mm loose. The permeability of this layer should be lower than 1 x 10-9m/s;

• Layer B: This is a double textured 2mm thick HDPE geomembrane, which must be

laid in direct contact with the upper surface of compacted Layer C. In an effort to

withstand potential mechanical damage when the discard is placed, this

specification exceeds the Class C specification (the regulations require a minimum

of 1.5mm); and

• Layer A: This is a cushion layer of approximately 500mm thickness of fine to

medium sandy or similar suitable material, which is placed immediately above the

HDPE geomembrane to protect it from mechanical damage.


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Figure 2.2 Proposed Liner for the Discard Dump (Source: Geotail, 2014)

2.3.4.3 PCD Liner

The liner system for the PCD generally complies with the Class B liner type as described in

the waste regulation, GNR643. The liner comprises three layers, as shown in Figure 2.3:

• Layer C: This is a base preparation layer consisting of a compacted layer of

reworked in-situ soils with a minimum thickness of 150mm. The layer must be

compacted to a minimum density of 95% Standard Proctor maximum dry density at

a moisture content of 0 to +2% of the optimum moisture content. The permeability

of this layer should be lower than 1 x 10-9m/s;

• Layer B: A 450mm thick compacted clay layer. The layer must be compacted to a

minimum density of 95% Standard Proctor maximum dry density at a moisture

content of 0 to +2% of the optimum moisture content in layers not exceeding

200mm loose. The permeability of this layer should be lower than 1 x 10-9m/s;

• Layer A: A 1.5mm thick HDPE geomembrane, which must be laid in direct contact

with the upper surface of compacted Layer B;


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Figure 2.3 Proposed Liner for the PCD (Source: Geotail, 2014)

2.3.5 Surface Water/Stormwater Management

The surface or stormwater management measures are designed to separate clean and dirty

water, divert clean water away from the Discard Dump and collect and contain water found

within the Discard Dump footprint, which is considered “dirty”.

2.3.5.1 Stormwater Diversion Channels

The hydraulic design for the clean storm water diversion system was undertaken by Ilanda

Water Services cc. (Ilanda) in June 2014 (refer to the “Kangra Pollution Control Dam and

Stormwater Channel Sizing Report” attached as Appendix C of the Design Report).

Based on the hydrological modelling undertaken (refer to Chapter 4 of the Ilanda report),

two channels are deemed necessary to divert clean stormwater away from the Discard

Dump, i.e. the North and South channel (refer to Figure 2.4).

A local watershed runs generally east west through the southern portion of Phase 2 (centre

compartment) of the Discard Dump. The two channels originate on this watershed. The

North Channel runs generally northwards while the South Channel runs southwards before

turning west and then northwest around the southern perimeter of the Discard Dump.

The proposed channels have been sized to comply with the GN704 requirements and as such

they are designed to convey the 50-year design flood peak (refer to the summary of the

channel sizing in Table 2.2). The catchments for the channels are relatively small.

Table 2.2 Stormwater Channel Dimensions

PARAMETER NORTH CHANNEL SOUTH CHANNEL


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PARAMETER NORTH CHANNEL SOUTH CHANNEL

Catchment Size 32.9ha 4.9ha

Shape Trapezoidal Trapezoidal

Base width 1m 1m

Side slopes 1:1.5 (V:H) 1:1.5 (V:H)

Flow depth 0.83m 0.48m

Channel depth* 1.1m 0.8m

Max flow velocity** 3.7m/s 2.7m/s-

Flow type at max velocity Supercritical Supercritical

*Note: Channel depths are based on the flattest downstream portion of the channel

carrying the full design flow.

**Note: Flow velocities are based on the maximum longitudinal gradient.

The stormwater channels have been sized assuming unlined channels, and excavated into

the ground. The material excavated from the channel should be placed in a berm on the

downstream side of the channel. This serves two purposes:

• The berm will increase the capacity of the channel above its design capacity and

provide additional freeboard where required; and

• The berm allows cost effective construction as load and haul volumes are

minimised.

The berm should be compacted and vegetated. The channel should be kept free of long

grass, shrubs and woody vegetation.

It is good practice to allow a further 0.3m of freeboard in the channel. This is to allow for

wave action and flow surges in the channel. A summary of the channel sizes is presented in

Table 2.2 (previous page). In order to keep channel depths practical to construct, the

freeboard allowance within the channels are varied. Where freeboard within the channels is

less than 0.3m, the berms on the outsides of the channels provide the additional freeboard.

A minimum of 0.3m freeboard is therefore available in the channel.

The portion of the North Channel adjacent to Phase 1 and downstream of this will require

erosion protection. The flow regime is supercritical and design flow velocities are likely to

exceed 3.5m/s.

The South Channel will require erosion protection once it turns west and north-west.

Erosion protection could include concrete, HDPE, grouted stone pitching, Reno matrasses,

Armourflex or similar technology.


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Figure 2.4 Proposed Liner for the PCD (Source: Geotail, 2014)


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2.3.5.2 Water Balance/Process Flow

A process flow diagram (PFD) (refer to Figure 2.5) was developed based on the information

provided in the design report (Appendix E) to depict the flow of water to and from the

proposed Discard Dump.

The Water Balance (WB) (refer to Figure 2.6) for the Discard Dump was compiled based on

the PFD. A simulation of water movement within the entire discard facility was conducted,

assuming that the facility has been filled and surfaces fully rehabilitated. Drain and storm

water inflows from the discard facility, direct rainfall on the surface of the PCD, limited

seepage through the lining and evaporation from the PCD surface were balanced.

The WB shows that 1 421 154m³ of water per annum would need to be pumped out of the

PCD to the Opencast Pit East in order to operate the PCD as empty and maintain sufficient

capacity for the 1:50 year storm event.

Figure 2.5 Discard Dump Process Flow Diagram


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Figure 2.6 Discard Dump Water Balance


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2.3.5.3 Discard Dump Design Features

The Discard Dump has been designed to avoid storage of water on the facility, thereby

increasing its stability.

The side slopes will be terraced and berm penstocks will be utilised to drain the permanent

benches. This water will be captured by the catchment paddocks, which will be located at

ground level. The run off will be diverted to the PCD.

It is recommended that the Discard Dump is operated with the minimum of water stored on

the top surface at all times.

2.3.5.4 Pollution Control Dams

The calculations for the sizing of the PCD was also undertaken by Ilanda and the

methodology for the modelling undertaken is provided in the Ilanga report (June 2014)

attached as Appendix C of the Design Report (Appendix E of this document).

The PCD will serve to collect and contain direct rainfall, runoff from the Discard Dump

surface and the “dirty water catchment” of the Discard Dump, as well as seepage captured

by the under-drainage system (within the catchment paddocks). The stormwater diversion

channels (refer to section 2.2.5.1 above) will divert clean water away from the “dirty” area

in order to reduce the amount of polluted water which must be contained, thereby

reducing the PCD capacity requirement.

The proposed maximum capacity of the PCD is 100 000m³. This capacity will be sufficient

provided that:

• Concurrent rehabilitation is undertaken: The Discard Dump has been designed in a

manner that provides for three development phases and concurrent rehabilitation.

Once rehabilitation is undertaken, the rehabilitated area is considered clean and

runoff from that area can be released to the environment. This reduces the volume

of water that needs to be captured and contained. Based on the Discard Dump’s

modular design, and the assumption that rehabilitation will be concurrent, the PCD

has been sized to service an area equivalent to one phase/compartment of the

Discard Dump. Should rehabilitation not be truly concurrent, a second, or even

third PCD may be required;

• Water is pumped out of the PCD: A return pumping capacity of 200m³ of water per

day is required in order to maintain the dam’s freeboard and capacity to

accommodate the 50 year design storm. If no water is returned from the PCD, it

will act as an evaporation dam, thereby requiring a 1.45Mm³ PCD with an average


13-347 9 March 2016 Page 37

depth of 2m. The full pump capacity for the PCD (200m³/day) will be used about

45% of the time (168 days a year on average). [In order to reduce the size of the

PCD to the minimum, i.e. able to accommodate only the 1:50 storm event, the PCD

would have to be emptied every day].

The PCD design specifications are provided in Table 2.3

Table 2.3 PCD Design Specifications

DESCRIPTION VALUE

Maximum capacity 100 000m³

Maximum water depth 4.2m

Dry freeboard 0.8m

Maximum embankment height < 5m

Crest width 5.0m

Upstream slope angle 1(v):2.5(h)

Downstream slope angle 1(v):2.5(h)

Box cut depth varies

Box cut base compaction standard

95% Standard Proctor density

Fill compaction standard 100% Standard Proctor density at 0 to +2% of the optimum moisture content in layers not exceeding 200mm loose

Liner system Refer to section 2.2.4.3 of this report

The water pumped out of the PCD will be sent to the washing plant, before being pumped

to Pit D East where it will be evaporated. The management of this water once it is pumped

out forms part of the scope of the mine-wide water management, therefore this is not

discussed in detail in this document, which is limited to the management of the proposed

Discard Dump.

2.3.6 Safety Classification

The safety classification was undertaken by Geotail (refer to section 4.3 of the Design

Report).

The safety classification allows for the development of a management system that is

tailored to suit the needs of the particular residue deposit, rather than imposing a one-size

fits all system that, of necessity, must cater for the most severe hazards and risks.

The safety classification undertaken defines the potential consequences of a failure of the

Discard Dump. The hazard rating is not associated with the risk (likelihood of adverse


13-347 9 March 2016 Page 38

impacts), which can be reduced and minimised through the implementation of risk

management techniques.

The South African Code of Practice for Mine Residue (SANS 0286:1998) will be utilised for

classification purposes. SANS 0286:1998 calls for a safety classification to differentiate

between residue deposits of high, medium and low hazard rating on the basis of their

potential to cause harm to life or property within the zone of influence. The classification

should be based on the anticipated configuration of the storage facility at the end of its

design life.

The overall hazard rating of the Discard Dump is “low” as shown in Table 2.4.

Table 2.4 Discard Dump Safety Classification

DESCRIPTION ZONE OF INFLUENCE HAZARD RATING

Number of residents in zone of influence

Not aware of any residents within zone of influence (Discard Dump is located within an existing mining

area).

Low

Number of workers in zone of influence

Only mine workers within zone Low

Value of third party property zone of influence

Value of third party property not significant Low

Depth to underground mine workings

The Discard Dump footprint is not undermined. Low

2.3.7 Access Control

A boundary fence will be erected around the perimeter of the Discard Dump facility to keep

out livestock and discourage entry by people.

A haul road will be constructed around the Discard Dump. This haul road will connect to the

existing haul road to the east of the proposed Discard dump Complex. The internal haul

road will also lead to the PCD. The haul roads within the Discard Dump Complex will not

exceed a width of 8m.

2.4 Discard Dump Rehabilitation

Concurrent rehabilitation is required for the effective management of environmental

impacts. Rehabilitation will comprise of correctly contouring the side to a final side slope

angle of 1(v):3(h) and giving the Discard Dump an overall slope of 1(v):4(h).


13-347 9 March 2016 Page 39

It is recommended that Discard Dump is constructed in accordance with the cover

specifications provided in the “Minimum Requirements for Waste Disposal by Landfill”

(1998). Figure 2.7 depicts the proposed soil cover, which has been adapted from the

Minimum Requirements (Figure A.8.12, Appendix A of the Minimum Requirements). The

following layers are proposed:

• V layer: A 450mm thick layer of selected material. The soil used should have a

Plasticity Index (PI) of between 5 and 15 and a maximum particle size of 25mm.

The soil should be compacted to achieve an in situ permeability of 0.5m per year,

as measured using a double ring infiltrometer test. The compaction standard should

be at least 85% of the maximum Standard Proctor dry density at +2% of optimum

moisture content in layers not exceeding 200 mm loose; and

• U Layer: A 200mm thick layer of topsoil planted with local grasses and shrubs. The

layer must be lightly compacted after spreading.

Figure 2.7 Proposed Cover for the PCD (Source: Geotail, 2014)

It is recommended that the topsoil removed during construction (approximately 400mm

thickness) is placed in dedicated stockpiles for use in rehabilitation.

In order to reduce the PCD capacity requirements, it is important that rehabilitation is

undertaken within the specified timeframes, i.e. the rehabilitation of one compartment

should be close to completion by the time construction of the next compartment begins.


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3 PROJECT ALTERNATIVES

The consideration of alternatives for the proposed development during the environmental

investigation, is required in terms of the NEMA, MPRDA and NWA processes. The developer

should be encouraged to consider alternatives that would meet the objective of the original

proposal and which could have an “acceptable” impact on the environment. The role of

alternatives in the EIA process is to therefore find the most effective way of meeting the

need and purpose of the proposed development, through reducing or avoiding potentially

significant negative impacts and enhancing the environmental benefits of the proposed

activity as far as possible.

3.1 Activity/Project

Three options were considered to accommodate the additional discard, i.e. the expansion

of the current Maquasa East Discard Dump, the no-go alternative, and the construction of a

new disposal facility.

3.1.1 Expansion of existing Maquasa East Discard Dump

The existing Maquasa East Discard Dump is located to the north-west of the coal washing

plant (refer to the centre of Figure 3.1).

According to the Maquasa West 2009 EMPr Amendment, the existing discard facility, has a

maximum calculated capacity of 12 000 000 tonnes (this estimate is currently being

confirmed through an assessment of the dump).

The current boundary of the existing discard dump is less than 500m from boundary fence

which separates the mining area from the Driefontein community.

The expansion of the dump was not considered feasible because the available area would

provide sufficient capacity for the additional discard disposal required for the extended

LoM for the Kangra Coal operations and the proposed Kusipongo expansion.

3.1.2 Development of a New Discard Dump (Preferred Option)

This option was identified as the preferred alternative due to fact that the current discard

dump could not be sufficiently expanded. In order to implement this option, a location

needed to be selected (refer to the discussion under Section 3.2 below) and the disposal

method (refer to section 3.3 below).


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Figure 3.1 Existing Discard Dump

[REFER TO A3 FIGURE UNDER APPENDIX A]


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3.2 Alternative Locations for New Discard Dump

Six (6) potential sites were identified by Hatch during their 2011 Concept Study (refer to

Appendix D), which included an assessment of the sites as well as the potential disposal

methods. The following sites were assessed (refer to the locality map under Figure 3.2):

• Site A: situated to the east of the coal washing plant;

• Site B: situated to the north of the coal washing plant;

• Site C: situated to the north west of the coal washing plant and includes the

existing Maquasa East Discard Dump site;

• Site D: situated to the west of the current wash plant position and is located on the

coal reserves in the area known as Maquasa West;

• Site E: opencast excavation situated approximately 2.4km to the west of the

current wash plant position in the Maquasa West Open Cast section; and

• Site F: The site is situated approximately 3.2km to the west of the current wash

plant position.

A fatal flaw assessment was undertaken by Hatch (now Hatch Goba) in 2011. According to

the assessment, “fatal flaws” are those factors which eliminate the use of the sites for

discard disposal because they do not adhere to the environmental and/or safety objectives

(Hatch, 2011). The fatal flaw assessment table extracted from the Site Selection Report is

presented in Table 3.1 below. This table shows that Site E was eliminated due to the

potential difficulty of controlling the Acid Mine Drainage (AMD) in the open cast excavation

Table 3.1 Fatal Flaw Assessment of Potential Sites (Hatch 2011)

SITE FATAL FLAW COMMENT

A No No Comment

B No Steep zone

C No Above old mined out area including existing Discard Dump

D No Acid Mine Drainage (AMD) could exclude this site

E Yes Unlikely to be able to control AMD and opencast operation not guaranteed

F No No comment

The remaining sites were ranked subjectively by considering:

• Safety classification;

• Environmental classification;

• Design and operation; and

• Economics.


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Critical factors were then weighted out of 10, with 1 having the least important and 10

being of critical importance. According to the Site Selection Report, “Critical Factors” are

those factors that do not adhere to the environmental and/or safety objectives, but can

effectively be mitigated by engineering solutions (Hatch, 2011).

Although Site C was identified as the preferred site in the Site Selection Report, Kangra

rejected this site due to the fact that it is located above an old mined out area. Site F as

therefore selected as the preferred site. The advantages and disadvantages of each site are

presented in Table 3.2.


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Figure 3.2 Potential Discard Dump Locations

[FIGURE NOT TO SCALE]


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Table 3.2 Assessment of Alternative Sites

SITE ID ADVANTAGES DISADVANTAGES

Site A

• The relatively flat topography.

• The close proximity (±0.2 km) to the proposed plant position.

• The dump cannot sterilise any coal reserves.

• The close proximity (± 0.6 km) to the Heyshope Dam.

• The collected seepage must be handled by a pumping system that must operate after mine closure.

• The visible impact of the dump.

• The polluted surface water and storm water runoff must be handled by a pumping system during operation.

Site B

• The close proximity (± 0.5 km) to the proposed plant.

• The dump can blend in with the natural topography to reduce the visible impact.

• The polluted surface water and storm water run-off can be handled by a gravity system (passive).

• The seepage can be handled by a gravity system (passive).

• The major seep zone that will require significant engineering design to overcome, and will have a low confidence level of success.

• The site is located partially above the old mined out area and the correct as mined out survey should be sourced to establish how many pillars have been left after mining activities stopped.

• The depth to underground workings is approximately 30 m.

Site C


• The polluted surface water and storm water run-off be handled by a gravity system (passive).


• That it is (± 1.2 km) from the existing washing area.

• The site is located directly above the old mined out area and the correct as mined out survey should be sourced to establish how many pillars have been left after mining activities stopped.

Site D


• The polluted surface water and storm water runoff can be handled by a gravity system (passive).


• The difficulty in containing seepage.

• The distance (± 1.9 km) from the plant position.

• The site is located partially above the old mined out area and the correct as mined out survey should be sourced to establish how many pillars have been left after mining activities stopped.

Site F (Preferred Option)

• The dump is on a slope which faces away from the Heyshope dam and Driefontein and therefore the visual impact is reduced.

• The two naturally occurring clay layers within the soil profile, and the elevation of the ground water is below the second layer.

• The dump cannot sterilise any coal reserves.

• The distance from the current washing plant position (3.2km).

• The introduction of a pumping system to, return the seepage to the plant during the operational life.


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3.3 Disposal Alternatives

Four disposal alternatives were considered during the 2011 Concept Study (refer to

Appendix D).

3.3.1 Integrated Discard “Dry” (Preferred Alternative)

Integrated discard “dry” process involves dumping coarse discard material the conventional

way in layers and mixing the low moisture “filter cake” fine discard material in layers with

the coarse discard.

The integrated discard “dry” technique will reduce the permeability of the coarse discard

and therefore a have a reduction in AMD. Although the expected AMD is significantly less

than that for co-disposal AMD is expected to continue after closure.

3.3.2 Co-disposal “Wet and Dry”

Co-disposal involves the impoundment of slurry within the body of the coarse discard,

which will lead to AMD during the operating life and a considerable period after closure.

3.3.3 Integrated Discard “Wet”

Integrated discard involves the mixing of slurry and the coarse discard which will be

deposited like conventional tailings. The tailings will beach, with the coarse product being

deposited first followed by the fine product which will accumulate at the pool centre.

The integrated discard technique will reduce the permeability of the coarse discard and

therefore a reduction in AMD is expected. Although the expected AMD is significantly less

than that for co-disposal, AMD is expected to continue after closure. However, this disposal

technique is relatively new and unproven technology.

3.3.4 Separate Disposal ”Wet – Site 1 and Dry Site 2”

Separate disposal involves the deposition of the slurry into the underground workings or a

separate above ground fines slurry pond, and the impoundment of the coarse discard above

the ground surface. This reduces the AMD potential of the coarse discard, and the control

and containment of AMD from the slurry if it is placed below ground.

In the case of Maquasa the fines could be transported and deposited in the form of a slurry

back into the underground workings. These areas of disposal would be prepared using the

appropriate preplanning and mining methods.


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The slurry would then be deposited at an elevation below the expected working level and

remains flooded thereby excluding or limiting the supply of oxygen. However, a decision

has been made to stop this operation and to dry the slurry and dispose of the “filter cake”

on the coarse discard dump.

Coarse Discard disposal involves impounding the coarse discard on a selected site above

natural ground. The coarse discard is then compacted to minimise the risk of spontaneous

combustion by limiting the ingress of air and water into the waste dump. The AMD that

could be generated from the coarse discard during operations would then be captured and

contained within the mine property and once the dump has been encapsulated, the amount

of seepage is likely to cease after a short period of time.

3.4 Land Use Alternatives

It is important to consider if there are any viable alternative uses of the land over which

the development is proposed. It must be noted that the proposed development area is

located within an existing mining right area (MRA), on land owned by the applicant.

3.4.1 Tourism

The proposed Discard Dump area is located within an existing MRA, adjacent to a

rehabilitated opencast pit and to the north-east of the Maquasa West current and proposed

pits. The use of this land for tourism is therefore not feasible.

3.4.2 Residential

As discussed above, the proposed Discard Dump area is located within an existing MRA, in

close proximity to the existing and proposed opencast pits of Maquasa East and West. The

surrounding land uses therefore precludes the use of this land for residential developments.

3.4.3 Grazing of Cultivated Land

The location of the proposed Discard Dump within a MRA, immediately adjacent to the

rehabilitated Maquasa East Pit D. This makes the discard dump area unsuitable for use as

grazing and cultivated land unfeasible during the LoM.

3.4.4 Mining

No viable ore reserves are located beneath the proposed Discard Dump site therefore the

used of the area for mining is not possible.


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3.5 No Go Alternative

This alternative would prevent the proposed expansions from being implemented, as there

would be no facility for the disposal of additional discard. This in turn would shorten the

LoM and prevent the exploitation of important coal resources and the retention of

employment in the long term.


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4 ENVIRONMENTAL BASELINE DESCRIPTION

This chapter comprises a description of the current, or baseline environmental, socio-

economic conditions of the proposed Discard Dump area, which is referred to here as the

“Study area”. Specialist studies were conducted over the extent of the proposed Discard

Dump area. Where appropriate, information has been extracted from the specialist studies

undertaken for the previously proposed Power Station and Ash Dump (not constructed),

which would have covered what is now the southern half of the study area (refer to Figure

4.14).

4.1 Climate

The study area lies at an average altitude of approximately 1430m. It is located in the

South African Highveld sub-humid climatic zone, which is a warm, mild summer rainfall

region. It is characterised by warm, wet summers and cool, dry winters.

4.1.1 Temperature

Daily summer (December to January) temperatures range between 15 - 27°C. Winter (June

to August) temperatures range between 3 - 17°C. The humidity is higher during the summer

months, ranging between an average of 80% during November and 65% during June.

4.1.2 Wind

The prevailing wind direction is north, northwest during the summer months with a slight

change to north east during the months of February to April.

The Piet Retief area experiences calms less than 1% of the time, and experiences very high

wind speeds (>0.8m/s) very infrequently.

4.1.3 Rainfall

The proposed Discard Dump is located in a summer rainfall area, with almost 84% of the

annual rainfall falling between the beginning of October and the end of March.

Rainfall data for the area was obtained from the Computing Centre for Water Research,

Natal University (CCWR) database. Gauge number 0407639 (Groot Rietvlei) was used, which

provided daily records starting on 1 July 1929 and ending on 31 August 2000, i.e.71 years

long. The gauge is located approximately 12.2km south of Kangra.


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This data was analysed to produce the average monthly rainfall and average rainfall days

figures presented in Table 4.1 (refer to Ilanda Services Report attached as Appendix C of

the Design Report attached under Appendix E of this EIR).

Table 4.1 Summary of rainfall data (Ilanda, June 2014)

MONTH AVERAGE RAINFALL (MM) AVERAGE RAINFALL DAYS

October 76.4 5.8

November 117.3 8.3

December 132.5 8.5

January 132.1 8.2

February 107.4 6.9

March 83.1 5.7

April 47.6 3.6

May 19.1 1.7

June 7.0 0.9

July 10.2 0.8

August 10.7 1.2

September 30.5 2.6

Total Rain days 54.2

Mean Annual Precipitation 772.1mm*

*Note that the mean annual precipitation will not necessarily equal the sum of the

monthly averages

4.1.4 Evaporation

The mean annual evaporation (MAE) is approximately 1 400mm according to the data

obtained from the WR2005 database for the W51B quaternary catchment (Middleton et al,

2009) (refer to Table 4.2).


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Table 4.2 Summary of monthly evaporation data (Ilanda, June 2014)

MONTH POTENTIAL EVAPORATION DEPTH (MM/MONTH)

January 153.7

February 131.5

March 127.3

April 99.0

May 82.3

June 69.2

July 77.6

August 100.1

September 127.0

October 137.1

November 142.7

December 152.7

Total 1 400mm/year

4.2 Geology

The information in this section is extracted from the Hydrogeological Investigation Report

compiled in respect of the proposed Discard Dump (refer to Appendix C-6).

4.2.1 Regional Geology

All of the known coal deposits in South Africa are hosted in sedimentary rocks of the Karoo

Basin, a large retro foreland basin, which developed on the Kaapvaal Craton and filled

between the Late Carboniferous and Middle Jurassic periods. The Karoo Supergroup is

lithostratigraphically subdivided into the Dwyka, Ecca, and Beaufort groups, succeeded by

the Molteno, Elliot, Clarens, and Drakensburg formations. The coal range in age from early

Permian (Ecca Group) through to Late Triassic (Molteno Formation) and are predominantly

bituminous to anthracite in rank, which is classification in terms of metamorphism under

influence of temperature and pressure.

Within the Karoo Basin, nineteen coalfields have been defined based on variations in

sedimentation, origin, formation, distribution and quality of the coals. These variations are

in tern related to specific conditions of deposition and the local tectonic history of each

area.


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4.2.2 Local Geology

The local geology of the study area is presented in Figure 4.1. The study area is located in

the Ermelo Coalfield, historically one of the most important coal producing areas of South

Africa. The Karoo Supergroup succession in the Ermelo Coalfield consists of the Dwyka

Group diamictites, which occur unconformably above a pre-Karoo basement which is

overlain by the coal bearing Vryheid Formation (Ecca Group); the basal Pietermaritzburg

formation of the Ecca Group not being present. The Vryheid Formation strata consist of five

(5) coal seams, namely A (at the base) – E Seams (Cairncross, 1986); of which all five (5)

seams is hosted by the Ermelo Coalfield coal seams.

Numerous Jurassic age dolerite dykes and sills intrude the Vryheid Formation at various

stratigraphic levels, which tends to influence the stratigraphy and coal qualities in places.

The geochemical environment is fundamentally dictated by the mineralogy of the various

lithological units. In general, the area has been divided into two (2) lithological units:

• arenite – siliciclastic coal-bearing rocks of the Eccca Group (and probably the

Vryheid Formation).

• dolerite – late-stage igneous rock which has been emplaced into the sedimentary

rocks.

Although the proposed development is situated within the Ermelo Coalfield, the coal seams

of interest has been logged as the Utrecht Coalfield seams of Gus and Dundas. The Gus

seam lies stratigraphically above the Dundas seam with a parting of ~15 to 20m. The Gus

seam occurs at a depth of approximately 100m from the surface, with an average width of

~1 to 2 m, whilst the Dundas seam occurs at a depth of approximately 45m from surface,

with varying thickness.

The surface geology in the study area is characterised by the development of a variable

thickness of unconsolidated overburden consisting of both transported and in-situ

weathering material.


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Figure 4.1 Geological Map of the Study Area



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4.2.3 Structural Geology

During the deposits of sediments in the still sagging basin, tension in the crust due to

continuing sagging led to failure and subsequently intrusion of the Post-Karoo dolerite sills

and dykes along week zones (e.g. fault/fracture zones). Consequently dykes and sills

varying between a few centimetres to a couple of metres in thickness intruded.

The highest topographic features comprise resistant remnants of the B4 and B6 dolerite

sills. The B4 sill basically lies concordant to sedimentation at the base of the Volksrust

Formation. Contrasting to the B4 sill, the B6 sill is highly transgressively active and creating

complex ring dyke structures that transgress the coal, causing vertical displacement and

areas of burnt or devolatilised coal.

Although no regional structural features are located within proximity of and / or traversing

the study area, site-specific geophysical data (GCS, 2009) indicates a number of inferred

structural features (interpreted as dolerite dykes) to traverse the study area.

4.3 Topography

The regional topography can be described as undulating with elevations ranging from 1750

metres above mean sea level (mamsl) in the highest regions to the south-east of the mining

operations in the south-eastern corner of the remainder portion of the farm Kransbank, to

1300 mamsl at the lowest point of the Heyshope Dam to the south-east of the Maquasa East

operations.

The Maquasa East and West mining operations are located on the eastern facing slopes of

the Heyshope Dam valley with elevations ranging from 1545 to 1305 mamsl with an average

gradient of 1:19 in an easterly direction.

The proposed Discard Dump site is topographically flat with a slight slope in a westerly

direction (i.e. towards the Egude River) at 4.9%. The topography of the project area is

presented in Figure 4.2.


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Figure 4.2 Topographical Map of the Study Area



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4.4 Soils, Land Use and Land Capability

A Soils, Land Use and Land Capability Assessment was undertaken by GCS (July 2014). The

information in this section is extracted from this report, which is attached under Appendix

C-1.

4.4.1 Soil forms

A total area of 106ha was surveyed during the soil assessment (refer to Figure 4.3). The

soils identified in the soil survey area are fairly uniform, with variations dependant largely

on degree of wetness in the lowermost horizon.

Four (4) soil forms were identified with the project area (refer to Figure 4.3), i.e. the

Pinedene, Clovelly and Glencoe forms, as well as an Anthrosol (this is a soil whose horizons

have been largely affected by human activity).


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Figure 4.3 Soil forms within the Study Area

[REFER TO REPORT UNDER APPENDIX C-1]


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Pindene (43.53ha of the study area)

The Pinedene (Pn) soil form is characterised by an Orthic A horizon, over a yellow-brown

Apedal B horizon, over an unspecified subsoil horizon with signs of wetness. Generally, the

Orthic A horizon has a slight red colour, which is a result of iron oxides (Fe) that

accumulate through weathering (Fey et al., 2010). Within the Pinedene soils found at the

proposed discard facility site, redox conditions have removed all hematite, forming a

yellow-brown colour in the A-horizon. Signs of wetness were identified in the lowermost

horizon.

Owing to a rocky lowermost horizon in places, it was difficult to dig auger holes to a depth

of greater than 1m. The Pinedene soil form was observed in the southern part of the study

area, as seen in Figure 4.3.

Clovelly (40.79ha of the study area)

The Clovelly (Cv) soil form has similar characteristics to the Pinedene soil form - the main

difference is that the Pinedene soil form comprises unspecified material with signs of

wetness below the B horizon, while the Clovelly soil form comprises unspecified material

below the B horizon. This soil varied in depth between 0.5 and 0.8m at the site.

Glencoe (17.06ha of the study area)

The Glencoe soil form is characterised by an Orthic A horizon, over a yellow-brown apedal B

horizon, over a hard plinthic subsoil horizon. Plinthate formation is commonly associated

with areas that are warm, with a humid climate and a distinct dry season.

The yellow-brown colour is attained through soil enrichment with iron oxides where

reduction and mobilisation of iron and its migration re-precipitate as mottles, nodules,

concretions and vesicular hardpan. Owing to a hard lowermost horizon in the area,

dominated by the Glencoe soil form, it was difficult to dig auger holes to a depth of greater

than 0.3m. The Glencoe soil form was observed in the mid-western part of the study area.

Anthrosol (4.62ha of the study area)

Anthrosols are soils formed through the effects of human activity, largely because these

soils have had their natural mantle converted or destroyed and the soils used to replace

these soils are anthropogenic soils. In South Africa, such soils are encountered on

rehabilitated areas, especially where open-cast mining methods have been employed,

mainly in coal mining activities in the Mpumalanga province (Martin, 2010).


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The horizons that constitute one of the Anthrosols found are shown in Figure 4.6 of the Soils

Report. Anthrosols were observed in the area in which rehabilitation is taking place.

4.4.2 Current Land Use

The study area comprises of two land uses (refer to Figure 4.4):

• Land that is currently under rehabilitation (4.60ha of the total 106ha study area);

and

• Grassland (Themeda triandra, also known as Redgrass) currently used for cattle

grazing (97.6ha), which has scattered patches of bare soil.


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Figure 4.4 Current Land Use of the Study Area



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4.4.3 Land Capability

Land Capability can be described as “the fitness of a given tract of land to sustain a defined

use; differences in the degree of capability are determined by the present state of

associated attributes of the area in question” (Schoeman et al., 2002). Land Capability

generally refers to the ability of given soil and contextual conditions to sustain productive

agricultural cultivation.

The following three Land Capability classes determined by Schoeman et al. (2002) were

assigned to the study area based on the soil classifications of the area (refer to Figure 4.5):

• Intensive Agriculture (84.22ha): Most of the study area is covered by Clovelly and

Pinedene soil forms, classified as Class II - arable land (highlighted in pink in Table

4.3). These soils can be used for intensive agriculture. These soils are major

agricultural soil forms in South Africa, owing to their deep, well-drained nature.

• Moderate Agriculture (17.06ha): The study area also comprises soils of the

Glencoe form, which are poorly drained owing to their moderately slow

permeability in the upper parts of the soil (Horizon A). This has an influence on

their high water holding capacity (James, 1986). These soils are suitable for

moderate agriculture owing to their high management requirements, as they

exhibit a seasonal water table or ponding. These were thus classified as Class III, as

highlighted in green in Table 4.3. These soils tend to compact and form clods when

worked while they are still wet (James, 1986).

• Undefined Use (4.62ha): The study area also comprises an area under

rehabilitation, comprising Anthrosols. These soils do not have a defined capability

owing to the mixed and unknown composition of these soil types. In this case this

area will initially be grassed once rehabilitation is completed.

Table 4.3 Land Capability Classes- Description and Suitability

CLASS DEFINITION CONSERVATION NEED USE SUITABILITY

I • No or few limitations.

• Very high arable potential.

• Very low erosion hazard.

Good agronomic practice. Annual cropping.

II • Slight limitations.

• High arable potential.

• Low erosion hazard.

Adequate run-off control

Annual cropping with special tillage or ley (25

%).

III • Moderate limitations.

• Some erosion hazards.

Special conservation practice and tillage

methods.

Rotation of crops and ley (50 %).

IV • Severe limitations.

• Low arable potential.

• High erosion hazard.

Intensive conservation practice.

Long term leys (75 %).


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CLASS DEFINITION CONSERVATION NEED USE SUITABILITY

V • Watercourse and land with wetness limitations.

Protection and control of water table

Improved pastures or Wildlife

VI • Limitations preclude cultivation.

• Suitable for perennial vegetation.

Protection measures for establishment e.g. Sod-

seeding

Veld and/or afforestation

VII • Very severe limitations.

• Suitable only for natural vegetation.

Adequate management for natural vegetation.

Natural veld grazing and afforestation.

VIII • Extremely severe limitations.

• Not suitable for grazing or afforestation.

Total protection from agriculture.

Wildlife.


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Figure 4.5 Land Capability of the Study Area



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4.5 Terrestrial Ecology (Flora and Fauna)

The information in this section has been extracted from the Ecological Assessment (GCS,

April 2015) and Avifaunal Assessment (GCS, February 2015), which are attached under

Appendix C-4 and C-5 respectively.

During the Scoping Phase, it was highlighted by BirdLife South Africa that the proposed

Discard Dump is located within an Important Bird and Biodiversity Area (IBA). The

MDARDLEA therefore requested that a separate avifaunal assessment is undertaken. The

information pertaining to avifauna is under a separate sub-heading in this section.

4.5.1 Vegetation Unit

The study area is comprised entirely of the Eastern Highveld Grassland (GM12) vegetation

unit (refer to Figure 4.6). To the south-west of the study area, a small portion of the mining

area is covered by the Wakkerstroom Montane Grassland vegetation unit.

The Eastern Highveld Grassland vegetation unit is distributed along slightly, to moderately

undulating plains, including some low hills and pan depressions in the Mpumalanga and

Gauteng Provinces. The vegetation is short, dense, grassland dominated by the usual

Highveld grass composition (Aristida, Digitaria, Erigrostis, Themeda, Tristachya, etc.) and

small, scattered rocky outcrops with wiry, sour grasses and some woody species (Acacia

caffra, Celtis Africana, Diospyros lyciodes subsp lycioides, Parinari capensis, Protea caffra,

P. welwitschii and Rhus magalismontanum).

The important taxa associated with this vegetation unit are:

• Graminoids: Aristida aequiglumis (d), A. congesta (d), A. junciformis subsp.

galpinii (d), D. tricholaenoides (d), Elionurus muticus (d), Eragrostis chloromelas

(d), E. curvula (d), E. plana (d), E. racemosa (d), E. sclerantha (d), Heteropogon

contortus (d), Loudetia simplex (d), Setaria sphacelata (d), Sporobolus africanus

(d), S. pectinatus (d), Themeda triandra (d), Trachypogon spicatus (d), Tristachya

leucothrix (d), T. rehmannii (d), Alloteropsis semialata subsp. eckloniana,

Andropogon, appendiculatus, A. schirensis, Bewsia biflora, Ctenium concinnum,

Diheteropogon amplectens, Eragrostis capensis, E. gummiflua, E. patentissima,

Harpochloa falx, Panicum natalense, rendlia altera, Schizachyrium sanguineum,

Setaria nigrirostris, Urelytrum agropyroides.

• Herbs: Berkheya setifera (d), Haplocarpha scaposa (d), Justicia anagalloides (d),

Pelargonium luridum (d), Acalypha angustata, Chamaecrista mimosoides, Dicoma

anomala, Euryops gilfillanii, E. transvaalensis subsp. setilobus, Helichrysum

aureonitens, H. caespititum, H. callicomum, H. oreophilum, H. rugulosum,


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Ipomoea crassipes, Pentanisia prunelloides subsp. latifolia, Selago densiflora,

Sencio coronatus, Vernonia oligocephala, Wahlenbergia undulate.

• Geophytic Herbs: Gladiolus crassifolius, Haemanthus humilis subsp. hirsutus,

Hypoxis rigidula var.pilosissima, Ledebouria ovatfolia.

• Succulent Herb: Aloe ecklonis.

• Low Shrubs: Anthospermum rigidum subsp. pumilum, Stoebe plumose.

The Eastern Highveld Grassland is an ‘Endangered’ vegetation type and only small fractions

are conserved in statutory reserves. Some 44% is already transformed by cultivation,

plantations, mines, urbanisation, and by the building of dams. Cultivation may have had a

more extensive impact, than indicated by land cover data. The Endangered status of this

vegetation type warrants a medium-high environmental sensitivity. The species previously

listed are regarded representative of the Eastern Highveld Grassland vegetation type.

The diversity of plants within the study area represents 56 plant families, typically

dominated by Poaceae (graminoids), comprising 29 species (15.3%) and Asteraceae (Daisy

family), comprising 28 species (14.7%).


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Figure 4.6 Vegetation Units within the Study Area



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4.5.2 Declared Conservation Areas

The conservation status of the Eastern Highveld Grassland vegetation is listed as

Endangered. This vegetation type has a conservation target of 24%. Currently only a small

fraction is conserved in statutory reserves (Nooitgedacht Dam and Jericho Dam Nature

Reserves) and in private reserves (Holkranse, Kransbank, Morgenstood). Some 44% is

transformed primarily by cultivation, plantations, mines, urbanization and by building

dams. There are 10 South African Natural Heritage Sites in this unit, although very little of

it is formally protected. Land use pressures from agriculture are low (5% cultivated) due to

the colder climate and shallow soils. The following conservation areas are located within

the vicinity of the MRA:

Protected Areas

• Paardeplaats Nature Reserve (approximately 6 km to the south east);

• Pongola Bush Nature Reserve (approximately 8 km to the south); and

• Wakkerstroom Wetland Nature Reserve (approximately 13 km to the south west).

National Protected Areas Expansion Strategy (NPAES) Focus Areas:

• Moist Escarpment Grasslands (distributed adjacent to mining area running from

north-west through to south east).

4.5.3 Flora

4.5.3.1 Botanical Diversity

A total of 28 plant species were recorded during the field investigations (March 2014). A

physiognomically dominant grass layer is represented by 20 grass species (71.4%) and 8 Forb

species (28.6). The list of plant families recorded during the survey is presented in Table

4.4.


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Table 4.4 Plant families recorded (March 2014 survey)

GROWTH FORM SCIENTIFIC NAME COMMON NAME

Grasses

Poaceae

Themeda triandra Red Grass

Hypparrhenia hirta Common Thatching Grass

Cymbopogon excavatus Broad Leaved Turpentine Grass

Cymbopogon plurinodes Narrow Leaved Turpentine Grass

Heteropogon contortus Spear Grass

Elionurus muticus Wire Grass

Setaria sphacelata Golden Bristle Grass

Aristida congesta subsp. congesta Tassel Three-awn

Sporobolus africanus Ratstail Dropseed

Eragrostis capensis Heart seed Love Grass

Eragrostis superba Saw tooth Love Grass

Loudetia simplex Common Russet Grass

Eragrostis trichophora Hairy Love Grass

Eragrostis gummiflua Gum Grass

Melenis repens Natal Red Top

Eragrostis lehmanniaqna Lehmann’s Love Grass

Eragrostis curvula Weeping Love Grass

Eragrostis choromelas Curly Leaf

Aristida congests subsp. barbicollus Spreading Three-awn

Pogonartria squarosa Herringbone Grass

Forbs

Asteraceae

Gerbera viridifolia Pink gerbera

Bidens pilosa Blackjack

Gerbera ambigua Common gerbera

Aster bakeranus Baker’s wild aster

Helichrysum mudifolium Hottenot’s tea

Gerbera piloselloides Small gerbera

Gazania krebsiana Common gazania

Verbanaceae Verbena bonariensis Purpletop verain

4.5.3.2 Macro-habitat Types

Natural (untransformed) vegetation of the study area and the surrounding areas are

strongly representative of the regional vegetation types, exhibiting extremely limited

(localised) divergence from the species composition, diversity and vegetation structure

described by Mucina and Rutherford (Vegmap, 2006). Typical of the vegetation of the

region is that extremely little zonality is observed in vegetation forms.

Documents

2.3.4 Groundwater/Seepage management · The hydraulic design for the clean storm water diversion system was undertaken by Ilanda Water Services cc. (Ilanda) in June 2014 (refer to