NEW KLEINFONTEIN GOLDMINE (PTY) LTD MODDER EAST OPERATIONS
AIR QUALITY IMPACT ASSESSMENT FOR THE PROPOSED HOLFONTEIN PROJECT, GAUTENG PROVINCE
AUGUST 2015
PREPARED FOR:
New Kleinfontein Goldmine (Proprietary) Limited P.O. Box 262 Petersfield Springs 1566
Declaration of Independence
Prime Resources is an independent environmental consulting firm with no vested interest in the proposed project other than to fulfil the contract for delivery of specialised services including, among others, those stipulated in the terms of reference.
I, Amanda Mooney, in my capacity as a specialist consultant, hereby declare that I – Act as an independent consultant; Do not have any financial interest in the undertaking of the activity, other than remuneration for the work performed in terms of the National Environmental Management Act, 1998 (Act No. 107 of 1998); Have no, and will not engage in, conflicting interests in the undertaking of the activity; Undertake to disclose, to the competent authority, any material information that has or may have the potential to influence the decision of the competent authority or the objectivity of any report, plan or document required in terms of the National Environmental Management Act, 1998 (Act 107 of 1998); Will provide the competent authority with access to all information at my disposal regarding the application, whether such information is favourable to the applicant or not; Based on information provided to me by the project proponent and in addition to information obtained during the course of this study, have presented the results and conclusion within the associated document to the best of my professional ability; Reserve the right to modify aspects pertaining to the present investigation should additional information become available through ongoing research and/or further work in this field; and Undertake to have my work peer reviewed on a regular basis by a competent specialist.
Report Compiled by: Report Reviewed by:
Amanda Mooney Harold Annegarn (Prof.)
Environmental Scientist Independent Atmospheric Consultant
Project Name: Modder North Holfontein Project Page i of ix Report Title: Air Quality Impact Assessment Project Number: 140668 Date: July 2015 SUMMARY
New Kleinfontein Goldmine (Pty) Ltd has targeted a gold resource in the Gauteng Province, adjacent to their existing Modder East Operations, for the extension of their operations to include the development of an underground mining operation - the proposed Holfontein Project. The project includes refurbishing the existing Holfontein shaft; the construction of a ventilation shaft near the Holfontein shaft; an area around the Holfontein shaft has been allocated for associated surface infrastructure; and a haul road from the Holfontein shaft to the existing Modder East Operations where ore will be processed.
The aim of this air quality impact assessment is to assess the potential air quality impacts of the proposed Holfontein Project. In order to quantify and describe potential air quality impacts of the proposed development, the following parameters are analysed and described in this report:
Meteorological characteristics; and Ambient air quality.
Meteorological Characteristics
5th-generation Mesoscale Model modelled meteorological data was purchased from Lakes Environmental and used for the baseline characterisation and the atmospheric dispersion modelling.
Ambient Air Quality
The relevant air quality management plans including that for Ekurhuleni Metropolitan Municipality, Gauteng Province and the Highveld Priority Area were reviewed to identify existing emissions in the area. A site visit was also conducted on 2 September 2014 to ground truth the desktop data relating to existing sources of emissions. Local sources of air pollution identified during the site visit include:
Existing mining activities and tailings storage facility at the Gold One International New Kleinfontein Goldmine Modder East Operations; Household fuel burning at surrounding settlements; Vehicle exhaust emissions from vehicles travelling on the highway; and Fugitive dust emissions from agricultural activities; Fugitive dust emissions from historic limestone quarrying and historic gold mine tailings; Industry including Sappi Enstra and the Impala Platinum Refinery; Fugitive dust emissions from drilling for prospecting activities; The Welgedacht Wastewater Treatment Works; Agricultural biomass burning.
Relevant air quality monitoring data (i.e. ambient concentrations of criteria pollutants) were sourced from the South African Air Quality Information System taken at the closest monitoring station. When comparing the annual average concentrations of criteria pollutants with the National Air Quality Standards (NAAQS), only the PM10 concentration of 104 µg/m3 exceeded the standard (40 µg/m3) for all months of the year.
Sensitive Receptors
Sensitive receptors include all permanently occupied surrounding areas which may be impacted by the proposed project in terms of air quality. These were identified as the Holfontein Community (comprising of the Khomponi Community residing in the historic mine house and historic mine hostel adjacent to the
Project Name: Holfontein Project Page ii of ix Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 proposed project site; and Holfontein Quarters Community located on the adjacent property across the N12 highway) as well as the residents of the Welgedacht Small Holdings, specifically those residing along Carnation Road
Atmospheric Dispersion Modelling
Atmospheric dispersion modelling was undertaken using the regulatory Gaussian plume AERMOD model to determine highest daily and annual average concentrations for fine particulate matter (PM2.5 and PM10); the average daily Total Suspended Particles / dust fallout rates; and the highest average hourly, daily and annual concentrations for sulphur dioxide. These averaging periods were selected to facilitate the comparison of predicted pollutant concentrations / deposition with relevant NAAQS and dust fallout limits to facilitate compliance and inform the impact assessment.
Impact Assessment
The findings of this air quality impact assessment indicate that dust fallout and PM10 emissions during operations for the Holfontein Project will exceed National Dust Control Regulations acceptable dust fallout and NAAQS limit values at the surrounding sensitive receptors to the west of the boundary for the maximum emission scenario (24-hour operations). However, for Scenario 2 (i.e. loading and hauling hours reduced to 12 hours, from 06h00 to 18h00), dust fallout is within the acceptable limits at all sensitive receptors but PM10 emissions still exceed limit values. Therefore, the only likely pollutant to be generated from the Holfontein Project activities which may be of concern is PM10 during the operational phase, which may contain harmful metals, increasing the potential health risk and will require mitigation. With the implementation of the recommended dust control measures (controlled emissions) the PM10 concentrations fall below the NAAQs limit values at all surrounding sensitive receptors.
As the cumulative impact of dust could not be modelled, it is recommended that the unpaved section of Carnation Road, between the Blesbokspruit crossing and the paved portion of the road, be paved in order to manage cumulative dust, as concerns have been raised by residents living directly adjacent to the proposed haul route.
If the recommended operating hours and mitigation measures are implemented it is unlikely that the proposed Holfontein Project will result in significant air quality impacts. However, due to the fact that the Holfontein Project is located within an air quality priority area (Highveld Priority Area) and within proximity (within 200 m) to permanently occupied areas it is imperative that air quality (dust fallout) monitoring be conducted throughout the life of mine to determine whether the emissions generated at the mine correlate with those modelled and fall below National Dust Control Regulations acceptable dust fallout values at mine boundaries and surrounding sensitive receptors, specifically the historic mine house and informal settlements located to the west of the boundary. If they do not correlate with modelled concentrations and exceed acceptable dust fall, additional management measures must be implemented to ensure that these are not exceeded.
Project Name: Holfontein Project Page iii of ix Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 NEW KLEINFONTEIN GOLDMINE (PTY) LTD MODDER EAST OPERATIONS
AIR QUALITY IMPACT ASSESSMENT FOR THE PROPOSED HOLFONTEIN PROJECT, GAUTENG PROVINCE
TABLE OF CONTENTS | REPORT STRUCTURE
1 Introduction ...... 1
1.1 Details of Author ...... 1 1.2 Terms of Reference ...... 1 1.3 Legal Context ...... 2 1.3.1 Constitution of the Republic of South Africa (No. 108 of 1996) ...... 2 1.3.2 National Environmental Management Act (No. 107 of 1998) ...... 2 1.3.3 National Environmental Management: Air Quality Act (No. 39 of 2004) ...... 3 1.3.4 Ekurhuleni Metropolitan Municipality Public Health By-laws (2009) ...... 6 1.4 Location ...... 6 1.5 Project Description ...... 8
2 Methodology ...... 12
2.1 Ambient Air Quality ...... 12 2.2 Meteorological Data ...... 12 2.3 Atmospheric Dispersion Modelling ...... 12 2.3.1 Model Overview ...... 13 2.3.2 Emissions Inventory ...... 15 2.3.3 Emission Factors and Rates ...... 15 2.3.4 Source and Pollutant Characterisation ...... 19 2.3.5 Modelled Concentrations at Sensitive Receptors ...... 20 2.3.6 Operating Scenarios Modelled ...... 20 2.3.7 Control Efficiencies...... 20
3 Baseline Characterisation ...... 22
3.1 Topography ...... 22 3.2 Land Cover and Land Use ...... 22 3.3 Climate and Meteorological Overview ...... 26 3.3.1 Local Wind Field ...... 26 3.3.2 Air Temperature and Relative Humidity ...... 29 3.3.3 Precipitation ...... 31 3.4 Ambient Air Quality ...... 32 3.4.1 Current Sources of Air Pollution ...... 32 3.4.2 Ambient Air Quality Monitoring ...... 35 3.5 Sensitive Receptors ...... 37
4 Description and Assessment of Potential Impacts ...... 39
4.1 Air Pollution Indicators ...... 39 4.2 Potential Health Effects ...... 39 4.3 Potential Impacts on Crops ...... 40 4.4 Emission Sources ...... 40 4.4.1 Construction Phase ...... 42
Project Name: Holfontein Project Page iv of ix Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 4.4.2 Operational Phase ...... 42 4.4.3 Decommissioning Phase ...... 43 4.5 Impact Assessment ...... 43 4.5.1 Direct Impacts: Construction ...... 43 4.5.2 Direct Impacts: Operation ...... 50 4.5.3 Impact Rating Methodology ...... 64 4.5.4 Modder East Operations ...... 67 4.5.5 Cumulative Impacts ...... 67 4.5.6 Residual Impacts ...... 67
5 Assumptions and Limitations ...... 68
6 Air Quality Management ...... 70
6.1 Construction ...... 70 6.1.1 Topsoil Stripping ...... 70 6.1.2 Earthworks ...... 70 6.1.3 Exposed Areas...... 70 6.1.4 Unpaved Roads ...... 70 6.1.5 Materials Handling ...... 72 6.1.6 Equipment Maintenance...... 72 6.2 Operation ...... 72 6.2.1 Topsoil Stockpile ...... 72 6.2.2 Unpaved Roads ...... 72 6.2.3 Materials Handling ...... 72 6.2.4 Equipment Maintenance...... 73 6.3 Decommissioning ...... 73 6.4 Cumulative Impacts ...... 73 6.5 Modder East Operations ...... 73 6.6 Residual Impacts ...... 74
7 Air Quality Monitoring ...... 75
7.1 Aim ...... 75 7.2 Monitoring Sites ...... 75 7.3 Weather Station ...... 78 7.4 Dust Fallout...... 78 7.4.1 Methodology ...... 78 7.4.2 Objectives ...... 78 7.4.3 Internal Visual Inspections and Audits ...... 78 7.5 Reporting ...... 78 7.5.1 Internal ...... 78 7.5.2 External ...... 79
8 Conclusions and Recommendations ...... 80
9 References ...... 81
Project Name: Holfontein Project Page v of ix Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 FIGURES Figure 1: The locality of the proposed project area ...... 7 Figure 2: Layout plan indicating the UTM co-ordinates ...... 10 Figure 3: Layout plan indicating proposed infrastructure within the boundary ...... 11 Figure 4: Topography of the proposed project area ...... 22 Figure 5: Ekurhuleni Metropolitan Municipality land use map ...... 23 Figure 6: Wind rose depicting the average wind speed and direction for the proposed project area for the period of January 2011 to December 2013 ...... 27 Figure 7: Diurnal wind rose for the period of January 2011 to December 2013 ...... 28 Figure 8: Nocturnal wind rose for the period of January 2011 to December 2013 ...... 28 Figure 9: Wind roses depicting the seasonal variability in wind field for the proposed project area for the period of January 2011 to December 2013 ...... 29 Figure 10: Modelled monthly average temperature for the proposed project area ...... 30 Figure 11: Modelled monthly average relative humidity for the proposed project area ...... 30 Figure 12: Modelled monthly average precipitation for the proposed project area ...... 31
Figure 13: Monthly average concentrations of NO2 recorded at the Etwatwa Station ...... 35
Figure 14: Monthly average concentrations of SO2 recorded at the Etwatwa Station ...... 36
Figure 15: Monthly average PM10 concentrations recorded at the Etwatwa Station ...... 36
Figure 16: Annual average NO2, SO2 and PM10 concentrations recorded at the Etwatwa Station ...... 37 Figure 17: Residential areas surrounding the proposed project area ...... 38 Figure 18: Average daily dust fallout for the construction phase ...... 45
Figure 19: Average daily PM10 concentrations for the construction phase ...... 46
Figure 20: Average annual PM10 concentrations for the construction phase ...... 47
Figure 21: Average daily PM2.5 concentrations for the construction phase ...... 48
Figure 22: Average annual PM2.5 concentrations for the construction phase ...... 49 Figure 23: Average daily dust fallout (Scenario 1) for the operational phase ...... 52 Figure 24: Average daily dust fallout (Scenario 2) for the operational phase ...... 53 Figure 25: Average daily PM10 concentrations (Scenario 1) for the operational phase ...... 54
Figure 26: Average daily PM10 concentrations (Scenario 2) for the operational phase ...... 55
Figure 27: Average daily PM10 concentrations (Scenario 2, Controlled Emissions) for the operational phase ...... 56
Figure 28: Average annual PM10 concentrations (Scenario 1) for the operational phase ...... 57
Figure 29: Average annual PM10 concentrations (Scenario 2) for the operational phase ...... 58
Figure 30: Average daily PM2.5 concentrations (Scenario 1) for the operational phase ...... 59
Figure 31: Average annual PM2.5 concentrations (Scenario 1) for the operational phase ...... 60
Figure 32: Average hourly SO2 concentrations (Scenario 1) for the operational phase ...... 61
Figure 33: Average daily SO2 concentrations (Scenario 1) for the operational phase ...... 62
Figure 34: Average annual SO2 concentrations (Scenario 1) for the operational phase ...... 63 Figure 35: Section of Carnation Road to be paved ...... 71 Figure 36: Proposed air quality (dust fallout) monitoring sites ...... 77
Project Name: Holfontein Project Page vi of ix Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 TABLES
Table 1: National air quality standard for criteria pollutants ...... 4
Table 2: National air quality standard for inhalable particulates (PM10) ...... 5
Table 3: National air quality standard for fine particulates (PM2.5) ...... 5 Table 4: National dust deposition standards ...... 5 Table 5: The average South African heavy-duty diesel vehicle emission factors for the Highveld (Liebenberg-Enslin et al., 2012) ...... 18 Table 6: Sources and pollutants modelled ...... 19 Table 7: Emission control methods ...... 21 Table 8: Modelled monthly average temperature and relative humidity for the proposed project area ...... 30 Table 9: Modelled monthly average precipitation for the proposed project area ...... 31 Table 10: Summary of the sources and pollutants within Ekurhuleni Metropolitan Municipality ...... 33 Table 11: Emissions inventory ...... 41 Table 12: Impact rating of potential air quality impacts for the Life of mine ...... 65 Table 13: Proposed (dust fallout) monitoring sites ...... 75 Table 14: Proposed additional dust fallout monitoring site ...... 76
Project Name: Holfontein Project Page vii of ix Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 LIST OF ACRONYMS
DMR Department of Mineral Resources EIA Environmental Impact Assessment GIS Geographical Information Systems MM5 5th-generation Mesoscale Model MPRDA Mineral and Petroleum Resources Development Act No. 28 of 2002 NAEIS National Atmospheric Emissions Inventory System NEM:AQA National Environmental Management: Air Quality Act, No. 39 of 2004 NEMA National Environmental Management Act, No. 107 of 1998 SAAQIS South African Air Quality Information System SANBI South African National Biodiversity Institute USEPA United States Environmental Protection Agency
Project Name: Holfontein Project Page viii of ix Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 GLOSSARY
A series of mathematical simulations of how air pollutants disperse in the Atmospheric Dispersion ambient atmosphere performed with computer programmes that solve the Modelling mathematical equations and algorithms which simulate the dispersion of pollutants. A core set of air pollution indicators referred to as criteria pollutants have been globally used to characterize air quality. They are common pollutants Criteria pollutants emitted into the atmosphere from various sources, which have detrimental health and environmental impacts that are relatively well-known. Dust Collective term for all airborne particulates, usually smaller than 1 mm. Is a representative value that attempts to relate the quantity of a pollutant Emission factor released to the atmosphere with an activity associated with the release of that pollutant. Emission rates The rate of release of a pollutant into the atmosphere by a specific activity. A list that comprises sources and pollutants to be emitted for the proposed Emissions inventory development. Fugitive dust Airborne particulates derived from undefined sources, i.e. mixed sources. A level fixed on the basis of scientific knowledge, with the aim of reducing Limit value harmful effects on human health or the environment (or both), not to be exceeded. Any area not permanently occupied or classified for residential use as per Non-residential area local town planning scheme. Material in solid or liquid phase suspended in the atmosphere. Particles are classified by their aerodynamic properties, because these determine Particulate transport and removal processes in the air and deposition sites and clearance pathways within the respiratory tract. Person or groups which may experience either a health or nuisance air quality Sensitive receptors related impact due to the proposed development. Total Suspended Particles All particulates with an aerodynamic diameter of less than 100 μm.
Project Name: Holfontein Project Page ix of ix Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 1 INTRODUCTION
New Kleinfontein Goldmine (Pty) Ltd (NKGM) “the Applicant” has targeted a gold resource in the Gauteng Province, adjacent to their existing Modder East Operations, for the extension of their operations to include the development of an underground mining operation - the proposed Holfontein Project. As such, the Applicant is pursuing an amendment to their existing Environmental Management Programme (DMR Ref. PWV 5/3/2/987 and PWV 6/2/2/1136) in terms of Section 102 of the Minerals and Petroleum Resources Development Act, No. 28 of 2002 (MPRDA), as well an application for Environmental Authorisation for activities listed in terms of the National Environmental Management Act, No. 107 of 1998 (NEMA) Environmental Impact Assessment (EIA) Regulations (GNR982 of 2014).
The Applicant has appointed Prime Resources (Pty) Ltd “Prime Resources” to conduct the scope associated with this air quality impact assessment, the purpose of which is to inform the EIA and Environmental Management Programme for the proposed Holfontein Project Environmental Authorisation process.
1.1 Details of Author
Name of Firm: Prime Resources (Pty) Ltd 70 - 7th Avenue, Parktown North, Physical Address: Johannesburg Postal Address: PO Box 2316, Parklands, 2121 Telephone Number: 011 447 4888 Fax Number: 011 447 0355 Email: [email protected]
Amanda Mooney, an Environmental Scientist and author, has a M.Sc. (Zoology) as well as a M.Sc. (Environmental Management) from the University of Johannesburg and three years’ experience in the field of environmental science. A copy of the author’s CV is attached as Appendix 1.
1.2 Terms of Reference
The terms of reference for this air quality impact assessment require:
. Existing air quality information available for the Modder East Operations and projects to be reviewed; . Relevant legislation and associated requirements to be addressed; . Existing land use and associated sources of emissions surrounding the site to be identified; . Potential sensitive receptors, including local communities, to be identified; . Environmental constraints relative to air quality to be discussed as the proposed project area is in an air quality priority area; . The ambient air quality to be characterised; Project Name: Holfontein Project Page 1 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 . The prevailing local weather conditions, and the influence on the dispersion and dilution potential of pollutants released into the atmosphere, to be evaluated; . An emissions inventory for the proposed mining activities to be compiled; . Emissions from the proposed mining activities to be modelled to determine the potential ambient air quality impacts during the construction, operation and decommissioning phases. Modelling simulations to be undertaken to determine the:
o Predicted incremental PM2.5 and PM10 concentrations and dust fallout from the proposed activities; and o Predicted cumulative PM concentrations and dust fallout from the proposed activities in relation to existing concentrations, if possible. . Results of the dispersion modelling to be presented graphically to illustrate the predicted results in terms of the surrounding sensitive receptors; . Comparison of the predicted concentrations to be made with the National Air Quality Standards (NAAQS) and National Dust Control Regulations to determine compliance and potential impacts on health; . The identified impacts to be evaluated in accordance with the Prime Resources methodology to determine significance (i.e. the nature, extent, duration, intensity and probability of each potential impact) prior to and after mitigation; . Recommendations to be provided regarding the mitigation and management of the identified potential impacts taking into consideration the best practicable environmental option; and . An air quality monitoring programme to be formulated.
1.3 Legal Context
There are a number of legislative requirements which must be considered in an air quality impact assessment. Below is a summary of the relevant legislation and guidelines.
1.3.1 Constitution of the Republic of South Africa (No. 108 of 1996)
Section 24 of South Africa’s Constitution guarantees all citizens the right to an environment that is not harmful to their health and / or wellbeing; and to have the environment protected, for the benefit of present and future generations, through reasonable legislative and other measures that prevent pollution and ecological degradation. The Constitutional obligations of the State to protect the environment with respect to new developments can only be met through the implementation, enforcement and monitoring of effective legislation.
1.3.2 National Environmental Management Act (No. 107 of 1998)
The NEMA is enabling legislation intended to provide a framework for integrating environmental management into all development activities to promote co-operative environmental governance with regard to decision making by state organs on matters affecting the environment.
The principles of NEMA are laid out in Section 2 of the Act:
Project Name: Holfontein Project Page 2 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 . To avoid and minimise disturbance to ecosystems or loss of biological diversity and to rectify damage where possible; . To avoid, minimise and remediate pollution and degradation; . Avoid and minimise the creation of waste and to promote recycling and re-use where possible; . Negative environmental impacts should be anticipated and prevented where possible, and where that is not possible, impacts should be minimised and remedied; and . The social and economic impacts must also be considered together with environmental impacts of activities when making decisions.
The air quality impact assessment was conducted in accordance with Section 13(1)(a-f) of the EIA Regulations (GNR982 of 2014). This report is also aligned with the reporting requirements for a specialist assessment as stipulated in Appendix 6 of the EIA Regulations (GNR982 of 2014).
1.3.3 National Environmental Management: Air Quality Act (No. 39 of 2004)
The NEM:AQA is the NEMA management tool for air quality management. One of the objectives of the NEM:AQA is to give effect to our constitutional right to an environment that is not harmful to the health and well-being of people.
The National Framework for Air Quality Management (GN115 of 2012) “National Framework”, serves as a blueprint for air quality management and aims to achieve the air quality objectives as described in the NEM:AQA.
According to the National Framework, the key requirements of the specialist impact study must take into account, amongst others, the pollution being or likely to be caused by that activity and the effect on the environment, including health, economic conditions, cultural heritage and ambient air quality. Specialist air quality impact assessment reports as prescribed in the National Framework have the following key requirements:
. A description of human health impacts; . The objective of achieving NAAQS for emissions; . Prescribe minimum standards for certain point source emissions; . The best practicable environmental option that would prevent, control, abate or mitigate pollution, must be recommended; . Determine whether an Atmospheric Emissions Licence (AEL) is required; and . Ensure national obligations are met in terms of greenhouse gas emissions (if applicable).
GN893 of 2013 lists activities which result in atmospheric emissions which have or may have a significant detrimental effect, thereby requiring an AEL. None of the activities associated with the proposed development trigger an activity in terms of GN893, therefore no AEL is required for the Holfontein Project. However, it might be required that the process plant at ME has in place a valid AEL for the processing of Holfontein material.
According to the National Emission Reporting Regulations (GN283 of 2015), any person that holds a mining right or permit in terms of the Mineral and Petroleum Resources Project Name: Holfontein Project Page 3 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 Development Act, 2002 (No. 28 of 2002) (MPRDA) is required to register as a data provider with and also submit emission reports to the internet-based National Atmospheric Emissions Inventory System (NAEIS). Reports must be submitted for the preceding calendar year to the NAEIS by 31 March for each calendar year. The relevant air quality officer at Ekurhuleni Metropolitan Municipality is the relevant authority in this regard.
Section 33 of NEM:AQA relates to rehabilitation of mining operations, which states that an Applicant must notify the Minister five years prior to mine closure of the planned closure and provide a closure and rehabilitation plan for the prevention of pollution of the atmosphere by dust after operations have ceased.
The NAAQS (GN1210 of 2009), the NAAQS for particulate matter of aerodynamic diameter
less than 2.5 micron metre (PM2.5), provide ambient air quality standards for criteria pollutants to ensure that harmful effects on human health and / or the environment are avoided.
The National Dust Control Regulations (GNR827 of 2013) provide acceptable dust fallout rates to ensure that nuisance impacts are avoided.
The NAAQS (GN1210 of 2009) were determined based on international best practice for
PM10 (particulates with an aerodynamic diameter of 10 micron), dust-fall, sulphur dioxide
(SO2), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO), lead (Pb), benzene and
recently PM2.5 (GN486 of 2012).
Table 1: National air quality standard for criteria pollutants AVERAGING CONCENTRATION FREQUENCY OF COMPLIANCE DATE PERIOD (µG/M3) EXCEEDANCE
Sulphur Dioxide (SO2)
10 minutes 500 526 Immediate
1 hour 350 88 Immediate
24 hours 125 4 Immediate
1 year 50 0 Immediate
Nitrogen Dioxide (NO2)
1 hour 200 88 Immediate
1 year 40 0 Immediate
Ozone (O3)
8 hours 120 11 Immediate
Benzene (C6H6)
1 year 5 0 Immediate
Lead (Pb)
1 year 0.5 0 Immediate
Carbon Monoxide (CO)
1 hour 30 88 Immediate
Project Name: Holfontein Project Page 4 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 AVERAGING CONCENTRATION FREQUENCY OF COMPLIANCE DATE PERIOD (µG/M3) EXCEEDANCE 8 hours 10 11 Immediate
Table 2: National air quality standard for inhalable particulates (PM10) AVERAGING CONCENTRATION FREQUENCY OF COMPLIANCE DATE PERIOD (µG/M3) EXCEEDANCE 24 hour 75 4 Immediate
1 year 40 0 Immediate
Table 3: National air quality standard for fine particulates (PM2.5)
AVERAGING CONCENTRATION FREQUENCY OF COMPLIANCE DATE PERIOD (µG/M3) EXCEEDANCE
65 4 Immediate – 31 Dec 2015
24 hour 40 4 1 Jan 2016 – 31 Dec 2029
25 4 1 Jan 2030
25 0 Immediate – 31 Dec 2015
1 year 20 0 1 Jan 2016 – 31 Dec 2029
15 0 1 Jan 2030
Section 32 of NEM:AQA allows for the promulgation of measures to control and monitor dust. The National Dust Control Regulations (GNR827 of 2013) prescribe general measures for the control of dust in all areas, including residential and light commercial areas.
Table 4: National dust deposition standards
DUST FALLOUT RESTRICTION RATE (MG/M2 /DAY PERMITTED FREQUENCY OF AREAS – 30 DAYS EXCEEDANCE AVERAGE)
Residential Areas D < 600 Two within a year, not sequential months
Non-Residential 600 < D < 1200 Two within a year, not sequential months Areas
In addition, the Regulations propose the prohibition of dust pollution above specified levels and the establishment of criminal liability for non-compliance, as well as new tools for air quality officers to better monitor dust emissions.
Regulations GNR533 of 2014 list the requirements for atmospheric dispersion modelling (including preferred model type, model inputs etc.).
The proposed project area falls within the Highveld Priority Area in terms of air quality. The Highveld Priority Area air quality management plan (GN144 of 2012) provides an emissions inventory and objectives for meeting the NAAQS and the National Dust Control Regulations for different industries from a policy and planning perspective.
Project Name: Holfontein Project Page 5 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 1.3.4 Ekurhuleni Metropolitan Municipality Public Health By-laws (2009)
Chapter 18 of the Ekurhuleni Metropolitan Municipality Public Health By-laws relates to air pollution control. Section 142 in particular relates to duty of care stating that any person who is wholly or partially responsible for causing significant air pollution or creating a risk of significant air pollution occurring must take all reasonable measures to prevent air pollution and mitigate and remedy air pollution which has already been caused. Section 157 states that any occupier or owner of premises from which a nuisance emanates, or where a nuisance exists, is guilty of an offence.
1.4 Location
The proposed Holfontein Project is located over Portion 68 and the Remaining Extent (RE) of the farm Holfontein 71 IR, near the towns of Daveyton and Springs within Ekurhuleni Metropolitan Municipality, Gauteng Province (refer to Figure 1).
Project Name: Holfontein Project Page 6 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Figure 1: The locality of the proposed project area
Project Name: Holfontein Project Page 7 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 1.5 Project Description
Background The purpose of the Holfontein Project is to supplement the drop in production once the NKGM Modder East Operations tonnage profile begins to decline. The above ground extent for infrastructure, roads, servitudes, etc. at the Holfontein Project is 13.58 ha. The area to be cleared for infrastructure is however only 4.5 ha. The Life of Mine will consist of two years of construction and development (2019-2020), and 8 years of gold production (2021-2028). A further 6 months to a year is assumed for decommissioning and closure. The mine will be operated as a section of the Modder East Operations with all services and support being provided by the Modder East Operations. Mine employees will be transported by bus from the Modder East Operations.
Mining – Construction
Access to the Main Reef will be through an existing shaft that was closed / sealed in the early 1940s. In order to refurbish this shaft, the shaft will concurrently be dewatered and re-equipped. This process will require 20-24 months. Construction of associated site infrastructure will also occur concurrently.
Mining – Operation
The shaft will consist of a steel headgear, with two winders (between 40 to 50 m in height), to be constructed above the existing rectangular shaft that will operate 24 hours a day. Rock hoisting will be limited to a 12 hour day shift to limit the noise associated with tipping of ore. Hoisting will take place 23 days a month at 1 200 tons per day. The skip (5 ton capacity) will tip every 2 minutes into a concrete bin (200 ton capacity). The bin will discharge into trucks below the ambient ground level. At steady state production a truck will load every 15 minutes. Loading will be by chute and will not require a front end loader. The material loaded will be wet therefore dust will be limited. There will be a trucking loop to avoid trucks having to reverse. All overburden and ore will be transported from the Holfontein Project to the Modder East Operations plant by road using conventional 30 ton road trucks. The estimated hauling cycle (i.e. return trip) time between the Holfontein Project and the Modder East Operations plant for a 30 ton road truck is 30 minutes. Two trucks will operate for 12 hours a day during daylight hours. The haul route consists of 3 km of existing gravel road and 3 km of existing tarmac surface. There will be two shifts per day, with an estimated 400 employees operating per shift.
Mining – Decommissioning
After the operations are finalised, decommissioning will commence. All shafts will be sealed; all surface infrastructure will be dismantled and removed; and all disturbed areas will be ripped, covered with a layer of topsoil and returned as closely as possible to the present state.
Project Name: Holfontein Project Page 8 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 Surface Infrastructure and Services at Holfontein will include:
Fuel storage. Electricity sourced from Modder East Operations via two 6MVA lines. Waste management (general waste storage area, salvage yard, timber yard, laydown area). Containerized toilets and modular sewage treatment plant (effluent treated on site and discharged to the Blesbokspruit catchment, and brine to be disposed of at a licensed landfill facility). Ventilation shaft (± 30 m in height), with single fan station on surface, and compressor running continuously to supply air to underground refuge bays. Ventilation shaft will also be equipped with a small headgear for purposes of emergency evacuation. Potable water will be trucked in from Modder East Operations. Water treatment plant to treat underground water to meet required standards as specified by DWS. Water will then be discharged to the Blesbokspruit catchment. Pollution Control Dam.
Refer to Figure 2 and Figure 3 below for maps showing the proposed layout plan.
Project Name: Holfontein Project Page 9 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Figure 2: Layout plan indicating the UTM co-ordinates
Project Name: Holfontein Project Page 10 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Figure 3: Layout plan indicating proposed infrastructure within the boundary
Project Name: Holfontein Project Page 11 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 2 METHODOLOGY
2.1 Ambient Air Quality
Relevant air quality monitoring data (i.e. ambient concentrations of criteria pollutants) were sourced from the South African Air Quality Information System (SAAQIS) taken at the closest monitoring station; the Etwatwa Station located 7 km north of the proposed project area, for the period March 2011 to September 2012. The relevant air quality management plans including that for Ekurhuleni Metropolitan Municipality, Gauteng Province and the Highveld Priority Area were reviewed. A site visit was also conducted on 2 September 2014 to ground truth the desktop data relating to existing sources of emissions and sensitive receptors.
2.2 Meteorological Data
5th-generation Mesoscale Model (MM5) modelled meteorological data was purchased from Lakes Environmental and used for dispersion modelling. The prognostic MM5 model is run for the specified location and site domain in order to obtain the MM5 meteorological data. Hourly MM5 meteorological data for the period January 2011 to December 2013 was obtained for the proposed project area. The MM5 data was in the form of AERMET-ready MM5 data files which are recognised by the AERMET meteorological pre-processor.
2.3 Atmospheric Dispersion Modelling
Atmospheric dispersion modelling is a valuable predictive tool for qualitatively evaluating the impacts of future developments. The United States Environmental Protection Agency (USEPA) Regulatory Gaussian plume AERMOD model was used in this study. The AERMOD model is an accepted model for air quality impact assessments according to the Code of Practice for Atmospheric Dispersion Modelling (GNR533 of 2014).
As with most Gaussian Plume models, a disadvantage is that spatial varying wind fields, due to topography or other factors, cannot be included. Also, the range of uncertainty of the model predictions could to be -50% to 200%. The accuracy improves with fairly strong wind speeds and during neutral atmospheric conditions. However, atmospheric dispersion modelling is standard practice and is the only established tool for evaluating the impacts of future developments.
Gaussian plume models are best used for near-field applications where the steady-state meteorology assumption is most likely to apply. The topography of the study area is fairly flat comprising of undulating hills, making it suitable for using a Gaussian plume model.
AERMOD has three components, namely the AERMOD Dispersion Model, AERMAP (the terrain pre-processor) and AERMET (the meteorological pre-processor).
Input data types required for the AERMOD model include source data, meteorological data (pre- processed using AERMET), terrain data (pre-processed using AERMAP) and information on the nature of the receptor grid. Refer to Section 2.3.1 for a detailed description of the modelling domain for this study. Project Name: Holfontein Project Page 12 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 Dispersion modelling was undertaken to determine highest daily and annual average
concentrations for PM2.5 and PM10; the average daily Total Suspended Particles (TSP) / dust
fallout rates; and the highest average hourly, daily and annual concentrations for SO2. These averaging periods were selected to facilitate the comparison of predicted pollutant concentrations / deposition with relevant NAAQS and dust fallout limits to facilitate compliance and inform the impact assessment. Typically, ambient air quality applies to areas where the occupational health and safety regulations do not apply, thus outside the boundary of a development. The NAAQS are therefore not occupational health indicators but are applicable to areas where the general public has access i.e. off-site.
Plots reflecting daily averaging periods contain only the 99th percentile of predicted ground level concentrations, for those averaging periods, over the entire period for which simulations were undertaken (3 years). It is therefore possible that even though a high daily average concentration is predicted at certain locations, this may only be true for one day during the modelling period, thus giving a worst case scenario (conservative) indication.
2.3.1 Model Overview
As per the requirements of the Atmospheric Dispersion Modelling Regulations (GNR533 of 2014) the following model overview is provided:
Proposed Holfontein Project. Refer to the Project Modelled Facility Description under Section 1.5 Rural - land use types including industrial, Land Use Characterization to determine commercial and residential account for less than dispersion co-efficients 50% of an area within 3 km radius from the source. Elevation data (DEM) SRTM ~ 90 m Sources modelled Refer to the emissions inventory in Section 2.3.2 Routine emissions for the proposed mining Operating scenarios modelled operations were simulated Meteorological data Modelled MM5 meteorological data for the period Source of data – period of data January 2011 to December 2013 Anemometer - MM5 modelled meteorological Description of station – location, tower station centre of the study area with an heights anemometer height of 13 m Modelled MM5 meteorological data for the site Temporal and spatial representativeness was used Season wind roses Refer to Section 3.3.1 Programme and version used to process AERMOD View V.8.8.9 data Not applicable as modelled MM5 meteorological Method used to replace missing hours data was used Method used to handle calm periods Calm periods were treated as missing values and
Project Name: Holfontein Project Page 13 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 not modelled - the average was taken for remaining values Modelled MM5 meteorological data for the site Upper air data – representativeness was used NAAQS (GN1210 of 2009), National Dust Control
Air quality standards used for comparison Regulations (GNR827 of 2013), Ambient Air
Quality Standards for PM2.5 (GN486 of 2012)
Air quality monitoring data were obtained from SAAQIS taken at the closest monitoring station; the Etwatwa Station located 7 km north of the Background ambient air quality – proposed project area, for the period March representativeness 2011 to September 2012. The data were used to describe the ambient conditions, but were not used to model cumulative impacts as it was not site specific and the data sets were incomplete. AERMOD - Assessment Level 2 as the activities
Model used – Assessment level proposed modelled do not require an AEL and the and justification; dispersion model used; topography of the study area is fairly flat making supporting models and input programmes it suitable for using a Gaussian plume model; and versions thereof AERMOD View V.8.8.9; AERMET V.8.8.9 and AERMAP V.8.8.9
Refer Section 2.3.4 for the modelled sources and Specify modelled emission – pollutants; pollutants and Section 2.3.6 for the modelled modelled scenarios and emissions; scenarios; the conversion of NOx to NO2 is not conversion factor utilized for NOx to NO2 applicable to this study Specify setting utilized within the Terrain settings- elevated; Land characteristics: model(s), which may include: Bowen ratio, surface albedo, surface roughness Recommended settings utilized within calculated using AERMET using the MM5 model; Terrain settings (simple flat/ modelled meteorological data input file; simple elevated/ complex); Land Assumptions: Refer to Section 5 characteristics (Bowen ratio, surface albedo, surface roughness); Specify number of sectors used and why (if applicable); Specify assumptions (if applicable) Describe the receptors grids utilized within Discrete receptors were used for the residences the analysis: Property line resolution; Fine within 500 m of the emission sources; a uniform grid resolution; Medium grid resolution(s); Cartesian grid was centred over the proposed Course grid resolution; Hotspots and project site with a 50 m resolution within 5 km sensitive location resolutions and sizes; of the site boundary, Refer to Figure 17 Figures that show locations of receptors relative to modelled facility and terrain
Project Name: Holfontein Project Page 14 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 features. Table(s) of modelling results including Refer Section 2.3.4 for the modelled sources and 1. Pollutant pollutants; averaging times modelled were 2. Averaging time based on the averaging times stated in the 3. Operating scenario NAAQS and National Dust Control Regulations to 4. Maximum modelled concentration allow for comparison; refer to Section 2.3.6 for 5. Receptor location of maximum impact the modelled scenarios; the other required (coordinates) information is contained in the AERMOD View 6. Receptor elevation output files generated for each model run saved 7. Date of maximum impact on file 8. Grid resolution at maximum impact 9. Name of output e-file(s) where data was taken from Figure(s) showing source impact area Refer to Figure 2 for the co-ordinates of the including modelled facility and Figure 3 for the layout of 1. UTM coordinates on horizontal and the modelled facility indicating the boundary and vertical axis emission sources; refer to Figure 4 for the 2. Modelled facility topographical features; refer to the Isopleth Boundary plots in Section 4.5 Buildings Emission points 3. Topography features 4. Isopleths of impact concentrations 5. Location and value of maximum impact 6. Location and value of maximum cumulative impact (if applicable)
2.3.2 Emissions Inventory
Emissions inventories are applicable only to emissions of primary pollutants (those) emitted from the source, as there is no simple way of including secondary pollutants i.e. those transformed in the atmosphere after emission (WHO, 2005). An emissions inventory was established for the proposed development to provide the source and emission rate data required as an input to the dispersion model (refer to Section 4.4 and Table 11).
2.3.3 Emission Factors and Rates
In most cases air emission rates can be estimated using emission factors combined with site- specific information such as the silt and moisture content of the material being handled (NPI, 2012). An emission factor is a representative value that attempts to relate the quantity of a pollutant released to the atmosphere with an activity associated with the release of that pollutant. These factors are usually expressed as the weight of pollutant divided by a unit weight, volume, distance, or duration of the activity emitting the pollutant. In most cases, these factors are simply averages of all available data of acceptable quality, and are generally Project Name: Holfontein Project Page 15 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 assumed to be representative of long-term averages for all facilities in the source category (EPA, 1998).
The Australian Government has in its national pollution inventory (NPI) emissions estimation technique manuals primarily based on the US-EPA techniques. Specific reference is made to the NPI estimation technique manual for mining (version 3.1 2012) (NPI, 2012), and the US-EPA AP-42 compilation of air pollutant emission factors were used to determine the emission factors for the activities identified in the emission inventory for the proposed project. These emission factors were then utilised to calculate the emission rates required for the model input.
Scraping (Excavations for Hard-Standing Areas)
AP-42 gives a default emission factor of 0.029 kg/ton of material scraped for TSP emissions
produced by scrapers while excavating subsoil. The PM10 emission factor as derived from NPI (2012) is 25 % of the TSP emission factor which equals 0.0073 kg/ton of material scraped.
According to EPA (Pace, 2005) the average ratio of PM2.5 to PM10 for scraping activities is 0.04 which equates to 0.0003 kg/ton.
Vehicle Entrainment on Unpaved Roads
Vehicles travelling on unpaved roads cause pulverization of the surface material. Particles are lifted and dropped from the rolling wheels, and the road surface is exposed to strong turbulent air shear with the surface. The turbulent wake behind the vehicle continues to act on the road surface after the vehicle has passed. Dust emissions from unpaved roads vary in relation to the vehicle traffic and the silt content of the road bed material. The unpaved road size-specific emission factor equation of the US-EPA (EPA, 2006) used in the quantification of emissions, is given as follows:
Where,
E = emissions in g of particulates per vehicle kilometre travelled (g/VKT)
K = particle size multiplier
S = silt content of road surface material (%)
W = mean vehicle weight (tons)
Unpaved road lengths and locations were determined from the site layout (805 m access road portion and 2.5 km portion between Carnation road and the Modder East Operations). The particle size multiplier in the equation (k) varies with aerodynamic particle size range and is
given as 1.5 for PM10 and 4.9 for TSP. The constants, a and b, are given as 0.9 and 0.45
respectively PM10 and as 0.7 and 0.45 respectively for TSP. The percentage silt content (less than 75 μm in diameter) on the road surface was taken to be 8.5 % (typical value given in AP- 42). The average weight of one haul truck as used in the calculation was 30 tons.
According to EPA (Pace, 2005) the average ratio of PM2.5 to PM10 for scraping activities is 0.10
which was used to calculate the PM2.5 emissions from unpaved roads.
Project Name: Holfontein Project Page 16 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 Wind Erosion
Wind-blown dust from open and exposed surfaces could result in considerable emissions under high wind speeds. Parameters which have the potential to impact on the rate of emission of fugitive dust include the extent of surface compaction, moisture content, ground cover, the shape of the storage pile, particle size distribution, wind speed and precipitation. The US-EPA AP-42 emission factor (NPI, 2012) equation for wind erosion is:
( ) ( )
( ) ( )
Where,
EF(TSP) = Emission factor for TSP (kg/ha/yr)
EF(PM10) = Emission factor for PM10 (kg/ha/yr)
s(%)= silt content (% by weight)
p = number of days per year when rainfall is greater than 0.25 mm
f(%) = percentage of time that wind speed is greater than 5.4 m/s
The percentage silt content of the soil to be stockpiled was taken to be 8.5 % (typical value given in AP-42). The number of days per year when rainfall is greater than 0.25 mm for the project site according to the MM5 modelled meteorological data is 27 days per year. The percentage of time that wind speed is greater than 5.4 m/s (at 13 m anemometer height) for the project site according to the MM5 modelled meteorological data is 9.5 %. At speeds less than 5.4 m/s it was assumed there would be no emissions caused by wind erosion.
According to EPA (Pace, 2005) the average ratio of PM2.5 to PM10 for wind erosion is 0.8 which
was used to calculate the PM2.5 emissions from wind erosion.
Grading Activities
Topsoil will be cleared using a grader and unpaved portions of the haul route will be graded.
The equations for the emission factors for estimating TSP and PM10 from grading are from AP- 42 (USEPA, 1998). The equations are very sensitive to the operating speed assumed.
Where,
EF(TSP) = Emission factor for TSP (kg/VKT)
EF(PM10) = Emission factor for PM10 (kg/VKT)
S = Vehicle speed (km/hr)
Project Name: Holfontein Project Page 17 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 A vehicle operating speed of 5 km / hr was assumed (typical value given in AP-42). According
to EPA (Pace, 2005) the average ratio of PM2.5 to PM10 for scraping activities is 0.8 which was
used to calculate the PM2.5 emissions from grading.
Materials Handling
The quantity of dust that will be generated from materials handling operations will depend on various climatic parameters, such as wind speed and precipitation, in addition to non-climatic parameters such as the nature and volume of the material handled. Fine particulates are most readily disaggregated and released to the atmosphere during the material transfer process, as a result of exposure to strong winds. Increases in the moisture content of the material being transferred would decrease the potential for dust emission, since moisture promotes the aggregation and cementation of fines to the surfaces of larger particles. The following US-EPA AP-42 predictive equation was used to estimate emissions from material handling and transfer operations:
( ) ( )
Where,
E = Emission factor (kg / ton of material transferred)
U = mean wind speed (m/s)
M = material moisture content (%)
k = particle size multiplier
The mean wind speed for the project site according to the MM5 modelled meteorological data is 4.65 m/s. The material moisture content of the ore to be handled is 5 % as it is the standard for the Main Reef, and 16 % for soil as it is the standard for the soil type identified as per the soil study. The particle size multiplier in the equation (k) varies with aerodynamic particle size 1 range and is given as 0.053 for PM2.5, 0.35 for PM10 and 0.74 for PM30 .
Vehicle Tailpipe Emissions
The average South African heavy-duty diesel vehicle emission factors for the Highveld were obtained for use in this study (Liebenberg-Enslin et al., 2012).
Table 5: The average South African heavy-duty diesel vehicle emission factors for the Highveld (Liebenberg-Enslin et al., 2012) POLLUTANT EXHAUST EMISSION FACTOR (G/KW.H)
NOx 11.42 CO 7.43
CO2 765
SO2 2.54 Particulates 1.35
1 PM-30 is often used as a surrogate for TSP.
Project Name: Holfontein Project Page 18 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 Vehicle tailpipe emissions are hotter than the ambient air (i.e. thermally buoyant). The current buoyancy algorithm in AERMOD only works for point sources and the volume source algorithm in AERMOD does not accurately account for thermal plume rise from vehicle tailpipe emissions. Vehicle tailpipe emissions were therefore not modelled in detail as part of this modelling assessment.
Due to the low frequency of haul trucks (i.e. the estimated return trip time is 30 minutes, and trucks will operate for 12 hours a day) and the low sulphur content of South African diesel (0.05
% for Sasol TurbodieselTM) it is unlikely that hauling activities will result in SO2 levels which
exceed the NAAQs. The SO2 emissions were modelled to give a high level indication of SO2 concentrations. It is also unlikely that the NOx and CO emissions from haul trucks will result in exceedances due to the low frequency of haul trucks to be present on the haul route.
Estimated Metal Emissions
PM10 and TSP may contain a metal fraction. The speciation of dust, both PM10 and TSP, using an emission factors approach may be determined using:
. Metals content of ore (generic or site-specific); and . Dust generation estimates (either through emission factors, modelling or direct monitoring).
The metals fraction for all dust sources may be assumed from site-specific assays or generic ore assays (NPI, 2012). As site specific information is not available for metals in the ore, and the generic ore assays (NPI, 2012) available were not deemed a suitable representation of the Main Reef ore, the metal fraction of dust to be generated from ore handling activities could not be estimated. Heavy metals normally associated with ore targeted for gold mining on the Witwatersrand include uranium and arsenic (Sami and Druzynski, 2003). The heavy metals are present in the ore in trace amounts, but above the average global crustal concentration (Z´avodsk´a et al., 2008).
2.3.4 Source and Pollutant Characterisation
The following table indicates the sources and pollutants modelled:
Table 6: Sources and pollutants modelled
ACTIVITY SOURCE TYPE POLLUTANTS MODELLED Construction PM Materials handling (topsoil 10 Volume TSP stockpiling) PM2.5 Grading (topsoil clearing for PM10 infrastructure areas and grading the Volume TSP
haul route) PM2.5 PM Scraping (excavations for hard- 10 Volume TSP standing areas) PM2.5 PM10 Wind erosion (exposed areas) Area TSP
PM2.5 Operation
Project Name: Holfontein Project Page 19 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 ACTIVITY SOURCE TYPE POLLUTANTS MODELLED PM Unpaved haul road sections (hauling 10 Line-Volume TSP and transport of personnel by bus) PM2.5 PM10 Materials handling (two separate TSP sources - discharging into bin at 5 m Volume
and ore loading into trucks at 3 m) PM2.5
PM10 Wind erosion (topsoil stockpile) Area TSP
PM2.5 Vehicle tailpipe emissions of haul Line-Volume SO trucks 2
It is expected that emissions during decommissioning will be similar to those generated during the construction phase with a similar duration (approximately 6 months to 1 year). Therefore the modelling results for the construction phase were used as an indication for decommissioning phase impacts.
2.3.5 Modelled Concentrations at Sensitive Receptors
A uniform Cartesian grid was centred over the proposed project site with a 50 m resolution spanning 5 km from the site boundary. Mine boundary receptors and all nearby residences (i.e. within 500 m from identified sources) were included, allowing for the evaluation of predicted impacts at each of these locations.
2.3.6 Operating Scenarios Modelled
The modelled operating scenario for the construction phase was 12 hours (between 06:00 and
18:00 using uncontrolled emission rates) for PM2.5, PM10 and TSP for all sources, excluding wind erosion, which was modelled as a 24 hour emission source.
The maximum emissions scenario (Scenario 1) was modelled for the operation phase (i.e. 24 hour operations for all sources using uncontrolled emission rates for all pollutants). Where exceedances (as per NAAQS and National Dust Control Regulations) at sensitive receptors were noted the operating hours were then refined to 12 hours (between 06:00 and 18:00 using uncontrolled emission rates) for the exceeded pollutants for all sources for the operation phase;
only wind erosion (for PM10 and TSP) remained at 24 hours.
Where the refined scenario (Scenario 2) indicated exceedances at sensitive receptors, Scenario
2 was further refined using controlled emission rates for the exceeded pollutants (refer to Section 2.3.7 and Section 6 for the control efficiencies used to determine the controlled emission rates modelled).
2.3.7 Control Efficiencies
The efficiency of fugitive dust emission mitigation measures, as specified, are obtained from the Australian NPI emission estimation document for mining.
Project Name: Holfontein Project Page 20 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 Table 7: Emission control methods ACTIVITY CONTROL METHOD AND EMISSION REDUCTION Construction Scrapers on topsoil 50 % control when soil is naturally or artificially moist 30 % for wind breaks Wind erosion - stockpiles 50 % for water sprays 99 % for total enclosure Operation 50 % for level 1 watering (2 litres/m2/h) Hauling on unpaved roads 75 % for level 2 watering (> 2 litres/m2/h) 100 % for sealed roads 50 % water sprays to keep ore wet Ore handling 99 % for enclosure and use of fabric filters Ore hauling 99 % for enclosure and use of fabric filters 30 % for wind breaks Wind erosion - stockpiles 50 % for water sprays 99 % for total enclosure 30 % for primary rehabilitation 40 % for vegetation established but not demonstrated to Wind erosion - rehabilitated be self-sustaining. Weed control and grazing control areas 60% for secondary rehabilitation 90% for re-vegetation 100% for fully rehabilitated self-sustaining vegetation
Controls are multiplicative when more than one control is applied to a specific operation or activity. For example, using controls from Table 7, water sprays used in conjunction with wind breaks give an emission that is (1 - 0.5) x (1 - 0.7) = 0.15 of the uncontrolled emission (NPI, 2012).
Project Name: Holfontein Project Page 21 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 3 BASELINE CHARACTERISATION
3.1 Topography
The topography of the proposed project can be described as gently undulating with elevations across the area ranging between 1559 m and 1657 m (refer to Figure 4).
Figure 4: Topography of the proposed project area
3.2 Land Cover and Land Use
The majority of the land associated with the proposed project area is classified as agriculture / cultivation according to spatial data obtained from the Ekurhuleni Metropolitan Municipality Geographical Information Systems (GIS) Land Use Map (Figure 5). From the site visit conducted the following land uses were identified within the proposed project area and surrounds: Historical mining remains (Photo 1); mining and industry (Photo 2 and Photo 3); numerous settlements and households (Photo 4, Photo 5 and Photo 6); roads and electricity infrastructure (Photo 7; Photo 8 and Photo 9); agricultural activities including chicken farms located to the south-east of the proposed project area (Photo 10), and maize and soy cultivation on the farms surrounding the proposed project area (Photo 11). The proposed haul route crosses over a dual carriage railway line (Photo 12).
Project Name: Holfontein Project Page 22 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Figure 5: Ekurhuleni Metropolitan Municipality land use map
Project Name: Holfontein Project Page 23 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Photo 1: Historic mining remains within the project Photo 2: Existing mining in the surrounding area – site – concrete foundations of the Holfontein Shaft Gold One International New Kleinfontein Goldmine Modder East Operations
Photo 3: Existing industry in the surrounding area – Photo 4: Settlements situated in the surrounding Impala Platinum Refinery area in proximity to the project site
Photo 5: Historic mine hostel adjacent to the Photo 6: Households situated in the surrounding project site which is inhabited area of Welgedacht SH
Project Name: Holfontein Project Page 24 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Photo 7: Highway running adjacent to the project Photo 8: Power lines within the surrounding area site
Photo 9: Substation adjacent to the project site Photo 10: Chicken farm located to the south-east of the project site
Photo 11: Cultivation within the surrounding area Photo 12: Dual carriage railway line crossed by the proposed haul route
Project Name: Holfontein Project Page 25 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Photo 13: Fugitive dust emissions from historic Photo 14: Sappi Enstra limestone quarrying
Photo 15: Fugitive dust emissions from drilling for Photo 16: The Welgedacht Wastewater Treatment prospecting activities Works
3.3 Climate and Meteorological Overview
3.3.1 Local Wind Field
According to the MM5 modelled meteorological data for the proposed project area, the prevailing winds for the period of January 2011 to December 2013 originate from the north-east and north- west sectors, with average wind speeds of between 3.60 and 5.70 m/s. Calm conditions (wind speeds < 1 m/s) are experienced for 6.73 % of the period (refer to Figure 6).
Project Name: Holfontein Project Page 26 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Figure 6: Wind rose depicting the average wind speed and direction for the proposed project area for the period of January 2011 to December 2013
The diurnal wind rose (refer to Figure 7) shows predominant winds originating from the north- westerly sector during day time, with calm conditions experienced 7.98 % of the time. The nocturnal wind rose (refer to Figure 8) indicates that the wind predominantly originates from the north-easterly sector at night, with increased wind speeds and fewer calm conditions experienced (5.12 %).
Project Name: Holfontein Project Page 27 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Figure 7: Diurnal wind rose for the period of January 2011 to December 2013
Figure 8: Nocturnal wind rose for the period of January 2011 to December 2013
The seasonal variability in the wind field for the proposed project area is shown in Figure 9. During spring and summer, winds predominantly originate from the north-easterly sector. In autumn and winter, wind flow predominantly originates from the north-westerly sector. Calm conditions occur
Project Name: Holfontein Project Page 28 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 mostly during the summer and autumn months (8.07 % and 7.58 % respectively), and the least during spring months (5.24 %).
Figure 9: Wind roses depicting the seasonal variability in wind field for the proposed project area for the period of January 2011 to December 2013
3.3.2 Air Temperature and Relative Humidity
Below are the average monthly temperature and relative humidity according to the MM5 modelled meteorological data for the proposed project area for the period of January 2011 to December 2013. According to the modelled data the highest average temperature (20˚C) was experienced in the summer months of December, January and February and the lowest average temperature (8 ˚C) was experienced in the winter months of June and July. The average monthly relative humidity was the lowest in November (59 %) and highest in June and July (73 % and 72 %) with the average relative humidity remaining fairly constant throughout the rest of the year.
Project Name: Holfontein Project Page 29 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Figure 10: Modelled monthly average temperature for the proposed project area
Figure 11: Modelled monthly average relative humidity for the proposed project area
Table 8: Modelled monthly average temperature and relative humidity for the proposed project area AVERAGE RELATIVE HUMIDITY MONTH AVERAGE TEMPERATURE (˚C) (%) 69 January 20 66 February 20 67 March 19 68 April 14 69 May 12 73 June 8 72 July 8 69 August 11 68 September 14
Project Name: Holfontein Project Page 30 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 AVERAGE RELATIVE HUMIDITY MONTH AVERAGE TEMPERATURE (˚C) (%) 64 October 17 59 November 19 64 December 20
3.3.3 Precipitation
Below is average monthly precipitation according to the MM5 modelled meteorological data for the proposed project area for the period of January 2011 to December 2013. The highest monthly precipitation was experienced in the summer months of December and January with the lowest experienced in the autumn and winter months May, June and July.
Table 9: Modelled monthly average precipitation for the proposed project area AVERAGE PRECIPITATION MONTH (MM/H) 0.26 January 0.12 February 0.11 March 0.06 April 0.01 May 0.01 June 0.00 July 0.01 August 0.03 September 0.10 October 0.21 November 0.30 December
Figure 12: Modelled monthly average precipitation for the proposed project area
Project Name: Holfontein Project Page 31 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 3.4 Ambient Air Quality
3.4.1 Current Sources of Air Pollution
Regional Setting
According to the Ekurhuleni Metropolitan Municipality air quality management plan (Scorgie et al., 2005) the current sources of air pollution within the area and surrounds include:
Household Fuel Burning
Coal and, to a lesser extent, wood burning is prevalent in settlements in Ekurhuleni Metropolitan Municipality. Coal burning emits a large amount of gaseous and particulate pollutants including
SO2, heavy metals, Total Suspended Particles (TSP), PM10 and PM2.5, CO, polycyclic aromatic
hydrocarbons (PAHs), and benzo(a)pyrene. Pollutants arising due wood combustion include PM10
and PM2.5, NO2, CO, PAHs, benzo(a)pyrene and formaldehyde. Paraffin is also used as a household fuel in settlements in Ekurhuleni Metropolitan Municipality. The main pollutants emitted from the
combustion of paraffin are NO2, particulates, CO and PAHs.
Industrial and Commercial Fuel Burning
Industrial and commercial fuel burning contributes to air pollution in Ekurhuleni Metropolitan Municipality, particularly coal-fired boilers in proximity to residential areas, which contribute
significantly to ambient SO2 and PM10 concentrations.
Vehicle Exhaust Emissions
Both petrol and diesel vehicle emissions are significant sources of air pollution in Ekurhuleni Metropolitan Municipality. Road traffic is the most significant source of NOx, CO and volatile
organic compound (VOC) emissions and is anticipated to contribute significantly to O3 formation (as NOx and VOCs are both important precursors of photochemical products). Air pollution from vehicle emissions may be grouped into primary and secondary pollutants. Primary pollutants are those emitted directly into the atmosphere, and secondary are those pollutants formed in the atmosphere as a result of chemical reactions, such as hydrolysis, oxidation, or photochemical
reactions. The significant primary pollutants emitted by motor vehicle exhausts include CO2, CO,
SO2, NOx, methane (CH4) and Pb particulates. Secondary pollutants formed due to vehicle exhaust
emissions include photochemical oxidants (e.g. O3), sulphuric acid, sulphates, NO2, nitric acid and nitrate aerosols.
Rail Transportation
Pollutants released from railway transport (diesel-powered locomotives) include CO2, CO, VOC,
particulates, NOx, SO2, CH4, ammonia and Pb.
Mine Tailings Storage Facilities
Unrehabilitated mine tailings storage facilities are a significant source of nuisance fall out dust and potentially contribute significantly to airborne concentrations of fine particulates. Approximately 86 mining sites are located in Ekurhuleni Metropolitan Municipality, of which 21 are operational and the majority of the remaining sites are abandoned derelict underground gold mines or mine Project Name: Holfontein Project Page 32 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 tailings deposits (Scorgie et al., 2005). Aside from the nuisance dust, gold tailings also contain compounds such as cyanide and heavy metals, increasing the health risk potential (Liebenberg- Enslin and Hurt, 2009).
Industrial Activities
Numerous large industries associated with various stack, vent and fugitive emissions occur within Ekurhuleni Metropolitan Municipality (Scorgie et al., 2005). Industrial activities contribute to,
amongst others, SO2, particulates and NOx, and are significant sources of emissions specifically in highly industrialized areas such as Ekurhuleni Metropolitan Municipality (Liebenberg-Enslin and Hurt, 2009).
Waste Treatment
Waste treatment within Ekurhuleni Metropolitan Municipality includes landfills, incineration and
wastewater treatment. The landfilling of waste produces landfill gas such as CO2 and CH4. The incineration of medical waste results in particulates, cadmium, mercury, thallium, chromium, beryllium, arsenic, antimony, barium, Pb, silver, cobalt, copper, manganese, tin, vanadium, nickel,
chloride, hydrofluoric acid and SO2. Wastewater treatment works have the potential for emissions of VOCs. Species measured at local wastewater treatment works have included: hydrogen sulphide, mercaptans, ammonia, formaldehyde, acetone, toluene, ethyl benzene, xylenes, erchloroethylene, butyric acid, propionic acid, valeric acid and acetic acid.
Agricultural Activities
Agricultural activities result in TSP, PM10 and PM2.5 emissions. Crop biomass burning contributes to
fine particulates, CO2 and CH4 emissions in Ekurhuleni Metropolitan Municipality.
Table 10: Summary of the sources and pollutants within Ekurhuleni Metropolitan Municipality (Scorgie et al., 2005)
Sources PM SO2 NOx CO CO2 CH4 HAPs Vehicle tailpipe emissions x x x x x x x Industrial operations, energy generation and commercial fuel x x x x x x x burning appliances Domestic fuel burning x x x x x x x Aviation emissions x x x x x x x Landfills x x x x Incineration x x x x x x x Vehicle-entrainment of road dust x Biomass burning x x x x x x x Mining activities x Agricultural activities x Tyre burning x x x x x x x Wind-blown dust from open areas x
Project Name: Holfontein Project Page 33 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 Local Setting
Local sources of air pollution identified during the site visit include (photos in Section 3.2 above):
. Existing mining activities and tailings storage facility at the Gold One International New Kleinfontein Goldmine Modder East Operations (Photo 2); . Household fuel burning at surrounding settlements (Photo 4 and Photo 5); . Vehicle exhaust emissions from vehicles travelling on the highway (Photo 7); and . Fugitive dust emissions from agricultural activities (Photo 11); . Fugitive dust emissions from historic limestone quarrying (Photo 13) and historic gold mine tailings; . Industry including Sappi Enstra (Photo 14) and the Impala Platinum Refinery (Photo 3); . Fugitive dust emissions from drilling for prospecting activities (Photo 15); . The Welgedacht Wastewater Treatment Works (WWTW) (Photo 16); . Agricultural biomass burning.
Project Name: Holfontein Project Page 34 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 3.4.2 Ambient Air Quality Monitoring
Regional Setting
According to the Ekurhuleni Metropolitan Municipality ambient air quality management plan (Scorgie et al., 2005) certain pollutants exceed guideline values within the Ekurhuleni Metropolitan
Municipality - these include PM10, SO2 and NO2. Benzene and O3 have also been noted to exceed health guidelines. Benzene thresholds are typically exceeded in proximity to busy highways and
intersections and at large filling stations. O3, which is formed in the atmosphere through the conversion of VOCs and NOx, and is typically elevated downwind of urban areas.
Local Setting
Air quality monitoring data were obtained from SAAQIS taken at the Etwatwa Station, located 7 km north of the proposed project area, for the period March 2011 to September 2012. Monthly and
annual averages for NO2, SO2 and PM10 are depicted in Figure 13 to Figure 16.
When comparing the annual average concentrations of NO2, SO2 and PM10 with the NAAQS, only 3 3 the PM10 concentration of 104 µg/m exceeded the standard (40 µg/m ) for all months of the year.
Figure 13: Monthly average concentrations of NO2 recorded at the Etwatwa Station
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Figure 14: Monthly average concentrations of SO2 recorded at the Etwatwa Station
Figure 15: Monthly average PM10 concentrations recorded at the Etwatwa Station
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Figure 16: Annual average NO2, SO2 and PM10 concentrations recorded at the Etwatwa Station
3.5 Sensitive Receptors
Sensitive receptors include all permanently occupied surrounding areas which may be impacted by the proposed project in terms of air quality. These were identified as the Holfontein Community (comprising of the Khomponi Community residing in the historic mine house and historic mine hostel adjacent to the proposed project site; and Holfontein Quarters Community located on the adjacent property across the N12 highway) as well as the residents of the Welgedacht Small Holdings (SH), specifically those residing along Carnation Road (refer to Figure 17).
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Figure 17: Residential areas surrounding the proposed project area
Project Name: Holfontein Project Page 38 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 4 DESCRIPTION AND ASSESSMENT OF POTENTIAL IMPACTS
The NEM:AQA is an effects-based legislation, stating that activities which may result in atmospheric emissions are to be determined with the objective of achieving health-based ambient air quality standards. Each new development proposal with potential impacts on air quality must be assessed not only in terms of its individual contribution, but in terms of its additive or cumulative contribution to baseline ambient air quality.
4.1 Air Pollution Indicators
A core set of air pollution indicators referred to as criteria pollutants have been globally used to characterize air quality. These include airborne particulate matter (PM) with an aerodynamic
diameter of less than 10 μm and gaseous pollutants NO2, SO2 and O3 (WHO, 2005). The NAAQS also include standards for additional criteria pollutants namely benzene which is used to indicate the concentration of VOCs, Pb and CO. These criteria pollutants are common pollutants emitted into the atmosphere from various sources, which have detrimental health and environmental impacts that are relatively well-known (DEAT, 2005).
Particulate air pollutants comprise material in solid or liquid phase suspended in the atmosphere. Particles are classified by their aerodynamic properties, because these determine transport and removal processes in the air, deposition sites, and clearance pathways within the respiratory tract (WHO, 2005).
The potential drift distance of particles is governed by the initial injection height of the particle, the terminal settling velocity of the particle, and the degree of atmospheric turbulence. Theoretical drift distance, as a function of particle diameter and mean wind speed, has been computed for fugitive dust emissions. Results indicate that, for a typical mean wind speed of 16 km/hr, particles larger than about 100 μm are likely to settle out within 6 to 9 meters from the edge of the road or other point of emission. Particles that are 30 to 100 μm in diameter are likely to settle further from the source. These particles, depending upon the extent of atmospheric turbulence, are likely to
settle within a few metres from the road. Smaller particles, particularly PM10 and PM2.5, have much slower gravitational settling velocities and are much more likely to have their settling rate retarded by atmospheric turbulence (EPA, 1995).
Dust is the collective term for all airborne particulates, usually smaller than 1 mm. The term fugitive dust is used for airborne particulates derived from non-ducted sources (i.e. not emitted from a chimney sources), therefore mixed sources (WHO, 2005). The term TSP is also used which refers to all particulates with an aerodynamic diameter of less than 100 μm (DEAT, 2005).
4.2 Potential Health Effects
The very fine fraction, smaller than 10 μm (PM10) and smaller than 2.5 μm (PM2.5), are typically those measured within the atmosphere for the purposes of health effects as these can be inhaled
Project Name: Holfontein Project Page 39 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 into the lungs, causing health problems (WHO, 2005). The coarser fraction (between 10 μm and 1 mm) cannot be inhaled but is the fraction that is visible when suspended in the air and may result in nuisance impacts. Nuisance impacts include soiling of materials and reduction in visibility.
Health effects of PM10 and PM2.5 include mild respiratory symptoms to severe respiratory symptoms such as asthma and chronic obstructive pulmonary disease deteriorations resulting in emergency room treatments. It may play a role in reduced lung growth in children and increased mortality in respiratory and cardiovascular conditions and increased rate of premature deaths (Sandström et al., 2005).
Exposure to the other criteria pollutants may also result in ill health effects. As with particulates,
concentrations of these criteria pollutants are often highest largely in the urban areas. O3 contributes to asthma morbidity and mortality, reduced lung function, lung diseases and
cardiovascular disease. NO2 and SO2 also play a role in the development and exacerbation of asthma, bronchial symptoms, lung inflammation and reduced lung function (WHO, 2014).
Inhalation of CO may result in impaired perception and concentration, slowed reflexes, drowsiness, angina, unconsciousness, and may result in death at high concentrations. Benzene is a known human carcinogen and has been associated with increases in the incidence of leukaemia. Pb exposure may result in brain damage, kidney damage, and gastrointestinal distress (DEAT, 2005).
4.3 Potential Impacts on Crops
According to Farmer (1993) the potential impacts of dust on plants include effects on photosynthesis, respiration, transpiration and penetration of phytotoxic gaseous pollutants. Visible injury symptoms may occur on plants and generally there is decreased productivity when there are high levels of dust deposition.
Prajapati (2012) found that deposition of particulate matter on vegetated surfaces depends on the size distribution of these particles and, to a lesser extent, on the chemistry. Effects of particulate matter on vegetation may be associated with the reduction in light required for photosynthesis and an increase in leaf temperature. Changes in energy exchange are more important than the diffusion of gases into and out of leaves which is influenced by dust load, colour and particle size. Alkaline dust materials may cause leaf surface injury while other materials may be taken up across the cuticle. The study also indicated that interception of dust by vegetation makes an important contribution to the improvement of air quality in the vicinity of vegetation.
4.4 Emission Sources
A number of activities associated with the Holfontein Project will result in the generation of gaseous emissions and airborne particulates which may have an impact on the ambient air quality. Wind exacerbates this impact through the additional generation of airborne particulates due to erosion.
There are various sources of emissions anticipated from the proposed project, during the construction, operational and decommissioning phases. Typical emissions include:
Project Name: Holfontein Project Page 40 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 . TSP and inhalable particulates (PM2.5 and PM10) which will have a metal fraction; and . Gaseous emissions.
Refer to Table 11 below for a summary.
Table 11: Emissions inventory EMISSION ACTIVITY / SOURCE
Construction Phase (2 years - of which land clearing and construction of surface infrastructure will take ±6 months)
Scraping Topsoil removal
Access and unpaved portions of the Grading haul roads Particulates (PM , 2.5 Materials handling operations Stockpiling of topsoil
PM10 and TSP) Vehicle entrainment on unpaved Transport of materials and personnel
roads Construction vehicles and equipment
Construction activities Construction of surface infrastructure
Transport of materials and personnel Gases Vehicle tailpipe emissions Construction vehicles and equipment
Operational Phase (8 years)
Hoisting, loading and transporting of Materials handling operations† ore
Vehicle entrainment on unpaved Hauling of ore roads Particulates (PM2.5, Transport of personnel by bus
PM10 and TSP) Wind Erosion Topsoil stockpile
Underground mining activities Ventilation shaft emissions including drilling and blasting
Grading Haul road maintenance - intermittent
Hauling activities Vehicle tailpipe emissions Transport of personnel by bus Gases Drilling, blasting and the operation of Ventilation shaft emissions underground mining equipment
Decommissioning Phase (±6 months)
Particulates (PM2.5, Demolition of surface infrastructure Demolition activities PM10 and TSP) Rehabilitation
† It is likely that the particulates being generated from handling ore at the Holfontein shaft and transporting ore to the Modder East operations will contain a metal fraction, the speciation of which is dependent on the composition of the Main Reef ore likely comprising of uranium and arsenic. The heavy metals are present in the ore in trace amounts, but above the average global crustal concentration. Project Name: Holfontein Project Page 41 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 EMISSION ACTIVITY / SOURCE
Vehicles used to transport materials
Gases Vehicle tailpipe emissions and personnel Decommissioning equipment
4.4.1 Construction Phase
Prior to any earthworks taking place, affected areas would be cleared (i.e. stripped of vegetation),
resulting in the generation of particulate emissions (i.e. PM2.5, PM10 and TSP). Particulate emissions will also be generated by construction/ building activities such as earthworks, material handling, cutting, grinding, sawing, filling of skips, stripping of waste rock, use of chutes, and vehicle entrainment on unpaved roads. Stockpiled materials (i.e. topsoil) as well as exposed areas are subject to wind erosion if not managed appropriately.
Gaseous emissions will be generated via vehicle tailpipe emissions from construction vehicles, and
include NOx, CO and SO2.
The construction phase of the project is anticipated to last for a period of approximately 2 years (of which only 6 months will involve clearing and construction of surface infrastructure; the remainder will involve dewatering and re-equipping the shaft). Heavy vehicles and equipment expected to be utilised during the construction phase are:
. Trucks (30 tonne Articulated Dump Trucks); . Concrete batch plant; . Scraper; and . Grader.
Construction comprises a series of different activities as mentioned above. Each of these operations has their own duration and potential for emissions generation. It is anticipated that the extent of emissions would vary substantially from day to day depending on the level of activity, the specific operations, and the prevailing meteorological conditions. Emissions from the construction phase will however be short-term.
The main pollutant of concern from construction activities is particulate matter, including PM10,
PM2.5 and TSP. Vehicle tailpipe emissions from construction vehicles and equipment are considered negligible due to the low volume of vehicles and equipment to be utilised which will be confined to site for most of the construction period.
4.4.2 Operational Phase
Particulate Emissions
The operational phase of the project is anticipated to last for approximately 8 years. Heavy vehicles and equipment expected to be utilised during the operational phase are:
. Two trucks (30 tonne Articulated Dump Trucks); and . Grader (intermittently when unpaved portions of the haul route are maintained).
Project Name: Holfontein Project Page 42 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 During the operational phase particulate emissions (i.e. PM2.5, PM10 and TSP) will be generated from ore hoisting and loading, vehicle entrainment on unpaved roads from hauling activities (40 trips per day), wind erosion from the topsoil stockpile, and the transportation of personnel by bus (15 trips per day from the Modder East Operations to accommodate two work shifts; 400 employees per shift).
Generation of particulate emissions is fairly constant throughout the year. Abnormal conditions may arise due to intermittent grading (maintenance of unpaved portions of the haul route) and ventilation shaft emissions. Particulate emissions will be generated from the ventilation shaft, associated with the underground mining activities including blasting, drilling and the operation of underground vehicles.
Gaseous Emissions
Gaseous emissions will be generated via vehicle tailpipe emissions and the ventilation shaft.
Vehicle tailpipe gaseous emissions include NOx, CO and SO2. Gas emissions from the ventilation shaft generated from diesel exhaust and blasting fumes from underground mining activities will be negligible given the combination of dilution by water in the shaft and the designed volumetric flow rate of 0.06 m³/s/kW through the underground workings.
4.4.3 Decommissioning Phase
It was assumed that all hoisting and hauling operations will have ceased by the decommissioning phase of the project. The potential for impacts during this phase will depend on the extent of demolition and rehabilitation efforts. It is expected that emissions during decommissioning will be similar to those generated during the construction phase with a similar duration (approximately 6 months to 1 year).
4.5 Impact Assessment
4.5.1 Direct Impacts: Construction
Dust Fallout (TSP)
The modelled average daily dust fallout for the construction phase scenario at the surrounding sensitive receptors falls below the National Dust Regulations “acceptable fall out” of 600 mg/m2/day for residential areas (refer to Figure 18). Therefore, the likelihood of the occurrence of nuisance impacts resulting from dust fallout due to construction activities is considered to be low.
The modelled average daily dust fallout beyond the site boundary, not within residential areas, is also below the acceptable dust fallout of 1200 mg/m2/day for non-residential areas. The modelled average daily dust fallout across surrounding cultivated areas ranges between 6 and 50 mg/m2/day for the construction phase scenario (refer to Figure 18). As the dust fallout across surrounding cultivated areas is expected to be low, the likelihood of impacts on crop growth is considered to be low.
Project Name: Holfontein Project Page 43 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 PM10
Average Daily and Annual Concentrations
The modelled average daily and annual PM10 concentrations generated from construction activities fall below the NAAQS limit values of 75 µg/m3 and 40 µg/m3 respectively at all the surrounding sensitive receptors for the construction phase scenario (Figure 19 and Figure 20 respectively).
Therefore, the likelihood of potential health impacts from PM10 emissions generated from construction activities is considered to be low.
PM2.5
Average Daily and Annual Concentrations
The modelled average daily and annual PM2.5 concentrations generated from construction activities fall below the applicable NAAQS limit values of 40 µg/m3 and 20 µg/m3 respectively (compliance with these limit values is required as of 1 January 2016) at all the surrounding sensitive receptors for the construction phase scenario (Figure 21 and Figure 22 respectively). Therefore, the
likelihood of potential health impacts from PM2.5 emissions generated from construction activities is considered to be low.
SO2
The SO2 emissions from construction vehicles were not modelled as they are of lower significance than those generated during operations. Construction vehicles will mostly be confined to the construction site which is in an open area and allows for dilution.
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Figure 18: Average daily dust fallout for the construction phase
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Figure 19: Average daily PM10 concentrations for the construction phase
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Figure 20: Average annual PM10 concentrations for the construction phase
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Figure 21: Average daily PM2.5 concentrations for the construction phase
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Figure 22: Average annual PM2.5 concentrations for the construction phase
Project Name: Holfontein Project Page 49 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 4.5.2 Direct Impacts: Operation
Dust Fallout (TSP)
The modelled average daily dust fallout at the surrounding sensitive receptors mostly fall within the National Dust Control Regulations acceptable dust fallout of 600 mg/m2/day for residential areas for Scenario 1 (24 hour operations), with the exception of the informal dwellings located directly adjacent to the western site boundary, where the dust fallout exceeds the acceptable limit, as it falls within 600 - 800 mg/m2/day (refer to Figure 23). For Scenario 2 (12 hour operations), average daily dust fallout concentrations at all of the surrounding sensitive receptors fall below the acceptable dust fallout of 600 mg/m2/day for residential areas (refer to Figure 24). Therefore, the likelihood of the occurrence of nuisance impacts resulting from dust fallout due to operational activities for Scenario 2 is considered to be low.
The modelled average daily dust fallout outside of the site boundary (approximately 112 m to the north / north-east of the project boundary) in the direction of the N12 highway indicate an exceedance of the acceptable dust fallout (below 1200 mg/m2/day for non-residential areas) for Scenario 1 and exceedances are noted approximately 28 m north of the project boundary for Scenario 2. Refer to Figure 24 and Figure 25 respectively. However, due to the conservative nature of the model, the predicted concentrations are expected to be greater than those that will likely occur in reality. Therefore, the likelihood of the occurrence of nuisance impacts resulting from dust fallout due to operational activities occurring between 06:00 and 18:00 is considered to be low.
The modelled average daily dust fallout across the surrounding cultivated areas range between 80 and 300 mg/m2/day for both Scenario 1 and 2 (refer to Figure 24 and Figure 25 respectively), and this falls below the acceptable dust fallout of 1200 mg/m2/day for non-residential areas. As the dust fallout across surrounding cultivated areas is expected to be low, the likelihood of impacts on crop growth is considered to be low.
PM10
Average Daily Concentrations
The modelled average daily PM10 concentrations indicate exceedances in the NAAQS limit value for residential areas ( 75 µg/m3) at the historic mine house and associated informal dwellings for both Scenario 1 and 2 (refer to Figure 26 and Figure 26 respectively). The historic mine house will be exposed to concentrations of 60 – 100 µg/m3 for Scenario 1, and concentrations of 30 – 50 µg/m3 for Scenario 2. The informal dwellings adjacent to the mine boundary are exposed to concentrations of approximately 50 – 80 µg/m3 for both Scenario 1 and 2. With the implementation of the mitigation measures recommended in Section 6 below (controlled
emissions), modelled average daily PM10 concentrations at all of the surrounding sensitive receptors are below the NAAQS limit value of 75 µg/m3 for residential areas (refer to Figure 27).
Project Name: Holfontein Project Page 50 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 It must be noted that the fine particulates generated from ore handling activities will also contain a metal fraction likely comprising of uranium and arsenic which may increase the potential health risk.
Therefore, potential health impacts from PM10 emissions generated from operational activities may arise if effective mitigation measures are not implemented.
Average Annual Concentrations
The modelled average annual PM10 concentrations at the surrounding sensitive receptors are below the NAAQS limit value of 40 µg/m3 at all of the surrounding sensitive receptors, for both Scenario 1 and 2 (refer to Figure 29 and Figure 29 respectively).
PM2.5
Average Daily and Annual Concentrations
The modelled average daily and annual PM2.5 concentrations generated from operational activities do not exceed the NAAQS limit values of 40 µg/m3 and 20 µg/m3 respectively (compliance with these limit values is required as of 1 January 2016) at all the surrounding sensitive receptors for Scenario 1 (refer to Figure 30 and Figure 31 respectively). Therefore, the likelihood of potential
health impacts from PM2.5 emissions generated from operational activities is considered to be low.
SO2
From the modelling results, SO2 emissions from the tailpipes of the haul trucks travelling along the proposed haul route will not result in exceedances in the NAAQS limit value at the surrounding sensitive receptors, which were identified as the residences of the Welgedacht SH (refer to Figure 33, Figure 34 and Figure 34). The NAAQS limit values are 350 µg/m3 for 1 hour, 125 µg/m3 over 3 24 hours, and 50 µg/m annually). Therefore, the likelihood of potential health impacts from SO2 emissions generated from haul trucks is considered to be low. However, these results only provide a high level indication of concentration as the AERMOD model does not accurately account for thermal plume rise of vehicle tailpipe emissions.
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Figure 23: Average daily dust fallout (Scenario 1) for the operational phase
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Figure 24: Average daily dust fallout (Scenario 2) for the operational phase
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Figure 25: Average daily PM10 concentrations (Scenario 1) for the operational phase
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Figure 26: Average daily PM10 concentrations (Scenario 2) for the operational phase
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Figure 27: Average daily PM10 concentrations (Scenario 2, Controlled Emissions) for the operational phase
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Figure 28: Average annual PM10 concentrations (Scenario 1) for the operational phase
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Figure 29: Average annual PM10 concentrations (Scenario 2) for the operational phase
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Figure 30: Average daily PM2.5 concentrations (Scenario 1) for the operational phase
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Figure 31: Average annual PM2.5 concentrations (Scenario 1) for the operational phase
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Figure 32: Average hourly SO2 concentrations (Scenario 1) for the operational phase
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Figure 33: Average daily SO2 concentrations (Scenario 1) for the operational phase
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Figure 34: Average annual SO2 concentrations (Scenario 1) for the operational phase
Project Name: Holfontein Project Page 63 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 4.5.3 Impact Rating Methodology
The following risk assessment model will be used to determine the significance of potential air quality impacts of the proposed project.
SIGNIFICANCE = (MAGNITUDE + DURATION + SCALE) X PROBABILITY
The maximum potential value for significance of an impact is 100 points. Environmental impacts can therefore be rated as high, medium or low significance on the following basis:
. High significance 60 – 100 points . Medium significance 30 – 59 points . Low significance 0 – 29 points
Magnitude (M) Duration (D) 10 – Very high (or unknown) 5 – Permanent 8 – High 4 – Long-term (ceases at end of operation) 6 – Moderate 3 – Medium-term (4-8 years) 4 – Low 2 – Short-term (0-3 years) 2 - Minor 1 - Immediate Scale (S) Probability (P) 5 – International 5 – Definite (or unknown) 4 – National 4 – High probability 3 – Regional 3 – Medium probability 2 – Local 2 – Low probability 1 – Site (within site boundary) 1 – Improbable 0 – None 0 – None
The impact significance rating table indicates the phases over which the impact spans. Each impact has been given a significance rating without and with mitigation (e.g. 50 [36]).
Project Name: Holfontein Project Page 64 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 Table 12: Impact rating of potential air quality impacts for the Life of mine
SIGNIFICANCE
RECEPTOR PROCESS / IMPACT (P)
(M) RATING VALUE
SCALE (S) SCALE
MAGNITUDE MAGNITUDE
PROBABILITY PROBABILITY DURATION (D)
Construction
. Dust will be generated from Ambient air quality at 6 2 2 3 Medium 30 construction activities which may sensitive receptors [6] [2] [1] [2] [Low] [18] result in nuisance impacts . Fine particulates will be Ambient air quality at generated from construction 8 2 2 3 Medium 36 sensitive receptors activities which may result in [8] [2] [1] [2] [Low] [22] health impacts . Dust will be generated from Surrounding cultivated 4 2 2 3 Low 24 construction activities which may areas [4] [2] [1] [2] [Low] [14] have an impact on crops
Operation
. Dust will be generated from Ambient air quality at 6 4 2 3 Medium 36 operational activities which may sensitive receptors [6] [4] [2] [2] [Low] [24] result in nuisance impacts . Dust will be generated from Surrounding cultivated 4 4 2 3 Medium 30 operational activities which may areas [4] [4] [2] [2] [Low] [20] have an impact on crops . Fine particulates (which contain a metal fraction from ore handling Ambient air quality at 10 4 2 5 High 80 activities) will be generated from sensitive receptors [10] [4] [2] [4] [High] [64] operational activities which may result in health impacts
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SIGNIFICANCE
RECEPTOR PROCESS / IMPACT (P)
(M) RATING VALUE
SCALE (S) SCALE
MAGNITUDE MAGNITUDE
PROBABILITY PROBABILITY DURATION (D)
. Gases will be generated from Ambient air quality at 8 4 2 3 Medium 42 operational activities which may sensitive receptors [8] [4] [2] [2] [Low] [28] result in health impacts
Decommissioning
. Dust will be generated from Ambient air quality at 6 2 2 3 Medium 30 decommissioning activities which sensitive receptors [6] [2] [1] [2] [Low] [18] may result in nuisance impacts . Fine particulates will be Ambient air quality at generated from decommissioning 8 2 2 3 Medium 36 sensitive receptors activities which may result in [8] [2] [1] [2] [Low] [22] health impacts . Dust will be generated from Surrounding cultivated 4 2 2 3 Low 24 decommissioning activities which areas [4] [2] [1] [2] [Low] [14] may have an impact on crops
Post-Closure
. Dust may be generated from Ambient air quality at 6 2 2 3 Medium 30 wind erosion of exposed areas sensitive receptors [6] [2] [1] [2] [Low] [18] due to unsuccessful rehabilitation
Project Name: Holfontein Project Page 66 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 4.5.4 Modder East Operations
The existing air quality impacts at the Modder East Operations relating to emissions generated by rock crushing activities, materials handling and transfer, ore crushing and screening activities, the tailings storage facility and the processing plant will be extended (in time, to account for the increase in life of mine) but not exacerbated by the supplementation of rock and ore from the Holfontein shaft.
4.5.5 Cumulative Impacts
From a regional perspective, the Highveld area is associated with poor air quality and elevated concentrations of criteria pollutants and has therefore been proclaimed as the Highveld Priority Area. The proposed project site falls within the Highveld Priority Area and the ambient air quality is considered to be significantly impacted. According to the air quality monitoring data obtained from 3 SAAQIS for the Etwatwa Station, the annual average concentration of PM10 (104 µg/m ) already exceeds the standard allowable concentration (40 µg/m3). As background concentrations already greatly exceed the NAAQS allowable concentration, the cumulative impact in terms of the
contribution of PM10 from the proposed development on the ambient air quality is likely to be high. This will need to be confirmed by on-site monitoring during the life of mine.
During the public consultation process residents of the Welgedacht SH raised concerns regarding the dust generated on the unpaved portion of Carnation Road (refer to Figure 35) due to vehicles travelling to and from the Welgedacht WWTW. Any dust generated due to the Holfontein Project haul trucks and buses transporting personnel to and from the Modder East Operations on the unpaved portions of Carnation Road will amplify the nuisance impact of dust already experienced by surrounding residents.
4.5.6 Residual Impacts
Residual impacts on the ambient air quality are unlikely unless the planned rehabilitation is unsuccessful (i.e. vegetation does not successfully re-establish) resulting in exposed areas, which will be susceptible to wind erosion.
Project Name: Holfontein Project Page 67 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 5 ASSUMPTIONS AND LIMITATIONS
The project assumptions and data limitations influencing the dispersion modelling results can be summarised as follows:
. The dispersion model (AERMOD) cannot compute real time mining production processes, therefore average process throughputs were utilised. Thus even though the nature of the operations may change over a given time, the proposed project was modelled to reflect the worst case condition (i.e. resulting in the highest impacts). . The range of uncertainty of the model predictions could be -50% to 200%. There will always be some error in any geophysical model, but it is desirable to structure the model in such a way to minimise the total error. A model represents the most likely outcome of an ensemble of experimental results. The total uncertainty can be thought of as the sum of three components: the uncertainty due to errors in the model physics; the uncertainty due to data errors; and the uncertainty due to stochastic processes (turbulence) in the atmosphere. . Routine emissions for the proposed mining operations were simulated. Emissions from intermittent or upset conditions were not simulated. . Wind erosion emissions are largely affected by the moisture content of the material and wind speed and will therefore vary as these parameters vary. . It should be noted that isopleth plots reflecting averaging periods contain the highest predicted ground level concentrations for that averaging period, over the entire period for which simulations were undertaken. It is therefore possible that, even though a high concentration is predicted to occur at certain locations, this may only be true for one day during the entire period. . The scope of the work only covers ambient concentration impacts beyond the mine’s boundaries; occupational health issues were not addressed. . Due to the unavailability of local emission factors, US-EPA and NPI emission factors for mining were used for the study. . Site specific information was not available for metals content of the ore, and the generic ore assays (NPI, 2012) available were not deemed a suitable representation of the Main Reef ore. The metal fraction of dust to be generated from ore handling activities could therefore not be estimated. . The estimation of greenhouse gases did not form part of the scope of this study. . No measured dust fallout rates and particulate air concentrations are available at the proposed site. Data were obtained from a site located 7 km to the north of the proposed project area, and these data sets were incomplete. Therefore, cumulative impacts could not be modelled; instead a qualitative description based on the existing activities in the area was provided. . Vehicle tailpipe emissions are hotter than the ambient air (i.e. thermally buoyant). The current buoyancy algorithm in AERMOD only works for point sources and the volume source algorithm in AERMOD does not accurately account for thermal plume rise of vehicle tailpipe emissions. Vehicle tailpipe emissions were therefore not modelled in detail.
Project Name: Holfontein Project Page 68 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 . The area allocated for all the surface infrastructure equates to 4.5 Ha. Although the entire area is unlikely to be worked, the entire area was used as a conservative approach to model the worst case scenario. . Construction activities may continue for up to 6 months, and although it is likely to be less, a conservative approach to model the worst case scenario was again utilised. . There was insufficient information available to determine the emissions from the ventilation shaft and therefore the ventilation shaft emissions were not included in the modelling. . Since the project is a proposed operation, all calculations and simulations were based on design information and layout plans. . Whilst care has been taken to assess the potential air pollution impact from the proposed development, changes to the proposed design and project description after this assessment may result in different conclusions.
Project Name: Holfontein Project Page 69 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 6 AIR QUALITY MANAGEMENT
The air quality management measures below will assist with the mitigation and/ or control of emissions to be generated during the construction, operational and decommissioning phases of the project.
6.1 Construction
6.1.1 Topsoil Stripping
. Access tracks used for soil stripping during the loading and unloading cycle must be watered; . Soil stripping must be limited to areas required for the construction of surface infrastructure; and . Free fall height during topsoil stockpiling must be limited to 3 m.
6.1.2 Earthworks
. A water spray dust suppression system must be implemented during earthmoving and dozing operations. Excavation area to be hosed down prior to removal of material in order to obtain 50 % control efficiency; and . Earthmoving activities must be phased to reduce the source area (i.e. total exposed area at one time).
6.1.3 Exposed Areas
. Frequency of disturbance of exposed areas must be reduced; and . Exposed areas must be re-vegetated as soon as possible to obtain 40% control efficiency.
6.1.4 Unpaved Roads
. Development of access roads must be limited and the locations clearly defined as per the project layout; . All existing unpaved roads must be graded prior to operations. Grading is to be avoided during dry windy conditions; . Speed of construction vehicle and haul trucks travelling on unpaved roads must be limited to 40 km/h; . Dust suppression through level 1 watering (2 ℓ/m² per hr) to obtain 50 % control efficiency must be implemented on unpaved access and haul roads; . Surface improvement must be implemented in the form of gravel to cap the road surface of unpaved roads; and . The unpaved portion of the haul route - between the Blesbokspruit crossing and paved portion of the Carnation Road (refer to Figure 35) - must be paved to obtain 100 % control efficiency. This is a precaution, as the cumulative impact of dust on residents in proximity could not be quantified.
Project Name: Holfontein Project Page 70 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Figure 35: Section of Carnation Road to be paved
Project Name: Holfontein Project Page 71 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 6.1.5 Materials Handling
. Truck overloading must be prevented to reduce spillage of waste rock during loading, unloading and hauling; and . The haul trucks must be covered with a tarpaulin to obtain 99 % control efficiency and it must be ensured that the waste rock material being hauled is wet to obtain 50 % control efficiency.
6.1.6 Equipment Maintenance
. An inspection and maintenance programme to service equipment in accordance with the equipment manufacturer specifications must be implemented; . Low-sulphur diesel must be used to fuel vehicles and equipment; and . Vehicle idling must be limited.
6.2 Operation
6.2.1 Topsoil Stockpile
. A water spray dust suppression system must be implemented to keep the topsoil stockpile moist to reduce wind erosion and obtain 50 % control efficiency.
6.2.2 Unpaved Roads
. All unpaved roads must be regularly maintained (using graders) to minimise the generation of dust. Grading is to be avoided during dry windy conditions and limited to affected areas only; . Dust suppression through level 1 watering (2 ℓ/m² per hr) to obtain 50 % control efficiency must be implemented on unpaved access and haul roads; . The routes must be clearly marked and drivers must only travel on this haul route; and . Speed of haul trucks and buses transporting personnel on unpaved roads must be limited to 40 km/h.
6.2.3 Materials Handling
. Free fall height from the skip to the bin during ore stockpiling must be limited; . A water spray dust suppression system must be used at the bin during truck loading of ore, to obtain 50 % control efficiency; . Sheltering measures to reduce wind speed must be implemented (i.e. enclosing the chute) to obtain 99 % control efficiency, thereby ensuring that particulates which may contain harmful metals are contained during ore hoisting and truck loading; . Truck overloading must be prevented to reduce spillage of ore during loading, unloading and hauling;
Project Name: Holfontein Project Page 72 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 . It must be ensured that the ore being hauled is wet to obtain 50 % control efficiency and the haul trucks must be covered while transporting ore from the Holfontein shaft to the Modder East Operations to ensure a 99 % control efficiency; and . Any spillage of ore from haul trucks along the haul route, although unlikely if the above measures are implemented, must be cleared and disposed of appropriately at the Modder East operations.
6.2.4 Equipment Maintenance
. An inspection and maintenance programme to service equipment in accordance with the equipment manufacturer specifications must be implemented; . Low-sulphur diesel must be used to fuel vehicles and equipment; and . Vehicle idling must be limited.
6.3 Decommissioning
As impacts during decommissioning will be similar in nature to those during construction the same mitigation measures are to be implemented.
6.4 Cumulative Impacts
Residents of the Welgedacht SH raised concerns regarding the dust generated due to vehicles travelling to and from the Welgedacht WWTW on the unpaved portion of Carnation Road (refer to Figure 35). Any dust generated due to the Holfontein Project haul trucks and buses transporting personnel to and from the Modder East Operations on the unpaved portions of Carnation Road will amplify the nuisance impact of dust already experienced by surrounding residents. As the cumulative impact of dust could not be modelled, the cumulative impact on Welgedacht SH residents could not be determined. It is recommended that the precautionary principle be implemented in terms of the management of cumulative dust in order to address concerns that have been raised by residents occupying properties directly adjacent to the proposed haul route. Therefore, it is recommended that the unpaved portion of the haul route between the Blesbokspruit crossing and the paved portion of Carnation Road be paved (refer to Figure 35), which will mitigate any dust generated from vehicle entrainment on unpaved roads.
6.5 Modder East Operations
The existing air quality impacts at the Modder East Operations (related to rock crushing activities, materials handling and transfer, ore crushing and screening activities, the processing plant, and the tailings storage facility) which are to be extended by the supplementation of rock and ore from the Holfontein shaft must continue to be managed as per the commitments in the approved Modder East Operations Environmental Management Programme. It must be ensured that provisions are in place to manage the extension of the air quality impacts as determined by the additional life of mine of the Holfontein Project. It is expected that the Modder East Operations Environmental Management Programme will need to be updated to address the additional ore and
Project Name: Holfontein Project Page 73 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 waste rock (and tailings material) to be received from Holfontein, prior to reaching the life of mine as stated within the current approved 2007 Environmental Management Programme.
6.6 Residual Impacts
Rehabilitation should be conducted with the aim of 100 % control efficiency in terms of dust generated from wind erosion across exposed areas. Therefore, the area must be fully rehabilitated and vegetation must be self-sustaining.
Project Name: Holfontein Project Page 74 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 7 AIR QUALITY MONITORING
7.1 Aim
The aim of this air quality (dust fallout) monitoring programme is to:
. Assess the effectiveness of air quality management measures; . Qualify air quality at sensitive receptors; . Evaluate compliance with National Dust Control Regulations acceptable dust fallout at key localities; and . Provide effective tools for auditing and spot checks of air quality management performance.
7.2 Monitoring Sites
Targeted residential air quality (dust fallout) monitoring must be undertaken wherever there is a
potential for residential receptors to experience adverse air quality impacts. PM10 and PM2.5 monitoring are not recommended as according to the air quality monitoring data obtained from 3 SAAQIS for the Etwatwa Station, the annual average concentration of PM10 (104 µg/m ) already exceeds the standard allowable concentration (40 µg/m3). As background concentrations already greatly exceed the NAAQS allowable concentration, monitoring would confirm this and it would be difficult to determine whether the exceedance was caused by, or what fraction contributed by the
Holfontein Project. Therefore, PM10 monitoring would not add greatly to the management of emissions from the Holfontein Project. In contrast, the dust fallout monitoring is sensitive to local influences and can be readily interpreted and related to local operations or to the failure of mitigation measures.
The sites selected for the dust fallout monitoring programme are considered to be the most appropriate localities to provide a reliable and representative indication of air quality impacts associated with the proposed project, as per the outcomes of the atmospheric dispersion modelling (refer to Table 13 and Figure 36).
Table 13: Proposed (dust fallout) monitoring sites MONITORING SITE CO-ORDINATES TYPE OF SITE Boundary 1 26° 9'55.01"S 28°30'8.87"E Non-residential Boundary 2 26° 9'56.38"S 28°30'14.24"E Non-residential Boundary 3 26°10'1.28"S 28°30'11.83"E Non-residential Boundary 4 26°10'1.69"S 28°30'6.93"E Residential Historic Mine House 26°10'3.92"S 28°30'6.66"E Residential
If the recommendation of paving the unpaved portion of the haul route between the Blesbokspruit crossing and the paved portion of Carnation road (refer to Figure 35) is not implemented, or until such time that is paved, an additional monitoring point should be located along Carnation Road to monitor dust fallout (refer to Table 14 and Figure 36).
Project Name: Holfontein Project Page 75 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 Table 14: Proposed additional dust fallout monitoring site MONITORING SITE CO-ORDINATES TYPE OF SITE Carnation Road 1 26°10'46.73"S 28°28'35.31"E Residential
Project Name: Holfontein Project Page 76 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
Figure 36: Proposed air quality (dust fallout) monitoring sites
Project Name: Holfontein Project Page 77 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 In response to any community complaints relating to air quality impacts, which can be corroborated by monitoring results, consultation with relevant residents must be undertaken to establish additional dust fallout monitoring sites.
7.3 Weather Station
A weather station must be installed on site to at least monitor wind speed and direction as well as rainfall to assist with interpretation and understanding of the dust fallout.
7.4 Dust Fallout
7.4.1 Methodology
Dust fallout monitoring must be conducted throughout the life of mine to confirm model predictions. A specialist service provider must install a comprehensive dust bucket monitoring network, and conduct monthly dust fallout monitoring using the American Society for Testing and Materials standard test method for the collection and analysis of dust fallout (ASTM D1739: 1970). A dust bucket must be installed at each of the monitoring sites identified in Section 7.2. A total of five (potentially six) single dust buckets are proposed.
7.4.2 Objectives
In residential areas dust concentrations should not exceed the dust fallout rates for residential areas (600 mg/m²/day over a 30 day averaging period). Two exceedances are allowed within a year but not in sequential months.
In non-residential areas beyond the site boundary (refer to the layout in Figure 3) dust fallout rates should remain below the non-residential limit of 1 200 mg/m²/day. Two exceedances are allowed within a year but not in sequential months.
7.4.3 Internal Visual Inspections and Audits
Daily site inspections by environmental personnel must be conducted to provide an indication on the effectiveness of the dust control measures. Visual monitoring must be conducted for activities which are expected to generate the most dust if not managed effectively (i.e. areas such as the skip, bin and chute at the shaft as well as the unpaved portions of the haul route). Haul trucks must be covered before leaving the site; random inspections must be done to ensure this is being implemented. Inspections for and the clearing of spillage of ore from haul trucks along the entire haul route must also be undertaken.
7.5 Reporting
7.5.1 Internal
. Dust fallout must be reported on monthly by the external service provider. Meteorological conditions from the weather station should be included in the report. The report to must
Project Name: Holfontein Project Page 78 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 meet the National Dust Control Regulations (GNR827 of 2013) prescribed reporting requirements for dust fallout. . Progress reporting must take place at regular intervals (at least quarterly) during operations. Results from site inspections, monitoring results and a summary of any complaints relating to air quality received must be combined to determine if monitoring objectives are being met and the effectiveness of management measures. Progress in terms of air quality management should be reported to all interested and affected parties, including authorities and persons who may be affected by emissions from the proposed project. Corrective action must be taken (i.e. the implementation of contingency measures) in the event that monitoring objectives have not been met.
7.5.2 External
. As per the requirements of the National Emission Reporting Regulations (GN283 of 2015) the Applicant is to register as a data provider with and also submit emission reports, in the format required, to the online National Atmospheric Emissions Inventory System (NAEIS). Reports must be submitted for the preceding calendar year to the NAEIS by 31 March for each calendar year. The relevant air quality officer at Ekurhuleni Metropolitan Municipality is the relevant authority in this regard. . As per the National Dust Control Regulations (GNR827 of 2013) any person who has exceeded the dust fallout limit must, within three months of submission of a dust fallout monitoring report, develop and submit a dust management plan to the air quality officer for approval. The dust management plan must be implemented within a month of the date of approval by the air quality officer. An implementation progress report must be submitted to the air quality officer at agreed time intervals. o The dust management plan must: o Identify all possible sources of dust within the affected site; o Detail the best practicable measures to be undertaken to mitigate dust emissions; o Develop an implementation schedule; o Identify the line management responsible for implementation; o Incorporate the dust fallout monitoring plan; and o Establish a register for recording all complaints regarding dust fallout, and for recording follow-up actions and responses to the complainants.
Project Name: Holfontein Project Page 79 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 8 CONCLUSIONS AND RECOMMENDATIONS
The findings of this air quality impact assessment indicate that dust fallout and PM10 emissions during operations for the Holfontein Project will exceed National Dust Control Regulations acceptable dust fallout and NAAQS limit values at the surrounding sensitive receptors to the west of the boundary for the maximum emission scenario (24-hour operations). However, for Scenario 2 (i.e. loading and hauling hours reduced to 12 hours, from 06h00 to 18h00), dust fallout is within
the acceptable limits at all sensitive receptors but PM10 emissions still exceed limit values. Therefore, the only likely pollutant to be generated from the Holfontein Project activities which
may be of concern is PM10 during the operational phase, which may contain harmful metals, increasing the potential health risk and will require mitigation. With the implementation of the
recommended mitigation measures (controlled emissions) the PM10 concentrations fall below the NAAQs limit values at all surrounding sensitive receptors.
As the cumulative impact of dust could not be modelled, it is recommended that the unpaved section of Carnation Road, between the Blesbokspruit crossing and the paved portion of the road, be paved in order to manage cumulative dust, as concerns have been raised by residents living directly adjacent to the proposed haul route.
If the recommended operating hours and mitigation measures are implemented it is unlikely that the proposed Holfontein Project will result in significant air quality impacts. However, due to the fact that the Holfontein Project is located within an air quality priority area (Highveld Priority Area) and within proximity (within 200 m) to permanently occupied areas it is imperative that air quality (dust fallout) monitoring be conducted throughout the life of mine to determine whether the emissions generated at the mine correlate with those modelled and fall below National Dust Control Regulations acceptable dust fallout values at mine boundaries and surrounding sensitive receptors, specifically the historic mine house and informal settlements located to the west of the boundary. If they do not correlate with modelled concentrations and exceed acceptable dust fall, additional management measures must be implemented to ensure that these are not exceeded.
Although not within the scope of this air quality impact assessment, mine health and safety requirements in terms of air quality within the boundaries of the proposed development must also be adhered to and compliance thereto audited regularly.
Project Name: Holfontein Project Page 80 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015 9 REFERENCES
Department of Environmental Affairs and Tourism (2005) State of Air Report, Department of Environmental Affairs and Tourism, Pretoria, ISBN 978-0-621-38724-7.
Farmer, A.M. (1993) The Effects of Dust on Vegetation - A Review, Environmental Pollution 79(1), pg. 63-75.
Liebenberg-Enslin, H. and Hurt, Q. (2009) Gauteng Province Air Quality Management Plan, Gauteng Department of Agriculture, Conservation and Environment.
Liebenberg-Enslin, H., Krause, K., Burger, L., Fitton, J. and Modisamongwe, D. (2012) Gauteng Department of Roads and Transport, Transport Air Quality Management Plan – Final Report.
National Pollutant Inventory (2012) Emission Estimation Technical Manual for Mining, Version 3.1, Department of Sustainability, Environment, Water, Population and Communities, Commonwealth of Australia, ISBN: 0-642-54700-9.
Pace, T.G. (2005) U.S. Environmental Protection Agency, Examination of the Multiplier Used to
Estimate PM2.5 Fugitive Dust Emissions from PM10.
Prajapati, S.K. (2012) Ecological Effect of Airborne Particulate Matter on Plants, Environmental Skeptics and Critics 1(1), pg. 12-22.
Sami, K. and Druzynski, A.L. (2003) Final Report to the Water Research Commission for the Project Mapping of Naturally Occurring Hazardous Trace Constituents in Groundwater, WRC Report No.: 1236/1/03.
Sandström, T., Nowak, D. and van Bree, L. (2005) Health Effects of Coarse Particles in Ambient Air: Messages for Research and Decision-making, European Respiratory Journal 26, pg. 187-188.
Scorgie, Y., Fischer, T. and Watson R. (2005) Air Quality Management Plan for the Ekurhuleni Metropolitan Municipality, Report No.: APP/04/EMM02c.
U. S. Environmental Protection Agency (1998) AP-42 Series, Office of Air Quality Planning and Standards, Emission Factor and Inventory Group.
World Health Organization (2005) Air Quality Guidelines Global Update, ISBN 92-890-2192-6.
World Health Organization (2014) Ambient (Outdoor) Air Quality and Health, Fact sheet N°313, Updated March 2014, http://www.who.int/mediacentre/factsheets/fs313/en/, Accessed 27 August 2014.
Závodská, L., Kosorínová, E., Ščerbáková, L. and Lesný, J. (2008) Environmental Chemistry of Uranium. HU ISSN 1418-7108: HEJ Manuscript no.: ENV-081221-A.
Project Name: Holfontein Project Page 81 of 81 Report Title: Air Quality Impact Assessment Project Number: 140668 Date: August 2015
APPENDIX 1
AUTHOR’S CV
Amanda Mooney – Environmental Scientist
Present Appointment Environmental Scientist, Prime Resources (Pty) Ltd
Period May 2012 - Present
Education BSc. Zoology and Biochemistry, University of Johannesburg BSc Hons. Zoology (Aquatic Health) cum laude, University of Johannesburg MSc. Zoology, University of Johannesburg MSc. Environmental Management, University of Johannesburg
Synopsis:
Working as an environmental scientist I have obtained a sound working knowledge of environmental legislation and permitting requirements. I have also gained experience in a variety of aspects including: Environmental Authorisation processes, i.e. Basic Assessments, Environmental Impact Assessments, stakeholder engagement and environmental management planning; rehabilitation planning; liability and closure assessments; Equator Principles and IFC Performance Standards reviews; environmental compliance auditing; water monitoring and reporting; atmospheric dispersion modelling and air quality impact assessments; as well as visual impact assessments.
Project History:
Environmental Authorisation Processes (Basic Assessments, Environmental Impact Assessments, Stakeholder Engagement and Environmental Management Programmes)
Gold One International, Modder East Operations, New Return Water Dam, Gauteng Province, South Africa Altius Trading 404, KaNgwane South Anthracite Mine, Mpumalanga Province, South Africa Anglo American Platinum, EMP Consolidation and MPRDA alignment, Amandelbult Section, Limpopo Province, South Africa Main Street 800, KaNgwane Anthracite Mine, Mpumalanga Province, South Africa HolGoun Energy, Canyon Springs Coal Mine, Mpumalanga Province, South Africa Gold One International, Randfontein Surface Operations, Reclamation of Material at the Lindum Tailings Storage Facility, Gauteng Province, South Africa
Anglo American Platinum, Amandelbult Chrome Recovery Plant, Limpopo Province, South Africa Koornfontein Mines, Wilmansrust Section, Mpumalanga Province, South Africa Samancor Chrome, Scheiding Chrome Mine, Limpopo Province, South Africa Southern Shaft Expansion Project at T-Project Colliery, Kinross, Mpumalanga, South Africa Mbila Resources, Msebe Opencast Anthracite Mine, KwaZulu-Natal Province, South Africa Mbila Resources, Mbila Anthracite Mine, KwaZulu-Natal Province, South Africa Gold One International, Holfontein Project, Gauteng Province, South Africa
Stand-Alone Plans
Emergency Preparedness and Response Plan for Gold One International, Modder East Operations, Gauteng Province, South Africa Emergency Preparedness and Response Plan for T-Project Colliery, Kinross, Mpumalanga, South Africa Alien Invasive Vegetation Eradication Plan for T-Project Colliery, Kinross, Mpumalanga, South Africa Stakeholder Engagement Plan and Grievance Mechanism for T-Project Colliery, Kinross, Mpumalanga, South Africa Wetland Rehabilitation Plan for T-Project Colliery, Kinross, Mpumalanga, South Africa
Mine Closure Planning
Preliminary Closure Plan for the KaNgwane Anthracite Mine, Mpumalanga Province, South Africa Prospecting Rehabilitation Plan for the Cabinda Phosphate Project, Cabinda, Angola Interim Closure Plan for the Gold One International, Holfontein Project, Gauteng Province, South Africa
Closure Liability and Performance Assessments
Performance Assessment and Evaluation of the Quantum for Closure-Related Financial Provision for the Samancor Chrome Mareesburg Prospecting Right, Limpopo Province, South Africa
Waste Management and Compliance Auditing
Waste Impact Report for the Ekurhuleni Metropolitan Municipality Weltevreden Landfill Site, Gauteng, South Africa Environmental compliance auditing of operational landfill sites, Ekurhuleni Metropolitan Municipality, Gauteng, South Africa Environmental compliance auditing of the Interwaste George and Mossel Bay depots, Western Cape South Africa
EMP Compliance Auditing
Environmental Control Officer and environmental compliance auditing for the Bio2Watt Biogas Plant, Bronkhorstspruit, Gauteng, South Africa
Water Management and Compliance Auditing
Water Use License Application and Integrated Waste and Water Management Plan for the Samancor Chrome, Scheiding Chrome Mine, Limpopo Province, South Africa
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Integrated Water Use Licence and GN704 compliance audit for the Modikwa Platinum Mine, Limpopo Province, South Africa Integrated Waste and Water Management Plan for the Gold One International, Holfontein Project, Gauteng Province, South Africa
Groundwater Quality Monitoring
Groundwater quality monitoring and reporting for operational landfill sites, Ekurhuleni Metropolitan Municipality, Gauteng, South Africa Groundwater quality monitoring and reporting for Interwaste FG Waste Disposal Site, Olifantsfontein, Gauteng, South Africa
Environmental Review (Compliance with National Legislation)
Review and report on the environmental requirements associated with the activities being undertaken by Shiva Uranium, North West, South Africa
Equator Principles (EPII) / IFC / World Bank Environmental and Social Assessments
Environmental and social baseline report (pre-feasibility) for the Horizonte Minerals, Araguaia Nickel Project, Brazil Review and gap analysis preparation for T-Project Colliery, Kinross, Mpumalanga, South Africa
Due Diligence (Compliance with Equator Principles)
Review of Tharisa Platinum Mine on behalf of HSBC, North West, South Africa Review of Maamba Colliery’s existing and proposed expansion project, Zambia Review of North River Resources, Lead and Zinc Project, Namibia
Air Quality Impact Assessments
Gold One International, Holfontein Project, Gauteng Province, South Africa
Visual Impact Assessments
Gold One International, Holfontein Project, Gauteng Province, South Africa
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