ENVIRONMENTAL RISK ASSESSMENT FOR CLOSURE PROJECT OF THE BORROW PIT ASSOCIATED WITH THE NR6, SECTION 4 AT PENHOEK PASS. Prepared for: Prepared by: SANRAL Southern Region EOH Coastal & Environmental Services P O Box 27230 Greenacres, 6057 P.O. Box 934 Grahamstown, 6140 South Africa South Africa December 2015
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ENVIRONMENTAL RISK ASSESSMENT FOR CLOSURE PROJECT OF
THE BORROW PIT ASSOCIATED WITH THE NR6, SECTION 4 AT PENHOEK PASS.
Prepared for:
Prepared by:
SANRAL Southern Region EOH Coastal & Environmental Services
P O Box 27230 Greenacres, 6057
P.O. Box 934 Grahamstown, 6140
South Africa South Africa
December 2015
Environmental Risk Assessment
Coastal & Environmental Services SANRAL: Risk Assessment ii
This Report should be cited as follows: Coastal & Environmental Services, December 2015. Environmental Risk Assessment for the Closure Project Borrow Pit associated with the NR6, Section 4 at Penhoek Pass: EOH CES, Grahamstown.
Environmental Risk Assessment
Coastal & Environmental Services SANRAL: Risk Assessment iii
REVISIONS TRACKING TABLE
EOH Coastal and Environmental Services
Report Title: Environmental Risk Assessment for closure of borrow pit
Report Version: Draft Report
Project Number: 175
Name Responsibility Signature Date
Ayanda Zide Report Writer
Lara Crous Report Writer
Tarryn Martin Report Reviewer
Copyright
This document contains intellectual property and propriety information that are protected by
copyright in favour of EOH Coastal & Environmental Services (CES) and the specialist consultants.
The document may therefore not be reproduced, used or distributed to any third party without the
prior written consent of CES. The document is prepared exclusively for submission to SANRAL Ltd
in the Republic of South Africa, and is subject to all confidentiality, copyright and trade secrets,
rules intellectual property law and practices of South Africa.
Environmental Risk Assessment
Coastal & Environmental Services SANRAL: Risk Assessment iv
THE PROJECT TEAM
Ms Ayanda Zide, Environmental Consultant
Ayanda holds a BSc in Botany, Microbiology and Chemistry and a BSc (Hons) in Botany where her thesis focused on identifying and characterising galls and gall forming insects and associated pathogens (Fungi) on the mangrove species Avicennia marina. Courses in her honours year included Diversity Rarity and Endemism (DRE), Pollination Biology, Estuarine Ecology, Rehabilitation Ecology, a Stats course and a short GIS course. Her research interests lie in biological invasion, conservation, rehabilitation ecology, plant biotechnology and water research. Ayanda conducts vegetation and impact assessments that guide proposed developments to reduce their impacts on sensitive vegetation. As part of these surveys she identifies and maps the vegetation communities and areas of high sensitivity. She has worked as a botanical assistant on the Lesotho Highlands Development Authority botanical baseline survey and has conducted groundtruthing surveys for developments in the Eastern Cape. Ms. Lara Crous (Cand. Sci.Nat)
Lara holds a BSc (Environmental Science and Geography) as well as a BSc Honours (Environmental Science) from Rhodes University. Her honours thesis evaluated Grahamstown’s Municipal water supply, focussing on aluminium for which she received a distinction. She is currently writing up her MSc (fisheries science) thesis on using constructed wetland technology in the treatment and beneficiation of brewery effluent. Lara presented her preliminary results at the International Water Association’s conference on Wetland Systems for Water Pollution Control in Venice (2010) and will present a case study titled “Turning of Industrial Wastewater into Irrigation water” at the constructed wetlands conference in Johannesburg later this year.
With interests in environmental, municipal and effluent water quality, Lara has worked on and managed various EIA’s relating to mining, wind energy facilities, upgrading of roads as well as agri-production projects in South Africa, Mozambique as well as Cameroon. Lara is also experienced in undertaking water use licence applications, mining applications and environmental control officer / auditor duties. Ms Tarryn Martin, Senior Environmental Ecological Specialist (Pri Sci Nat), Report reviewer
Tarryn holds a BSc (Botany and Zoology), a BSc (Hons) in African Vertebrate Biodiversity and an
MSc with distinction in Botany from Rhodes University. Tarryn’s Master’s thesis examined the
impact of fire on the recovery of C3 and C4 Panicoid and non-Panicoid grasses within the context of
climate change for which she won the Junior Captain Scott-Medal (Plant Science) for producing
the top MSc of 2010 from the South African Academy of Science and Art as well as an Award for
Outstanding Academic Achievement in Range and Forage Science from the Grassland Society of
Southern Africa. She conducts vegetation assessments including vegetation and sensitivity
mapping to guide developments and thereby minimise their impacts on sensitive vegetation. Tarryn
has conducted a number of vegetation and impact assessments in Mozambique (to IFC standards)
which include the Lurio Forestry Project in Nampula, the Syrah Graphite Mine in Cabo dDelgado
and the Baobab Iron Ore Mine in Tete, Mozambique. Tarryn has also co-designed and
implemented the Terrestrial Monitoring Program for Kenmare, MOMA, a heavy minerals mine in
Mozambique. This monitoring program includes an assessment of forest health. She has also
worked on the Lesotho Highlands Development Authority botanical baseline survey for phase 2 of
the Lesotho Highlands Water Project.
Environmental Risk Assessment
Coastal & Environmental Services I SANRAL: Risk Assessment
KEY TERMS Ecological Succession: refers to more or less predictable and orderly changes in the composition or structure of an ecological community. Succession may be initiated either by formation of new, unoccupied habitat (e.g., a severe landslide) or by some form of disturbance (e.g. fire, severe wind , logging) of an existing community. Succession that begins in areas where no soil is initially present is called primary succession, whereas succession that begins in areas where soil is already present is called secondary succession. Habitat: An ecological or environmental area that is inhabited by a particular animal and plant species. It is the natural environment in which an organism lives, or the physical environment that surrounds (influences and is utilized by) a species population. Indigenous vegetation: Plants native to the locale in question. Species originating in a particular area are said to be indigenous plants for that area. Monitor: To monitor or monitoring generally means to be aware of the state of a system. The rehabilitation monitoring methodology is usually a standard and simple procedure that can be easily replicated over any vegetation community or rehabilitation area. Re-vegetation: re-vegetation implies restoration without the objective of reinstating a particular native ecosystem. In re-vegetation, any plant species is acceptable (for instance, sowing a mixture of commercially available grasses for soil rehabilitation) although a commercial crop or timber producing trees are often used. Replacement: is the establishment of a different type of vegetation on the degraded environment following construction, for example agriculture. Restoration: is the process of reconstituting a degraded system to its original state. Rehabilitation: is a general term that encompasses the replacement, restoration and re-vegetation, and is the process or programme implemented to achieve restoration or replacement.
Coastal & Environmental Services I SANRAL: Risk Assessment
TABLE OF CONTENTS 1 INTRODUCTION ..................................................................................................................... 3
1.1. Project background and locality ....................................................................................... 3 1.2. Site description ................................................................................................................ 5 1.3. Project description ........................................................................................................... 5
1.3.1. Mining permit ........................................................................................................... 5 1.3.2. Current status of the Borrow Pit associated with the NR6, Section 4 at Penhoek Pass. 6 1.3.3. Mining method ......................................................................................................... 6 1.3.4. Scale of mining ........................................................................................................ 6 1.3.5. Rehabilitation ........................................................................................................... 6 1.3.6. Water supply ............................................................................................................ 6
2 LEGISLATION......................................................................................................................... 8 2.1. Mineral and Petroleum Resources Development Act, 2002 (Act No. 28 of 2002)............. 8
3 APPROACH AND METHODOLOGY ....................................................................................... 9 3.1. Data collection and objectives ......................................................................................... 9 3.2. Risk Rating Assessment Methodology ............................................................................. 9 3.3. Ranking of risk According to MPRDA Regulations ......................................................... 11 3.4. Assumptions and limitations .......................................................................................... 11
4 DESCRIPTION OF THE PHYSICAL SETTING ..................................................................... 12 4.1. Topography and hydrology ............................................................................................ 12
5 DESCRIPTION OF THE BIOLOGICAL SETTING ................................................................. 14 5.1. Regional Context ........................................................................................................... 14
5.1.1. Vegetation : Tsomo Grassland ............................................................................... 14 6 REHABILITATION ................................................................................................................. 16 7 DESCRIPTION OF RISKS AND RECOMMENDATIONS ...................................................... 19
7.1. Issues identified on the borrow pit area: ........................................................................ 19 7.1.1. Issue 1: Presence of Alien Invasive species .......................................................... 19 7.1.2. Issue 2: Un-vegetated Areas .................................................................................. 19 7.1.3. Issue 3: Soil Health ................................................................................................ 20 7.1.4. Issue 4: Visual ....................................................................................................... 21
8 GENERAL RECOMMENDATIONS ....................................................................................... 27 8.1. Management measures ................................................................................................. 28
8.1.1. Time frames and schedule for the implementation of the management measures . 28 8.1.2. On-going maintenance of the area will include ....................................................... 28 8.1.3. Monitoring .............................................................................................................. 28 8.1.4. Responsibilities for implementation and long-term maintenance of the management measures .............................................................................................................................. 29 8.1.5. Financial provision for long-term maintenance ....................................................... 29
REFERENCES ............................................................................................................................. 31 APPENDIX A – MINE PLAN ......................................................................................................... 32 APPENDIX B: SPECIES LIST....................................................................................................... 34 APPENDIX C: LANDOWNER CLEARANCE CERTIFICATE......................................................... 37 APPENDIX D: WASTE MAN COLLECTION SLIP ......................................................................... 38
LIST OF TABLES Table 3.1: Severity (Impact/Consequence) ............................................................................................................ 9 Table 3.2: Probability ............................................................................................................................................. 10 Table 3.3: Risk Matrix ............................................................................................................................................ 10 Table 7.1: Table showing the Risks associated with the Borrow pit, EOH Coastal and Environmental
Services rating without mitigation and with mitigation and provides recommendations to deal with the
Coastal & Environmental Services II SANRAL: Risk Assessment
Table 8.2: Closure costs ........................................................................................................................................ 29 Table 8.3: Closure costs: Re-seeding, grassing of the Borrow Pit area. ............................................................ 29
LIST OF FIGURES Figure 1.1: Locality map for the Borrow Pit associated with the NR6, Section 4 at Penhoek Pass. Project
area is located in Sterkstroom, near Dordrecht within the Eastern Cape .................................................... 4 Figure 1.2: NFEPA River and drainage lines occur in the farm portion and wetlands occurring in the
surrounding areas of the Borrow pit location. ................................................................................................ 7 Figure 4.1: Underlying geology of the project area. ............................................................................................. 13 Figure 5.1: Map illustrating the vegetation type (Tsomo Grassland) which the borrow pit occurs in. .............. 15
LIST OF PLATES
Plate 1-1: Site Photographs showing 8 compass pictures of the borrow pit area (22 October 2015). .............. 5 Plate 4-1: Photograph illustrating the general topography of the area ............................................................... 12 Plate 6-1: Photograph illustrating the disturbance to the area due to the mining of weathered dolerite at the
borrow pit (Photograph was taken in March 2015). ..................................................................................... 17 Plate 6-3: Photographs A and B illustrating alien invasive species that occurred on the stockpiles at borrow
pit during the operation phase (information from audit report). .................................................................. 18 Plate 7-1: Photograph illustrates the bare area which is a result of the mining activities at the borrow pit. .... 20 Plate 7-2: (A-B) Areas where the soil has been compacted and may require some additional loosening to
1.1. Project background and locality The road upgrade of the National Route 6 section 4, Penhoek Pass (between Kilometers 52.0 and 66.2), between Queenstown and Jamestown in the Eastern Cape Province has resulted in the extension of an existing borrow pit to provide building material for the road upgrade. The borrow pit is situated on Remaining Extent of Farm Valschfontein No.180 (Figure 1.1). This borrow pit was mined for weathered dolerite to a depth of 2 - 5 metres and had a foot print of 5.3 ha. The mining of the borrow pit ceased in February 2015. Rehabilitation in this area has been on-going and has included the following:
Filling of the borrow pit with overburden, soil and crushed concrete aggregate.
Hazardous waste such as contaminated soils were safely removed and disposed of at an appropriate facility that accepts hazardous waste.
The ground at the borrow pit site was levelled and re-shaped.
Alien vegetation from the stockpiles and surrounding areas (road verge) was removed.
The area was re-seeded (October 2015) with Indigenous grasses which included (Eragrostis tef, Eragrostis curvula, Cynodon dactylon, Cenchrus ciliaris, Panicum maximum, Chloris gayana, Anthephora pubescens, Digitaria eriantha) to allow for the establishment of vegetation on the disturbed area.
Temporary structures and storage units on the site have been dismantled and removed. The South African National Roads Agency (SANRAL) is applying for a Closure Certificate for the borrow pit associated with the road upgrade of the National Route 6, Section 4 at Penhoek Pass. According to Section 57 (2b) of the Mineral and Petroleum Resources Development Act, A closure certificate application must be accompanied by A Risk Assessment Report contemplated in regulation 60.
Figure 1.1: Locality map for the Borrow Pit associated with the NR6, Section 4 at Penhoek Pass. Project area is located in Sterkstroom, near Dordrecht within the Eastern Cape
Approximately 5.3 ha has been impacted on by activities associated with the borrow pit for the NR6, Section 4 at Penhoek Pass road upgrade. Most of this area (5.3 ha) is still undergoing rehabilitation. Below are photographs showing an overview of the area disturbed due to the mining activities.
Plate 1-1: Site Photographs showing 8 compass pictures of the borrow pit area (22 October 2015).
1.3. Project description
1.3.1. Mining permit SANRAL currently hold the rights to mine the borrow pit and the exemptions provisions of Section 106(1) of the Act were applicable. Thus a mining permit was not applied for, but the use of any materials sources from the borrow pit was subject to an Environmental Management Plan (EMP) which was compiled in accordance with Regulation 51 of the MPRDA. The Environmental Management Plan was approved by DMR on the 4th January 2013.
1.3.2. Current status of the Borrow Pit associated with the NR6, Section 4 at Penhoek Pass.
The borrow pit is no longer operational, and all equipment and infrastructure has been removed from the site. Mining ceased in February 2015 as the borrow pit was used to provide material for the upgrading of the National Route 6, Section 4 at Penhoek Pass. The material from the borrow pit is no longer required and rehabilitation of the site has been on-going.
1.3.3. Mining method Mining at the borrow pit occurred through mechanical means with a frontend loader. No blasting took place at site. Once material was obtained from the borrow pit, it was then transported from the workface to the stock pile area where it was then collected by trucks and transported to the point of use. Oversize rock was crushed first to a preferred size and then stockpiled on site.
1.3.4. Scale of mining Material sourced at the borrow pit was weathered dolerite, where a total quantity of 100 000 m3 of material was extracted and used for the road upgrade. The extent of the mining was 120 608.49 m3.
1.3.5. Rehabilitation Rehabilitation of the area included the back filling of the borrow pit with overburden, soil and crushed concrete aggregate. Hazardous waste such as contaminated soils were safely removed and disposed of at an appropriate facility that accepts hazardous waste. The ground at the borrow pit site was levelled and re-shaped. Alien vegetation from the stockpiles and surrounding areas (road verge) was removed. The area was re-seeded with Indigenous grasses which included (Eragrostis tef, Eragrostis curvula, Cynodon dactylon, Cenchrus ciliaris, Panicum maximum, Chloris gayana, Anthephora pubescens, Digitaria eriantha) to allow for the establishment of vegetation on the disturbed area. Temporary structures and storage units that were on the site have been dismantled and removed. Due to Rehabilitation being an on-going process which may require additional inputs, the area will require on-going aftercare and maintenance to ensure that rehabilitation is successful.
1.3.6. Water supply There are no rivers or water courses within 32m and 500m respectively of the borrow pit, as seen on Figure 1.2. A drainage line occurs in the south-western section of the Valsfontein Farm (Re/180) and a number of wetlands are found on surrounding portions. To suppress dust on the borrow pit site, water was obtained from a borehole belonging to SANRAL. This borehole (S 31.530 E 26. 673) is located about 6.4 km away from the project area. General Authorisation (dated 20 August 2014) for the use of this borehole was obtained from Eastern Cape Water and Sanitation Department.
2 LEGISLATION This Environmental risk assessment report has been prepared to ensure that the borrow pit associated with the NR6, Section 4 at Penhoek Pass is compliant with the Legislation provided below:
2.1. Mineral and Petroleum Resources Development Act, 2002 (Act No. 28 of 2002) Regulation 57 (2b): An application for a closure certificate must be accompanied by an environmental risk report contemplated in regulation 60.
Regulation 60: This environmental risk must include:
(a) the undertaking of a screening level environmental risk assessment where-(i) all possible environmental risks are identified, including those which appear to be insignificant; (ii) the process is based on the input from existing data; (iii) the risks that are considered are qualitatively ranked as — (aa) a potential significant risk; (bb) a uncertain risk; (cc) an insignificant risk;
(b) the undertaking of a second level risk assessment on issues classified as potential significant risks where-(i) appropriate sampling, data collection and monitoring be carried out; (ii) more realistic assumptions and actual measurements be made; and (iii) a more quantitative risk assessment is undertaken, again classifying risks as posing a potential significant risk or insignificant risk.
(c) an assessment of whether risks classified as posing potential significant risks are acceptable without further mitigation;
(d) risks classified as uncertain risks be re-evaluated and re-classified as either posing potential significant risks or insignificant risks;
(e) documenting the status of insignificant risks;
(f) identifying alternative risk prevention or management strategies for potential significant risks that have been identified, quantified and qualified in the second level risk assessment; and
(g) agreeing on management measures to be implemented for the potential significant risks that must include-(i) a description of the management measures to be applied; (ii) a predicted long-term result of the applied management measures; (ii) the residual and latent impact after successful implementation of the management measures; (iii) time frames and schedule for the implementation of the management measures; (iv) responsibilities for implementation and long-term maintenance of the management measures; (v) financial provision for long-term maintenance; and (vi) monitoring programmes to be implemented.
3.1. Data collection and objectives A site visit was conducted on the 22 October 2015 by Ms Ayanda Zide and Professor Roy Lubke of EOH CES. The purpose of this site visit was to assess the area for any possible risks that may be present or could be potential risks in the future.
3.2. Risk Rating Assessment Methodology
To determine the environmental risks associated with the borrow pit used to source material for the upgrade of the NR6, Section 4 at Penhoek Pass , a risk rating that provides the rationale for and the priority for any further risk control actions was used. The rating scheme given in Tables 3.1 and 3.2 was used to decide on the appropriate risk rate. The Impact Severity Table (Table 3.1) allows for the severity of any consequence to be ranked qualitatively as insignificant, minor, moderate, major and catastrophic. The likelihood of a consequence (including its associated impacts) is then described according to the scales presented in Table 3.1. Due to the mine no longer being in operation, only certain sections of these tables will be relevant. Table 3.1: Severity (Impact/Consequence)
Aspect Catastrophic
(1)
(critical)
Major (2)
(High Impact )
Moderate(3)
(Medium
Impact)
Minor (4)
(Low
Impact)
Insignificant
(5)
Health and
safety Multiple fatalities Single fatality MTI/LTI * FAI*
A Almost Certain The event is expected to occur during the life of
the project within 0-1 year
B Likely The event is likely to occur during the life of the
project within 1-5 years
C Moderate The event might occur at some time during the
project within 5-25 years
D Unlikely Low probability that the event could occur at
some time during the project and within 25-50
years
E Rare The event may occur in exceptional
circumstances but would not be expected to
occur
Evaluating the risk involved combining the severity of the consequences resulting from the potential incident or aspect and the likelihood of that consequence occurring. Single hazards/aspects are positioned on the matrix by using the axes of consequence/severity and the likelihood of that outcome (Table 3.3). The risk is then ranked as either; Low, Medium, High, or Critical.
Wherever the consequence severity is critical, the task / activity / change / modification cannot continue before approvals by the Operations/Project Director. Table 3.3: Risk Matrix
3.3. Ranking of risk According to MPRDA Regulations According to the regulations one is required to rank each risk on whether it is (aa) potential significant risk, (bb) uncertain risk, (cc) significant risk. This has been included in Chapter 7.
3.4. Assumptions and limitations Due to the brief nature of the site visits conducted at the study area, this assessment is based largely on our understanding of the physical and ecological setting from available literature and based on information that has been gathered in the life span of the mine and during the rehabilitation process.
4.1. Topography and hydrology Topography According to the Environmental Management Plan (Klages, 2013), the borrow pit lies in a wide flat valley at a mean altitude of 1585 metres falling slightly from 1594 m in the southwestern corner to 1578 m in the northeastern corner. In the north and in the east, the Salpeterberg and the Penhoekberg rise to 1937 m and 2019 m, respectively. Plate 4-1 illustrates the general topography of the area
Plate 4-1: Photograph illustrating the general topography of the area
4.2. Climate
The Eastern Cape Province of South Africa has a complex climate due to its location at the confluence of two climatic regimes, namely temperate and subtropical. As a result there are wide variations in temperature, rainfall and wind patterns, mainly as a result of movements of air masses, altitude, mountain orientation and the proximity of the Indian Ocean. The climate description is based on data from the Sterkstroom weather station which is the closest weather station to the site. The weather data for Sterkstroom shows that it receives an average of 391 mm of rain per year (SA explorer, 2015). The average temperature is 21˚ C with the hottest month occurring in January with an average high of 28˚ C and the coldest month occurring in July where the average temperature is said to drop below 0.1˚C during the night (SA explorer, 2015).
4.3. Geology and Soils According to Mucina and Rutherford (2006), the borrow pit occurs on the Tsomo Grassland vegetation type. The underlying geology prevalent in this area is characterised by red to yellow sandy soils found on mudstones of the Tarkastad Subgroup (Beaufort Group in Karoo Supergroup). These land types are of moderate depth.
The Beaufort Group sediments mainly consist of Arenite, Mudstone and Siltstones (Turner, 1981). Of these only the Mudstone formation and the Arenite formation occur within the farm portion (RE/180).The Mudstone formation only occurs in a small area in the northern section of the farm, whilst the Arenite formation occurs in most of the farm portion and where the borrow pit is found (Figure 4.2). Arenite is medium sized sedimentary rocks which are sandy (sandstone).
Figure 4.1: Underlying geology of the project area.
5.1. Regional Context The project area falls within the Grassland biome, one of the seven occurring in South Africa, Lesotho and Swaziland (Mucina & Rutherford 2006). The Grassland Biome is made up by “The warm-temperate and cool-temperate grasslands (and shrublands embedded within these) of the Highveld, Drakensberg and its northern continuation in the form of the Northern Escarpment, a whole suite of sub-escarpment grasslands, and small pockets of (most) summit sourveld composed of grasslands and savannoid bushveld” (Mucina & Rutherford,2006). Mucina and Rutherford (2006) defines the grassland vegetation as: “herbaceous vegetation of relatively short and simple structure that is dominated by graminoids, usually of the family Poaceae. Woody plants are rare (usually low or medium-sized shrubs) or absent or are confined to specific habitats, such as smaller escarpments or koppies. Core grassland areas usually have deep, fertile soils although a wide spectrum of soil types occurs. Precipitation is strongly seasonal and the growing season lasts approximately half the year.”
5.1.1. Vegetation : Tsomo Grassland
The study site is characterised by the presence of the Tsomo Grassland which is found to occur in Eastern Cape Province of South Africa. It occurs on undulating lowland plains between mountain peaks and ridges where its eastern boundaries are found to occur in villages of Tsomo, Cala and Engcobo and its western boundaries occurs in Cathcart, Queenstown and Sterkstroom. A number of gramnoides, herbaceous species, small trees and tall shrubs are found to occur in this vegetation type.
This vegetation type is classified as “Vulnerable” and about 23% of this vegetation is targeted for conservation with only 1% being conserved in private reserves. None is statutorily conserved. About 27 % has already been transformed by cultivation and by dense concentrations of rural settlements (Mucina and Rutherford, 2006).
According to the EMP (Environmental Management Plan), the grasses of the genera Aristida, Cynodon, Digitaria, Eragrostis, Heteropogon, Hyparrhenia and Themeda, typical for Tsomo grassland, were found on the site. The herbs Argyrolobium, Aster, Berkheya, Commelina, Cyanotis, Gazania, Helichrysum, Oxalis and Pelargonium were also present and low shrubs of the species Felicia muricata, Helichrysum odoratissimum, Senecio burchellii, Sutera pinnatifida and Tephrosia capensis, as well as Euryops floribundus were present during the previous assessment. However, the previous assessment found the study area to be degraded (Klages, 2013). The vegetation that was found in the surrounding areas of the borrow pit during this survey was grassland vegetation (Figure 5-2). In the Southern (upper) parts of the borrow pit, this vegetation was dominated by Themeda triandra (rooigras) which forms an almost continuous sward of almost 50% cover in this region (Figure 5-3). This area was somewhat disturbed which has resulted in more species being found. An increase in the number of species over time after a large scale disturbance event especially one that is caused by human activities is an attribute of ecological succession (Cadotte 2007). Whilst in the north (bottom) end of the site, undisturbed Themeda triandra (rooigras) occurred as a solid sward or mat with the only other species present being Felicia filifolia, Eragrostis curvula and Wahlenbergia stellariodes (Figure 5-4). Along the fence line the grass had been disturbed.
In the top corner of the borrow pit area there were four Acacia karroo trees with the following grasses growing below them: Cynodon dactylon and Bromus catharticus. The following weeds were also present Lepidium africanum, Solanum nigrum and Raphanus raphanisrum.
6 REHABILITATION Rehabilitation is a key mitigation action to reduce many of the impacts on the natural environment. A rehabilitation programme was prepared and approved by the Department of Mineral Resources in 1993. Rehabilitation was carried out on site during the mining activities and a number of rehabilitation exercises were carried out post mining activities (as discussed above). The most important component of a rehabilitation project is the specification of the goals for rehabilitation (Ehrenfeld 2000). This is important as it determines which procedures should be implemented and the extent of monitoring that will be required after these have been applied for the successful rehabilitation of the previously disturbed or degraded system. The objective of rehabilitation for this area was not to return the vegetation to its previous state, but to leave the area in a functional state where the land could be used sustainably. The anticipated land-use after rehabilitation is an area that the land-owner can use for grazing livestock. The specific goals of rehabilitation which are relevant post mining for the borrow pit associated with the NR6, Section 4 at Penhoek Pass include:
Site to be cleared of all litter and scrap, which had accumulated during the operation phase.
Sufficient contours constructed to prevent soil erosion.
Ensure that the sidewalls of the borrow pit are not sloped too steeply (slope should not exceed 1:3).
Establish vegetation cover by filling borrow pit with overburden and application of topsoil.
Monitoring of site to determine the progress of rehabilitation.
Rehabilitation must comply with provisions in the Environmental Management Programme.
Borrow pit area to be left in a manner where Landowner could use the area as grazing pasture.
The most important goals in rehabilitation are to establish plant cover and species diversity, ideally with the same composition as pre-disturbance (Burke, 2003). Such objectives are not excessively demanding under suitable environmental conditions, and provided changes to the upper layers of the soil are not significant (Harris et al., 1996; Glenn et al., 2001; Mahood, 2003). The mining of the borrow pit has resulted in the loss of vegetation and a change in landscape (see Plate 6-1). The site visit indicated that rehabilitation in the borrow pit area is in progress. To date the borrow pit has been filled, reshaped, levelled and topsoil has been applied. Activity of hydro-seeding the area was completed in October 2015. Most of this area now remains bare although there are a few small patches of vegetation (see Plate 6-2) that have returned to this area as a result of applying topsoil.
Plate 6-1: Photograph illustrating the disturbance to the area due to the mining of weathered dolerite at the borrow pit (Photograph was taken in March 2015).
Plate 6-2: Establishment of vegetation on the Borrow Pit area. The audits that have been done for the borrow pit indicate that there has been active management of alien invasive species. The site visit confirmed this as the area was not heavily infested with alien or weedy species. Strategies to control alien invasive species need to be continued and properly managed, as these species compete with indigenous species. Should vegetation not establish in the bare areas, these areas should be re-seeded or other methods implemented as these bare areas may also encourage the establishment of undesirable alien invasive species. Measures to establish vegetation on un-vegetated areas and those which could be applied to control alien invasive species are discussed in Chapter 8.
Plate 6-3: Photographs A and B illustrating alien invasive species that occurred on the stockpiles at borrow pit during the operation phase (information from audit report).
7 DESCRIPTION OF RISKS AND RECOMMENDATIONS Potential risks have been identified based on the information gathered during the site visit (October 2015) and from historical information compiled during the life span of the mine The significance of each identified risk and recommendations to mitigate these are provided below. Risks identified:
7.1. Issues identified on the borrow pit area:
7.1.1. Issue 1: Presence of Alien Invasive species
Risk 1: Invasion of alien invasive plant species
A single alien invasive species (Argemone ochroleuca) was found to occur in the borrow pit and surrounding areas. A number of species such as Tagetes minuta and Schkuhria pinnata which are considered weeds and are undesirable but are not listed as an alien invasive species by the Alien and Invasive Species Regulations (2014) were also found. All these should be monitored and removed from the area, to ensure that only indigenous species establish in the borrow pit area. In the areas outside of the study area, Agave and Pinus species were found. These species should be controlled by the respective landowners. Environmental audits indicate that there has been active management of alien species on the study area and that there were strategies implemented for the control of alien invasive species on site. However, controlling for alien species is an ongoing task as seedlings continuously emerge from the seedbank. For this reason, it is recommended that this borrow pit is monitored for the next two years.
7.1.2. Issue 2: Un-vegetated Areas
Risk 2: Wind erosion
The mining activities associated with the borrow pit has resulted in the clearance of natural vegetation. This has resulted in a large area of unvegetated, bare soil that is susceptible to wind erosion. Even though the area has been recently seeded, a cover crop that will bind the soil has not yet been established on the site The condition of the soil and the current state of this area suggests that a cover crop can be established under favourable conditions.
Risk 3: Pollution of nearby streams Without vegetation to bind the soil in the borrow pit area, heavy rainfall events will result in the topsoil eroding and washing away into nearby rivers causing an increase in turbidity. The pollution of watercourses will affect the quality of these systems (including aquatic fish such as amphibians and fish). However, this impact is considered to be minor due to the distance of nearby watercourses from the borrow pit.
Risk 4: Generation of dust as a nuisance factor Some dust may be generated as a result of the exposed ground. The generation of dust may be higher during windy, dry periods. Dust may be a nuisance to the neighbours and also people who use the NR6 Road which is adjacent to the borrow pit. It is therefore imperative that the borrow pit is re-vegetated as soon as possible.
Plate 7-1: Photograph illustrates the bare area which is a result of the mining activities at the borrow pit.
7.1.3. Issue 3: Soil Health
Risk 5: Lack of establishment of vegetation due to soil compaction The soil has been compacted by construction vehicles during the operation phase of the borrow pit and during rehabilitation (clearing of the site, removal of storage units etc.). Sowing in soil that is compacted or soil with a ‘crust’ will result in the seed being washed away after the first rains. The site visit indicated that during rehabilitation of this area, soil has been loosened in some areas but not in other areas (as per Site visit on 22 October 2015, and Audit report 21 (16 October 2015)). Re-vegetation is unlikely to occur in compacted areas resulting in erosion, dust and run-off.
Risk 6: Lack of establishment of vegetation due to poor soil properties
Due to the mining activity which has occurred at the borrow pit, the soil properties may have been altered and may therefore not be ideal for the establishment of indigenous pioneer species. It is important that there are nutrients and moisture (water) available in the soil for plant establishment in the area. During the rehabilitation activity, soil in this area has been improved by application of Superphosphate (fertilizer containing plant-available sulphur and phosphate), topsoil and mulch to improve the soil properties and encourage the establishment of indigenous vegetation in this area.
Plate 7-2: (A-B) Areas where the soil has been compacted and may require some additional loosening to encourage plant establishment.
7.1.4. Issue 4: Visual
Risk 7: Low Aesthetic Appeal The area does not currently look like the surrounding areas as it remains devoid of vegetation and is therefore not aesthetically pleasing to the neighbouring landowners and motorists that use the NR6. However, it has been levelled out and this will be compatible with the surrounding area once it has been rehabilitated.
Table 7.1: Table showing the Risks associated with the Borrow pit, EOH Coastal and Environmental Services rating without mitigation and with mitigation and provides recommendations to deal with the risks.
RISKS TO THE NATURAL ENVIRONMENT
Post-Mining Phase
Risk Cause and Comment Rating withou
t Mitigati
on
Recommendations Rating Mitigation
Alien Invasive Species
A single alien invasive species (Argemone ochroleuca) was found to occur in the borrow pit and surrounding areas. A number of species such as Tagetes minuta and Schkuhria pinnata which are considered weeds and are undesirable but are not listed as an alien invasive species by the Alien and Invasive Species Regulations (2014) were also found. All these should be monitored and removed from the area, to ensure that only indigenous species establish in the borrow pit area. In the areas outside of the study area, Agave and Pinus species were found. These species should be controlled by the respective landowners. Environmental audits indicate that there has been active management of alien species on the study area and that there were strategies implemented for the control of alien invasive species on site. However, controlling for alien species is an ongoing task as seedlings continuously emerge from the seedbank. For this reason, it is recommended that this borrow pit is monitored for the next two years.
The mining activities associated with the borrow pit has resulted in the clearance of natural vegetation. This has resulted in a large area of unvegetated, bare soil that is susceptible to wind erosion. Even though the area has been recently seeded, a cover crop that will bind the soil has not yet been established on the site The condition of the soil and the current state of this area suggests that a cover crop can be established under favourable conditions.
HIGH 3B
Should a cover crop not
establish other methods should
be employed such as using
cuttings of indigenous plants
from the surrounding area and
mulch.
Seeds should be planted during
the rainy season to give them
the best chance of survival.
During the dry season, bare
areas should be watered to allow
for germination of the planted
seeds.
LOW 5D
Pollution of nearby streams
Without vegetation to bind the soil in the borrow pit area, heavy rainfall events will result in the topsoil eroding and washing away into nearby rivers causing an increase in turbidity. The pollution of watercourses will affect the quality of these systems (including aquatic fish such as amphibians and fish). However, this impact is considered to be minor due to the distance of nearby watercourses from the borrow pit.
Lack of establishment of vegetation due to soil compaction
The soil has been compacted by construction vehicles during the operation phase of the borrow pit and during rehabilitation (clearing of the site, removal of storage units etc.). Sowing in soil that is compacted or soil with a ‘crust’ will result in the seed being washed away after the first rains. The site visit indicated that during rehabilitation of this area, soil has been loosened in some areas but not in other areas (as per Site visit on 22 October 2015, and Audit report 21 (16 October 2015)). Re-vegetation is unlikely to occur in compacted areas resulting in erosion, dust and run-off.
Critical 3A
Loosening of compacted soil;
this may include using rakes or
sharp-pointed hoes.
No machinery or heavy vehicles
should be allowed on the area
after it has been sown as this
may lead to further compaction
of the soil.
LOW 5D
Dust
Some dust may be generated as a result of the exposed ground. The generation of dust may be higher during windy, dry periods. Dust may be a nuisance to the neighbours and also people who use the NR6 Road which is adjacent to the borrow pit. It is therefore imperative that the borrow pit is re-vegetated as soon as possible.
High 3B
Employ dust suppression
measures such as wetting of the
study area during dry, windy
periods.
Encourage the establishment of
vegetation in the area.
LOW 5D
Lack of establishment of vegetation due to poor soil properties
Due to the mining activity which has occurred at the borrow pit, the soil properties may have been altered and may therefore not be ideal for the establishment of indigenous pioneer species. It is important that there are nutrients and moisture (water) available in the soil for plant establishment in the area. During the rehabilitation activity, soil in this area has been improved by application of Superphosphate (fertilizer containing plant-available sulphur and phosphate), topsoil and mulch to improve the soil properties and encourage the establishment of indigenous vegetation in this area.
The area does not currently look like the surrounding areas as it remains devoid of vegetation and is therefore not aesthetically pleasing to the neighbouring landowners and motorists that use the NR6. However, it has been levelled out and this will be compatible with the surrounding area once it has been rehabilitated.
Ranking of risks according to the Regulations According to the regulations one is required to rank each risk on whether it is (aa) potential significant risk, (bb) uncertain risk, (cc) insignificant risk. All the identified risks associated with the mining activity require mitigation as they rank from Medium to Critical according to the EOH CES risk rating method.
Risks MPDR ranking (Without mitigation)
MPDR ranking (With mitigation)
Alien Invasive Species Potential significant risk Insignificant Risk
The main goal is to minimise the risks that are currently present on the project area, this can be done by establishing plants on the bare areas, even if it is not plants that were previously there before the mining activities. And to prevent alien invasive species as these compete with the natural species.
The mitigation measures provided in Table 7.1 should be implemented, as this will reduce most of the risks associated with the mining activity at the borrow pit to low and medium.
Monitoring and active management of the area especially for the first two years as this will ensure that rehabilitation reaches the desired state.
Guidelines for the removal of Alien invasive species
General requirements
All weeds and alien invasive species should be removed from the site.
The site must be monitored every two months to remove emerging AIS seedlings.
In cases where large scale alien and plant removal has been conducted, measures to stabilise the soil from wind and water erosion must be taken. Soils may be mulched and planted with indigenous pioneer species.
Continued monitoring for the next two years will be required as the risk of alien plant species invasion is never eliminated. Landowners will have to take over this responsibility once this period is over.
Removal of alien invasive species through various methods There are a number of possible methods which can be used to control alien invasive species; these include mechanical, chemical and biological control. The sections below outline possible techniques used in mechanical methods. Biological control and chemical control methods are not feasible or suitable options for this site, and are thus not discussed further. Table 4.2 (below) outlines specific management details for the alien invasive species identified on site, It is also recommended that species considered as weeds and are undesirable should also be removed from the site. Mechanical control methods
Mechanical methods for alien plant removal may include felling, removing or burning invading alien plants. Young plants can be pulled by hand by gripping them low down and pulling them out by hand (using gloves).
Due to these risks there being potential significant risks (Without Mitigation), Section 60 (g) becomes relevant. See section below:
8.1. Management measures
By applying the recommended management measures, the long term results will include: o Management and control of Alien invasive species on the site o The return of indigenous species on the site o An improvement in the ecosystem function o Control of Erosion on the site
Residual and latent impact after successful implementation of the management measures o Alien invasive plants may return to the site as they are present in the surrounding
area.
8.1.1. Time frames and schedule for the implementation of the management measures
Management of alien invasive species should be continued on the project area o Monitor that active management is being implemented for at least 2 years
Mulching and revegetation of the bare areas o This should be implemented should no vegetation establish on the bare areas o Monitoring for erosion and areas barren of vegetation will be done on a quarterly
basis for the area where vegetation has not established. o Cuttings of indigenous species from the surrounding areas may be used to re-
vegetate the bare area. o Once the vegetation has established, monitoring will be on an annual basis. o The rehabilitation programme of seeding should commence during the rainy
season. Germination and seedling establishment is likely to have a maximum chance of success if the soils have been well soaked by rains, and irrigation will therefore not be needed.
8.1.2. On-going maintenance of the area will include
The control of alien invasive vegetation
Erosion control
Watering of plants in 1st year during periods of drought.
Monitoring of rehabilitation
Top soiling and seeding was completed on October 2015. The progress of establishment of vegetation should be monitored and if required another phase of replanting the area should be carried out prior to the end of the current rainy season, i.e. by February 2016.
8.1.3. Monitoring As per the rehabilitation principles, monitoring and review is an assessment and record of management achievements, a periodic review of the rehabilitation plan, and renewal or revision of the rehabilitation implementation programme. Monitoring generally means to be aware of the state of a system. Monitoring is necessary to determine if the rehabilitation process was successful or not. It is important to monitor and manage rehabilitated areas until the vegetation is self-sustaining and meets the requirements of the landowner or land manager, or until the management can be integrated into the overall management of the surrounding area. For the overall rehabilitation of the area to be successful, it is strongly recommended that SANRAL monitor the areas undergoing rehabilitation.
8.1.4. Responsibilities for implementation and long-term maintenance of the management measures
Section 12: The holder of a permit or authorization remains liable for complying with the relevant provisions of the Act until the Regional Director has issued to him a certificate to the effect that he has compiled with the said provisions.
8.1.5. Financial provision for long-term maintenance The closure costs tabulated below refer only to the Borrow Pit associated with the NR6, Section 4 at Penhoek Pass based on the existing area. The closure cost totals inclusive of VAT. The rate per hectare for 2 – 3 years of maintenance and aftercare (line item 14) was R700 per ha when the guideline was produced in 2005. Assuming 7.5% increase (inflation) every year this amount has been adjusted to R1342 /ha Table 8.2: Closure costs
No. Description Unit A B C D E=A*B*C*D
Quantity
Master rate
Multiplication factor
Weighting factor 1
Amount (Rands)
Step 4.5 Step 4.3
Step 4.3 Step 4.4
14 2 to 3 years of maintenance and aftercare
ha 5.5 R1342 1 1 R7 381
SubTotal 1 R7 381
1 Weighting factor 2 1.05 R7 750
Preliminary and General
6.00%
if Subtotal 1 < 100 000 000
R465
7 Contingency 10.00% R775
SubTotal 2 R8 990
Add Vat (14%) R1 259
GRAND TOTAL R10 249
Provision for the amount stipulated above (R10 249.00 inclusive of VAT) will have to be made by SANRAL to ensure that all possible risks are dealt with on the affected area. Should the area require another exercise of soil improvement and planting grasses in the area, an extra amount of R69 426 (Table 8.3) should be provisioned for. With regards to the alien vegetation found in the area, it is recommended that the amount required for the removal of these species will be covered by the maintenance and aftercare. It should be noted that this is important to ensure that aliens are monitored on the site, this will ensure that these are controlled on site and that they do not disturb the progress of rehabilitation on the project area.
Table 8.3: Closure costs: Re-seeding, grassing of the Borrow Pit area.
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