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DESCRIPTION OF THE ENVIRONMENT:
• SOIL SURVEY,
• PRE-MINING LAND CAPABILITY,
• LAND USE, AND
• SENSITIVE LANDSCAPES (INCLUDING WETLAND CLASSIFICATION AND
DELINEATION),
AS WELL AS
ENVIRONMENTAL IMPACT ASSESSMENT AND
ENVIRONMENTAL MANAGEMENT PROGRAMME
OF
PROPOSED VANDYKSDRIFT SOUTH SECTION
OPENCAST AND SURROUNDS (PORTIONS OF THE ORIGINAL FARMS VANDYKSDRIFT 19 IS,
STEENKOOLSPRUIT 18 IS, MIDDELDRIFT 42 IS
AND RIETFONTEIN 43 IS)
DOUGLAS COLLIERY
EMALAHLENI DISTRICT
WARD 24
Prepared for
BHP BILLITON ENERGY COAL SOUTH AFRICA
by
B.B. McLeroth
July 2009 REMS46
Members:BRUCE McLEROTH B.Sc.Agric.(Natal),MSAIF, MSSSSA
ccearth red
2
CONFIDENTIALITY AND COPYRIGHT RECORDAL
It is recorded that the author of this report claims ownership copyright thereto and will take all
necessary action to protect his interest should his copyright be infringed.
This report may not be either distributed to (electronically or hard copy), or viewed by third
parties other than the client, those directly involved in the project and the relevant authorities.
3
CONTENTS
EXECUTIVE SUMMARY .................................................................................... 5
1.0 INTRODUCTION (Maps 1 and 2) ............................................................ 10
2.0 DESCRIPTION OF THE PRE-MINING ENVIRONMENT .................. 12
2.1 SOIL .............................................................................................................................. 12
2.1.1 SURVEY METHODS AND DATA COLLECTION (Map 1) ................................ 12
2.1.2 THE SOIL MAP (Table 1 and Map 2). ................................................................... 13
2.1.3 SOIL TYPES AND SUITABILITY FOR AGRICULTURE AND ‘TOPSOIL’ ...... 15
2.1.4 SOIL ANALYTICAL DATA (Table 2) ................................................................. 20
2.1.5 SOIL ANALYTICAL CHARACTERISTICS AND SOIL FERTILITY ................. 23
2.1.6 EROSION HAZARD AND SLOPE (Tables 2 and 3 and Figure 1) ........................ 27
2.1.7 DRYLAND PRODUCTION POTENTIAL (Maps 2 and 3) ................................... 32
2.1.8 IRRIGATION POTENTIAL .................................................................................. 35
2.2 PRE-MINING LAND CAPABILITY (Tables 4 and 5 and Map 3) ................................. 36
2.2.1 WETLAND CLASSIFICATION (Tables 5 and 6, and Map 3) ............................... 38
2.3 LAND USE (Table 7 and Map 4) ................................................................................... 41
2.4 SITES OF ARCHAEOLOGICAL AND CULTURAL INTEREST ................................ 45
2.5 SENSITIVE LANDSCAPES (Table 8, and Maps 2, 3, 4 and 5) ..................................... 47
3.0 DETAILED DESCRIPTION OF THE PROPOSED PROJECT ............ 49
3.1 SURFACE INFRASTRUCTURE (Map 4) .................................................................... 49
3.2 CONSTRUCTION/OPERATIONAL PHASES ............................................................. 49
3.3 SOIL UTILIZATION (STRIPPING) GUIDE (Map 5 and Table 9) ................................ 49
3.4 REHABILITATION TOPSOIL BUDGET (Map 5) ....................................................... 52
4.0 ENVIRONMENTAL IMPACT ASSESSMENT ...................................... 54
4.1 SOIL/LAND CAPABILITY/LAND USE ...................................................................... 54
5.0 ENVIRONMENTAL MANAGEMENT PROGRAMME ........................ 56
5.1 MITIGATION MEASURES BY SUBJECT .................................................................. 56
5.1.1 STRIPPING RECOVERY RECOMMENDATIONS (Map 5) ................................ 56
5.1.2 COMPACTION ..................................................................................................... 57
5.1.3 STORAGE LIFE AND STOCKPILING ................................................................ 58
5.1.4 ‘TOPSOILING’ DEPTH ........................................................................................ 58
5.1.5 ORGANIC CARBON ............................................................................................ 59
5.1.6 FERTILITY ........................................................................................................... 60
5.1.7 SLOPE GRADE AND ERODIBILITY .................................................................. 60
5.1.8 SUITABLE ‘TOPSOILING’ MATERIALS ........................................................... 62
5.1.9 SEQUENCE OF REHABILITATED HORIZONS ................................................. 62
5.1.10 POLLUTION ......................................................................................................... 63
5.1.11 RE-VEGETATION ................................................................................................ 65
5.1.12 PERCHED WATER TABLE ................................................................................. 66
6.0 REFERENCES ........................................................................................... 67
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TABLES AND FIGURES
Table 1. Summary of Soil Form .................................................................................................. 14
Table 2. Soil Analytical Data ........................................................................................................ 21
Figure 1. The Soil Erodibility Nomograph of Wischmeier, Johnson and Cross (1971) ............... 28
Table 3. Data Used and Results Obtained from the Soil Erodibility Nomograph ......................... 29
Table 4. Pre-Mining Land Capability Requirements .................................................................... 36
Table 5. Summary of Pre-Mining Land Capability Units ............................................................. 37
Table 6. Wetland Indictors and Corresponding Wetland Types ................................................... 40
Table 7. Summary of Present Land Use ....................................................................................... 42
Table 8. Sensitive Landscapes (Wetlands and Riparian Areas) .................................................... 47
Table 9. Summary of Soil Utilization (Stripping) Guide............................................................... 51
MAPS These maps are presented in map folders at the back of the report document.
Map1. Location and Grid References of Soil Observation Points 68
Map 2. Soil Mapping Units 69
Map 3. Pre-Mining Land Capability Units 70
Map 4. Present Land Use 71
Map 5. Soil Utilization (Stripping) Guide Showing Average Usable Depth and Volume 72
5
EXECUTIVE SUMMARY
Introduction
This survey was conducted as part of the development of an environmental management programme. To this
end a 150m grid survey was conducted in order to quantify the soils, erosion hazard and slope, agricultural
potential, land capability, present land use, sensitive landscapes (wetland classification and delineation),
Environmental Impact Assessment and Environmental Management Programme. Parent material (geology) types encountered include ferricrete (dominant, occurring as an intermittent underlying band), sandstone
(also dominant), shale (limited area on the western boundary), colluvium of mixed origin (in a number of the
valley-bottom areas), alluvium (narrow intermittent band on the edge of the Olifants River and Steenkoolspruit) and possibly dolerite (rare). The total area surveyed is 3075,95 ha, this being made up of the
proposed opencast and surrounds areas.
Soils (survey area as a whole)
Broad Soil Group Soil Forms Area (ha) %
i) Red apedal soils Hutton, Lichtenburg, Bainsvlei, Bloemdal 987,12 ha (32,09 %)
ii) Yellow-brown apedal soils Glencoe, Avalon, Clovelly,
Pinedene 791,23 ha (25,72 %) iii) Neocutanic soils Tukulu, Oakleaf 322,01 ha (10,47 %)
iv) Shallow soils Dresden, Mispah, Glenrosa 101,19 ha ( 3,30 %)
v) E-horizon soils Wasbank, Longlands, Kroonstad 372,24 ha (12,11 %)
vi) Wetland soils Westleigh, Katspruit 194,14 ha ( 6,31 %) vii) Vertic soils Rensburg 3,52 ha ( 0,11 %)
viii) Structured (i.e. pedocutanic)
soils Swartland, Sepane 16,82 ha ( 0,55 %) ix) Alluvial soils Dundee, Vilafontes, Fernwood 16,78 ha ( 0,55 %)
x) Man-made soils Witbank 86,84 ha ( 2,82 %).
The remaining portion of the survey area is comprised of rivers [Olifants River and Steenkoolspruit] (34,94
ha, 1,13 %) and man-made features (149,12 ha, 4,83 %).
Textures for the potential cropping soils (red apedal, yellow-brown apedal and neocutanic broad soil groups)
range from sand to sandy-clay-loam, the dominant texture in these areas being sandy-loam. The wetland,
pedocutanic and vertic broad soil groups display a clay-loam to clay texture, the remaining broad soil groups (E-horizon, shallow and alluvial) generally displaying a sand to sandy-loam texture. Soil structure is
generally apedal in the orthic topsoils which dominate throughout the survey area. However, the orthic and
vertic topsoils of the limited areas of the pedocutanic and vertic broad soil groups which occur, display weak
and strong blocky structure respectively. Soil structure is apedal for B-horizons (except the pedocutanic B-horizon which is strong blocky), single grain for E-horizons and massive for G-horizons. The majority of the
soils have a moderate base status (mesotrophic = poorly leached), given the interaction of the moderate
rainfall, the low mean annual temperature and the low to moderate base reserve of the majority of parent materials in the area. However, the vertic, pedocutanic and wetland broad soil groups have a high base status
(eutrophic = very poorly leached), mostly due to the more base rich parent materials (colluvium and dolerite)
which occur in the majority of these areas.
The non-cultivated (i.e. unfertilized) topsoils have a pH which ranges from 4,5 (very strongly acid) to 6,4
(slightly acid), while that for the cultivated (i.e. fertilized) topsoils (analysed red apedal and yellow-brown
apedal soils) ranges from 6,1 (slightly acid) to 8,0 (moderately alkaline). The increased pH in the cultivated areas is a direct result of the liming of these areas. Topsoil organic carbon of the potential cropping soils is
low (topsoils <0,75 %) to very low (subsoils <0,29 %). The highest organic carbon percentages (>2,0 %) are
found in the topsoils of the E-horizon, wetland and vertic broad soil groups. The soils are neither sodic nor
6
saline. The soil fertility status of the potential cropping soils (for cropping and pasture purposes) is as
follows: Phosphorus (seriously deficient in both A- and B-horizons), Potassium (generally seriously deficient
in both horizons), Magnesium (adequate to slightly deficient in both horizons) and Nitrogen (deficient in both horizons).
Erosion Hazard and Slope
• Pre-Mining areas (i.e. in-situ soils)
Slope in the survey area varies as follows:
vast majority (all slope positions) : 1,8 % (1 degree) - 7,0 % ( 4 degrees),
occasionally (midslopes near rivers) : 8,8 % (5 degrees) - 14,1 % ( 8 degrees), and
very rarely (lower-midslopes near rivers) : 15,8 % (9 degrees) – 28,7 % (16 degrees).
Unacceptable erosion is likely to occur on bare soils (after burning or overgrazing) in undisturbed areas with slopes of greater than 9,2 degrees (red apedal, yellow-brown apedal and neocutanic broad
soil groups), 6,0 degrees (shallow broad soil group) and 4,9 degrees (wetland, E-horizon, vertic and
pedocutanic broad soil groups).
In order to provide for a buffer against soil erosion in cultivated areas, 8,5 degrees was chosen as the
maximum permissible slope for an area to be accepted into the arable capability class.
• Post-Mining areas
The maximum critical slope at which unacceptable levels of soil erosion will begin to occur (bare soils
without vegetative cover) in rehabilitated areas (two scenarios) is as follows:
- Rehabilitated ‘topsoiled’ areas overlying spoil and building rubble (not compacted): utilize red apedal, yellow-brown apedal and neocutanic broad soil groups only
: 13,3 % (7,5 degrees).
- Compacted ‘re-moulded’ soil layer (seal) overlying rehabilitated discard dumps and
pollution control dams.
Only vertic (first choice), pedocutanic (A- or B-horizons) and wetland (G-horizons more
suitable than B-horizons) soils should be utilized for the compacted ‘re-moulded’ layer (seal) in the area.
In terms of the ‘topsoil’ layer (overlying the compacted layer), the following slope should not be exceeded when utilizing:
utilize red apedal, yellow-brown apedal and neocutanic broad soil groups only (A-horizons preferred)
: 9,9 % (5,6 degrees) [non-vegetated, but considerably
steeper after re-vegetation].
However, discard dumps and pollution control dams are not likely to exist in the area after
closure, this being due to the planned (by the mine) practice of in-pit disposal. In this case
the rehabilitation of the aforementioned features will not be necessary.
Dryland Production
Dryland production is suitable in the area. The most commonly planted crops include maize (3,5 tons/ha on a soil depth of 70cm, to 8,0 tons/ha on a soil depth of ≥150cm), dry beans (i.e. sugar beans) [1,5 – 2,5 tons/ha],
soya beans (2,0 – 2,6 tons/ha) and sunflowers (2,0 tons/ha). These yields are for arable areas (soil depth
≥75cm) in years when the rainfall is not limiting. However, the ten year average yield for maize would be
7
closer to 5 – 6 tons/ha/annum for the range of arable soils, incorporating both wet and dry years. Cattle
ranching is also practiced in the area.
Irrigation Potential
The irrigation potential of the arable capability class varies from very high - high (Hutton, Bainsvlei,
Bloemdal and Lichtenburg forms) to moderate (Avalon, Glencoe, Pinedene and Clovelly forms) to moderate-low (Tukulu and Oakleaf forms).
The remaining soils are drainage impaired, shallow and either sandier or very high in clay. Thus complex irrigation scheduling, drainage control and lower yields make them unfeasible for irrigation purposes.
Bearing in mind the numerous mining operations in the area, water quality in the Olifants River and Steenkoolspruit would have to be carefully evaluated before considering irrigation.
Pre-Mining Land Capability Wetland (permanent) 92,35 ha (3,00 %), wetland (seasonal) 199,70 ha (6,49 %), wetland (temporary) 296,80
ha (9,64 %), wetland (Olifants River and Steenkoolspruit) 34,94 ha (1,13 %), riparian (outside of wetlands)
28,31 ha (0,92 %), arable 1587,46 ha (51,61 %), grazing 512,66 ha (16,67 %), wilderness (natural) 87,77 ha (2,85 %), wilderness (man-made features) 149,12 ha (4,83 %), rehabilitated arable 11,57 ha (0,38 %),
rehabilitated grazing 7,57 ha (0,25 %), and rehabilitated wilderness 67,70 ha (2,20 %).
It should be noted that the neocutanic broad soil group (Tukulu and Oakleaf soil forms) [322,01 ha; 10,47 %]
has been included in the grazing capability class (three exceptions are temporary wetlands) as per our
interpretation. However, a more stringent interpretation may qualify many of these areas as temporary
wetlands (see Section 2.5 – SENSITIVE LANDSCAPES).
Present Land Use
Man-made Features: Infrastructure 38,04 ha (1,23 %), major roads 22,75 ha (0,74 %), soil stockpile 2,29
ha (0,08 %), prepared surface 7,70 ha (0,25 %), dumping area 15,71 ha (0,50 %),
banks 3,56 ha (0,11 %), excavations 3,13 ha (0,10 %), trench 0,48 ha (0,02 %),
surface water 48,61 ha (1,58 %), and pollution control 6,85 ha (0,22 %). Sub-total 149,12 ha (4,83 %).
Other: Rehabilitated vegetation 97,84 ha (3,20 %), grassland 848,76 ha (27,59 %),
cultivated presently or previously 1311,31 ha (42,64 %), trees 39,69 ha (1,28 %), land use in the identified wetlands 589,61 ha (19,16 %) [note that a number of
patches of cultivated land and exotic trees also occur in wetlands, these having been
summarized in the wetland category], farmyard 4,64 ha (0,15 %), reservoir 0,15 ha (0,00 %), and rivers 34,94 ha (1,13 %). Sub-total 2926,83 ha (95,16 %).
See Section 2.3 (LAND USE) for the numerous further sub-divisions of the aforementioned present land use
categories.
Sensitive Landscapes The seasonal and temporary wetlands in the study area are typical soil catenas of the Mpumalanga Highveld
(common) and are considered to be of moderate to low significance from a preservation point of view. This
is because they are neither in contact with the regional water table, nor display a broader vegetative diversity than similar wetlands in other areas (outside of the survey area). However, the permanent wetlands are of
high significance and must be preserved. Although the proposed mining plan indicates that a number of
temporary and seasonal wetland areas will be mined, the plan has been structured in order to preserve the
majority of the permanent wetland areas which occur in the study area.
8
The soils which are likely to be more sensitive to erosion then others (red apedal, yellow-brown apedal and
neocutanic broad soil groups) are those of the wetland, E-horizon, pedocutanic, vertic and shallow broad soil
groups.
Soil Utilization (Stripping) Guide and Rehabilitation Topsoil Budget
Government Regulations (R537 of 21 March 1980) require that all topsoil (as defined) removed be replaced on the disturbed surface during rehabilitation. The unsuitable (for rehabilitation purposes) soil must be
replaced below the suitable ‘topsoil’. In the survey area, unsuitable materials include the following: hard
plinthic B-horizon, soft plinthic B-horizon, unspecified/unconsolidated material with signs of wetness, hard rock, weathering rock and G-horizon. These materials can perform a useful function in that they can be
placed as a breaker layer (to intercept the upward capillary movement of acid water) between the pit
(discard) and the ‘usable’ topsoil.
Given that the cropping soils (red apedal, yellow-brown apedal and neocutanic broad soil groups) are both
the most suitable for rehabilitation ‘topsoiling’ purposes, and comprise 91,31 % (23 522 490m³) of the total
available ‘topsoil’ volume (25 761 520m³), they are recommended for surface placement (overlying the less desirable ‘topsoil’ types) during rehabilitation. Map 5 (Soil Utilization [Stripping] Guide) indicates the
location and volume of suitable ‘topsoil’ material.
Thus only the volume of the cropping soils are considered for the rehabilitation scenarios which are
presented in Section 3.4 (REHABILITATION TOPSOIL BUDGET) of this report.
In the rehabilitated scenario, at least the same percentage of arable and grazing land should exist as were
present before disturbance. The highly (majority) to moderately (red apedal and yellow-brown apedal broad
soil groups), and moderately to poorly (neocutanic broad soil group) suitable ‘topsoiling’ materials should be
utilized for rehabilitation purposes in the top 0,6m (arable), 0,25m (grazing) and 0,15m (wilderness, wetland and riparian). The mixing of suitable/unsuitable materials in this zone must be avoided. However, the
aforementioned prescription will lead to a non-utilized ‘topsoil’ surplus of approximately 11 435 005m³.
The surplus ‘topsoil’ reserves must be utilized to increase the ‘topsoiling’ depth to 0,8m throughout the
mining area. (i.e. arable capability class since ‘topsoiling’ depth is ≥0,6m).
For this scenario 23 633 360m³ of ‘topsoil’ will be required to rehabilitate 2954,17 ha (actually less since the entire area will not be mined).
For this scenario ‘topsoil’ (cropping soils) reserves will be short by 110 870m³ (23 522 490 minus 23 633 360m³). This small cropping soils shortage must be made up by utilizing a small proportion of the other
‘usable’ (moderate to low suitability) ‘topsoil’ types which occur in the survey area. This shortage (110
870m³) represents 4,95 % of the volume (2 239 030m³) of the other ‘usable’ topsoil types.
However, the mine must also cater for the provision which must be made for limited stockpiling of ‘topsoil’
material for use in repair work (particularly closure and post-closure phases).
Detailed Description of the Proposed Project
Features which will be constructed during the construction/operational phases of the proposed opencast mining project, include the following:
‘moving’ open pit/pits; haul roads; water management infrastructure (intercept/clean water diversion drains
and/or berms); and temporary overburden rock/discard dumps, product stockpiles and soil (‘topsoil) stockpiles. The overburden rock/discard dumps will be temporary features since the mine has planned for in-
pit disposal of the discard. Thus the final topography (after re-grading, i.e. re-sloping) is planned to be freely
draining. A plant will not be constructed in this area, the product being processed elsewhere (at existing
facilities).
9
Topsoil stripping will commence ahead of the opencast mining operations. This stripped material will largely
be re-distributed immediately on mined-out areas, where the leveling and re-grading of discard and
overburden rock is completed (i.e. ‘moving’ opencast). However, excess soil material will be stockpiled. The amelioration of topsoil fertility and re-grassing will continue in areas undergoing rehabilitation.
Environmental Impact Assessment
Read Section 4.1 (SOIL/LAND CAPABILITY/LAND USE).
Environmental Management Programme
Read Section 5.1 (MITIGATION MEASURES BY SUBJECT).
10
1.0 INTRODUCTION (Maps 1 and 2)
A soil survey (fieldwork) of the proposed Vandyksdrift South Section opencast and
surrounds was carried out from June till October 2008 by L.J. Vivian. The mapping and
report writing was conducted by B.B. McLeroth of Red Earth cc. The area surveyed
(3075,95 ha) is comprised of portions of the original farms Vandyksdrift 19 IS,
Steenkoolspruit 18 IS, Middeldrift 42 IS and Rietfontein 43 IS.
The aforementioned portions are collectively referred to (by the mine) as the ‘Vandyksdrift
South Section’.
The objectives of this survey are:
• to describe the soils (distribution, types, depth, surface features, wetness hazard and
cultivation factors per horizon, suitability for agriculture and ‘topsoil’, physical and
chemical characteristics, fertility, erodibility, dryland production potential and irrigation
potential),
• to determine the pre-mining land capability (Chamber of Mines),
• to classify and delineate the wetlands into the permanent/semi-permanent, seasonal and
temporary classes,
• to determine the present land use,
• to identify sites of potential archaeological and cultural interest,
• to identify the location of sensitive landscapes,
• to produce a soil utilization (stripping) guide,
• to produce a rehabilitation topsoil budget,
• to conduct an environmental impact assessment for the soils, land use and land
capability, and
• to propose mitigation measures for the same (environmental management programme).
This study was conducted in order to both satisfy the EMPR requirements, as well as to
comply with the Rehabilitation Guidelines as specified by the Chamber of Mines for any
site which is to be disturbed.
Sandstone is the dominant parent material (rock) type encountered in the area. Although
sandstone rarely outcrops (except on the steeper northern and western slopes in proximity to
the Olifants River and the Steenkoolspruit respectively), its dominant presence elsewhere in
the survey area is indicated by the following:
i) sandstone is frequently encountered below the soils within augered depth (1,8m);
ii) soil texture and soil colour; and
iii) the presence of hard plinthite (ferricrete) in the majority of the soil profiles (gently
sloping to flat areas), generally indicates that the hard plinthite overlies relatively
impermeable sandstone rock at depth. The colluvial movement of sandstone-derived
soils (dominant in the area) over a long period of time have frequently diluted or
hidden the influence of other parent material types on soil formation, and particularly
so for the red apedal broad soil group.
11
Evidence of shale was encountered at the bottom of a number of soil profiles in one distinct
patch (for location see Map 2 – Soil Mapping Units) on the western boundary of the survey
area.
Colluvium of mixed origin occurs in the valley-bottom (wetland) positions where the
Katspruit soil form is present, while narrow intermittent bands of alluvium are present on
the edges of the Olifants River and the Steenkoolspruit. Five small patches of structured
soils and two small patches of vertic soils occur in bottom-land positions, these soils being
indicative of more base rich parent material types (probably dolerite). However, the parent
material was not encountered within augered depth in the latter areas.
The lithology is indicated on Map 2 for each soil polygon. Those polygons without an
indicated lithology (majority) are derived from sandstone or ferricrete.
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2.0 DESCRIPTION OF THE PRE-MINING ENVIRONMENT
2.1 SOIL
2.1.1 SURVEY METHODS AND DATA COLLECTION (Map 1)
An intensive systematic grid survey was undertaken with sampling points 150m apart
throughout the survey area. A total of one-thousand-four-hundred-and-fourteen auger points
were conducted at pre-determined grid points in the survey area. However, extra auger
points were occasionally conducted for clarification purposes. Furthermore, numerous visual
observations aided in the compilation of the map set. Auger points were frequently shifted
off the pre-determined grid, in order to be conducted in meaningful positions and frequently
to avoid man-made obstacles. The distribution of the sample points examined with a 100mm
bucket soil auger are shown on Map 1.
Auger points were conducted to a maximum depth of 1,8m, or less if a depth limiting
material (for roots) such as hard rock, hard plinthite, soft plinthite or gleyed material was
encountered at lesser depth.
Recorded per profile: soil form/series, effective rooting depth, surface features, compaction,
topsoil organic carbon, depth limiting material, lithology, ground
roughness and remarks.
Recorded per horizon: name/depth of horizons, clay content, sand grade, Munsell colour,
structure, wetness hazard and cultivation factors.
This information is summarized in the soil code (for each distinct polygon) on Map 2 (Soil Mapping Units).
Soils were classified as per the Soil Classification Working Group, 1991 (Taxonomic
System for South Africa). Although the soil classification system requires augering (i.e.
considers diagnostic horizons) to a maximum depth of 1,5m, we have augered to a
maximum depth of 1,8m in order to further clarify lithology and perched water table depths.
13
2.1.2 THE SOIL MAP (Table 1 and Map 2).
The different soil types identified were grouped together into soil-mapping units on the basis
of soil form, effective soil depth for mining (stripping depth) and cropping (effective rooting
depth), surface features, lithology and perched water table depth. Each soil-mapping unit has
a unique code, which describes these factors.
Table 1 summarises the information on Map 2 in terms of soil form.
Table 1. Summary of Soil Form
2.1.3 SOIL TYPES AND SUITABILITY FOR AGRICULTURE AND ‘TOPSOIL’
The soils encountered in the survey area may be divided into ten broad groups, the relative
abundance of which are as follows:
i) Red apedal soils Hutton, Lichtenburg, Bainsvlei,
Bloemdal 987,12 ha (32,09 %)
ii) Yellow-brown apedal soils Glencoe, Avalon, Clovelly, Pinedene 791,23 ha (25,72 %)
iii) Neocutanic soils Tukulu, Oakleaf 322,01 ha (10,47 %)
iv) Shallow soils Dresden, Mispah, Glenrosa 101,19 ha ( 3,30 %)
v) E-horizon soils Wasbank, Longlands, Kroonstad 372,24 ha (12,11 %) vi) Wetland soils Westleigh, Katspruit 194,14 ha ( 6,31 %)
vii) Vertic soils Rensburg 3,52 ha ( 0,11 %)
ix) Structured (i.e. pedocutanic) soils Swartland, Sepane 16,82 ha ( 0,55 %)
ix) Alluvial soils Dundee, Vilafontes, Fernwood 16,78 ha ( 0,55 %)
x) Man-made soils Witbank 86,84 ha ( 2,82 %).
The remaining portion of the survey area is comprised of rivers [Olifants River and
Steenkoolspruit] (34,94 ha, 1,13 %) and man-made features (149,12 ha, 4,83 %).
The Lichtenburg (Li) soil form (orthic A/red apedal B/hard plinthic B) is a new soil form
which will be included in a future (not yet published) soil classification book for South
African soils.
(i) Red apedal soils
These well-drained intermediate [depth] to very deep (majority 0,8 – >1,8m; range
0,3 - >1,8m) soils are widespread in crest and sloping midslope positions (dominant
in the north-western half of the survey area and scattered elsewhere). Textures are
generally loamy-sand to sandy-loam in the topsoil and sandy-loam to sandy-clay-
loam in the subsoil.
Structure varies from apedal (very rarely weak blocky) to single grain. Subsoil (B1-
horizon) S-values (cmol (+)/kg¯¹ = leaching status) are mesotrophic (5 - 15 poorly
leached).
The variation in texture (parent material dependant) shows that both texture
(particularly) and soil form should be considered in determining the suitability of the
various soil materials for agricultural suitability, for rehabilitation purposes and for
waste dump cover.
The ‘usable’ soil depth is dependant on the depth of the unsuitable underlying hard
plinthite (solid iron and manganese oxides layer), soft plinthite (hydromorphic
horizon), unspecified material with signs of wetness (hydromorphic horizon) or
hard/weathering rock. Soil depth was frequently greater than auger depth (1,8m).
The red apedal soils have developed on siliceous (sandstone) parent materials, which
have a low content of weatherable minerals and thus a low clay-forming potential.
The clay mineral suites are dominated by non-swelling 1:1 types (hence the lack of
structural development). The iron mineral hematite imparts the red pigment to the
red apedal soils and is indicative of oxidizing conditions.
The high quality orthic A and red apedal B-horizons are suitable materials for annual
cropping (good rooting medium) and use as ‘topsoil’, having very favourable
structure (apedal or rarely single grain in the cultivated topsoils) and consistence
(very friable to friable).
(ii) Yellow-brown apedal soils
These relatively moderately drained intermediate [depth] to deep (majority 0,5 –
1,3m; range 0,2 - >1,8m) soils are slightly less common in the survey area than the
red apedal soils. These soils are derived from sandstone or ferricrete. Textures are
generally sandy-loam to loamy-sand in the topsoil and sandy-loam to sandy-clay-
loam (occasionally loamy-sand) in the subsoil. The ‘usable’ soil depth is dependent
on the depth of the unsuitable underlying hard plinthic B- or soft plinthic B-horizons,
occasionally hard rock or saprolite, or rarely unspecified material with signs of
wetness.
Distinct weak mottling is evident in the shallower yellow-brown apedal B-horizons,
of the Avalon form, these mottles becoming more common with depth on account of
increasing hydromorphy. The soft plinthic B-horizon is deemed to occur once this
mottling reaches 10 % of soil volume.
Yellow-brown apedal soils develop on parent material types/phases which have a
lower ferrous iron reserve than their red counterparts, as well as in areas with a
higher average moisture status (slightly concave). The texture and structure of these
soils is again dependant on the content of weatherable minerals (low for sandstone
thus apedal to single-grain). The clay suite is predominantly of the 1:1 type. The iron
mineral goethite imparts the yellow pigment to the yellow-brown apedal soils and is
also indicative of oxidizing conditions. A large number of areas (strong-brown or
occasionally reddish-yellow) have both goethite (dominant) and hematite present in
the profile. Subsoil S-values are mesotrophic.
The high to moderate quality orthic A and yellow-brown apedal B-horizons of these
forms are suitable materials for annual cropping (good rooting medium) and use as
‘topsoil’, having favourable structure (apedal, or occasionally single grain in the
topsoil) and consistence (friable to loose).
(iii) Neocutanic soils
These relatively slightly poorly drained shallow to deep [depth] (generally 0,4 -
1,0m; range 0,4 - 1,5m) soils occur in patches in lower midslope, footslope and
concave positions, bordering the E-horizon and wetland soils. Textures are generally
loamy-sand or sand, and occasionally sandy-loam in a number of the subsoils. These
soils are essentially yellow-brown apedal soils, the only difference being that they
either bleach (vast majority) in the dry state (frequently slightly mottled) or are non-
uniform in colour due to the presence of cutans and channel infillings (very rarely).
17
The moderate to poor quality orthic A and neocutanic B-horizons of these soils are
suitable materials for use as ‘topsoil’, having favourable structure (single grain or
apedal) and consistence (loose to very friable). Although these soils are not ideal for
annual cropping in the survey area, given either their limited depth, or alternatively
their sandy nature (low total available moisture), they may however be utilized.
A number of neocutanic soil polygons are derived from alluvium. However, these
polygons have been allocated to the alluvial broad soil group.
(iv) Shallow soils
These shallow (generally 0,1 - 0,3m; range 0 – 0,4m) soils are poorly (majority) to
moderately drained. The Mispah form (overlying rock) occurs in intermittent bands
on the moderately sloping lower-midslopes adjacent to the Olifants River and the
Steenkoolspruit, while the Dresden form (overlying hard plinthite) occurs in small
scattered isolated patches on very gently to gently sloping crest, midslope and
footslope positions throughout the survey area. The soil texture is sand to sandy-
loam. Concretion gravel is common in the ferricrete derived Dresden profiles, while
10 – 80 % surface rocks are frequently present in the sandstone derived Mispah
areas. The ‘usable’ soil depth is dependant on the depth of the unsuitable underlying
hard plinthic B-horizon (which is frequently solid in nature) [Dresden form], hard
rock [Mispah form], or rarely weathering rock [Glenrosa form].
The Mispah form has formed in slope positions (steeper) where the average moisture
status of the soil is lower (increased runoff), resulting in a limited weathering of the
parent rock. The Dresden form has generally formed on the harder phases of the relic
ferricrete parent material, or occasionally in areas adjoining the E-horizon soils,
where a fluctuating water table has led to the localization and accumulation of iron
and manganese oxides, which have become indurated over a long period.
The orthic A-horizon is unsuitable for annual cropping or forage plants (poor rooting
medium since the very low total available moisture causes the soil to be drought
prone).
These poor topsoils are not recommended for rehabilitation purposes as a surface
placement. However, they may be utilized further down in the rehabilitated profile.
(v) E-horizon soils
These poorly drained sand to loamy-sand soils are widespread in slightly concave
lower-midslope, footslope and valley-bottom positions. The unsuitable E-horizons of
these soils are generally intermediate in depth (0,4 – 0,8m) and overlie hard or soft
plinthite or G-horizon. However, given the mottled, bleached and frequently
waterlogged (summer) nature of the E-horizon, the effective rooting depth of these
soils is generally shallow (0,1 – 0,4m).
The poor quality (dark or bleached and mottled) orthic A-horizons of these forms,
having favourable structure (single grain to apedal) and consistence (loose to very
friable), are capable of supporting indigenous grassland and wetland vegetation.
These soils may not be cropped since they fall into the wetland (temporary or
18
seasonal) capability class. These materials are not recommended for rehabilitation
purposes (as a surface placement), given that they have a low moisture holding
capacity (sandy) and are relatively erodible when overlying a relatively impermeable
depth limiting material.
(vi) Wetland soils
Hydromorphic soils of the Westleigh (dominant) and Katspruit (sub-dominant)
forms occur in gently sloping concave valley-bottom positions. These poorly drained
(dark or bleached and mottled, and frequently waterlogged in summer) soils have a
sandy-loam to sandy-clay-loam texture in the topsoil and a sandy-clay-loam to clay
texture in the subsoil. The unsuitable underlying hydromorphic soft plinthic B or G-
horizon occurs at shallow depth (0,1 – 0,4m).
Such soils have formed due to either a fluctuating water table (soft plinthic B –
alternating cycles of oxidation and reduction accompanied by an accumulation of
iron and manganese oxides) or a permanent water table (G-horizon – continuous
reduction and marked clay illuviation).
The poor quality (dark or bleached and mottled) orthic A-horizons of these soil types
may not be cropped, since these are wetland (seasonal and permanent) areas. These
topsoils are recommended for rehabilitation purposes in future drainage/wetland
areas only.
(vii) Vertic soils
These relatively poorly to moderately drained (‘dark’ colours including very-dark-
grey and black) [hue 10YR] calcareous soils occur in two small patches in
floodplain/valley-bottom slope positions.
These strongly structured fine grained clay-loam to clay textured vertic topsoils are
intermediate (0,5 – 0,8m) in depth, and are probably derived from base rich (dolerite
and/or colluvium) parent material.
The vertic A-horizon of the Rensburg form overlies a G-horizon (synonymous with
gley or gleyed) at depth. This underlying gleyed (intense reduction as a result of
prolonged saturation with water) horizon is thin to thick (0,2 – 0,8m) in these
floodplain/valley-bottom positions (permanent wetlands).
Topsoil (A-horizon) S-values (cmol (+) kg¯¹ clay = leaching status) will be eutrophic
(S-value >15 = high base status = very poor leached). These vertic topsoils are also
calcareous (effervesces visibly when treated with cold 10 % hydrochloric acid) at
depth (and also in the underlying G-horizon). These soils are poorly leached, given
the interaction of the high base reserve of the dolerite/colluvium parent materials,
and the moderate effective rainfall (interaction of the moderate mean annual
precipitation, and the moderate mean annual temperature) in the area, whereby the
leaching potential is insufficient to remove base cations (calcium and/or calcium-
magnesium carbonates) from the soil profile.
19
Due to their high clay content and the predominance of smectitic clay minerals,
vertic soils possess the capacity to swell and shrink markedly in response to moisture
changes. Such expansive materials have a characteristic appearance: structure is
strongly developed, ped faces are shiny, and consistence is highly plastic when moist
and sticky when wet. Swell-shrink potential is manifested typically by the presence
of conspicuous vertical cracks (dry state), and the presence of slickensides (polished
or grooved glide planes produced by internal movement). Once the soils are moist,
the permeability becomes slow to very slow, and rainfall runs off laterally on the
surface.
The pH in the vertic areas is likely to be moderately alkaline (7,90 – 8,40).
The poor (to moderate) quality vertic A-horizons have an unfavourable structure
(strong blocky), consistence (very firm to firm) and permeability (slow once moist).
This material is most useful (most suitable of all of the broad soil groups) for sealing
purposes (underlying slimes/pollution control dams), or overlying [as a compacted
layer below the ‘topsoil’] rehabilitated slimes/pollution control dams or discard
dumps, since it naturally displays a slow permeability once moist, and possibly a
very slow permeability once compacted.
(viii) Structured (i.e. pedocutanic) soils
These relatively poorly (bleached or ‘dark’ colours) [hue 10YR] drained clay-loam
to clay textured (both horizons) shallow (0,2 – 0,4m) soils occur in five small
patches on basic parent material types (colluvium and dolerite), in concave,
footslope and valley-bottom positions.
Structure is generally weak or moderate in the topsoil, and strong blocky in the
subsoil, while consistence (dry) is hard to very hard. The subsoils are eutrophic and
occasionally become calcareous at depth. The pedocutanic subsoils are non-uniform
in colour due to the presence of cutans (clay skins) on most ped surfaces, and both
the presence of 2:1 clays and the generally high clay contents have given rise to the
pedality (structure) of the soils.
The usable soil depth is dependant on the depth of the unsuitable (bleached colours)
pedocutanic B-horizon.
The poor quality (in the area) orthic A-horizon is not suitable for cultivation and
rehabilitation ‘topsoiling’ purposes. However, both the A- and B-horizons are useful
for sealing purposes.
(ix) Alluvial soils
Small narrow intermittent bands (twenty-seven soil polygons) of alluvial (detrital
deposits resulting from the operation of modern streams and rivers) soils occur along
the edges of the Olifants River (predominantly) and the Steenkoolspruit. Soil forms
include Dundee (dominant), Tukulu (dominant), Vilafontes (occasional), Oakleaf
(rare) and Fernwood (very rare).
20
These poorly (bleached colours, and generally waterlogged throughout the year) and
occasionally moderately drained soils generally display a sand to loamy-sand
(occasionally sandy-loam) texture. The unsuitable underlying neocutanic B-horizons
and/or E-horizons are generally waterlogged at a shallow to deep (0,3 – 1,2m) depth
below the soil surface.
The effective rooting depth is determined by either the depth of the waterlogging in
the neocutanic B-horizon, or alternatively by the depth of the A-horizon which
overlies the unsuitable E-horizon.
These riparian (see Section 2.2.1 – WETLAND CLASSIFICATION) areas must not
be disturbed.
(x) Man-made soils
Rehabilitated areas (Witbank form) occur in a number of patches in the survey area,
where shallow to intermediate [depth] (generally 0,1 – 0,3m, range 0 – 1,5m)
‘topsoil’ material overlies spoil, discard or coal.
Perched water tables in augered depth (1,8m) were a feature of many of the wetland and E-
horizon soils at the time of the soil survey. However, perched water tables also occur in a
number of areas of the neocutanic (occasionally), yellow-brown apedal (rarely) and red
apedal (rarely) soils. Water tables generally occur in summer after rainfall events, where
there is a relatively impermeable horizon (hard plinthic B, soft plinthic B, G-horizon or hard
non-fractured rock) below the A, B or E-horizon. Water tables largely disappear altogether
in winter, except in the most low-lying positions. The distribution and upper depth of these
water tables are indicated on Map 2.
2.1.4 SOIL ANALYTICAL DATA (Table 2)
Table 2 shows the analytical data for topsoil (A-horizon) and subsoil (B, E and G-horizons)
samples collected from modal examples of six different soil forms in the area. These
samples represent five of the ten broad soil groups, which occur in the current survey area.
These samples are those from an adjoining (north of the Olifants River) soil survey
(REMS45). The aforementioned samples are applicable to the current survey area given that
the prevailing climate and geology are the same. Thus the soil physical and chemical
characteristics are also the same (in the non-cultivated/unfertilized state).
The analytical determinations were conducted in the laboratories of the Institute for Soil,
Climate and Water (ARC) in Pretoria.
The interpretation of this data is discussed in the next section.
21
Table 2. Soil Analytical Data SOIL SAMPLE AND GRID
REFERENCE PIT 1 (AUGER Q20) PIT 2 (AUGER AA8) PIT 3 (AUGER AH28) PIT 4 (AUGER D12) PIT 5 (AUGER Y16)
HORIZON AND DEPTH A(10cm) B(60cm) A(10cm) B(60cm) A(10cm) B(60cm) A(10cm) A(10cm) E(60cm)
LABORATORY REFERENCE (ISCW)
M741 M742 M737 M738 M739 M740 M743 M744 M745
TEXTURE(%) Sand: Coarse
Medium
Fine
Very fine
Silt : Coarse
: Fine
Clay :
TEXTURE CHART
17,8 ] 10,3 ]
26,1 ] 82,7 17,1 ] 72,4
30,0 ] 32,8 ]
8,8 ] 12,2 ]
3,7 } 5,6 6,2 } 9,2
1,9 } 3,0 }
11,7 11,7 18,4 18,4
CoLmSa FiSaLm
7,6 ] 7,2 ]
24,6 ] 83,3 15,2 ] 74,6
38,4 ] 36,9 ]
12,7 ] 15,3 ]
4,1 } 6,4 6,4 } 9,1
2,3 } 2,7 }
10,3 10,3 16,3 16,3
FiLmSa FiSaLm
5,5 ] 5,1 ]
27,2 ] 84,4 21,3 ] 78,9
41,9 ] 40,9 ]
9,8 ] 11,6 ]
4,0 } 5,0 4,4 } 6,2
1,0 } 1,8 }
10,6 10,6 14,9 14,9
FiLmSa FiSaLm
13,7 ]
18,5 ] 80,5
34,3 ]
14,0 ]
7,9 } 8,9
1,0 }
10,6 10,6
FiLmSa
12,5 ] 9,3 ]
28,9 ] 85,7 27,7 ] 86,0
33,4 ] 36,0 ]
10,9 ] 13,0 ]
5,2 } 8,3 8,2 } 8,9
3,1 } 0,7 }
6,0 6,0 5,1 5,1
MeLmSa MeSa
EXCHANGEABLE
CATIONS (cmol (+) kg¯¹ soil [ppm or
or meq 100g soil) mg/kg]
Ca
Mg
K
Na
1,40 280 0,93 186
0,80 97 0,42 51
0,12 46 0,05 19
0,02 5 0,03 7
2,12 425 0,74 148
0,77 94 0,41 49
0,15 59 0,05 19
0,03 7 0,03 7
0,63 126 0,39 77
0,45 54 0,30 36
0,08 33 0,34 133
0,04 8 0,04 10
0,26 52
0,21 26
0,08 30
0,02 6
0,59 118 0,28 57
0,42 51 0,30 37
0,08 32 0,03 10
0,08 18 0,05 11
S-VALUE cmol (+)kg¯¹ soil
cmol (+)kg¯¹ clay
2,33 1,43
19,9 7,8
3,08 1,22
29,9 7,5
1,19 1,07
11,2 7,2
0,57
5,4
1,17 0,66
19,5 12,9
CEC at pH7 cmol (+)kg¯¹ soil
cmol (+)kg¯¹ clay
3,52 4,34
30,1 23,6
5,35 5,53
51,9 33,9
5,97 5,40
56,3 36,2
2,34
22,1
4,02 1,46
67,0 28,6
BASE SATURATION (%) 66,2 32,9 57,6 22,1 19,9 19,8 24,4 29,1 45,2
ESP (%) 0,57 0,69 0,56 0,54 0,67 0,74 0,85 1,99 3,42
SATURATION EXTRACT
SOLUBLE CATIONS (mmol(+)/l or [ppm or
me/l) mg/kg]
Ca
Mg
Na
Total
N/D
N/D
N/D
N/D
N/D
SAR N/D N/D N/D N/D N/D
EC (mS/m) N/D N/D N/D N/D N/D
RESISTANCE (ohms) N/D N/D N/D N/D N/D
pH (1:2,5 H2O) 6,2 5,7 8,0 7,1 6,1 5,3 4,5 5,0 5,5
ORGANIC CARBON (%)
Walkley Black 0,69 0,25 0,75 0,29 0,44 0,29 0,62 2,27 0,20
TOTAL N (TKN) (%) N/D N/D N/D N/D N/D
P (Bray P1) (ppm or mg/kg) 26,0 30,6 5,6 9,0 14,6 13,7 31,8 23,1 22,4
SOIL FORM
SOIL FAMILY
CODE
DEGREE OF LEACHING
DOMINANT PARENT
MATERIAL
PRESENT LAND USE
Hutton
Suurbekom
Hu2200
Mesotrophic
Sandstone
Maize
Avalon
Vryheid
Av2200
Mesotrophic
Sandstone
Maize
Glencoe
Driehoek
Gc2100
Mesotrophic
Sandstone
Eucalyptus/Grassland
Mispah
Myhill
Ms1100
Mesotrophic
Sandstone
Grassland
Longlands
Sherbrook
Lo1000
Mesotrophic
Sandstone
Grasslands
BROAD SOIL GROUP RED APEDAL YELLOW-BROWN APEDAL YELLOW-BROWN APEDAL SHALLOW E-HORIZON
22
Table 2. Soil Analytical Data (continued) SOIL SAMPLE AND GRID
REFERENCE PIT 6 (AUGER AF34)
HORIZON AND DEPTH A(10cm) G(50cm)
LABORATORY REFERENCE (ISCW)
M746 M747
TEXTURE(%) Sand: Coarse
Medium
Fine
Very fine
Silt : Coarse
: Fine
Clay :
TEXTURE CHART
6,0 ] 1,5 ]
10,3 ] 47,3 4,0 ] 17,9
20,7 ] 7,7 ]
10,3 ] 4,7 ]
12,7 } 23,4 6,1 } 13,2
10,7 } 7,1 }
29,3 29,3 68,9 68,9
FiSaClLm FiCl
Note: Textural rounding off errors
were added to the clay
content.
EXCHANGEABLE
CATIONS (cmol (+) kg¯¹ soil [ppm or
or meq 100g soil) mg/kg]
Ca
Mg
K
Na
3,58 717 5,31 1064
2,77 336 5,92 719
0,22 87 0,15 60
0,77 177 5,72 1315
S-VALUE cmol (+)kg¯¹ soil
cmol (+)kg¯¹ clay
7,34 17,10
25,1 24,8
CEC at pH7 cmol (+)kg¯¹ soil
cmol (+)kg¯¹ clay
10,84 21,68
37,0 31,5
BASE SATURATION (%) 67,7 78,9
ESP (%) 7,10 26,38
SATURATION EXTRACT
SOLUBLE CATIONS (mmol(+)/l or [ppm or
me/l) mg/kg]
Ca
Mg
Na
Total
N/D
SAR N/D
EC (mS/m) N/D
RESISTANCE (ohms) N/D
pH (1:2,5 H2O) 6,4 8,7
ORGANIC CARBON (%)
Walkley Black 2,03 0,49
TOTAL N (TKN) (%) N/D
P (Bray P1) (ppm or mg/kg) 21,0 20,9
SOIL FORM
SOIL FAMILY
CODE
DEGREE OF LEACHING
DOMINANT PARENT
MATERIAL
PRESENT LAND USE
Katspruit
Lammermoor
Ka1000
Eutrophic
Sandstone Colluvium
Grassland
BROAD SOIL GROUP WETLAND
23
2.1.5 SOIL ANALYTICAL CHARACTERISTICS AND SOIL FERTILITY
(Table 2)
(i) Soil texture
Soil texture is considered to be a permanent property of soils and as such it is
particularly important in determining soil behaviour. Many soil properties are
dependent on the proportions of sand, silt and clay including inter alia nutrient
and water holding ability, permeability, porosity, erodibility, and susceptibility to
compaction.
With the exception of Pit 6 (Katspruit – wetland broad soil group), which has a
sandy-clay-loam (29,3 % clay) topsoil and a clay (68,9 % clay) subsoil, the
majority of pits have a large amount of sand in both topsoils (82,7 to 85,7 %) and
subsoils (72,4 to 86,0 %). The clay content range for the same soils is as follows:
topsoils (6,0 to 11,7 %) and subsoils (5,1 to 18,4 %). This results in a topsoil and
subsoil textural range of sand (E-horizon broad soil group) to sandy-loam (red
apedal and yellow-brown apedal soils). The soil survey obviously showed a
larger variation in the measured variables (both within and between soil forms)
than those determined for the typical samples in Table 2. Thus sandy-clay-loam
textures were also common in the red apedal broad soil group. The structured and
vertic broad soil groups were not sampled (very small combined percentage [0,66
%] of current survey area), these areas displaying clay-loam to clay textures.
(ii) Soil pH (reaction)
Soil pH is the degree of acidity of a soil. Descriptive terms commonly associated
with certain ranges in soil pH (van der Watt, 1995) measured in distilled water
are:
extremely acid (<4,5), very strongly acid (4,5-5,0), strongly acid (5,1-5,5),
medium acid (5,6-6,0), slightly acid (6,1-6,5), neutral (6,6-7,3),
mildly alkaline (7,4-7,8), moderately alkaline (7,9-8,4), strongly alkaline (8,5-9,0) and
very strongly alkaline (>9,0).
The soil pH has a direct influence on plant growth in a number of ways:
• through the direct effect of the hydrogen ion concentration on nutrient uptake;
• indirectly through the effect on trace nutrient availability; and by the
• mobilizing of toxic ions such as aluminium and manganese, which restrict plant growth.
The midslope (red apedal and yellow-brown apedal broad soil groups) topsoils
range in pH from 4.5 to 8,0 and subsoils from 5,3 to 7,1, while the E-horizon and
wetland soil pits topsoils range in pH from 5,0 to 6,4 and subsoils from 5,5 to
8,7, the latter pH reflecting the presence of calcium carbonate in a number of the
vlei areas.
The non-cultivated (i.e. unfertilized) topsoils have a pH which ranges from 4,5
(very strongly acid) to 6,4 (slightly acid), while that for the cultivated (i.e.
fertilized) topsoils (analysed red apedal and yellow-brown apedal soils) ranges
from 6,1 (slightly acid) to 8,0 (moderately alkaline). The increased pH in the
cultivated areas is a direct result of the liming of these areas.
24
(iii) Saturated extract
Saturated extracts are used to determine the amounts of easily water-soluble
elements, especially the amounts of Ca (calcium), Mg (magnesium) and Na
(sodium) in order to determine the salinity and sodicity of the soil.
Background
Electrical conductivity (EC: measured in millisiemens/m : mS/m) is a measure of
the ability of a soil saturation extract to conduct electricity and is a measure of
the concentration of salts in solution. For example low salinity irrigation waters
have values less than 25 mS/m and high salinity irrigation waters have values
greater than 75 mS/m.
Highly saline (high soluble salt content of which sodium forms a modest
proportion [usually exchangeable sodium percentage or ESP <15]) soils will
result in the reduction of plant growth, caused by the diversion of plant energy
from normal physiological processes to that involved in the acquisition of water
under highly stressed conditions.
The sodium adsorption ratio (SAR) measures soil sodicity and is a measure of the
quality of a solution (eg. saturation extract or an irrigation water regards sodium
content). At high levels of exchangeable sodium, certain clay minerals, when
saturated with sodium, swell markedly. With the swelling and dispersion of a
sodic soil, pore spaces become blocked and infiltration rates and permeability are
greatly reduced. The critical SAR for poorly drained grey soils is 6, for slowly
draining black swelling clays is 10 and for well drained soils and recent sands 15.
The exchangeable sodium percentage (ESP) [percentage of the cation exchange
capacity (CEC) that is occupied by sodium] is also an indicator of soil sodicity. A
sodic (low soluble salt content and a high exchangeable sodium percentage
[usually ESP >15] soil has sufficient adsorbed sodium to have caused significant
deflocculation.
The Chamber of Mines specifies that for a soil to be defined as arable (or to be
utilized as ‘topsoil’), that it must have an EC of less than 400 mS/m at 25°C and
an ESP of less than 15 throughout the upper 0,75m of soil.
Survey Area
The saturated extract determination was not carried out for the current soil
survey, since cropping (red apedal, yellow-brown apedal and neocutanic broad
soil groups) soils in the region are neither saline nor sodic. The EC and ESP of
these soils will be very low (<10 and <4 respectively). However, the EC and ESP
will be raised for the limited areas of the vertic, structured and wetland broad soil
groups which occur. The ESP of the latter broad soil groups is likely to be >15
(sodic) in a number of cases (i.e. non-arable).
(iv) Organic carbon, nitrogen and phosphorus
Organic matter (indicated by the amount of organic carbon) is of vital importance
in soil. It improves the structural condition of both coarse- and fine-textured soils
and improves the water holding capacity, especially of sandy soils. It therefore
greatly reduces the erodibility of soil. Organic matter supplies greater than 99 %
of total soil N (nitrogen) and 33-67 % of total soil P (phosphorus). Humus, the
25
active fraction of soil organic matter has a very high CEC (between 150 and 300
cmol(+) kg-1
) and can adsorb up to about 6 times its own weight in water. The
C:N (carbon : nitrogen) ration of humus is often about 10:1 to 12:1.
In all the potential cropping soils (crest and midslope positions) the value for
organic carbon is low (topsoils <0,75 %) to very low (subsoils <0,29 %). The
highest organic carbon (2,27-2,03 %) is found in the topsoils of the E-horizon
and wetland soils, these soils not being utilized for rehabilitation purposes (as a
surface placement).
Total N, as expected will generally follow the same trend as organic carbon with
the highest amount being found in the topsoil of Pit 6, the remaining soils having
low levels of N. The topsoil C:N ratios will exhibit a larger range than in the
subsoil reflecting the more stable condition of the organic matter at depth.
Extractable P is usually lower in the subsoil, reflecting the low solubility of this
element in soil. However, in the case of Pits 1, 2 and 3 this situation has been
reversed. All of the soils analysed are deficient in P in terms of maintaining a
high producing pasture crop.
(v) Exchangeable cations
It is normal practice to determine what are known as the ‘exchangeable bases’
i.e., Ca, Mg, K (potassium) and Na because they include three of the major plant
nutrients, and Na because it indicates the possible sodicity of the soil, especially
in circumstances where saturated paste data are not available. Lack of organic
matter and clay minerals, which provide exchange sites that serve as nutrient
stores, results in the soil having a low ability to retain and supply nutrients for
plant growth. The maximum potential of a soil to retain nutrients in an
exchangeable form is assessed by measuring the cation exchange capacity (CEC).
The percentage base saturation is then calculated as:
(sum of the four bases / CEC) * 100
In general the amounts of exchangeable cations follow the same trend as outlined
for pH, texture and saturated paste data. Thus Pit 6 (high pH, as well as highest
clay and organic carbon contents) contains the highest amount of exchangeable
bases. In all soils (except in Pit 6) the cations follow the typical trend Ca > Mg >
K > Na. Of the loamy-sand to sandy-loam textured soils (i.e. Pits 1 - 5), Pits 1, 2
and the topsoil of Pit 3 contain a higher amount of both Ca and Mg than Pits 4 or
5 or the subsoil of Pit 3, and this corresponds to the higher pH within these soils.
Amounts of exchangeable sodium are very low and thus the exchangeable
sodium percentage is negligible (all being less than about 1%, with the exception
of Pit 6).
The base saturation values for Pits 1 to 5 range from 22.1 to 66.2 % and should
be interpreted with some caution. The CEC value was measured at pH 7.0 and
thus is only truly representative of the actual field value when the pH of the soil
being analyzed is close to that value. The further the pH of the soil diverges from
pH 7.0, then the less accurate the CEC determination becomes. In addition the S-
value does not include any exchangeable acidity that may exist, especially in the
more acid soils. In spite of these cautionary comments it is clear that the base
saturation and CEC values generally follow the same trend as those for pH and
26
texture with the coarser-textured, more acid soils having lower base saturation
values and CEC than the finer-textured soils with higher pH.
(vi) Soil fertility
The comments that follow are based on the laboratory data discussed above and
thus reflect the fertility of the soils as currently exists in the field, with the soils
in-situ. It does not take into account any changes that may occur as a result of
stripping, stock-piling and compaction, or the rehabilitation methods or purposes
for which the soil may be used. It would be imperative that if any of the soils are
to be used for rehabilitation purposes, that their fertility status be re-analyzed at
that time prior to their use, in order that recommendations concerning possible
ameliorative actions can be given, depending on the species to be planted. In
addition different crops have different soil fertility requirements and so the
discussion here can be of a general nature only, rather than specific to a particular
crop.
With the exception of Pit 6 (Katspruit – wetland soil) which is sodic, none of the
other soils are either saline or sodic and the extremely low values of ESP (and
thus SAR if determined) show that salinity and sodicity will not be a problem in
the cropping soils in the future. The amounts of soluble cations compared to the
exchangeable fraction are likely to be low suggesting that leaching of bases is not
likely to be a serious problem and that the bases held in the soils are likely to
remain available to plant roots.
In terms of fertility for maize, the optimal levels of nutrients (exchangeable
cations) are: K (120 ppm optimal – 100 ppm acceptable) and Mg (60 ppm). Thus
the topsoils of the cropping soils (Pits 1 - 3) are highly deficient in K and
acceptable (Pits 1 and 2) to slightly deficient (Pit 3) in Mg. The subsoils of the
same pits are (bar Pit 3, K) highly deficient in all nutrients, while both the
topsoils and subsoils are also highly deficient in P (optimum levels are 34 ppm
given the sandy nature of the soils in the area). Levels of Ca should normally be
in the range of 300 to 400 ppm in the area.
All the cropping soils (topsoils and subsoils) are also deficient in N (due to low
organic carbon percentages). The low amounts of organic matter, coupled with
low clay percentages, would mean that fertilizer would have to be added
regularly and often to maintain levels adequate for crops. The low organic matter
is especially of concern on the coarser-textured soils which have low water and
nutrient holding capacity.
In terms of fertility for improved or natural pasture there are no accepted data for
the elemental concentrations required in the soil to ensure optimum yields. Most
of the available data is based on leaf analysis from various field experiments. The
Guidelines for the rehabilitation of land disturbed by surface coal mining in
South Africa (1981) suggest that optimal concentrations for P, K and Mg are 36,
120 and 50 mg kg-1
, respectively. Given these values it is clear that all the soils
are deficient in P and K, while Mg values are generally adequate.
27
2.1.6 EROSION HAZARD AND SLOPE (Tables 2 and 3 and Figure 1)
It is necessary to determine the maximum critical slope (at which unacceptable soil
erosion will begin to occur) for a site to be regarded as arable, for the range of broad soil
groups that occur. To this end, minimum erosion slopes were calculated (for the topsoils
and subsoils of the six typical soil pits) from the soil erodibility nomograph of
Wischmeier, Johnson and Cross (1971), based on the soil analytical data (Table 2)
gathered during the soil survey.
The nomograph uses the following five soil parameters, which have been shown by
research to have a major effect in determining erodibility:
(a) The mass percentage of the fraction between limiting diameters of 0.1 and
0.002mm (very fine sand plus silt) of the topsoil.
(b) The mass percentage of the fraction between 0.1 and 2.0mm diameter (residue of
sand fraction – fine, medium and coarse) of the topsoil.
(c) Organic matter content of the topsoil, obtained by multiplying the organic carbon
content (in grams per 100g soil, Walkley Black method) by a factor of 1.724.
(d) A numerical index of soil structure.
(e) A numerical index of soil permeability of the soil profile as a whole.
Although topsoil permeability’s were generally rapid, the permeability classes refer to
the permeability of the profile as a whole which is determined by the controlling soil
layer (horizon). Thus profiles overlying horizons of slow permeability (eg. hard plinthite,
hard rock or a gleyed horizon) or luvic soils (with relatively permeable sandy topsoils
overlying less permeable higher clay subsoils) are likely to reach field capacity relatively
quickly, and particularly so when the soil depth is limited and the storm is heavy or of
long duration. Therefore, the permeability classes cater for the worst scenario (heavy
storm of long duration on a shallow example of the soil type). Other controlling soil
horizons with a slow permeability include vertic A-horizons (very rare in survey area),
pedocutanic B-horizons (rare in survey area) and prismacutanic B-horizons (none in
survey area). The nomograph exercise was not conducted for these soils (not sampled)
since they are not recommended for rehabilitation purposes (as a surface placement).
Both soil structure and soil permeability have a large influence on the soil erodibility
factor (K) and thus the maximum slope for a site to be regarded as arable. The soil
permeability index is the most subjective of the five parameters and is difficult to decide
upon.
Figure 1 shows the nomograph while Table 3 is a summary of the data used and the
results obtained.
28
Figure 1. The Soil Erodibility Nomograph of Wischmeier, Johnson and Cross (1971)
29
Table 3. Data Used and Results Obtained from the Soil Erodibility Nomograph
DATA USED RESULTS OBTAINED
SOIL SAMPLE
MASS PERCENTAGE OF:
ORGANIC
MATTER
%
(organic carbon
x 1,724)
SOIL STRUCTURE
(type and size)
SOIL
PERMEABILITY
BASED ON
CONTROLLING
SOIL HORIZON
(profile as a whole)
SOIL
ERODIBILITY
FACTOR K
(From
nomograph)
MAXIMUM
CRITICAL SLOPE
FOR ARABLE.
IN-SITU AND
REHABILITATION
OF SPOIL
% Degrees
vf sand sand
& silt residue
PIT 1: HUTTON
Orthic A
Red apedal B
14 74
1,2
Fine granular (2)
In-Situ – moderate (3)
0,082
24,4 14,2
21 60
0,4
Fine granular (2)
Rehab – moderate (3)
0,128
15,6 8,9
PIT 2: AVALON
Orthic A
Yellow-brown apedal B
19 71
1,3
Fine granular (2)
In-Situ – moderate (3)
0,112
17,9 10,2
24 59
0,5
Fine granular (2)
Rehab – moderate (3)
0,150
13,3 7,5
PIT 3: GLENCOE Orthic A
Yellow-brown
apedal B
15 75 0,8 Fine granular (2)
In-Situ – slow to moderate (4)
(Controlling – hard
plinthite)
0,124
16,1 9,2
18 67
0,5
Fine granular (2)
Rehab – moderate to
rapid (2)
0,088
22,7 12,8
PIT 4: MISPAH
Orthic A
23 67
1,1
Fine granular (2) In-Situ – slow (5) (Controlling – rock)
0,190
10,5 6,0
PIT 5: LONGLANDS
Orthic A
E-horizon
19 75
3,9
Fine granular (2)
In-Situ – slow (5)
(Controlling – soft
plinthite)
0,138 14,5 8,2
22 73
0,3
Very fine granular (1)
In-Situ – slow (5)
(Controlling – soft
plinthite)
0,182 11,0 6,3
PIT 6: KATSPRUIT
Orthic A
G-horizon
34 37
3,5
Blocky (4)
In-Situ – slow (5)
0,232
8,6 4,9
18 13
0,8
Blocky (4)
In-Situ – slow (5)
0,150
13,3 7,5
30
Table 3 shows the K factor to increase, and the maximum slope for a site to be classed as
arable to decrease with the following:
i) increasing very fine sand plus silt,
ii) decreasing organic matter percentage,
iii) increasing structure index, and
iv) decreasing permeability.
We regard the minimum slope for an unacceptable erosion hazard to exist, as the
maximum slope for the site to be regarded as arable in terms of The Chamber of Mines
land use capability (see PRE-MINING LAND CAPABILITY). The specification that the
product of percent slope and soil erodibility factor (K) must not exceed 2.0 for land to be
classed as arable, was the basis of calculating the maximum slope for arable in Table 3.
Once the value of 2.0 is exceeded, an unacceptable erosion hazard exists and conservation
measures are required.
In-Situ (undisturbed) soils
Table 3 indicates the following critical slopes for topsoils (orthic A-horizon):
• Yellow-brown apedal (Generally arable, : Pits 1 - 3 :16,1 % (9,2 degrees) – 24,4 %
and red apedal soils occasionally grazing (14,2 degrees)
(also applicable to capability class,
neocutanic soils) depending on depth
and slope among
other criteria)
• Wetland and E-horizon (Wetland capability : Pits 6 and 5 : 8,6 % (4,9 degrees) – 14,5 % soils (also applicable to class), (8,2 degrees)
vertic and pedocutanic
soils)
• Shallow soils (Majority wilderness, : Pit 4 : 10,5 % (6,0 degrees).
and rarely grazing
capability class)
The subsoil values are not normally considered (not exposed) for the determination
of the arable class.
The worst scenario critical arable slope for the yellow-brown apedal and red apedal (also
applicable to neocutanic) broad soil groups is thus 16,1 % (9,2 degrees), which is similar
to that of Scotney et al (1987) for ferrallitic soils, vis 15,0 % (8,5 degrees). In order to
provide for a buffer against soil erosion in cultivated areas, the latter slope was
chosen as the maximum permissible slope for an area to be accepted into the arable
capability class.
Scotney et al (1987) [not considered in this report] makes use of the following critical
arable slopes:
- Ferrallitic (highly weathered) soils : < 15,0 % (8,5 degrees),
- Non-ferrallitic soils without a ‘clay increase B horizon’ : < 12,0 % (6,8 degrees), - Non-ferrallitic soils with a ‘clay increase B horizon’ : < 10,0 % (5,7 degrees), and
- Duplex soils : < 8,0 % (4,5 degrees).
31
Slope in the survey area varies as follows:
vast majority (all slope positions) : 1,8 % (1 degree) - 7,0 % ( 4 degrees),
occasionally (midslopes near rivers) : 8,8 % (5 degrees) - 14,1 % ( 8 degrees), and
very rarely (lower-midslopes near rivers) : 15,8 % (9 degrees) – 28,7 % (16 degrees).
Thus slope was not a limiting factor in the vast majority of the survey area with regard to
the determination of the arable capability class. However, a number of areas in the
vicinity of the Olifants River were removed from the arable (to the grazing) capability
class because of slopes of greater than or equal to 8,5 degrees. Other moderate to
moderately-steep sections in the same area display shallow soils and thus already
classified as either grazing or wilderness areas.
It should be noted that the Department of Agriculture stipulates that conservation
measures should be implemented on slopes of over 2,0 % (1,1 degrees) on disturbed
(where the original grass cover has been removed) sites. These measures involve practices
such as building contour banks, re-grassing and cultivating on the contour, etc. The
maximum allowable slope for annual cropping is 12 % (6,8 degrees).
Rehabilitated (‘topsoiled’) areas overlying spoil and building rubble (not compacted)
Table 3 indicates the following critical slopes for subsoils, at which an unacceptable
erosion hazard will exist when stripped soil material is used for rehabilitation purposes.
• Subsoils : 13,3 % (7,5 degrees) Pit 2 – 22,7 % (12,8 degrees) Pit 3
Red apedal and yellow-brown apedal soils
(also acceptable for neocutanic soils)
The subsoils were considered since these B-horizons constitute the majority of the
suitable available volume, and in practice subsoil (B-horizon) and topsoil (A-horizon)
mixing is likely, despite the fact that it would be desirable to strip and topsoil these
reserves separately (A-horizons replaced at the surface).
Given that the permeability of the spoil will (nomograph exercise point of view) be rapid
[360-3600 mm/hour], while the permeability of the ‘topsoil’ (red apedal, yellow-brown
apedal and neocutanic subsoils) will be moderate [36 - 360 mm/hour], then the ‘topsoil’
itself becomes the controlling soil horizon.
Thus in rehabilitated areas (particularly of the rehabilitated arable capability class),
slopes of over 13,3 % (7,5 degrees) should be minimized. The determined maximum
slope is also similar to that determined by Scotney et al (1987) for ferrallitic soils, vis 15,0
% (8,5 degrees). The implementation of the former maximum slope will also provide
a safety buffer.
The recommended maximum gradient (Chamber of Mines) for spoil dumped on level to
gently sloping terrain is at least lv:3h (33,0 % or 18,4 degrees), the least erosion occurring
if the slope angle reduces in the direction of the toe of the pediment (ie. concave).
32
2.1.7 DRYLAND PRODUCTION POTENTIAL (Maps 2 and 3)
Agricultural potential of the various capability classes, as determined in the chapter PRE-
MINING LAND CAPABILITY are discussed for the survey area as a whole.
(i) Arable : 1587,46 ha (51,61 %)
: deeper (>75cm) red apedal, yellow-brown
apedal and neocutanic broad soil groups.
• Maize : 3,5 tons/ha (soil depth 70cm) to 8 tons/ha
(soil depth 150cm and deeper)
These maize yields are for years where the rainfall is not limiting. However, the
ten year average for the range of arable soils, incorporating both wet and dry years
would be closer to 5 tons/ha/ annum.
Given that the majority of the arable (Chamber of Mines) soils in the survey area
are relatively deep (>90cm with many >180cm), the average maize yields should
be able to be increased substantially (in years where the rainfall is not limiting),
provided that the fertilizer status of the soils are improved and constantly
monitored.
• Dry Beans
(sugar beans) : 2 tons/ha (range 1,5-2,5 tons/ha)
• Soya Beans : 2,0-2,6 tons/ha
• Sunflowers
(as cash crop) : 2 tons/ha
• Potatoes
Non-irrigated : 30-40 tons/ha
Irrigated : 60 tons/ha
The aforementioned yields assume that the pH and nutrient status of the soils are
optimum (ameliorated) for a particular crop.
(ii) Grazing : 512,66 ha (16,67 %)
: shallower (<75cm) yellow-brown apedal,
neocutanic and red apedal broad soil groups,
as well as a limited number of examples of
the shallow broad soil group.
• Pastures
(Eragrostis curvula or
Digitaria eriantha) : 8 tons/ha dryland
• Grazing (Natural veld)
Summer : 2 ha/LAU
Year round average : 4 ha/LAU
Although a number of intermediate [depth] (0,5 –0,6m) yellow-brown apedal, red
apedal and neocutanic soils occur (occasionally cultivated), the maize yield (2,5 -
33
3,5 tons/ha) for example on these soils would be considered to be slightly above or
slightly below the long term financial break even (3 tons/ha). However, shallow
patches inevitably occur within a land. Scotney et al (Soil Capability
Classification, March 1987) defines many such areas as arable, albeit with
decreasing production possibilities, an increased hazard of use, and an increased
intensity of conservation techniques required.
(iii) Wetland
These areas include the E-horizon, wetland and vertic broad soil groups. Also
rarely included are the neocutanic, pedocutanic and yellow-brown apedal broad
soil groups, where these soils overlie a hydromorphic horizon at ≤50cm below the
soil surface.
Wetland (permanent) : 92,35 ha ( 3,00 %)
: Katspruit and Rensburg forms
Wetland (seasonal) : 199,70 ha ( 6,49 %)
: Westleigh and Kroonstad forms, as well as
the three areas of the Sepane form which
exist, and
Wetland (temporary) : 296,80 ha ( 9,64 %)
: Longlands and Wasbank forms, as well as a
limited number [three polygons] of areas of
the Tukulu form, and one area of the
Pinedene form.
Wetland (total soils) : 588,85 ha (19,14 %).
Grazing may take place in these areas as per the carrying capacities indicated in
the grazing capability class. Wetland areas must not be cultivated. Although the
farmers have generally avoided cultivating the wetland areas, a number of these
areas (particularly temporary wetlands) are either presently, or were previously
cultivated. Wetland areas should ideally be reserved for the conservation of
wildlife/plants and biodiversity.
Wetland (Olifants River : 34,94 ha (1,13 %)
and Steenkoolspruit)
(iv) Riparian (outside of wetlands): 28,31 ha (0,92 %)
: alluvial broad soil group
Riparian (see Section 2.2.1 – WETLAND CLASSIFICATION) vegetation
(grasses and sedges) exist in a number of intermittent narrow bands along the edge
of both the Olifants River (majority) and the Steenkoolspruit.
Riparian areas should normally be reserved for the conservation of wildlife/plants
and biodiversity.
(v) Wilderness
Wilderness (natural) : 87,77 ha (2,85 %)
: majority of the shallow broad soil group.
34
A number of small patches of the wilderness capability class occur in the survey
area. Such areas are normally reserved for the conservation of wildlife/plants and
biodiversity, as well as recreation.
Wilderness (man-made : 149,12 ha (4,83 %)
features) : Infrastructure, Roads, Soil Stockpile,
Prepared surface, Dumping Area, Banks,
Excavations, Trench, Surface Water, and
Pollution Control.
See Table 1 or Maps 2, 3 or 5 for further
subdivisions of these mapping units, as well
as their location.
(vi) Rehabilitated
Rehabilitated Arable : 11,57 ha (0,38 %)
: ‘topsoil’ depth ≥0,6m.
One of the five patches of rehabilitated arable land which exist in the survey area
is presently cultivated to maize.
Rehabilitated Grazing : 7,57 ha (0,25 %)
: ‘topsoil’ depth 0,25 - <0,6m.
These areas must not be cultivated and must be reserved for the grazing of
livestock/wildlife.
Rehabilitated Wilderness : 67,70 ha (2,20 %)
: ‘topsoil’ depth <0,25m.
Rehabilitated (total) : 86,84 ha (2,82 %).
These areas must not be cultivated and must be reserved for the grazing of
livestock/wildlife.
35
2.1.8 IRRIGATION POTENTIAL
The irrigation potential of the arable capability class varies from very high - high (Hutton,
Bainsvlei, Bloemdal and Lichtenburg forms) to moderate (Avalon, Glencoe, Pinedene and
Clovelly forms) to moderate-low (Tukulu and Oakleaf forms).
The trend of very high - high, moderate and moderate-low potential is related to the depth
of occurance of the depth limiting horizon (thus effective rooting depth), the texture (clay
content) and the organic matter content of the soil, which interact to influence the
moisture holding capacity (readily and plant available water).
The very high - high potential soils tended to have the greatest effective rooting depth and
clay content and visa versa for the moderate-low potential soils. Textures for the various
soil potentials are generally as follows: very high-high potential (sandy-clay-loam: 35 - 20
% clay), moderate potential (sandy-loam: 20 - 15 % clay) and moderate-low potential
(loamy-sand: 15 - 10 % clay).
The allocation of soil forms to the various potentials is a guideline only, since there tends
to be a large variation in effective rooting depth and a lesser variation in clay content
within a particular soil form. Thus the irrigation potential of each polygon of cropping
soils needs to be evaluated on it’s own merits, irrespective of soil form. However, this is a
separate exercise which is not covered by the scope of this report.
The remaining soils are drainage impaired, shallow and either sandier or very high in clay.
Thus complex irrigation scheduling, drainage control and lower yields make them
unfeasible for irrigation purposes.
Bearing in mind the numerous mining operations in the area, water quality in the Olifants
River and Steenkoolspruit would have to be carefully evaluated before considering
irrigation.
36
2.2 PRE-MINING LAND CAPABILITY (Tables 4 and 5 and Map 3)
Land capability classes were determined using the guidelines outlined in The Chamber of
Mines Handbook of Guidelines for Environmental Protection (Volume 3, 1981), a
summary of which is given in Table 4.
Table 4. Pre-Mining Land Capability Requirements
Criteria for Wetland • Land with organic soils or
A horizon that is gleyed throughout more than 50 % of its volume and is significantly thick, occurring within
750mm of the surface.
{Note: The DWAF definition (DWAF. Edition 1, September 2005) has now superceded this definition, and
instead considers a wetland to occur if the soil wetness indicator occurs within 500mm of the surface.
Exceptions are the Champagne, Rensburg, Katspruit and Willowbrook forms which may be of any depth. The
topsoils of the former two forms are frequently deeper than 500mm}
Criteria for Arable Land • Land, which does not qualify as a wetland
• The soil is readily permeable to the roots of common cultivated plants to a depth of 750mm
• The soil has a pH value of between 4.0 and 8.4
• The soil has a low salinity and SAR
• The soil has a permeability of at least 1.5mm per hour in the upper 500mm of soil
• The soil has less than 10 % (by volume) rocks or pedocrete fragments larger than 100mm in diameter in the
upper 750mm
• Has a slope (in %) and erodibility factor (K) such that their product is <2.0
• Occurs under a climatic regime, which facilitates crop yields that are at least equal to the current national average for these crops, or is currently being irrigated successfully
Criteria for Grazing Land • Land, which does not qualify as wetland or arable land
• Has soil, or soil-like material, permeable to roots of native plants, that is more than 250mm thick and contains
less than 50 % by volume of rocks or pedocrete fragments larger than 100mm
• Supports, or is capable of supporting, a stand of native or introduced grass species, or other forage plants,
utilizable by domesticated livestock or game animals on a commercial basis
Criteria for Wilderness Land • Land, which does not qualify as wetland, arable land or grazing land.
A further document was utilized in order to sub-divide the wetlands into three classes
(permanent/semi-permanent, seasonal and temporary), as well as to identify riparian areas. The
aforementioned document is entitled ‘A Practical Field Procedure for Identification and
Delineation of Wetlands and Riparian Areas’, and is published by the Department of Water
Affairs and Forestry (Edition 1, September 2005). For further information see Section 2.2.1
(WETLAND CLASSIFICATION) of our report document.
37
Table 5 is extracted from Map 3 (Pre-Mining Land Capability Units) and summarises the
information for the survey area.
Table 5. Summary of Pre-Mining Land Capability Units
38
2.2.1 WETLAND CLASSIFICATION (Tables 5 and 6, and Map 3)
Wetlands
The wetland classification process is presented for information purposes.
The wetland delineation procedure is based on the document ‘A Practical Field Procedure
for Identification and Delineation of Wetlands and Riparian Areas’ published by the
Department of Water Affairs and Forestry (DWAF) (Edition 1, September 2005). This
document was in turn largely based on the document ‘Wetland and Riparian Habitats: A
Practical Procedure for their Identification and Delineation’ (2000) by The Wetland and
Riparian Habitat Working Group (Forest Owners Assoc. S.A.). Both of these documents
were utilized in the current delineation procedure. Table 6 summarises the major points
from the latter document.
The aforementioned documents have superceded the wetland capability class definition of
The Chamber of Mines. This is because The Chamber of Mines definition is both too
broad (no sub-division for permanent/semi-permanent, seasonal and temporary wetlands),
and considers signs of wetness at depths of up to 0,75m, (as opposed to 0,5m, which is the
current practice) below the soil surface.
The wetland delineation procedure makes use of four wetland indicators.
• Soil form indicator
For a site to be classified as a wetland in the first place, it must display a soil form
indicator. These include any one of a list of soil forms which are associated with
prolonged and frequent saturation, such soils being termed hydromorphic soils.
• Soil wetness indicator
These morphological ‘signatures’ include grey colours in the soil matrix, and/or
mottling within the top 0,5m of the soil surface, these morphological ‘signatures’
having developed in the soil profile as a result of prolonged and frequent saturation.
This depth has been chosen since experience internationally has shown that frequent
saturation of the soil within 0,5m of the surface is necessary to support hydrophytes
(plants typically found in wet habitats). Exceptions to this rule are the Champagne,
Rensburg, Willowbrook and Katspruit soil forms, where it is not necessary for the
profile or horizon to qualify as hydromorphic, since the topsoil horizon may be thicker
than 0,5m. The topsoils of the aforementioned forms are usually dark in the permanent
wetness zone, due to the accumulation of organic matter. In the case of the
Champagne form, the organic carbon content is over 10 %.
The wetland indicators of soil form and soil wetness factor are of over-riding
importance since soil characteristics (soil form and soil wetness indicators) have often
developed over hundreds of years. The next two wetland indicators should be used as
guidelines only (for reasons which will be explained).
• Terrain unit indicator
This practical index identifies valley-bottom units, as well as depressions in crest,
midslope and footslope positions, as the most likely sites for wetlands to occur.
However, ground water discharge may also take place through seeps in non-
depression areas on mild to steep slopes, these seeps also being classified as wetlands.
39
• Vegetation indicator
Hydrophytes are plant species which have developed mechanisms to grow, compete,
reproduce and persist in anaerobic soil conditions. Obligate hydrophytes are only
found in wetlands, while facultative hydrophytes can occur in both wetland and non-
wetland areas. Thus vegetation in an untransformed (virgin) state is a helpful field
guide in finding the boundary of a wetland. However, it should be borne in mind that
the original vegetation may have been transformed or destroyed as a result of previous
agricultural, land use, drainage or mining practices.
Once the site has been classified as a wetland, the four Wetland Indicators are used to
further sub-divide the wetland into one of three types, viz.: permanent/ semi-permanent,
seasonal and temporary.
Table 5 summarises the permanent, seasonal and temporary wetlands which are indicated
on Map 3 (Pre-Mining Land Capability Units).
40
Table 6. Wetland Indictors and Corresponding Wetland Types
WETLAND INDICATOR
WETLAND TYPE
Permanent Seasonal Temporary
‘Old Chamber of
Mines wetland
definition cutoff
depth’. Now grazing
capability class.
Soil Form Katspruit, Rensburg,
Champagne, Willowbrook
(ANY VEGETATION)
Any form, which incorporates wetness at the Form or Family level.
Soil Wetness Factor
Wetness all year round Wetness long periods
(3-10 months p.a.) at
< 50 cm
Wetness short periods
(< 3 months p.a.)
at < 50 cm
Wetness short periods
(< 3 months p.a.)
at 50-75 cm
Vegetation Obligate Wetland species
accounting for
> 50 % of aerial cover
Obligate/Facultative
Wetland species
accounting for
> 50 % of aerial
cover
Facultative and
Facultative Dryland
species. (Facultative
Wetland species
accounting for < 50
% of aerial cover)
Facultative Dryland
and/or Facultative
species mandatory.
Slope Position Valley-bottom mandatory Typically lower
footslope
Typically upper
footslope
Typically lower
midslope
VEGETATION DEFINITIONS: Obligate Wetland species – almost always grow in wetland (> 99 % of occurrences)
Facultative Wetland species – usually grow in wetlands (67 - 99 % of occurrences) but occasionally
are found in non-wetland areas.
Facultative species – are equally likely to grow in wetlands (34 – 66 % of occurrences) and
non-wetland areas.
Facultative dryland species – usually grow in non-wetland areas but sometimes grow in wetlands
(1 - 34 % of occurrences)
NOTE: The Wetland Indicators of soil form and soil wetness factor are of over-riding importance, since the original
vegetation may have either been removed or transformed by previous land use, drainage or mining practices.
Riparian Areas
Riparian habitat (as defined by the South African National Water Act) includes the physical
structure and associated vegetation of the areas associated with a watercourse which are
commonly characterized by alluvial soils, and which are inundated or flooded to an extent and
with a frequency sufficient to support vegetation of species with a composition and physical
structure distinct from those of adjacent land areas.
DWAF (Edition 1, September 2005) states that riparian areas: are associated with a watercourse;
contain distinctly different plant species than adjacent areas, and contain species similar to
adjacent areas but exhibiting more vigorous or robust growth forms; and may have alluvial soils.
41
2.3 LAND USE (Table 7 and Map 4)
Table 7 is extracted from Map 4 (Present Land Use) and summarises the information for
the survey area.
Map 4 also shows the location of natural (and other) vegetation communities in the survey
area. The vegetative composition of these communities is addressed in more detail in
other specialist reports.
42
Table 7. Summary of Present Land Use
43
• Present Land Use is indicated on Map 4.
• Historical Agricultural Production
Map 4 shows the presently and previously cultivated (cultivated for many years)
areas, as well as the areas which have been utilized for the grazing of cattle (grassland
and wetland vegetation [predominantly grasses] areas) in the past. Predicted crop
yields and livestock carrying capacities are discussed in Section 2.1.7 (DRYLAND
PRODUCTION POTENTIAL) of this report.
• Evidence of Misuse
From an agricultural perspective, there has been little evidence of misuse. Given that
51,61 % of the survey area is defined as arable and that only 43,82 % of the area is
cultivated (presently or previously), the selection of areas for cultivation was
reasonably well thought out. The vast majority of the wetlands were delineated prior
to the establishment of agricultural lands. However, a number of temporary (rarely
seasonal) wetland areas are presently (25,02 ha; 0,82 % of survey area), or were
previously (11,07 ha; 0,36 % of survey area) cultivated. These areas must be returned
to grassland.
From a mining perspective however, a number of poor decisions were made a long
time ago, these being regarding the siting of mining operations and man-made features
in wetlands and floodplains (see Maps 3 and 4). The issues of concern from a mining
perspective include the following:
i) Opencast mining operations were previously conducted in the north-eastern
corner of the survey area, adjacent to the Olifants River. These operations were
frequently conducted close to the edge of the river in the floodplain
(i.e.insignificant buffer zone), and thus frequently lie within the 1:100 year
flood line of the river. Furthermore, the mining operations have been
conducted in permanent and seasonal wetlands in portions of this area. Five
voids (depth unknown) remain in the old mining area (indicated on the map set
as Water/X3), these presently being filled with water. These voids have filled
with water given that they are probably in contact with the ground water table
in this area. Additional moisture will have seeped into these areas from the
Olifants River, while run-off from upslope also flows into these depressed
areas. A non-utilized pond (pollution control dam) also exists to the west of the
mined area. Rehabilitation (leveling, ‘topsoiling’ and re-vegetation) operations
have been completed in the areas surrounding the voids and the pollution
control dam.
ii) A large discard dump as well as a non-utilized pond (pollution control dam)
have been constructed to the south of the survey area, on portion of the
original farm Middeldrift 42 IS. The western side of the discard dump has
truncated a narrow permanent wetland, while the pond largely overlies a
temporary wetland. Furthermore, the discard dump has not yet been
rehabilitated.
The aforementioned issues are historical problems. Future mining
operations/infrastructure areas must be sited both above the 1:100 year flood line, as
well as outside of permanent wetland areas.
44
• Existing Structures
Table 7 is a summary of the present land use, including the man-made features which
are present in the area. Although a number of the man-made features are related to
agriculture, the majority are related to previous mining activities.
45
2.4 SITES OF ARCHAEOLOGICAL AND CULTURAL INTEREST
(Map 4)
The following features are of interest, their locations being indicated on Map 4 (Present
Land Use). The graveyards have been allocated a site number (on Map 4 and in this
section of the report document).
(i) Graveyards
Site 1. Approximately 36 graves of the Sikosana Family.
Headstone dates 1940’s – 1970’s.
Form: stone piles with a rough headstone, as well as more
contemporary graves with engraved headstones.
Site 2. 1 grave.
Form: low stone pile.
Site 3. Unknown number of graves.
Site 4. Approximately 141 African (and/or Coloured) graves.
Site 5. Approximately 2 – 3 possible graves?
Form: low stone piles in the veld with the surface collapsing.
Site 6. 15 graves of the Mnguni Family.
Site 7. Approximately 20 graves of the Bezuidenhout Family.
Headstone dates 1920’s – 1970’s.
Form: contemporary with headstones.
The farmhouse ruins lie to the north.
Site 8. Approximately 18 graves south of the dam.
Site 9. Approximately 18 graves.
Site 10. Approximately 230 - 260 graves (old Albion Colliery cemetery).
Form: stone piles with headstones of rough stone, homemade, and
rarely cut. The limited number of cut headstones show dates of the
1960’s and 1970’s.
Site 11. Approximately 136 graves.
Site 12. Approximately 7 graves.
(ii) Kraals (K) [i.e. informal settlements]
Numerous (32) contemporary kraals (K) exist, these being constructed of a
combination of mud, brick and corrugated iron.
(iii) Kraal Ruins (KR) [i.e. informal settlement ruins]
The numerous (19) kraal ruins (KR) indicated on the map are contemporary
(probably less than 4 – 50 years old) and are related to previous farming/mining
activities.
(iv) Farmhouse (FH)
Seven encountered – age unknown.
(v) Farmhouse Ruins (FR)
Five sites of farmhouse ruins (FR) exist in the survey area.
Site FR1. Sandstone foundation 70m south-west (or at) of graveyard Site 3.
46
Site FR2. Foundations.
Sites FR3
and FR4. Two brick/ferricrete ruins from the late 1800’s – early 1900’s. A
number of outbuilding ruins also exist in this area.
Site FR5. Old ruin.
(vi) Agricultural (related) Buildings (AB)
Numerous (19) contemporary agricultural buildings (AB), and one older building
exist in the survey area.
(vii) Agricultural (related) Ruins (AR)
Numerous (18) contemporary agricultural related ruins (AR), and three older ruins
exist in the survey area.
(viii) Agricultural Structures (AS)
A number (5) of contemporary structures exist in the survey area (e.g. livestock
troughs, dips, windmills, etc).
(ix) Mine Ruins (MR)
A number (10) of contemporary mining related ruins exist in the survey area.
The aforementioned information, as well as the location (latitude/longitude) of the
features was provided to the archaeologist/historian in December 2008 for further
investigation. More detailed information is thus provided in the relevant specialist report.
47
2.5 SENSITIVE LANDSCAPES (Table 8, and Maps 2, 3, 4 and 5)
Wetlands and riparian areas (Map 3 - Pre-Mining Land Capability Units) are especially
sensitive landscapes under statutory protection, and as such must not be disturbed,
polluted, cultivated or overgrazed. Furthermore, the wetland capability class is comprised
of broad soil groups (wetland, E-horizon and vertic) which are relatively highly erodible
as determined in Section 2.1.6 (EROSION HAZARD AND SLOPE). The soils occurring
in the wetland areas are indicated on Map 2 (Soil Mapping Units) while the location of the
natural vegetation communities are indicated on Map 4 (Present Land Use).
The wetlands and riparian areas occurring in the study area are summarized in Table 8.
Table 8. Sensitive Landscapes (Wetlands and Riparian Areas)
Capability
Class
Area
- ha
% of
Study
Area
Wetland/Riparian Area sustained by Soil Forms Present
Permanent
wetland 92,35 3,00
Seepage and occasional flow from seasonal and
temporary wetlands (predominantly) as well as
possible contact with the Regional Water Table.
Katspruit (dominant)
and Rensburg (two areas).
Seasonal
wetland 199,70 6,49
Hillslope seepage (predominantly) and run-off
(smaller component) into concave areas.
Westleigh (dominant),
Kroonstad (sub-dominant) and
Sepane (rare).
Temporary
wetland 296,80 9,64
Hillslope seepage (predominantly) and run-off
(smaller component) into lower-midslope,
footslope and concave areas.
Wasbank (dominant),
Longlands (sub-dominant) and
Tukulu (rare).
Riparian 28,31 0,92 Seepage and flooding from the Olifants River
and the Steenkoolspruit.
All alluvial examples of the
following soil forms: Dundee (dominant), Tukulu
(dominant), Vilafontes
(occasional), Oakleaf (rare) and
Fernwood (very rare).
‘Rivers’
(permanent
wetland)
34,94 1,13
Regional water table, seepage, run-off and flow
from upstream. Includes Olifants River and
Steenkoolspruit.
-
TOTAL 652,10 21,18
Further wetlands would originally have been present in the areas currently occupied by a
number of the mining related man-made features (see Map 3), these having been
discussed in Section 2.3 (LAND USE – Evidence of Misuse).
Although Map 3 (Pre-Mining Land Capability Units) shows wetland soils (not including
riparian or ‘rivers’) to presently occupy 588,85 ha (19,14 % of the survey area), Map 4
(Present Land Use) shows that natural wetland vegetation (i.e. undisturbed virgin
grassland [majority], sedges, cottonwool grass [Imperata cylindrica], reeds, or
degraded/naturally re-established vegetation) occupies only 542,23 ha (17,61 % of the
survey area). This is because alternative land uses, other than wetland vegetation
occasionally exist in the wetland areas. Such alternative land uses include the following:
cultivated presently (25,02 ha; 0,82 % of the survey area), cultivated previously [now
weeds] (11,07 ha; 0.36 %), trees [exotics] (5,77 ha; 0,18 %), kikuyu grass (5,03 ha; 0,17
%) and bare (0,49 ha; 0,02 %). These areas must be returned to grassland.
The temporary and seasonal wetlands, and consequently also the majority of the
permanent wetlands which occur in the study area, owe their existence to hillslope
seepage (predominantly) and run-off (small component, except after storms which are
48
heavy and/or of long duration) and are thus not due to the presence of the floodplains of
the Olifants River or the Steenkoolspruit (which lie to the north and west of the survey
area respectively).
However, a limited number of sections of permanent wetlands make contact with the
Olifants River (particularly) and the Steenkoolspruit, these sections intruding into the
floodplains of these rivers. The proposed mining boundary has already been moved
upslope in these areas, in order to avoid the scenario (mining within a permanent wetland
on the floodplain of the Olifants River) which took place in the historically mined area in
the north-eastern corner of the survey area.
The hydrological component of the project will determine whether the permanent
wetlands within the study area are in contact with the ‘flip-flop’ zone of the regional
water table, and thus whether these areas are sustained only by hillslope seepage/runoff,
or not. Should these permanent wetlands be sustained only by hillslope seepage/runoff,
then it is likely that should the permanent wetlands remain intact, that they will largely
dry up after mining operations of the surrounds are completed.
The seasonal and temporary wetlands in the study area are typical of soil catenas in the
Highveld (common) and are considered to be of moderate to low significance from a
preservation point of view. This is because they are neither in contact with the regional
water table, nor display a broader vegetative diversity than similar wetlands in other areas
(outside of the study area). However, the permanent wetlands are of high significance and
must be preserved.
Although the proposed mining plan indicates that a number of the temporary and seasonal
wetland areas will be mined, the plan has been structured in order to preserve the majority
of the permanent wetland areas which occur in the study area.
It should be noted that although the Tukulu soil form (182,61 ha; 5,94 %) [neocutanic
broad soil group] displays signs (mottling, as well as bleaching of the soil matrix in the
dry state) of wetness, that the form has only been included in the temporary wetland class
on three occasions (three polygons). This is because the effective rooting depth was
considered to be greater than 50cm (DWAF, Edition 1, September 2005) in the majority
of occasions. Furthermore, the Oakleaf form (139,40 ha; 4,53 %) [neocutanic broad soil
group] also displays signs (bleaching of the soil matrix in the dry state) of wetness.
However, the B-horizon is underlaid by hard plinthite or hard rock, and furthermore the
form is not defined as a wetland due to its lack of inclusion in the list of soil form
indicators (DWAF, Edition 1, September 2005).
The neocutanic broad soil group (total 322,01 ha; 10,47 %) has thus been largely (three
exceptions are temporary wetlands) included in the grazing capability class as per our
interpretation. However, a more stringent interpretation may qualify many of these areas
as temporary wetlands. If all of the neocutanic soils were classified as temporary wetlands
instead, then temporary wetlands would increase from 296,80 ha (9,64 % of the survey
area) to 610,05 ha (19,83 %), while the total wetland area would increase from 588,85 ha
(19,14 %) to 902,10 ha (29,33 %). However, the aforementioned is not our interpretation
given both the effective rooting depth (majority >50cm), as well as the moist soil colour
(yellow-brown as defined) of the soils. Cottonwood grass and sedges occasionally occur
in these areas.
49
3.0 DETAILED DESCRIPTION OF THE PROPOSED PROJECT
3.1 SURFACE INFRASTRUCTURE (Map 4)
Map 4 (Present Land Use) indicates the boundary and existing surface infrastructure of
the area, the majority of which (excluding buffer zones around the various permanent
wetlands) is proposed to be mined using the opencast method.
3.2 CONSTRUCTION/OPERATIONAL PHASES
The activities which will be undertaken during these phases, and which will impact on the
soils, land capability and land use, are discussed.
Features which will be constructed during the construction/operational phases of the
proposed opencast mining project, include the following:
‘moving’ open pit/pits; haul roads; water management infrastructure (intercept/clean
water diversion drains and/or berms); and temporary overburden rock/discard dumps,
product stockpiles and soil (‘topsoil) stockpiles. The overburden rock/discard dumps will
be temporary features since the mine has planned for in-pit disposal of the discard. Thus
the final topography (after re-grading, i.e. re-sloping) is planned to be freely draining. A
plant will not be constructed in this area, the product being processed elsewhere (at
existing facilities).
Topsoil stripping will commence ahead of the opencast mining operations. This stripped
material will largely be re-distributed immediately on mined-out areas, where the leveling
and re-grading of discard and overburden rock is completed (i.e. ‘moving’ opencast).
The immediate utilization of stripped ‘topsoil’ material will have the following benefits:
i) reduced probability of compacting the soils,
ii) maintenance of soil fertility levels to a certain extent,
iii) preservation of the reproductive seed bank, and
iv) cost savings associated with a reduced number of handling operations.
Excess soil material will be stockpiled. However, given Section 5.1.3 (STORAGE LIFE
AND STOCKPILING), it is not desirable for stockpiles to be left unutilized for too long a
period.
The amelioration of topsoil fertility and re-grassing will continue in areas undergoing
rehabilitation.
3.3 SOIL UTILIZATION (STRIPPING) GUIDE (Map 5 and Table 9)
During the construction/operational phases, the soils should be stripped, based on the soil
utilization (stripping) guide (Map 5). The map summarises the soil map (Map 2) into
broad soil groups and average usable depth. The broad soil groups indicated on the soil
utilization (stripping) guide include cropping (i.e. mineral soils including red apedal,
yellow-brown apedal and neocutanic), shallow, E-horizon, wetland, vertic, pedocutanic
and man-made soils.
50
Table 9 is extracted from Map 5, and summarises the information for the survey area.
Table 9 shows that 25 761 520m³ of usable (high to low suitability) ‘topsoil’ (suitable A-
and B-horizons) is present in-situ in the survey area. However, the cropping soils (23 522
490m³) which predominate are the most suitable and are recommended for rehabilitation
‘topsoiling’ purposes.
51
Table 9. Summary of Soil Utilization (Stripping) Guide
52
3.4 REHABILITATION TOPSOIL BUDGET (Map 5)
Government Regulations (R537 of 21 March 1980) require that all topsoil (as defined)
removed be replaced on the disturbed surface during rehabilitation. The unsuitable (for
rehabilitation purposes) soil must be replaced below the suitable ‘topsoil’. In the survey
area, unsuitable materials include the following: hard plinthic B-horizon, soft plinthic B-
horizon, unspecified/unconsolidated material with signs of wetness, hard rock,
weathering rock and G-horizon. These materials can perform a useful function in that
they can be placed as a breaker layer (to intercept the upward capillary movement of acid
water) between the pit (discard) and the ‘usable’ topsoil.
Given that the cropping soils (red apedal, yellow-brown apedal and neocutanic broad soil
groups) are both the most suitable for rehabilitation ‘topsoiling’ purposes, and comprise
91,31 % (23 522 490m³) of the total available ‘topsoil’ volume (25 761 520m³), they are
recommended for surface placement (overlying the less desirable ‘topsoil’ types) during
rehabilitation. Map 5 (Soil Utilization [Stripping] Guide) indicates the location and
volume of suitable ‘topsoil’ material.
Thus only the volume of the cropping soils are considered for the rehabilitation scenarios
which follow in this section of the report.
In the rehabilitated scenario, at least the same percentage of arable and grazing land
should exist as were present before disturbance. The highly (majority) to moderately (red
apedal and yellow-brown apedal broad soil groups), and moderately to poorly
(neocutanic broad soil group) suitable ‘topsoiling’ materials should be utilized for
rehabilitation purposes in the top 0,6m (arable), 0,25m (grazing) and 0,15m (wilderness,
wetland and riparian). The mixing of suitable/unsuitable materials in this zone must be
avoided.
Rehabilitation Scenario 1
The following volumes of suitable ‘topsoil’ material would be required to reinstate the
pre-mining land capability percentages (albeit to a lower production potential):
arable (9 524 760m³; 1587,46 ha); grazing (1 281 650m³; 512,66 ha) and wilderness
[also incorporating wetland and riparian] (1 057 395m³; 704,93 ha).
Then there is the matter of the area presently occupied by man-made features which
must be rehabilitated to at least the wilderness standard (223 680m³; 149,12ha).
Thus assuming that the entire area surveyed will be mined (which it will not), then a total
of 12 087 485m³ of ‘topsoil’ will be required to rehabilitate 2954,17ha (total area, less
rivers, less currently rehabilitated area). Of the survey area, 86,84ha has already been
rehabilitated to an acceptable standard.
Thus surplus ‘topsoil’ (cropping soils) reserves amount to approximately 11 435 005m³
(23 522 490 minus 12 087 485m³). The large surplus ‘topsoil’ reserves are due to the fact
that the majority of the in-situ cropping soils in the survey area are deep, while the
‘topsoiling’ depth requirement for rehabilitated arable areas (Chamber of Mines) is
intermediate (0,60m minimum) in depth.
53
Rehabilitation Scenario 2
The surplus ‘topsoil’ reserves must be utilized to upgrade the rehabilitation
standard (i.e. ‘topsoiling’ depth) to the arable capability class (0,6m minimum)
throughout the mining area.
For this scenario 17 725 020m³ of ‘topsoil’ will be required to rehabilitate 2954,17 ha
(actually less since the entire area will not be mined).
Thus surplus ‘topsoil’ (approximately 24,6 % of the volume of the cropping soils)
reserves will still amount to 5 797 470m³ (23 522 490 minus 17 725 020m³), this surplus
being too large.
Rehabilitation Scenario 3 (recommended)
The surplus ‘topsoil’ reserves must be utilized to increase the ‘topsoiling’ depth to 0,8m
throughout the mining area.
For this scenario 23 633 360m³ of ‘topsoil’ will be required to rehabilitate 2954,17 ha
(actually less since the entire area will not be mined).
For this scenario ‘topsoil’ (cropping soils) reserves will be short by 110 870m³ (23 522
490 minus 23 633 360m³). This small cropping soils shortage must be made up by
utilizing a small proportion of the other ‘usable’ (moderate to low suitability) ‘topsoil’
types which occur in the survey area. This shortage (110 870m³) represents 4,95 % of the
volume (2 239 030m³) of the other ‘usable’ topsoil types.
However, the mine must also cater for the provision which must be made for limited
stockpiling of ‘topsoil’ material for use in repair work (particularly closure and post-
closure phases).
Alternatively, other scenarios may be selected whereby only one consolidated block is
‘topsoiled’ with more than 0,6m of ‘topsoil’. This consolidated block could be
‘topsoiled’ with considerably more than 0,6m (or 0,8m) of ‘topsoil’, thus leading to a
block with a high agricultural potential.
.
54
4.0 ENVIRONMENTAL IMPACT ASSESSMENT
4.1 SOIL/LAND CAPABILITY/LAND USE
The impact of the opencast mining operation on the existing soils, land capability and
land use are described collectively.
OPENCAST AND HAUL RAMP
VERY SIGNIFICANT / IMMEDIATE / TEMPORARY IMPACT.
• Very Significant The magnitude of the impact will be very significant since the existing soils, land
capability and land use will be completely destroyed in the area which is to be
mined (opencast), as well as in the footprint of the haul ramp.
• Immediate The timing of the impact will be immediate as mining operations commence in
the area. The commencement of the mining operation may be defined as the time
that the vegetation is removed and the ‘topsoil’ is stripped (before blasting or the
removal of the overburden rock).
• Temporary The duration of the impact will be temporary until rehabilitation
operations/procedures (overburden rock replaced in the opencast void, re-grading
[slope], ‘topsoiling’, ‘topsoil’ sampling and amelioration [fertilizing], and re-
vegetation) are completed, which are ongoing behind the mining operations,
(operational and closure phases). Thus ‘topsoils’ stripped in one area (ahead of
mining operations), are generally replaced immediately in another area in close
proximity which is in the process of being rehabilitated (where the overburden
rock has been leveled and re-graded behind the mining operations). The period of
the opencast operation from construction to closure is not known at present.
HAUL ROAD AND OVERBURDEN ROCK/DISCARD DUMPS
The impact assessment for the haul road and overburden rock/discard dumps will not be
necessary as a separate exercise (to that for the opencast and haul ramp areas), if these
temporary features fall within the boundary of the opencast area itself.
VERY SIGNIFICANT reducing to LOW / IMMEDIATE / TEMPORARY
IMPACT.
• Very Significant reducing to Low The magnitude of the impact will be very significant since the existing soils, land
capability and land use will be largely to completely destroyed in the footprint of
these areas. The magnitude of the impact will be reduced to low after
rehabilitation operations/procedures are completed in the closure (and
operational) phases.
55
• Immediate The timing of the impact will be immediate as the construction phase commences
in the area.
• Temporary The duration of the impact will be temporary until rehabilitation operations/
procedures (gravel haul road surface and overburden rock/discard dumps
removed and placed in the opencast void, re-grading [slope], ripping the resultant
haul road surface, ‘topsoiling’, ‘topsoil’ sampling and amelioration [fertilizing],
and re-vegetation) are completed in the closure (and operational) phases.
56
5.0 ENVIRONMENTAL MANAGEMENT PROGRAMME
5.1 MITIGATION MEASURES BY SUBJECT
This discussion is of a general nature and covers the rehabilitation of both man-made
infrastructure and mining (opencast and underground). The opencast and
infrastructure (limited) facets are present in the current operation. The discussion is
written in the context of a project which has not yet commenced.
The successful rehabilitation of infrastructure or mined areas (soil, land capability and
potential land use perspective) is determined by a number of critically important factors,
as follows:
• Soil – compaction, organic carbon, fertility, suitable ‘topsoiling’ materials and
‘topsoiling’ depth;
• Sequence of horizons;
• Slope – must not exceed critical erosion slopes;
• Pollution – soluble pollutants, acid mine drainage and dust;
• Re-vegetation; and
• Climate.
These factors interact and have a large bearing on the ease with which roots colonise the
soil. In areas where plants thrive, there will consequently be a higher level of vegetative
basal cover, and lower level of run-off and soil erosion. Any one of the aforementioned
factors (either singly or in combination) may jeopardize the successful rehabilitation of
infrastructure and opencast areas. Thus the discussions and recommendations which
follow must be strictly adhered to, in order to promote a desirable medium for adequate
levels of plant growth.
5.1.1 STRIPPING RECOVERY RECOMMENDATIONS (Map 5)
The available ‘topsoil’ reserves must be stripped as per Map 5 (Soil Utilization
[Stripping] Guide) during the construction and operational phases (varies for different
features), and either utilized immediately (ongoing rehabilitation in ‘moving’ opencast
pits) or stockpiled for later use (rehabilitation operations).
In the case of the footprints of : the various proposed facilities/features in an
infrastructure area, an opencast initial box-cut (width of one bench excavation),
overburden rock dump area, ‘topsoil’ stockpile/berm area, box-cut and ramp
(underground area), and haul roads; the soils must be stripped at the commencement of
the construction phase, while in the case of the second till the final cuts of an opencast
area, the soils must be stripped during the operational phase as the opencast moves (not
before). The in-situ soils in areas proposed for soil stockpiles/berms must not be
stripped.
Apart from stripping, stockpiling (not recommended for long periods) and re-distributing
of the A-horizon/B-horizon ‘topsoil’ separately (not feasible given the
machinery/method used), and the suitable/unsuitable soils separately (feasible), the
major issue of concern during this phase of the exercise is the limiting of surface
compaction caused by the heavy machinery used.
57
5.1.2 COMPACTION
Problems caused by compaction include the following:
• Drainage impedance.
An increase in bulk density reduces the total porosity (reduced pore spaces and
pore size), thus reducing the saturated flow of moisture through the soil. Halving
the pore size would reduce the flow by a factor of 16.
• Root impedance.
Since large pores also function in the aeration of the soil, compacted soils
(reduced pore size) have a limited oxygen supply. Soil strength also increases
with compaction. Thus roots will not elongate if large pores are absent (limited
oxygen) or if soil strength is high (prevents active displacement of soil by root
pressure). As a general guideline (varies from soil to soil), roots will fail to
penetrate materials compacted to bulk densities greater than about 1500 kg/ m³
for clayey (>35 % clay), and about 1700 kg/m³ for sandy (<15 % clay) soils
(Chamber of Mines Guidelines, 1981).
Factors affecting compaction:
• Fine sand and silt.
Soils with high proportions of fine (including very fine) sand (survey area
cropping soils generally high: approximately 30 – 42 %) and silt (survey area
cropping soils generally low: approximately 5 – 9 %), are most susceptible to
compaction and the formation of high bulk densities. If the soils in the survey
area are handled (stripping and ‘topsoiling’) in the dry state, then they are likely
to be only slightly to moderately susceptible to compaction. However, if they are
handled in the moist or wet states, then they are likely to be moderately to highly
susceptible to compaction.
• Moisture content.
In order to avoid (stripping and ‘topsoiling’ operations) or alternatively to
achieve (compacted layer over a redundant slimes dam, pollution control dam or
slag dump if present) compaction (i.e. high bulk density), machinery should
ideally operate at or near to the optimum moisture content required to achieve the
desired compaction, which varies from soil to soil for the two extremes.
Thus in order to limit compaction (stripping and ‘topsoiling’ operations),
machinery should ideally operate at a moisture content of below approximately
8 or 10 % (i.e. during the dry winter months).
• Pressure and duration of pressure.
Tracked vehicles are more desirable for the stripping and ‘topsoiling’ operations,
since tracked vehicles have a lower point loading and slip than wheeled vehicles.
Vehicle speed should be maintained in order to reduce the duration of the applied
pressure, thereby minimizing compaction.
58
5.1.3 STORAGE LIFE AND STOCKPILING
The most critical and important part of the soil is the uppermost 0,2m as this is the
repository for seeds, tubers, bulbs etc. Under natural conditions most grass seed remains
viable for only about 1 year (reproductive seedbank life), with only few species having
seed that can survive for up to 2 - 3 years.
Under stockpile conditions it is probable that the seedbank life will be shorter than under
natural conditions. Thus ‘topsoil’ stockpiles should ideally not exceed a maximum depth
of one metre, as greater depths than this can lead to the following: anaerobic conditions
developing in the pile; a reduction in soil fertility; the accelerated loss of the
reproductive seedbank; and compaction.
However, a one metre deep stockpile is not practical since such a stockpile will have a
large footprint, the stockpile itself having a detrimental effect on the underlying (in-situ)
soils, as well as killing the vegetation and reproductive seedbank, which exist. From this
perspective a high stockpile with a small footprint will impact on a smaller surface area,
although the soils within the stockpile will be affected negatively. However, given
Sections 5.1.6 (FERTILITY) and 5.1.11 (RE-VEGETATION), the negative aspects
associated with a high stockpile may be largely mitigated.
In addition it is most advantageous if the soil is not stockpiled while wet, since this can
increase the risk of seeds etc rotting. Timing of stripping and stockpiling is also
important to prevent the soil from being deprived of new seed for excessive periods. If
the soil is stripped and stockpiled, and then moved and utilized before newly germinated
grass on the stockpile has seeded, then effectively the soil would have been without any
new seed for 2 years. It is therefore clearly not advisable to stockpile the ‘topsoil’ at all,
but to strip and use it immediately (ideally in winter).
Apart from the limited amount of ‘topsoil’ which will have to be stockpiled until closure,
the organisation must plan to utilize stripped ‘topsoil’ material immediately (vast
majority) [in an area that is being rehabilitated], whenever it can. Should small ‘topsoil’
stockpiles/berms be created in the vicinity of the various scattered infrastructure, drains
or haul roads (i.e. soil originally stripped from the footprint of these sites during
construction) then this ‘topsoil’ must be utilized to rehabilitate (‘topsoil’) these localized
features during the closure phase. Provision should also be made for limited stockpiling
of excess ‘topsoil’ material for use in repair work (closure and post-closure phases).
5.1.4 ‘TOPSOILING’ DEPTH
Section 2.2 (PRE-MINING LAND CAPABILITY) of this report should be consulted
regarding the rehabilitation which should be applied to the various pre-disturbance/pre-
mining land capabilities, at the time that the various features of the operation become
redundant (operational and closure phases). These features must be re-graded to an
acceptable slope, ripped a number of times to reduce compaction, ‘topsoiled’, sampled
(fertility analysis), ameliorated (fertilized) and re-vegetated.
The pre-disturbance/pre-mining land capabilities and soils, form the basis for the
rehabilitation which must take place in these areas.
59
The Chamber of Mines specifies that at least the same percentage of arable and grazing
land should exist, as were present before disturbance. Furthermore, Government
Regulations (R537 of 21 March 1980) require that all topsoil (as defined) removed must
be replaced on the disturbed surface during rehabilitation.
Thus the soil polygons disturbed must end up in their pre-disturbance/pre-mining
condition, that is to say with a minimum ‘topsoil’ depth of suitable material of at least
0,6m (arable), 0,25m (grazing) and 0,15m (wilderness, wetland and riparian), the
‘topsoil’ depth applied being dependant on both the pre-disturbance/pre-mining land
capability (Map 3), as well as the additional ‘topsoil’ applied in order to utilize the
balance of the ‘topsoil’ stripped. The mixing of suitable/unsuitable materials in this zone
must be avoided.
5.1.5 ORGANIC CARBON
Organic matter (indicated by the amount of organic carbon) is of vital importance in soil.
It improves the structural condition of both coarse- and fine-textured soils and improves
the water holding capacity, especially of sandy soils. It therefore greatly reduces the
erodibility of soil. Organic matter supplies greater than 99 % of total soil nitrogen (N)
and 33 - 67 % of total soil phosphorus (P). Humus, the active fraction of soil organic
matter has a very high CEC (between 150 and 300 cmol(+) kg-1
) and can adsorb up to
about 6 times its own weight in water. The C:N (carbon : nitrogen) ratio of humus is
often about 10:1 to 12:1.
Topsoil organic carbon in the survey area is low (topsoils <0,75 %) to very low (subsoils
<0,29 %) for the cropping soils (red apedal, yellow-brown apedal and neocutanic
[probably – not analysed] broad soil groups). The highest organic carbon (approximately
2,0 – 2,27 %) is found in the topsoils of the E-horizon and wetland broad soil groups,
these soils generally not being utilized for rehabilitation purposes (as a surface
placement). Total N (not analysed), will generally follow the same trend as organic
carbon, with the highest amount being found in the topsoil with the highest organic
carbon percentage. The topsoil C:N ratios will exhibit a larger range than in the subsoil,
reflecting the more stable condition of the organic matter at depth. Extractable P is
almost always lower in the subsoil, reflecting the low solubility of this element in soil.
However, this was not always the case in the current survey area.
Given the above, we recommend the following:
- the A-horizon soil material should ideally be replaced at the surface, the B-horizon
material only contributing to the required ‘topsoiling’ depth. Thus the A-horizon
and B-horizon material must ideally be stripped, stockpiled and re-distributed
separately from each other. Given the machinery/method which the organisation
plans to utilize for the ‘topsoil’ stripping operation, the separation of the A-
horizons and B-horizons is not feasible. In the current survey area, the mixing of
A- and B-horizon material is not critical since both the prevailing climate and
soils are conducive to the re-establishment and maintenance of grasslands
(especially after amelioration of the fertility status of the soils).
60
5.1.6 FERTILITY
Soil analysis (top 15cm) in order to provide corrective fertilization regimes is an ongoing
procedure and is required periodically in order to facilitate vigorous plant growth for
high levels of production.
This procedure should initially be carried out immediately after the construction of
‘topsoil’/’topsoiled’ berms and ‘topsoil’ stockpiles, as well as after rehabilitation
(‘topsoiling’), the soil fertility status being corrected before re-vegetation. Thereafter the
soils should be sampled on an annual basis until the required phosphorus (seriously
deficient in both A- and B-horizons), potassium (generally seriously deficient in both
horizons), and magnesium (adequate to slightly deficient in both horizons) levels have
been built up, the aforementioned being for the cropping soils. The pH of the broad soil
groups as a whole (both horizons, but excluding the G-horizon sample) is frequently
problematic since it ranges from being too low (4,5 : very strongly acid) to too high (8,0
: moderately alkaline), while that for the remaining soils is ideal (slightly acid to
neutral). Once the desired nutritional status of post-disturbance/post-mining grazing and
wilderness capability class areas has been achieved, intervals of three to four years can
be allowed between sampling. However cultivated arable areas must be sampled on an
annual basis.
Section 2.1.5 (SOIL ANALYTICAL CHARACTERISTICS AND SOIL FERTILITY) of
this report should be consulted in this regard.
5.1.7 SLOPE GRADE AND ERODIBILITY
Slope is one of the main parameters of erodibility.
Given the findings in Section 2.1.6 (EROSION HAZARD AND SLOPE), rehabilitated
areas must be re-graded (re-sloped) in order to ensure that the critical erosion slopes are
not exceeded. The critical erosion slopes are determined by both the type of feature
which is being rehabilitated (i.e. whether the ‘topsoil’ overlies a compacted horizon or
not), as well as by the broad soil group which is being utilized for ‘topsoiling’ purposes.
(i) Rehabilitated ‘topsoiled’ areas overlying spoil and building rubble (not
compacted)
• Red apedal, yellow-brown apedal and neocutanic soils only : 13,3 % (7,5 degrees).
In rehabilitated infrastructure and opencast areas, the pre-disturbance/pre-mining
grade (slope), slope shape, contours and drainage density (not necessarily pattern)
should be implemented where possible, at all times bearing in mind the calculated
critical erosion slopes for the various broad soil groups which occur. This will be
done by surface re-grading. Concave (rather than convex) slopes should be
maximized wherever possible, while the creation of undulating ‘basin and ridge’
topography with frequent blind hollows should be avoided. In rehabilitated
infrastructure/opencast areas, the negative impact of drainage systems
approximating their original course is that the re-established drainage systems may
incise their beds into the rubble/overburden rock/discard over time (unless these
drainage systems are constructed of concrete in such areas). The consequences of
this possible deepening of drainage systems is firstly that the ‘clean’ water flowing
over rehabilitated areas may become contaminated, and secondly that some
61
(unknown volume) of this water may infiltrate into the polluted zone (rubble from
infrastructure, or pit) itself.
Erosion control measures such as intercept drains, contour bank canals, grassed
waterways and toe berms should be implemented where necessary.
(ii) Compacted ‘re-moulded’ soil layer (seal) overlying rehabilitated discard
dumps, slag dumps, slimes dams and pollution control dams
Of these features: slag dumps are not relevant; discard dumps will not be sealed
since they will be temporary features; slimes dams will not occur since a plant
will not be constructed in the survey area; and pollution control dams are not
likely (not known at present) to be constructed.
Only vertic (first choice), pedocutanic (A- or B-horizons) and wetland (G-
horizons more suitable than B-horizons) soils should be utilized for the
compacted ‘re-moulded’ layer (seal) in the area.
In terms of the ‘topsoil’ layer (overlying the compacted layer), the following
slopes should not be exceeded when utilizing:
• Red apedal, yellow-brown apedal and neocutanic soils only
A-horizons preferred 9,9 % (5,6 degrees) [non-vegetated, but considerably steeper after re-vegetation].
62
5.1.8 SUITABLE ‘TOPSOILING’ MATERIALS
The broad soil groups which are recommended for rehabilitation ‘topsoiling’ purposes as
a surface placement (ranked in descending order of suitability for rehabilitation
purposes) are as follows:
• Red apedal and yellow-brown apedal, high (occasionally moderate) suitability, and
• Neocutanic soils, moderate to low suitability.
The following broad soil groups are not recommended for surface placement, but may be
utilized further down in the rehabilitated profile:
• Structured (i.e. pedocutanic), low suitability, and
• Wetland, shallow, E-horizon, alluvial and vertic, low suitability to unsuitable.
The wetland broad soil group topsoils (A-horizon) may however be utilized to rehabilitate future
drainage/wetland areas. The use of this material will contribute to the maintenance of vegetative continuity
within the wetland areas.
5.1.9 SEQUENCE OF REHABILITATED HORIZONS
Ideally, from the surface:
• A-horizon – surface placement due to its higher organic carbon percentage (thus
inherent fertility and lower erodibility) than that of the B-horizon, as well as its
relatively high natural reproductive seedbank store,
• B-horizon – sub-surface placement, the material only contributing to the required
‘topsoiling’ depth (as determined by the pre-mining land capability class),
• Overburden rock and lime rich materials (hardpan carbonate and soft carbonate
horizons – not present in current survey area) – these materials function as both a
breaker layer to the upward capillary movement of polluted/acid water from the
rehabilitated feature/pit (rubble/ overburden rock), as well as neutralize Acid Mine
Drainage to a greater or lesser extent (lime rich materials), and
• Polluted material/discard at the bottom. The polluted material/discard must never
directly underlie the ‘topsoil’ (A-horizon and B-horizon soil material), since this
may lead to pollution/Acid Mine Drainage contaminating the overlying ‘topsoil’
layers by capillary action.
Given the machinery/method which the industry/mine plans to utilize for the ‘topsoil’
stripping, ‘topsoil’ stockpiling and ‘topsoiling’ operations, the separation of the A-
horizons and B-horizons is not feasible. In the current survey area, the mixing of A-
and B-horizon material is not critical since both the prevailing climate and soils are
conducive to the re-establishment and maintenance of grasslands (especially after amelioration of the fertility status of the soils). Furthermore, the industry/mine must
not allow the suitable ‘topsoil’ (A-horizons and B-horizons) to become mixed with
overburden rock/lime rich materials, or to become contaminated with polluted
material/discard.
63
5.1.10 POLLUTION
(i) Polluted Water – Limitation/Prevention of Seepage in Waste-Water and
Other Disposal Facilities
Slimes dams, pollution control dams, slag dumps, discard dumps and
infrastructure areas must ideally be constructed in midslope positions, well away
from wetland areas. Of these features, only discard dumps (temporary
features) and pollution control dams (possible temporary features) may
possibly be constructed in the survey area, the material in these features
ultimately being disposed of in the pit. However, the discussion which follows
is of a general nature and applies equally to all of the aforementioned features.
Intercept drains (and possibly a clean water canal) must be constructed upslope
of such features, in order to re-direct clean water away from these potential
pollution sources.
Drains should be constructed on the downslope sides of an infrastructure area, in
order to direct this dirty water to a pollution control dam via a dirty water canal.
The dirty water canal should be deep enough so as to directly overlie the
underlying hard rock, thereby intercepting the polluted perched water table. The
base and downslope side of a dirty water canal should ideally be clad with an
impermeable membrane or concreted.
The base of slimes dams, pollution control dams, slag dumps and discard dumps
should be constructed with soil material which naturally possesses a low
coefficient of permeability, the objective being to limit the infiltration of polluted
water in order to avoid contamination of the ground water. The topsoil (vertic A-
horizon) of the vertic broad soil group is the most suitable of all materials for this
purpose. Due to their high clay content and the predominance of smectitic clay
minerals, vertic soils possess the capacity to swell or shrink markedly in response
to moisture changes. Once moist the soil swells and the permeability is slow
(0,36 – 3,6mm/hour).
This material must be compacted (‘re-moulded’) to a high (say 85 - 93 % of
Proctor maximum dry density at a water content of Proctor optimum to Proctor
optimum +2 %) density in order to achieve a ‘seal’ with at least a slow
permeability. The surrounding walls of pollution control dams must be similarly
compacted. An impermeable membrane should ideally overlie the compacted ‘re-
moulded’ soil layer.
In the case of redundant slimes dams, pollution control dams, slag dumps and
discard dumps, where the objective is to limit the infiltration of rain water, a
layer of compacted ‘re-moulded’ soil must be placed immediately overlying the
feature (before ‘topsoiling’, fertilization or re-vegetation). Features with a high
pollution potential must also make use of an impermeable membrane (below the
compacted ‘re-moulded’ layer).
Intercept drains (or other) should be constructed downslope of slimes dams and
pollution control dams in order to intercept any seepage, this water either being
returned to the feature, or treated (purified) and re-utilized by the plant (if one is
present), or released to the environment. Intercept drains and soil berms should
be constructed surrounding the downslope sections of slag dumps and discard
dumps.
64
(ii) Acid Mine Drainage (AMD)
The phenomenon of AMD is commonly encountered in coal mining areas and
leads to acid water which leaches out heavy metals such as manganese, copper
and zinc (among others), this water often exhibiting increased levels of sulphate,
nitrate, total dissolved solids, calcium, sodium and electrical conductivity. Thus
such water must not be allowed to pollute the soils (in-situ and rehabilitated) in
an area, since this will drastically reduce plant growth.
Preventative/remedial measures include the following:
� in-situ undisturbed soils
- polluted or acid water must not be allowed to enter undisturbed areas. Thus
dirty water canals and dirty water dams in an infrastructure area must be well
sealed (compacted ‘re-moulded’ base, and cladded or concreted), while a
berm should ideally surround infrastructure and opencast areas, which must
effectively contain dirty water run-off, and
- the spraying of water on haul roads and conveyors will to a certain extent
limit the amount of dust being blown into the surrounding areas.
� rehabilitated soils (infrastructure, opencast, and box-cut/ramp areas)
- areas which display mildly alkaline, moderately alkaline or strongly alkaline
(pH generally 7.4 – 9.0) soils are likely to buffer/neutralize AMD to a certain
extent (not the case in the current survey area, the pH generally being very
strongly to slightly acid in the non-cultivated areas),
- wherever possible, if naturally occurring, hardpan carbonate and soft
carbonate horizons (rich in calcium and/or calcium-magnesium carbonates)
are present in the soil profile (not present in the current survey area), then
these should be replaced directly below the ‘topsoil’ as a buffer to AMD,
- polluted materials/discard must not directly underlie the ‘topsoil’, but rather
the ‘topsoil’ and polluted material/discard must be separated by a breaker
layer of overburden rock or carbonate material,
- rehabilitated areas and ‘topsoil’ stockpiles/berms must not become
contaminated with polluted material/discard and/or coal dust(on coal mines),
and
- ‘topsoiled’ areas which become polluted by AMD must be limed in order to
neutralize the pH, and thus precipitate out the heavy metals.
(iii) Dust
The particle sizes most at risk from wind erosion are clay and silt, despite the fact
that they are themselves too small to be dislodged by the wind directly. However,
fine and medium sand particles moving by saltation knock the clay and silt
particles into the air to create so-called ‘dust’. The soils most prone to wind
erosion are those with high amounts of fine sand; the least prone being those with
high clay contents. However, the soils most likely to cause dust pollution are
those with both high fine sand and high silt contents.
The soils which will be utilized for rehabilitation ‘topsoiling’ purposes (red
apedal, yellow-brown apedal and neocutanic broad soil groups) in the survey area
have low amounts of silt ranging from 5,0 to 5,6 % (analysed samples) in the
topsoils, and from 6,2 to 9,2 % in the subsoils. These soils also have moderately
65
low clay contents ranging from 10,3 to 11,7 % in the topsoils, and from 14,9 to
18,4 % in the subsoils. They do, however, contain high fine (including very fine)
sand contents that range from 30,0 to 41,9 % in the topsoils, and from 32,8 to
40,9 % in the subsoils, this indicating that the soils will be prone to saltation.
These figures exclude the remaining broad soil groups which will not be utilized
for rehabilitation purposes (as a surface placement). Thus, given the combination
of high fine (including very fine) sand contents, low silt contents and moderately
low clay contents, the topsoils and subsoils are likely to be moderately prone to
wind erosion.
Given the high wind speeds which frequently occur before a thunderstorm
rainfall event in the area, as well as the high fine sand contents in the soil, wind
erosion is likely to occur on the soil surface where the vegetative cover has been
removed. Evidence of wind erosion in cultivated areas is provided by the fact that
the top 2 – 5cm of the soil is frequently more sandy (less clay) and displays less
organic carbon than further down in the A-horizon. The wind speeds are great
enough on occasion in order to blow fine sand particles as well.
In general the natural vegetation (grass cover) should be maintained for as long
as possible prior to the commencement of ‘topsoil’ stripping, the stripping
operation not being conducted earlier than required. Grass cover should also be
re-established, as soon after ‘topsoiling’ as possible. This is in order to prevent
the erosion (by wind and water) of topsoil organic matter, clay and silt.
The spraying of water on haul roads, conveyors, rock dumps, slag dumps, slimes
dams and ‘topsoil’ stockpiles/berms is also recommended for suppressing dust.
From the pollution point of view in coal mining areas, the contamination of soils
with coal dust also has implications linked to AMD.
(iv) Sedimentation
The sedimentation of wetlands, streams and rivers around infrastructure and
opencast areas will be reduced by the construction of surrounding run-off
interception berms. Furthermore, the ‘topsoiling’ and re-vegetation of berms and
‘topsoil’ stockpiles will also be beneficial to the slowing and trapping of
sediment.
5.1.11 RE-VEGETATION
‘Topsoil’ stockpiles/berms must be re-vegetated until this material is required for
rehabilitation purposes. Rehabilitated areas must also be re-vegetated as soon after
‘topsoiling’ as possible, in order to limit raindrop and wind energy, as well as to slow
and trap run-off. Indigenous (to the area) grassland species are preferred, given both their
hardy nature as well as their lower maintenance requirements. The vegetation must be
well established (reasonable basal cover) before the onset of the rains. If not, much of the
newly laid ‘topsoil’ may be washed away.
66
5.1.12 PERCHED WATER TABLE
A perched water table is that which temporarily develops above relatively impermeable
subsoil horizons, hard plinthite, hardpan carbonate and hard rock, after heavy rainfall
events. However, perched water tables in augered depth were a feature of many of the
wetland and E-horizon soils at the time of the soil survey. Perched water tables also
occurred in a number of areas of the neocutanic (occasionally), yellow-brown apedal
(rarely) and red apedal (rarely) soils. However, perched water tables frequently occur at
greater depths than are accessible with a soil auger (standard length : 1,5m). Temporary
perched water tables aid the growth of hydrophytic (wetland) vegetation when they
occur close (<50cm) to the soil surface, and trees (particularly in dry areas) when they
occur at greater depths below the soil surface. This is because the overlying soils remain
moist for longer periods of time than in other areas. Temporary perched water tables
generally no longer occur in rehabilitated areas after opencast mining.
Once a rehabilitated opencast pit fills up with water, after an undetermined period of
time after rehabilitation, tree roots may be able to access the moisture derived from the
pit. The pH of this moisture is likely to have been ameliorated (i.e. increased in coal
mining areas) to a certain extent, by the breaker layer (overburden rock, and lime rich
materials when available), which separates the discard from the ‘topsoil’.
67
6.0 REFERENCES
Acocks, J.P.H.
Veld Types of South Africa
Chamber of Mines of South Africa. 1981.
Handbook of Guidelines for Environmental Protection, Volume 3/1981. The
Rehabilitation of Land Disturbed by Surface Coal Mining in South Africa.
Department of Water Affairs and Forestry. Edition1,September 2005.
A Practical Field Procedure for Identification and Delineation of Wetlands and
Riparian Areas.
Land use and Wetland/Riparian Habitat Working Group. September 1999.
Wetland/Riparian Habitats : A Practical Field Procedure for Identification and
Delineation.
Schulze, R.E. (1997).
South African Atlas of Agrohydrology and Climatology.
Soil Classification Working Group. 1991.
Soil Classification, A Taxonomic System for South Africa.
Scotney, D.M., F.Ellis, R.W. Nott, K.P. Taylor, B.T. van Niekerk, E. Verster and P.C.
Wood. March 1987.
A System of Soil and Land Capability Classification for Agriculture in the
SATBVC States.
Wischmeier, W.H., C.B. Johnson and B.V. Cross. 1971.
A Soil Erodibility Nomograph for Farm Land and Construction Sites. J. Soil
Water Conserv. 26: 189 – 193.
-----------------------------
SPECIALIST REPORTS REFERRED TO:
REMS30, August 2004. Author: B.B. McLeroth, Red Earth cc
Soil Survey, Pre-Mining Land Capability (Including Wetland Classification and
Delineation), Land Use, Sites of Archaeological and Cultural Interest and
Sensitive Landscapes of Proposed Pillar Mining (Vandyksdrift 19 IS) and
Opencast (Steenkoolspruit 18 IS and Kleinkopje 15 IS) Operations. Douglas
Colliery.
DOUGLAS COLLIERY - PROPOSED VANDYKSDRIFT SOUTH SECTION OPENCAST AND SURROUNDS
Middeldrift 42 IS and Rietfontein 43 IS)Map 1. Location and Grid References of Soil Observation Points
(Portions of the original farms Vandyksdrift 19 IS, Steenkoolspruit 18 IS,
MAP NUMBER REFERENCE NUMBER : REMS46-1
BHP BILLITON ENERGY COAL SOUTH AFRICA
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98
76
54
32
140
3637
3839
4142
4344
4546
3534
3332
3130
2928
2726
2524
2322
2120
1918
1716
1514
1312
1110
CR CQ CP CO CN CM CL CK CJ CI CH CG CF CE CD CC CB CA BZ BY BX BW BV BU BT BS BR BQ BP BO BN BM BL BK BJ BI BH BG BF BE BD BC BB BA AZ AY AX AW AV AU AT AS AR AQ AP AO AN AM AL AK AJ AI AH AG AF207
206205
204203
202201
200
24000
24000
25000
25000
26000
26000
27000
27000
28000
28000
29000
29000
30000
30000
31000
31000
32000
32000
-2894000-2894000
-2893000-2893000
-2892000-2892000
-2891000-2891000
-2890000-2890000
-2889000-2889000
-2888000-2888000
-2887000-2887000
-2886000-2886000
-2885000-2885000
-2884000-2884000
-2883000-2883000
SURVEY DETAILSMAPREFERENCENUMBER
DATEAREA (ha)
PEDOLOGIST
REMS46-1July 2009
3075.95ha
Fieldwork:
L. J. VivianSoil Science Diploma(Pretoria Technikon)
Mapping and Report W
riting :
B. B. McLerothB.Sc. Agric. (Natal)MSAIF, MSSSSA
2000
200400
600800
MetersScale : 1 :15 000
N
LEGEND
AF1 - CR29 : Grid references of auger observation points
N
Scale : 1 :15 000200
0200
400600
800Meters
Fieldwork:
L. J. VivianSoil Science Diploma(Pretoria Technikon)
Mapping and Report W
riting :
B. B. McLerothB.Sc. Agric. (Natal)MSAIF, MSSSSA
3075.95haJuly 2009
REMS46-2
PEDOLOGISTAREA (ha)
DATEMAPREFERENCENUMBER
SURVEY DETAILS
24000
24000
25000
25000
26000
26000
27000
27000
28000
28000
29000
29000
30000
30000
31000
31000
32000
32000
-2894000-2894000
-2893000-2893000
-2892000-2892000
-2891000-2891000
-2890000-2890000
-2889000-2889000
-2888000-2888000
-2887000-2887000
-2886000-2886000
-2885000-2885000
-2884000-2884000
-2883000-2883000
Ir
Hu-18+
Hu-18+
Gc-4-6
Hu-18+
Hu-18+
Dd
Wb-1-5
Hu-18+
Ka-2-4
Av-8-10
We-2-4
Av-9
Water/X3
Hu-18+
Gc-8-10
Wa-3-4
Ka-2-3
Rd
Hu-18+
Wa-2-3
Kd-2-4
Bd-10-12Tu-7-8
Li-8
Dr-2
Kd-2-3
Tu-6
Gc-8
Gc-8
Li-12-16
Av-10-12
Tu-7-9
Rt
Tu-7
Gc-7
Av-7-9
Av-10-12
Wa-4
Li-10-12
Wa-3-4
Hu-18+
Gc-8-10
Tu-7-9
Wb-1-2
Av-8
Hu-18+
Ka-2
Li-13-15
Hu-18+
Li-10/11
We-2-3
OLIFANTS RIVIER
Gc-8-9
Dr-2
Li-10
Oa-4-6
Av-7-8
Bd-15-16
Li-13-16
Li-7-9Hu-18+
Hu-18+
Bv-11-13
Rd
Lo-2
Li-4-6
Tu-8-9
Gc-3
Kd-3
Ka-1
Hu-18+
Gc-5
Li-8-10
Stc
Kd-2-3
Hu-18+
Bv-12-14
Pond
Oa-5
Oa-3-5
Wall
Tu-2/7
Gc-5
Gc-12
Av-7-8
We-2
Hu-18+
Gc-4-5
Oa-6
Bd-12-15
Lo-2
Dr-3
Ka-1
Gc-12
Tu-8
Av-10-12
Li-13
Kd-3
Kd-2-3
Wa-3
Dr-2
Lo-2
Rd
Wb-1-2
Tu-5
Wb-2
Gc-5-6
Av-12-14
Li-8
Li-6/8
Gc-8
Li-14-16
Lo-2
Av-11
Gc-8-10
Gc-4-5
Lo-4-5
Ms-1-2
Hu-18+
Av-9-12
Av-11
Av-9-10
Av-13
Av-7-9
Hu-18+
Li-6-8
Lo-2
Av-9-12
We-2
Gc-7-9
Tu-7
Li-9-11
Lo-2
Wa-2-3
Li-10-12
Av-8
Li-5/7
Tu-6
Tu-7
Av-7-10
Li-15
Oa-3-4Oa-4/6-7
Lo-2-3
Wb-1
Gc-4-5
Bv-10
Hu-18+
Tu-4/8
Lo-2/5
Oa-8-9
Li-14-16
Rd
Gc-6
Bv-10/13
Li-12
Li-5-6
Lo-2
Li-13-15
Ms-1
Gc-9
Cv-6
Hu-18+
Lo-2-4
We-3
Water/X3
Oa/Tu-9
Sw-2[3-6]
Oa-5
Gc-7-10
Li-7
We-2
Li-12-13
Li-12-13
Av-10
Gc-5-6
Ka-2-3
Oa-4-6
Gc-8-10
Kd-1
Lo-4/10[10-13]
Lo-2
Li-9-10Hu-15-18
Li-9
Hu-18+
Hu-9/12[18]
Ms-1
Ka-3
We-2
Gc-Li-10-13
Lo-2-3
Wa-4-5
Tu-9
Av-6
Bd-12-15
Wb-4
Li-8
Hu-18+
Wb-1-4
Lo-3
Tu-7-8
Wa-2
Av-7-9
Li-14-16
Ka-2
Av-11
Av-6
Pn-5
Wa-2-3
Li-8
Gc-3-6
Av-9
Hu-18
Wa-1-3
Li-8/10-12
Wa-3
Kd-3
Av-7-9
Bd/Bv-14
Wa-3
Gc-9-12 Bd-15
Tu-7
Hu-14-17
Tu-6
Av-6
Gc-6-7
Wa-2
Gc-5-6
Hu-5/7[15]
Oa-7-8
Wa-2
Sct
Av-10-14
Gc-8-10
Li-9-12
Hu-18Gc-8-9
Gc-5-7
Ka-1
Oa-8
Pn-8
Av-8
Kd-2
Gc-8-9
Tu-8
Tu-8-10
Water/X3
Gc-5-7
Lo-2
Av-9
Bv-14
Li-12-14
Li-6
Kd-3
Av-8
Tu-5
Av-8-10
Gc-6
Li-6
We-2
Pn-8
Av-10-12
Kd-2
Wa-2-4
Tu-8
Oa-6
Av-9-10
Gc-8-10
Rd Gc-8-10
Gc-4
Li-6
Hu-18+
Li-8
Av-12
Dr-3
Hu-6
Hu-18+
Hu-15-18
Gc-8
Li-6/9
Wb-0[6-18]
Li-6
Gc-5-6
Wa-5
Hu-18+
Av-12
Li-14
Oa-10
Ms-1-2
Tu-10
Li-8-9
Wa-2-4
Cv-5
We-3
Ms-1-2
Av-14
Ms-0-2
Bv-9-10
Oa-5
Lo-2[7]
Gc-3-4
Av-9
Av-8-10
Av-8-10
Sc
Wa-3-5
Li-Gc-8-10
Ms-1-2
Wa-3-4
Oa-3/7
Gc-5-6
Li-15-16
Rd
Bv-14-15
Gc-10
Tu-9-12
Wb-2-3
Ms-1
Tu-10
Tu-4/8-10
Av-12
Ka-2-3Oa-7
Oa-6-7
Tu-7-8
Bv-10-13
Oa-3/6
Se-3[5]
Gc-6
Wb-0
Hu-18+
Hu-18+
Oa-5
Hu-18+
Gc-7Ka-2
Lo-3
Gc-7
Wa-3/7
Gc-5
Gc-7-8
Wb-0[6]
Kd-4
Li-7-8
Rd
Gc-Li-8-9
Bc
Li-11
Av-6-7
Dr-2-3
Hu-18+
Bv-15
Lo-3
Gc-8
Av-12-13
Av-14
Gc-6-7
Is
Rg-8
Av-6
Oa-6
We-2-3
Hu-10/17
Hu-18+
Wa-2
Tu-2/8
Gc-7-9
Li-12-14
Li-13-14
Li-9-12
Bv-8-9
Wa-3
Av-14
Hu-12/15-17
Hu-4/5
Wa-3/6
Wa-3
Gc-7
Av-8-10
Tu-7
Pn-9-10
Av-11
Lo-3
Bv-13/14
Gc-6
Gc-9-10
Wa-2/6
Dr-2
Oa-4/8
We-4
Av-10
Bv-11
Du-6-12
Gc-8Dr-2
Tu-8-9
Bv-14
Cv-2
Gc-8-11
Wb-2
Bv-15
We-4
We-3
Lo-3
Dr-2
Av-7-9
Bd-6/8
Dr-3
Tu-7-8
Gc-Oa-8
Gc-3-4
Tu-7
Li-14-16
Li-11-13
Oa-4
Wa-5/8
Dr-2
Ka-2
Av-10-12
Li-5
Wa-3
We-2
Lo-3
Oa-7-8
Dk/Bc
Se-2[5]
Li-5
Hu-18+
Wa-Oa-5-7
Gc-8-10
Lo-3
Gc-5-6
Oa-4
Gc-12-14
Bv-12
Av-11-12
We-2
Kd-2
Av-10
Gc-5
Wa-2
Li-9-10
Kd-3
Oa-8-9
Oa/Gc-5-6
Tu-7
Av-12
Kd-2
Kd-2-4
Vf/Du-2[6]
Bv-12
Bs
Gc-9
Hu-18+
Ms-2
Li-7
Kd-2
Av-10
Cv-9/12
Gc-8
Av-10
Pd
Ka-2-4Oa-Gc-4-5
Hu-18+
Av-6
We-3-4
Dr-4
We-3
Ka-1
Wa-2
Li-13-15
Lo-2-3
Li-11-12
Dr-3
Cv-18+
Li-Gc-8-9
Gc-6
Av-10
Li-6-7
Gc-Oa-6
Lo-3
Gc-3
Wa-4
Tu-9
Lo-3
Gc/Cv-5-7
Tu-Av-2/9
Tu-3/7
Hu-14/16
We-2
Bv-13
Hu-18
Gc-7-9
Av-7-8
Bd-15
Hu-10/15
Ms-0
Oa-7
Lo-2-3
Li-Gc-3
Li-3-6
Hu-11/18
Oa-8
Gc-8
Av-12
Hu-10/11
Wa-2
Av-10-11
Oa-4/5
Gc-10
We-2
Li-6-7
Bv-12
Ms-1
Dr-2
Cv-4-6
Wall
Bv-14
Hu-12/15-17
Av-Cv-0/12
Hu-17
Wa-3
Dr-2
Ms-2
Dr-2-3
Li-10
Kd-3
Lo-1/8
Wa-3
Bd-12
Av-13
Li-14
Dr-3
Lo-3
Tu-8
Cv-6-7
STEENKOOLSPRUIT
Cv-2-3
Kd-2
Gc-10
Tu-9-12
We-4
Dr-1
Hu-15
Oa-10
Tu-14
Bv-14
Li-12-14
Gc-9
Av-6-7
Wa-3-4
Av-8-10
Wa-2
Tu-6
Bc
Hu-0/17
Du-4/10
Wa-2/7
Oa-3/5-7
Ms-1Lo-3
Cv-10/11
Hu-18+
Bd-14
Av-9-12
Tu-11
Ka-1-2
Wb-2
Li-7/8
Li-12-13
Gc-Li-4
Av-12
Cv-2
Oa-6Oa-7
Ka-1
Gc-8
We-2
Bv-12
Li-13
Oa-We-3/7
Ka-2
Wa-2[4]
Bv-9
Wa-2/7[7]
Hu-12/15W
a-2
Gc-10-11
Oa-5
Kd-2-4
Av-12
Gc-Li-4-5
Av-7-8
Bd/Li-11
Tu-3[9]
Ms-2
Bv-11
Bv-Li-9
Cv-15-18
Li-9-12
Ka-3
We-2
Li-3-4
Av-13Av-0/15
Cv-8
Li-5-7
We-3
Hu-18+
Cv-Pn-12
Lo-3
Cv-6
Wa-4
Av-12-14
Rg-5-6
We-3
Du-12-18
Av-13
Dr-3
Gc/Cv-6-8
Kd-2
We-3
Tu-7
Li-8-9Gc-12
We-3
Kd-2
Tu-6
Bv-12
We-Oa-3
Tu-Av-8
Lo-2
We-2
Li-Gc-6-7
Ms-1
Av-10
Sw-2-3[9]
Cv/Gc-5
Tu-5/9
Cv-Hu-18
Gc-Oa-4
Li-10-11
Cv-Hu-12
Wa-2/7
Tu-9-12
Cv-12
Wa-3
Oa-Tu-7/8
Ms-2
Hu-18+
Oa-7
Wa-4/10
Hu-13/16
Av-11
Cv-14
Dr-3
Hu-18+
Kd-4
Bv-Bd-6-10
Lo-4
Gc-8
Wb-1
Bv-12
Tu-5/9
Hu-10
Lo-4
Av-8-10
Hu-14/16
Gc-Oa-6
Gc-Li-3-6
Lo-3[10]
We-2
We-3
Ka-2-3
Av-8
Se-2[4]Li-10-12
We-Ka-2
Rd
Water/X3
Dr-2
X3
Oa-3/6
Hu-10/11
Gc-Wa-8
Tu-6
Gc-10-12
Gc-6
Tu-8-9
Cv-6
Av-11
Oa-3/5-9
Oa-We-4/9
Gc-6
Gc-9
Av-12
Av-8
We-3
Sc
Av-8
Hu-15-18
Lo-3[9]
Dk
Cv-2-3
Lo-3
Ms-1
Cv-7-9
Pp
Dam
Cv-Gc-5
Bd-12
Li-11
Wb-5
We-3
Wb-1-18
Lo-5/6
Av-6
Tu-12
Gc-9
We-3-4
Lo-3
Tu-7
Li-10-12Gc-10-12
Wa-3
Hu-18
Tu-8-10
Pond
Gc-Li-11
Av-12
Li-6
Oa-3/6-8
Ka-3
Wb-5/15
Hu-14/16
Lo-2
Tu-Wa-4-5
Li-7
Dr-2
Bd
Is
We-2
Lo-4[10]
Ms-1
Li-15
Av-9
Ms-2
Oa-4
Li-5
Ms-1
Li-Gc-8
Tu-4/11
Vf-2[10]
Hu-13/14[18]W
a-3
Tu-3/8
Av-Bv-10
Ms-2
Li-14
Bv-15
Cv-3
Gs-1/3
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Oa-6
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Gc-6-9
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Oa-8
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Pp
Av-12
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Bd-12
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Wa-3[12]
Lo-3
Av-12
We-1
Gc-Li-6
Av-11
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Oa-4/6
Wall
Av-12
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Dr-2
Hu-15
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We-3
Av-Cv-6-8
Dr-1
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Wa-3[7]
Db
Ms-2-3
Hu-18+
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Dr-3
Ms-1
Gc-8
Ms-2
Cv-10Pp
Av-6
Du-18+
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Du-10-11
Av-8-10
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Oa-6
Li-12-13
Lo-3
Tu-4/10
We-1
Hu-17
Du-10[18+]
Av-12-14
Rd
Hu-6
Lo-2
Av-13-15
Hu-0/16
Gc-5
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Av-10
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Li-8
Oa-3-4
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Bs
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Hu-14/16
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Water/X3
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Dam
Du-Lo-8
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Gc-5
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Av-10
Water/X2
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X3
Water/X3
Gc-7
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Oa-Ik-4/15
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Av-12
Ms-1
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ater/X2Trench
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o4
b6
o2o4
<r1 rubble
o6-o8
b2r2
o8
d1
r1 rubble
o2
r5
<r1 rubble<r1
b6
b2r3
g1
<r1 rubble
g1
o6-o8
wet:12-15
wet:0
wet:10
wet:1-4
wet:9
wet:13-15
wet:0
wet:12-15wet:4-10
wet:6
wet:8
wet:14
wet:12
wet:0
wet:7
wet:9-15
wet:4
wet:3-9
wet:15
wet:0
wet:9
wet:0
wet:13
wet:0
wet:3
wet:8
wet:0
wet:0
wet:0
wet:0
wet:0
wet:9
wet:2
wet:0
wet:0
wet:6
wet:10
wet:0
(island)
wet:4wet:12
wet:0
wet:0
wet:0
wet:12
wet:0
wet:9
wet:0
wet:12
wet:12
wet:0
wet:2
wet:9
wet:12
wet:4
wet:6
wet:0
wet:4
wet:10
wet:1
wet:8
wet:9
wet:8
wet:0
wet:8
wet:13
wet:8
wet:10
wet:4
wet:7-9
wet:10
wet:0-6
wet:3-7
wet:11
wet:9
wet:15
wet:0
wet:4
wet:0
wet:0
wet:7
wet:0
wet:14
wet:14
wet:0
wet:0
wet:6
wet:0
wet:0
wet:6
wet:14
wet:11
wet:14
wet:8
wet:10
wet:3
wet:0
wet:2
wet:3
wet:12
wet:12
wet:14
wet:5
wet:0
wet:6
wet:2
wet:12
wet:0
wet:16
wet:2
wet:0
wet:9
wet:7
wet:12
wet:12
wet:12
wet:9
wet:14
wet:0
wet:2
wet:0
wet:12wet:0wet:11
wet:0
wet:6
wet:4
wet:15
wet:12
wet:8
wet:12
wet:2
wet:0
wet:10
wet:6
wet:6
wet:0
wet:7
wet:15
wet:14
wet:0wet:0
wet:2
wet:9
wet:11
wet:12
wet:10
wet:15
wet:3
wet:4
wet:6-9
wet:8
(pan)
wet:2
wet:8
wet:10
wet:0
wet:9
wet:10
water:4-6
water:12
water:8
water:5
water:6
water:6
water:5
water:10
water:10
water:5
water:5
water:10
water:7
water:5
water:6
water:6
water:7
water:7
water:5
water:2-7
water:11
water:7
water:4
water:4
water:6
water:8
water:2
water:12
water:9
water:10
water:13
water:7
water:7
water:2
water:12
water:2
water:4
water:12
water:7
water:8
water:8
water:5
water:10
water:7
water:6
water:6
water:0
T1(S1)
C
A
A
A
T1(S1)
A
A
T1/S1
A
T1/A
T1/S1
A
A
S1
A
A
A
A
T1/S1
A
A
A
T1/S1
A
A/T1
A
A
A
A
A
T1/S1
T1/S1
T1/S1
A
A
A
A
T1/S1T1/S1
A
S1
S1
T1/S1
(over rock)
(over gley/rock)
red
(over rock)
(over rubble)
(over rock)
salts
(OB1SB)
(over coal)
(over coal)
(over saprolite/rock)
(over rock)
(OB3SB)
(over rock)
(over rock)
(over gley)
(OB1dust)
(over coal)
(burned We)
(OB2 coal dust)
A/T1
A
A
BHP BILLITON ENERGY COAL SOUTH AFRICA
MAP NUMBER REFERENCE NUMBER : REMS46-2
(Portions of the original farms Vandyksdrift 19 IS, Steenkoolspruit 18 IS,
Map 2. Soil Mapping Units Middeldrift 42 IS and Rietfontein 43 IS)
DOUGLAS COLLIERY - PROPOSED VANDYKSDRIFT SOUTH SECTION OPENCAST AND SURROUNDS
N
Scale : 1 :15 000200
0200
400600
800Meters
Fieldwork:
L. J. VivianSoil Science Diploma(Pretoria Technikon)
Mapping and Report W
riting :
B. B. McLerothB.Sc. Agric. (Natal)MSAIF, MSSSSA
3075.95haJuly 2009
REMS46-3
PEDOLOGISTAREA (ha)
DATEMAPREFERENCENUMBER
SURVEY DETAILS
24000
24000
25000
25000
26000
26000
27000
27000
28000
28000
29000
29000
30000
30000
31000
31000
32000
32000
-2894000-2894000
-2893000-2893000
-2892000-2892000
-2891000-2891000
-2890000-2890000
-2889000-2889000
-2888000-2888000
-2887000-2887000
-2886000-2886000
-2885000-2885000
-2884000-2884000
-2883000-2883000
Ir
C5
C18+
R2C9
C18+
C9
C18+
C18+
E4
W3
E2
W3
E3
C11
C7
E3W
3
C9
C18+
C9
E3
Dd
C8
R2
C11
C8
C18+
C11
C14
E4
C8
E4C8
C11
C18+
C5
C8
S2
C8
C6
C8
W3
C7
C15
Water/X3
C14
C7
C11
T2
C8
E3
C12
C8
C9
C4
R2
C6
C15
C8
C5
C8
E3
C8
Rd
C7
E3
C12
C5
S1
C6
C14
C9
C5
C11
C18+
E5
S2
C9
C8
C13
C8
C9
E3
C18+
C4
E3
E2
W2
C18
C18+
C12
C3
C9
C4
E2
C5
C15
C10
E2
C8
R2
C5
E4
C8
C7
C6
E3
Rt
C5
C11
C10
E3
C13
C11
E3
C5
C12
C6
E2
E2
R2
C7
C18+
C18+
C9C10
S3
C8
W2
E2
C8
C8
C15
S2
E3
C18C5
R1
C5
C12
C14
E2
C18+
W1
C12
C10
C15
C9
C5
C11
C18+
C13
C7
C8
C8
E2
C13
C9
C8
C13
C7
C7
E2
E4
C6
C18+
C8
C7
S1
E5
W2
C8
C10
W1
OLIFANTS RIVIER
C8
C14
C7
C6
C7
W2
C16
C6
R12
C11
C9
C9
C6
C11
C9
C13
C12
E3
E2
C5
E2
C6
C15
R4
C18+
C8
S1
E3
C9C18+
C9
E4
C13
E4
E1
E3
S1
Rd
C11
C5
W3
E2
S1
E6
T5
C10
C16
E2
S0
E2
C11
C10
C6
R6
C5
W2
R3
S1
E2
C15
E3
Stc
C18+
C4
E6
C14
C9
C6
C6
C6
E3
C8
W2
C7
Pond
Wall
E3
C6
C18+
C5
C9
E3
C9
C10
C15
C6
C6
C10
C9
C9
E2
C8
C7
C15
C10
Rd
C8
C12
C7
C9
C8
C6
E2
C7
C12
C6
C7
E5
C12
C8
T2
C18+
C9
E5
S3
C6
E3
C8
C7
W3
C18
C6
C5
C9
C11
C8
E2
C6
C8
E2
C6
C8
C12
C16
C17
C9
C18+
C8
C8
C10
C15
C8
C4
C8
W2
C18
C5
C8
E2
C3
W3
C11
C8
C6
C8
C8
C7
C16
W3
W2
C9
C8
C8
C8
C7
C6
R0
C14
C5
Rd
C9
E3
E2
S3
S1
C14
C13
E3
C5
C6
C14
W1
C13
C7
E3
C11
C4
C8
C3
C12
C7T2
Water/X3
C11
C10
W3
C10
C5
C9
C6
E3
C10
C12
C9
C11
E4
C7C7
V8
C5
C6
C15
C11
C8
E4
C9
E3
E2
C6
R2
E3
C6
C18+
C7
C8
C12
E3
C9
C5
C18+
C7
C9
E2
C10
C7
C16
E2
C12
C15
W3
C10
C6
E3
C8
C14
C5
C18
C18+
C7
C11
C6
C6
C4
C6
S2
C10
C6
E1
C8
C2
C12
E2
C10
E3
C15
C12
E4
C4
C7
C6
C4C4
E4
C2
C12
W3
C7S2
C4
Sct
C5
C4
S2
E3
C8
C18+
C18+
W4
C14
E2
C15
S2
C14
E2
C18+
E3
E3
S2
C9
C9 S3
C5
C7
W4
C8
W2
C10
W3
E3
C7
E2
S2
C6
C14
E3
C11
C18+
Water/X3
W3
E3
E3
E2
C9
C4
V5
C18+
W2
C11
E3
C7
S0
E2
C7
C11
C8
C15
C10
W2
C11
C7
C6
C14
C3
C15
C14
C7
C15
Rd
C8
S1
C12
E2
E12
C8
C10
E10
C6
T2
E3
S2
S4
C11
E3
C13
C8
S3
C17
W3
C9
R1
C8
C12
C12
C10W
2
C5
C18
E2
R2
W2
C11
C12
W2
E3
C18+
C12
W2
C9
C12
E2
S1
C4
C5
C10
C8
Sc
C5
C5
C10
Rd
S2
W2 C18
C9
E4E3
S2
C10
C16
C18+
C15
E3
C8
C6
S3
C13
C9
C9
C6C15
C18+
C7
C10
E4
W1
S2
C14
C16
S1
C7
C8
C18+
C12
C9
E3
Rd
C5
W4
Bc
C17
C2
C6
C8
C10
C11
C11
C12
Is
E3
C14
C2
C10
C10
C12
C12
C8
C9
C15
C13
C15
C10
W2
S1
C8
E2
C14
E5
C14
C6
E2
R1
C12
C14
E3
S2
W2
E3
E5
C11
C7
C8
C12
W2
W3
C11
C12
S3
Dk/Bc
C7
C18+E2
W3
C7
C6
W3
W3
C12
E4
W3
C10
W1
C11
C14
C16
W2
C8
C13
W2
Bs
E2
C5
C12
C11
E4
Pd
S3
W3
C13
E4
R5
C12
E3
S3
R15
C18+
S1
C7
C12
C6
C8
C6
C9
C10
C10
C13
C8
C6
C12
C7
S2
W2
W3
C6
C14
C7
C10
C8
C11
Wall
C8
E3
E3
C12
W3
C6
C18+
STEENKOOLSPRUIT
C9
E3
C18+
E10
S1
C6
S2
C11
Bc
E3
W3
C11
S1
C12
C7
C6
R11
C4
S2
E2
S3
C12
C10
C9
C12
S2
C9
C12
W2
C18
E10
S3
C6
S1
C12
C3
C8
E11
C7
W3
C11
C8
C6
C7
E5
C15
C5
Rd
Water/X3
X3
C5
C4
C12
E3
C15
C13
Sc
Dk
C12
C18
C13
S1
W1
Pp
Dam
E18
C18+
S2
S2
C8
C12
C6
C12
W2
S1
E2
S1
C14
W3
C10
C8
C8
C8
C12
C15
Pond
C11
C6
C12
C10
C10
S3
C5
C16
Bd
C6
Is
R10
E3
C14
T3
C6
C10
W1 C5
C18+
S2
E2
E8
C17
C5
C7
C18+
Pp
W2
W3
C16
X2
C7S1
C11
C10
C8
E10
X1
Wall
Water/X3
E2
E2
Dam
C8
W2
X3
C10
C14
E3
Db
C9
C12
Pp
C6
S2
C15
C14
Rd
S3
Im
C5S2
X3
C6
C8
STEENKOOLSPRUIT
Db
C15
C14
E7
C7
Im
X3
Pd
X2
Bs
C7
Bs
Ie
Bs
E6
S1
C10
Ic
C10
Sc/Dk
Ih
X3
ImS3
X2
E18
Dam
C8
Im
Water/X3
C12
C8
Dam
X1
Ih
S1
Water/X2
Dam
X3
Water/X3
S1
X3
X2/Im
C9
Im
Trench
W2
C6
C11W
all
Pd
W2
Pd
X1/Pp
W3
E4
C10
Im
X2
Pond
S2
X2
Trench
C7
Pond
Im
Water/X2
Trench
Pp
X3
Ih
X1
Im
Ie
C11
Wall
S1
Wall
Wall
Dam
Im
E10
E3
X3
X3
Im
Im
Im
X3
Dam
Im
Wall
IcIm
BHP BILLITON ENERGY COAL SOUTH AFRICA
MAP NUMBER REFERENCE NUMBER : REMS46-3
(Portions of the original farms Vandyksdrift 19 IS, Steenkoolspruit 18 IS,
Map 3. Pre-Mining Land Capability UnitsMiddeldrift 42 IS and Rietfontein 43 IS)
DOUGLAS COLLIERY - PROPOSED VANDYKSDRIFT SOUTH SECTION OPENCAST AND SURROUNDS
N
Scale : 1 :15 000200
0200
400600
800Meters
Fieldwork:
L. J. VivianSoil Science Diploma(Pretoria Technikon)
Mapping and Report W
riting :
B. B. McLerothB.Sc. Agric. (Natal)MSAIF, MSSSSA
3075.95haJuly 2009
REMS46-4
PEDOLOGISTAREA (ha)
DATEMAPREFERENCENUMBER
SURVEY DETAILS
24000
24000
25000
25000
26000
26000
27000
27000
28000
28000
29000
29000
30000
30000
31000
31000
32000
32000
-2894000-2894000
-2893000-2893000
-2892000-2892000
-2891000-2891000
-2890000-2890000
-2889000-2889000
-2888000-2888000
-2887000-2887000
-2886000-2886000
-2885000-2885000
-2884000-2884000
-2883000-2883000
á
á
á
á
á
á
á
á
á
á
á
á#
#
#
#
#
#
##
#
#
#
#
#
#
#
# ## # #
#
#
#
#
#
##
#
###
#
##
#
#
#
#
#
#
#
#
#
#
#
#
#
#
#
##
##
#
#
#
#
##
# #
# # #
#
##
#
#
#
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#
#
#
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#
#
#
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#
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#
#
####
#
#
#
#
##
##
##
#
##
#
#
C
C
C
C
C
C
Gg
Ir
C
Gg
GgwW
g
Gg
C
Gg
Gg
Ggw
Gg
Gg
Gg
C
Ggw
Gg
Wgc
C
Wg
Wgc
C
C
Gg
RGE
Wgs
Cpw
Gg
Wgw
Cpw
Wg(wc)
Dd
C
Gg
Wgw
Gk
Ggw
Wsg
Cpw
Wg
Wg(w)
GgwW
g
Wp
Te
Water/X3
GsgwW
g
Wgw
Ggw
Wc
C
Ggw
Ggw
RGE
Rd
RB
Gg
Ggw
Gg
Gg
Ggw
Wg
Wgc
Ggw
GgGg
Wg(w)
Rt
Wgc
Wg
Wg
RG
Ggw
Cp
Te
RE
Wv
Cp
Gg
Gg
Wsgw
Gg
OLIFANTS RIVER
RE
Cp
Tl
C
Ggc
Wg
Wsw
Wg
Gg
RGT
Rd
Wg
Cp
Gd
Wg
RC
Stc
Ggw
PondW
all
Wv
RBW
Ggw
Rd
Wsg
Cp
Wgw
Wc
Gg
TeW
g
Grg
Wg
Gd
Ggw
Te
Wk
Wsc
Ggw
Te
Gg
Cp
Rd
Cp
Wg
Wsg
Gg
Gg
Wgw
Gg
RB
Water/X3
Wg
Wg
Wgw
Ggc
Wcg
RGB
Wg
RGK
Gc
Wv
Gg
Wg
Wsg
Ggc
RB
Wv
RGS
Wgw
Ge
Gc
Wg
Ggw
Wgw
Wgw
Ws
Sct
Gg
Te
Wg
Gb
Ws
Water/X3
Te
Wgw
Wg
Wg
Ws
Rd
Gbe
Gg
Gsw
Ggw
Wgw
Te
Gew
Sc
Wg
Rd
Wg
Wc
Wg
Ggw
RE
Ws
Wg
Wsg
Gk
RG
Ws
Rd
Bc
Te
Gsg
Gcw
To
Ws
Gg
Gg
Te
Ws
C
Gg
Wsc
RG
Wsc
Wsg
Wgs
Gs
Ge
RGW
Wgr
Wg
Gkc
Te
Dk/Bc
Wgc
Wg
Wv
Te
Gew
Ge
Gw
Gr
RB
Ggw
Bs
Gwg
Farmyard
Gkg
Pd
Ggw
Wsr
RG
Wsgw
Gg
Wg
Wgw
C
Wv
Wv
Te
Wg
Ggw
Wgw
RK
We
Wkg
Wg
Ge
Gg
Wall
Tw
Tw
Gg
Ggw
STEENKOOLSPRUIT
Wg
Gkg
Wg
Te
Wg
Bc
Te
Gsg
Wgc
Wv
TeW
sg
Wg
Wg
Wsc
Tk
Wr
Wgs
Te
Wcw
Gg
Cp
Gg
Cp
Wv
Wv
Ggw
Wv
Gr
Gr
Wt(gum)
Ggc
Ge
Gm
Wg
Gg
Wsw
RE
Rd
Water/X3
X3
Wv
Gg
Te
Sc
Dk
Wcg
Wgw
Wv
Ggw
Pp
Dam
Wrg
Wv
Wg
Farmyard
Pond
Ge
Wkg
GgwTw
Gw
Bd
Gr
Gg
Ge
Wb
Is
Gr
Ws
Wv
GbW
v
Gg
Gsg
Wv
Pp
Wv
Wsr
Te
Te
Wdgs
X2
X1
RT
Wall
Te
Water/X3
Tw
Ggw
Dam
Wv
Ggw
Gd
X3
Db
Pp
Wdc
Wv
Gg
Wt(gum)
Ggc
Rd
Wv
Cp
Im
Gw
Wp
Ggw
X3
Te
Wgw
STEENKOOLSPRUIT
Te
Db
Gg
Wt(gum)
Im
Ge
X3
Pd
X2
Wsc
Bs
Bs
Ie
Bs
Wv
Ic
Wv
Wt(gum)
Sc/Dk
Ih
Wdc
X3
Wgw
Im
Is
X2
Dam
Im
Water/X3
Dam
Cp
Te
X1
Ih
Wt(poplar)
Water/X2
Ggw
Dam
Tp
X3
Water/X3
Wt(oak/pine)
X3
Gb
X2/Im
Wv
Gw
Wg
Wd
Im
Trench
Ggc
Ggw
TkW
k
Wall
Dam
Wv
Pd
Ws
Te
Ge
Wt(gum)
Tw
Wv
Ge
Wt(gum)
Pd
Ge
Wt(poplar)X1/Pp
Im
X2
Pond Wgs
Gs
Wt
Tw
Gw
X2
Pond
Wg
Ge
Trench
Ge
Pond
Im
Water/X2
Trench
Pp
Gkg
X3
Ih
Wt(gum)
X1
Im
Ie
Bd
Wall
Wt(gum)
Gg
Wt(gum)
Gg
Wv
Wall
Wc
Wall
Wv
Wall
Dam
Wv
Im
Ge
Wv
Ggc
X3
X3
Im
Im
Im
Wt(wattle)
Wt(gum)
X3
Dam
Im
Wall
Reservoir
Im
Reservoir
Ic
Reservoir
Wg
Reservoir
Reservoir
Reservoir
Im
Reservoir
Reservoir
Reservoir
Reservoir
Reservoir
Reservoir
ReservoirReservoir
Reservoir
Reservoir
Dam
9
8
5
6
7
4
3
2
1
12
11
10
K
K
K
K
KK
K KKKK
K
K
KK
K
KK K
KK
K
K
K
K
K
K
K
K
K
K
KR
MR
MR MR
KR
AR
ABFH
AR
MR
AB
AR AB
FH
ABAB
AB ABAB
AB
AB
AB
AR
FR
ABAB
AB
ABAB
ABAB
ABABFH
AR
AR
AR
AB
FR
KR
KR
AB
AR
AR
AR
AS
ASAS
MRMR
MR
KR
KR
AR
AR
FH
ARARAR
AB
AR
KR
KR
KR
KR
KR
KR
KRKR
AR
FHMR
FRARARFR
AR
AS
AS
ARFH
KRFH
KRKR
FRKR
MR
MR
BHP BILLITON ENERGY COAL SOUTH AFRICA
MAP NUMBER REFERENCE NUMBER : REMS46-4
(Portions of the original farms Vandyksdrift 19 IS, Steenkoolspruit 18 IS,
Map 4. Present Land Use Middeldrift 42 IS and Rietfontein 43 IS)
DOUGLAS COLLIERY - PROPOSED VANDYKSDRIFT SOUTH SECTION OPENCAST AND SURROUNDS
DOUGLAS COLLIERY - PROPOSED VANDYKSDRIFT SOUTH SECTION OPENCAST AND SURROUNDS
Middeldrift 42 IS and Rietfontein 43 IS)Map 5. Soil Utilization (Stripping) Guide Showing Average Usable Depth and Volum
e
(Portions of the original farms Vandyksdrift 19 IS, Steenkoolspruit 18 IS,
MAP NUMBER REFERENCE NUMBER : REMS46-5
BHP BILLITON ENERGY COAL SOUTH AFRICA
A
A
Ir
A
A
G
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
L
A
A
Ws
Wt
A
A
A
A
Wp
A
A
A
A
A
Wt
A
A
A
A
G
A
A L
A
A
A
G
A
A
L
A
Wp
A
A
A
A
A
A
A
A
A
Ws
A
A
A
Dd
A
Wt
G
A
A
A
G
A
RL
G
A
A
G
A
A
A
A
A
Ws
G
A
G
A
A
RL/RG
A
G
A
A
A
A
A
G-A
L
Wt
A
A
A
A
G
A
A
A
G
A
A
A
A
Wt
G
Ws
A
L
A
G
G-A
A
G
G
Water/X3
A
A
G
A
G
A
A
A
L
A
AA
A
L
A
A
G-A
L
A
L
RL
G
A
A
A
L
A
A
A
G
A
A
A
A
A
Rd
A
A
A
A
A
A
G
A
G
GW
t
A
G
G
Ws
A
A
A-G
A
A
A
A
A
GWt
G
A
A
G-A
A
A
A
A
R
A
A
Ws
A
Wp
A
A
A
G
A
A
A
A
A
G-A
Wt
G
G
A
Wt
RL
A
A
A
A
Wt
R
A
A
A
A
A
A
Rt
G
A
RA
Wt
A
G
G
G
Wt
L
A
A
A
A
G
Wt
A
G-A
A A
A
RL
A
Ws
A
G
G
A
A
A
A
Wt
Wt
A
Wt
Ws
A
A
A
G
A
A
A
A
A
G
RL
Wt
A
G
Wt
A
Wp
A
A-G
G
A G
Wt G
A
G-L
G
A
G
G
G
A
Wt
A
A
A
Ws
L
A
GA
A
A
A
Ws
A-G
Wt
G
A
Wp
OLIFANTS RIVIER
L
G
A
Wp
A
Wt
Wt
A
A
A
G
A
A
A G
A
G-A
L
A
A
A-G
L
A
A
G
A
L
R
G
A
LA
G
G
R
A
A
L
R
A
Ws
A
Wt
Wt
A
Wt
Rd
G-L
A-G
G
A
A
A
G
L
A
Ws
Wt
A
A G
A
G-A
Wt
A
G
Wt
Wt
A
A
G
A
Wt
G
L
Wt
G
A
GStc
Wt
A
A
A
Ws
A
A
L
A
A
A-G
Wt
A
A
RG
A
G
A
PondW
all
G-A
RA
A
A-G
G
A
A
A
G
Wt
G
G-A
A
A-G
A
G-A
A
R
L
G
G
Wt
G
A
G
G
A
A-G
Rd
G-A
Ws
A
L
RG
A
G
A
A
L
G
G
G
A
A
A
A
L
G
R
Wp
G
A
R
L
L
G
Ws
A
L
A
A
A
G
A
A
Ws
A
A-G
Ws
Wp
R
Wt
A
G
Ws
Wt
A
A
Wp
L
G
A
A
RL
A
A
A
Rd
A
L
G
Ws
A
A-G
Wp
A
G-AA
Ws
Ws
Wt
Water/X3
Wt
G
A-G
G
A
A
G
WsWs
Wt
A
Wt-G
G-A
G-A
G
G-A
G
RL
A
A-G
Wt
A
A-G
Ws
G
A
A
L
G
L
G
Wt
Wt
Wt
Wt
R
Wt
A
A
A
Ws
G-A
G-A
Wt
G-A
L
Wt
A
G-A
G-A
G-A
Wp
G
Ws W
t
A
Wt
G-A
Sct
Wt
Ws
Ws
G-L
A
G-L
G
Ws
Wt
A-G
Ws
R
Wt-G
A
Wp
L
A
Ws
L
Wt
Wp
G
Water/X3
L
A-GWt
R
Ws
Wt
G-A
R
A
Wt
AW
t
Wt-G
A
L
Wt
Wt
G
L
Rd
Wt
A
A-G
Wt-G
G-A
G-A
L
Ws
R
A
G-A
G
G
Wt-G
G
G-A
A-G
Ws
Wt
A-G
A
Wt-G
Wp
GL
G-A
RL
Wp
Wt
Wt
L
A
Ws
G
A
A-G
Ws
Ws
AA
Ws
A
A
Ws
G-A
Sc
Wt
A
Rd
A
Ws
G
RW
t-G
A
A
A
A
Wp
Ws
Wp
G
G-A
G-L
Wt
Wt
A
A-G
Rd
Wt
BcA
A-G
G
A
RA
A
R
Wt
Is
A
G-L
G
A
Ws
Wt
G-A
Ws
Ws
Wt
AW
s
G-A
Ws
RL
G-L
G-A
L
Ws
L
L
A
G-L
Ws
L
Wp
L
G
Wt
Ws
Dk/Bc
G
Wt-G
Ws
Wt
Wt
A
Ws
Wp
A-G
Wt
Wp
G-A
RA
G-A
Bs
G
A-G
R
A
G-L
Wt-G
Pd
Wp
G-A
A-G
G-A
Ws
A-G
G
Ws
Wt
Ws
G
A-G
Ws
A
A
A
Wt
Wt
GG-A
A
A
R
A-G
Ws
Wall
L
Wt-G
Ws STEENKOOLSPRUIT
RG
Wt
Ws
A
A
R
Bc
Wt
G-L
G-A
G-A
G
Wt
G
L
G
A-G
Ws
G-L
Wt
R
G
G-A
Ws-W
p
RL/RA
G-A
G
R
R
G-A
G
Wp
G
A
RA
Wt-G
Rd
Water/X3
X3
LA
A
A
Sc
Ws
Dk
Ws
A-G
Wt
Pp
Dam
Ws
A-G
Ws-W
p
Pond
G-A
A
L
A
G-A
Bd
Is
Wt-G
G-A
G
A-G
Wt
A
Ws
L
A
Ws
Ws
Pp
Wt
G-A
R
G
G
X2
G-L
R
L
X1
Water/X3
Ws
Dam
R
X3
Wt
Pp
Wt
A-G
L
A
A
Ws
Rd
L
G-A
Im
X3
A
STEENKOOLSPRUIT
Db
X3
Pd
X2
Bs
Bs
Ie
Bs
Ic
G-L
Sc/Dk
Ih
L
G
X2
Dam
Im
A-GA
Dam
A-G
X1
Ih
Water/X2
Dam
X3
Water/X3
X3
G-A
X2/Im
Wall
L
Pd
R
Pd
Ws
X1/Pp
Im
X2
Wt
A-G
X2
Trench
X3
Ih
X1
Im
Ie
Wall
A-G
Wall
Dam
Wt
X3
Im Im
X3
Dam
ImIc
Im
L
X3
24000
24000
25000
25000
26000
26000
27000
27000
28000
28000
29000
29000
30000
30000
31000
31000
32000
32000
-2894000-2894000
-2893000-2893000
-2892000-2892000
-2891000-2891000
-2890000-2890000
-2889000-2889000
-2888000-2888000
-2887000-2887000
-2886000-2886000
-2885000-2885000
-2884000-2884000
-2883000-2883000
SURVEY DETAILSMAPREFERENCENUMBER
DATEAREA (ha)
PEDOLOGIST
REMS46-5July 2009
3075.95ha
Fieldwork:
L. J. VivianSoil Science Diploma(Pretoria Technikon)
Mapping and Report W
riting :
B. B. McLerothB.Sc. Agric. (Natal)MSAIF, MSSSSA
2000
200400
600800
MetersScale : 1 :15 000
N
