air quality specialist report for a proposed maize wet mill ......air quality specialist report for...

Address: 480 Smuts Drive, Halfway Gardens | Postal: P O Box 5260, Halfway House, 1685 Tel: +27 (0)11 805 1940 | Fax: +27 (0)11 805 7010

www.airshed.co.za

Air Quality Specialist Report for a Proposed Maize Wet Mill Plant, Vereeniging, Gauteng

Project done on behalf of SLR Consulting (South Africa) (Pty) Ltd

Report Compiled by T Bird

Project Manager H Liebenberg-Enslin

Report No: 17SLR25 | Version: Rev 2 | Date: October 2018

Air Quality Specialist Report for a Proposed Maize Wet Mill, Vereeniging, Gauteng

Report No.: 17SLR25 Report Version: Rev 2 i

Report Details

Project Name Air Quality Specialist Report for a Proposed Maize Wet Mill, Vereeniging, Gauteng

Client SLR Consulting (South Africa) (Pty) Ltd

Report Number 17SLR25

Report Version Revision 2

Date October 2018

Prepared by Terri Bird, Pr. Sci. Nat, PhD (Wits)

Project Manager Hanlie Liebenberg-Enslin, PhD (Geography) (University of Johannesburg)

Reviewed by Gerrit Kornelius PrEng BEng Hons (Chem) MBA PhD (University of Pretoria)

Notice

Airshed Planning Professionals (Pty) Ltd is a consulting company located in Midrand, South Africa, specialising in all aspects of air quality, ranging from nearby neighbourhood concerns to regional air pollution impacts as well as noise impact assessments. The company originated in 1990 as Environmental Management Services, which amalgamated with its sister company, Matrix Environmental Consultants, in 2003.

Declaration Airshed is an independent consulting firm with no interest in the project other than to fulfil the contract between the client and the consultant for delivery of specialised services as stipulated in the terms of reference.

Copyright Warning

Unless otherwise noted, the copyright in all text and other matter (including the manner of presentation) is the exclusive property of Airshed Planning Professionals (Pty) Ltd. It is a criminal offence to reproduce and/or use, without written consent, any matter, technical procedure and/or technique contained in this document.

Revision Record

Revision Number Date Reason for Revision

Draft July 2018 Original for client comment

Revision 1 July 2018 Minor text updates based on client comments.

Revision 2 October 2018 Additional boiler mitigation options. Report restructuring for additional mitigation recommendations.


Report No.: 17SLR25 Report Version: Rev 2 ii

NEMA Regulation (2017), Appendix 6

NEMA Regulations - Appendix 6 Relevant section in report

Details of the specialist who prepared the report. Report Details (page i)

The expertise of that person to compile a specialist report including curriculum vitae.

Competency Profiles

Section 14: Appendix A: Authors’ Curriculum Vitae (page 63)

A declaration that the person is independent in a form as may be specified by the competent authority.

Report Details (page i)

An indication of the scope of, and the purpose for which, the report was prepared.

Section 1.1: Background (page 1)

Section 1.2: Terms of Reference (page 1)

An indication of quality and age of base data used. Section 5.2 and 5.3; Section 7.1

A description of existing impacts on the site, cumulative impacts of the proposed development and levels of acceptable change.

Section 5.3; Section 8; Section 4

The date and season of the site investigation and the relevance of the season to the outcome of the assessment.

A site investigation was undertaken on the 23rd November 2017, to identify surrounding receptors and sources. A baseline air quality measurement campaign was initiated on the 21st April 2018.

Description of the current land use in the region, simulations undertaken for the current operations and meteorological data included used in the study are considered representative of all seasons.

Section 5.1 and 5.3.

A description of the methodology adopted in preparing the report or carrying out the specialised process.

Section 2: Methodology (page 3)

The specific identified sensitivity of the site related to the activity and its associated structures and infrastructure.

Section 5: Air Quality Baseline (page 16)

An identification of any areas to be avoided, including buffers. Not applicable

A map superimposing the activity including the associated structures and infrastructure on the environmental sensitivities of the site including areas to be avoided, including buffers.

Section 3: Project Description

A description of any assumptions made and any uncertainties or gaps in knowledge.

Section 2.4

A description of the findings and potential implications of such findings on the impact of the proposed activity, including identified alternatives, on the environment.

Section 6: Impact Assessment: Construction Phase (page 28)

Section 7: Impact Assessment: Operational Phase – Design Mitigated (page 30)

Section 8: Impact Assessment: Operational Phase – Additional Mitigation (page 42)

Any mitigation measures for inclusion in the EMPr. Section 11: Air Quality Management Measures (page 56)

Any conditions for inclusion in the environmental authorisation

Section 11: Air Quality Management Measures (page 56)

Any monitoring requirements for inclusion in the EMPr or environmental authorisation.

Section 11: Air Quality Management Measures (page 56)

A reasoned opinion as to whether the proposed activity or portions thereof should be authorised.

Section 12: Findings and Recommendations (page 60)

If the opinion is that the proposed activity or portions thereof should be authorised, any avoidance, management and mitigation measures that should be included in the EMPr, and where applicable, the closure plan.

Section 12: Findings and Recommendations (page 60)

A description of any consultation process that was undertaken during the course of carrying out the study.

Not applicable.


Report No.: 17SLR25 Report Version: Rev 2 iii

A summary and copies if any comments that were received during any consultation process.

No Comments received

Any other information requested by the competent authority. None



Executive Summary

The development of a maize wet mill is proposed near Vereeniging, Gauteng. The wet mill will produce liquid products and

dry solid products. Airshed Planning Professionals (Pty) Ltd was appointed by SLR Consulting (South Africa) (Pty) Ltd (SLR)

to undertake an Air Quality Impact Assessment (AQIA) for the proposed facility.

The main findings of the baseline assessment are:

• Several air quality sensitive receptors (AQSRs) are located near to the proposed property, the closest of which is

the staff accommodation of the Department of Correctional services.

• The main sources likely to contribute to baseline pollutant concentrations include industrial operations, vehicle

entrained dust from local roads, vehicle exhaust, household fuel burning, biomass burning, and windblown dust

from unvegetated areas.

• The area is dominated by winds from the north-east and north-west. Wind speeds above 7 m/s are more common

from the north-west. Calm conditions (wind speeds less than 1 m/s) occurred less than 10% of the period of

assessment.

The main findings of the impact assessment are as follows:

• Only the operational phase air quality impacts were quantified since construction and decommissioning phase

impacts will likely be similar and less significant than the operational phase impacts.

• Pollutants of concern include particulate matter (PM), SO2 and NO2 where PM emissions from maize handling and

vehicle entrainment from haul trucks were quantified to be the most significant during the operational phase.

• Construction phase:

o The significance of construction related inhalation health and nuisance impacts are likely “low” risk

without mitigation, and “very low“ with mitigation.

• Operational phase:

o PM10 and PM2.5 concentrations were simulated to be in non-compliance over the short- (up to 3 500 m

off-site) and long-term (up to 460 m off-site).

▪ Compliance with PM10 and PM2.5 National Ambient Air Quality Standards (NAAQS) can be

achieved by implementation of the recommended mitigation measures.

▪ With additional mitigation, the International Finance Corporation (IFC) contribution guideline

can be met within 300 m of the facility for PM2.5 and 100 m for PM10.

o Simulated SO2 concentrations were in non-compliance with the hourly, daily, and annual standards

beyond the boundary, if the boilers operate at the Minimum Emission Standards (MES).

▪ Compliance with SO2 NAAQS can be achieved by implementation of the recommended

mitigation measures.

▪ Annual average SO2 concentrations meet the IFC contribution guideline (25% of NAAQS)

o Simulated NO2 concentrations, under both the design and additionally mitigated scenarios, were

compliant with the hourly and annual NAAQS.

▪ Annual average NO2 concentrations meet the IFC contribution guideline (25% of NAAQS)

o Dustfall rates are below the NDCR limits for residential areas and non-residential areas off-site.

o Simulated TVOC concentrations may exceed the annual benzene NAAQS if all TVOCs are assumed to

be benzene. The TVOC profile is likely to include many compounds and therefore compliance with the

benzene standard is expected.

o The significance of operations related inhalation health impacts is likely to have a “medium” significance

with design mitigation; and “low” with additional mitigation measures.



o The significance of operations related to nuisance impacts, associated with dustfall and odours, is likely

to have a “low” significance with design and additional mitigation.

To ensure the lowest possible impact on AQSRs and the environment it is recommended that the air quality management

plan as set out in this report should be adopted. This includes:

• design and management of the boiler plant as per the Subcategory 1.1 listed activity;

• mitigation of emissions from the maize and dry maize-product handling (using cyclones, fabric filters, or a

combination) resulting in the management of associated air quality impacts;

• mitigation of vehicle entrainment emissions from the paved access roads using a mechanical sweeper; strict

enforcement speed limits (maximum 20 km/h on access roads); covers for vehicles; and regular clean-ups of road

spillages;

• emissions monitoring in accordance with the reporting requirements for Section 23 controlled emitters;

• emissions monitoring of maize wet mill control system chimneys;

• ambient air quality monitoring;

• dustfall monitoring; and

• implementation of the reporting procedures.

Based on these findings, it is the specialist opinion that the project would not have a significant impact on the surrounding environment and could be authorised.



Table of Contents

1 Introduction....................................................................................................................................................................... 1

1.1 Background ............................................................................................................................................................ 1

1.2 Terms of Reference ................................................................................................................................................ 1

2 Methodology ..................................................................................................................................................................... 3

2.1 Analysis .................................................................................................................................................................. 4

2.1.1 AERMOD Modelling Suite ................................................................................................................................. 4

2.1.1 Meteorological Requirements ............................................................................................................................ 5

2.1.2 Topographical and Land Use Data .................................................................................................................... 5

2.1.3 Receptor Grid .................................................................................................................................................... 5

2.1.4 Dispersion results .............................................................................................................................................. 5

2.1.5 Uncertainty of Modelled Results ........................................................................................................................ 6

2.2 Impact Assessment ................................................................................................................................................ 6

2.3 Mitigation and Management Recommendations .................................................................................................... 7

2.4 Assumptions, Limitations and Exclusions ............................................................................................................... 7

3 Project Description ........................................................................................................................................................... 8

4 Applicable Legislation..................................................................................................................................................... 10

4.1 Controlled Emitters ............................................................................................................................................... 10

4.2 Atmospheric Emissions Reporting Regulations .................................................................................................... 11

4.3 Atmospheric Dispersion Modelling Regulations ................................................................................................... 12

4.4 South African National Ambient Air Quality Standards ......................................................................................... 12

4.5 National Dust Control Regulations ....................................................................................................................... 13

4.6 The Vaal Triangle Airshed Priority Area ............................................................................................................... 13

4.7 International Finance Corporation Environmental, Health and Safety Guidelines ................................................ 14

5 Air Quality Baseline ........................................................................................................................................................ 16

5.1 Affected Environment ........................................................................................................................................... 16

5.2 Atmospheric Dispersion Potential ......................................................................................................................... 18

5.2.1 Local Wind Field .............................................................................................................................................. 18

5.2.2 Ambient Temperature ...................................................................................................................................... 20

5.3 Existing Air Quality – Sharpeville AQMS .............................................................................................................. 20

5.3.1 Particulate Matter (PM2.5 and PM10) ................................................................................................................. 21

5.3.2 Sulfur Dioxide (SO2) ......................................................................................................................................... 22

5.3.3 Nitrogen Dioxide (NO2) .................................................................................................................................... 23

5.4 Existing Air Quality – On-site Measurement Campaign ....................................................................................... 24



5.4.1 Fine Particulates .............................................................................................................................................. 24

5.4.2 Passive-Diffusive Sampling ............................................................................................................................. 26

6 Impact Assessment: Construction Phase....................................................................................................................... 28

6.1 Emissions Inventory for Construction Phase ........................................................................................................ 28

6.2 Assessment of Impact .......................................................................................................................................... 28

6.2.1 Potential Impact A1: Potential for impacts on human health from increased pollutant concentrations

associated with general construction activities............................................................................................................... 28

6.2.2 Potential Impact A2: Increased nuisance dustfall rates associated with general construction activities ......... 28

7 Impact Assessment: Operational Phase – Design Mitigated ......................................................................................... 30

7.1 Emissions Inventory ............................................................................................................................................. 30

7.1.1 Point Sources .................................................................................................................................................. 30

7.1.2 Fugitive Sources .............................................................................................................................................. 33

7.1.3 Emission Source Summary ............................................................................................................................. 35

7.2 Assessment of Impact –Operational Phase with Design Mitigation Measures ..................................................... 35

7.2.1 Respirable Particulate Matter (PM2.5) .............................................................................................................. 35

7.2.2 Inhalable Particulate Matter (PM10) .................................................................................................................. 37

7.2.3 Fallout Dust ...................................................................................................................................................... 39



7.2.6 Total Volatile Organic Compounds (TVOCs) ................................................................................................... 40

8 Impact Assessment: Operational Phase – Additional Mitigation .................................................................................... 42

8.1 Emissions Inventory ............................................................................................................................................. 42

8.1.1 Point Sources .................................................................................................................................................. 42

8.1.2 Fugitive Sources .............................................................................................................................................. 45

8.1.3 Emission Source Summary – With Additional Mitigation ................................................................................. 47

8.2 Assessment of Impact –Operational Phase with Additional Mitigation ................................................................. 47

8.2.1 Respirable Particulate Matter (PM2.5) .............................................................................................................. 47

8.2.2 Inhalable Particulate Matter (PM10) .................................................................................................................. 49

8.2.3 Fallout Dust ...................................................................................................................................................... 49



8.2.6 Total Volatile Organic Compounds (TVOCs) ................................................................................................... 50

8.3 Impact Significance Rating for Design and Additional Mitigated Scenarios ......................................................... 51

9 Impact Assessment: Cumulative .................................................................................................................................... 53

10 Impact Assessment: No Go Option ................................................................................................................................ 55


Report No.: 17SLR25 Report Version: Rev 2 iii

10.1 Baseline State of the Air Quality ........................................................................................................................... 55

11 Air Quality Management Measures ................................................................................................................................ 56

11.1 Air Quality Management Objectives ..................................................................................................................... 56

11.1.1 Source Specific Management and Mitigation Measures ............................................................................. 56

11.1.2 Source Monitoring ....................................................................................................................................... 56

11.1.3 Ambient Air Quality Monitoring ................................................................................................................... 57

11.2 Record-keeping, Environmental Reporting and Community Liaison .................................................................... 58

11.2.1 Periodic Inspections and Audits .................................................................................................................. 58

11.2.2 Liaison Strategy for Communication with I&APs ......................................................................................... 59

11.2.3 Financial Provision ...................................................................................................................................... 59

12 Findings and Recommendations .................................................................................................................................... 60

12.1 Main Findings ....................................................................................................................................................... 60

12.2 Air Quality Recommendations .............................................................................................................................. 61

13 References ..................................................................................................................................................................... 62

14 Appendix A: Authors’ Curriculum Vitae .......................................................................................................................... 63

15 Appendix B: Competencies for Performing Air Dispersion Modelling ............................................................................ 71

16 Appendix C: Comments/Issues Raised .......................................................................................................................... 73

17 Appendix D: Impact Significance Methodology .............................................................................................................. 74


Report No.: 17SLR25 Report Version: Rev 2 iv

List of Tables

Table 2-1:Summary description of AERMOD model suite with versions used in the investigation ........................................... 4

Table 2-2:Simulation domain ..................................................................................................................................................... 5

Table 3-1: Potential malodours emissions from the proposed maize wet mill ........................................................................... 9

Table 4-1: Minimum Emission Standards for Solid Fuel-fired Small Boilers ............................................................................ 10

Table 4-2: Minimum Emission Standards for Subcategory 1.1: Solid Fuel Combustion Installations ...................................... 11

Table 4-3: National Ambient Air Quality Standards for pollutants of concern in this assessment ........................................... 13

Table 4-4: Acceptable dust fall rates ........................................................................................................................................ 13

Table 5-1: Distance to nearby air quality sensitive receptors .................................................................................................. 16

Table 5-2: Minimum, average and maximum temperature per month from the Sharpeville AQMS (2014 - 2016), and long-

term (1950 to 2000) statistics at the same location ................................................................................................................. 20

Table 5-3: Summary of the ambient measurements at Sharpeville for the period 2014 - 2016 ............................................... 21

Table 5-4: On-site ambient PM10 concentrations measured during April – May 2018 (red shading indicates exceedance of

the NAAQ limit concentration) .................................................................................................................................................. 25

Table 5-5: On-site ambient PM2.5 concentrations measured during April – May 2018 (red shading indicates exceedance of

the current NAAQ limit concentration) ..................................................................................................................................... 25

Table 5-6: Ambient SO2 and NO2 concentrations measured near the proposed site of the maize wet mill (all units: μg/m3) .. 27

Table 6-1: Health risk impact significance summary table for the construction operations ..................................................... 29

Table 6-2: Nuisance impact significance summary table for the construction operations ....................................................... 29

Table 7-1: Parameters for point sources of atmospheric pollutant emissions at the proposed facility .................................... 31

Table 7-2: Atmospheric pollutant emission rates for the proposed facility ............................................................................... 32

Table 7-3: Point Source Emission Estimation Information ....................................................................................................... 32

Table 7-4: Area, volume and/or line source parameters .......................................................................................................... 33

Table 7-5: Fugitive source emissions ...................................................................................................................................... 34

Table 7-6: Area Source Emission Estimation Information ....................................................................................................... 34

Table 7-7: Annual pollutant emission rates (by source group) [units: t/a] ................................................................................ 35

Table 8-1: Parameters for point sources of atmospheric pollutant emissions at the proposed facility – with additional

mitigation.................................................................................................................................................................................. 43

Table 8-2: Atmospheric pollutant emission rates for the proposed facility – with additional mitigation .................................... 44

Table 8-3: Point Source Emission Estimation Information ....................................................................................................... 44

Table 8-4: Area, volume and/or line source parameters – with additional mitigation............................................................... 45

Table 8-5: Fugitive source emissions – with additional mitigation ........................................................................................... 46

Table 8-6: Area Source Emission Estimation Information ....................................................................................................... 46

Table 8-7: Annual pollutant emission rates (by source group) [units: t/a] ................................................................................ 47

Table 8-8: Health risk impact significance summary table for the proposed facility – particulates (PM2.5 and PM10) .............. 51

Table 8-9: Health risk impact significance summary table for the proposed facility – SO2 ...................................................... 51

Table 8-10: Health risk impact significance summary table for the proposed facility – NO2 .................................................... 51

Table 8-11: Health risk impact significance summary table for the proposed facility - TVOCs ................................................ 51

Table 8-12: Nuisance dustfall impact significance summary table for the proposed facility .................................................... 52

Table 9-1: Cumulative annual average pollutant concentrations (bold text indicates non-compliance with NAAQS) ............. 54

Table 10-1: Impact significance summary table for the no-go option ...................................................................................... 55

Table 15-1: Competencies for Performing Air Dispersion Modelling ....................................................................................... 71


Report No.: 17SLR25 Report Version: Rev 2 v

List of Figures Figure 1-1: Local setting of the proposed facility ....................................................................................................................... 2

Figure 3-1: Maize wet mill process flow diagram ....................................................................................................................... 8

Figure 5-1: Location of the proposed project in relation to surroundings ................................................................................. 17

Figure 5-2: Period, day-time and night-time wind roses for Sharpeville AQMS, 2014-2017 .................................................... 19

Figure 5-3: Seasonal wind roses for Sharpeville AQMS, 2014-2017 ....................................................................................... 19

Figure 5-4: Diurnal temperature profile for Sharpeville AQMS, 2014-2017 ............................................................................. 20

Figure 5-5: Daily PM2.5 and PM10 (µg/m3) polar plots for Sharpeville ...................................................................................... 22

Figure 5-6: Hourly SO2 (ppb) polar plot for Sharpeville ........................................................................................................... 23

Figure 5-7: Hourly mean NO2 (ppb) polar plot for Sharpeville ................................................................................................. 24

Figure 5-8: Location of passive diffusive samplers for SO2 and NO2 monitoring ..................................................................... 26

Figure 7-1: Simulated area of exceedance of the daily PM2.5 NAAQ limit concentration ......................................................... 36

Figure 7-2: Simulated annual PM2.5 concentrations ................................................................................................................. 36

Figure 7-3: Simulated annual PM2.5 concentrations – with IFC contribution guidelines ........................................................... 37

Figure 7-3: Simulated area of exceedance of the daily PM10 NAAQ limit concentration ......................................................... 38

Figure 7-4: Simulated annual PM10 concentrations ................................................................................................................. 38

Figure 7-5: Simulated area of exceedance of the hourly SO2 NAAQ limit concentration ........................................................ 39

Figure 7-6: Simulated area of exceedance of the daily SO2 NAAQ limit concentration ........................................................... 40

Figure 7-7: Simulated area of exceedance of the annual benzene NAAQS ............................................................................ 41

Figure 8-1: Simulated area of exceedance of the daily PM2.5 NAAQ limit concentration ......................................................... 48

Figure 8-2: Simulated annual PM2.5 concentrations – additionally mitigated operations ......................................................... 48

Figure 8-3: Simulated annual PM10 concentrations – additionally mitigated operations .......................................................... 49

Figure 11-1: Dustfall collection unit example ........................................................................................................................... 58


Report No.: 17SLR25 Report Version: Rev 2 vi

List of Abbreviations

AIR Atmospheric Impact Report

Airshed Airshed Planning Professionals (Pty) Ltd

AQA Air quality act

AQG Air quality guidelines

AQIA Air quality impact assessment

AQMS Air quality monitoring station(s)

AQMP Air quality management plan

AQSRs Air quality sensitive receptors

ASTM ASTM International (international standards organisation)

CO Carbon monoxide

EHS Environmental, Health and Safety (guidelines)

EIA Environmental Impact Assessment

EMPr Environmental Management Programme

FOE Frequency of Exceedance

g Gram

g/s Gram per second

GIIP Good International Industry Practice

H2S Hydrogen sulfide

I&AP Interested and Affected Parties

IFC International Finance Corporation

m Metre

m² Metre squared

m³ Metre cubed

m/s Metres per second

MW Mega Watt

NAAQ Limit National Ambient Air Quality Limit concentration

NAAQS National Ambient Air Quality Standards (as a combination of the NAAQ Limit and the allowable frequency of exceedance)

NAEIS National Atmospheric Emissions Inventory System

NDCR National Dust Control Regulations

NEMA National Environmental Management Act

NEM:AQA National Environmental Management Air Quality Act

NH3 Ammonia

NO2 Nitrogen dioxide

NOx Oxides of nitrogen

NPI (Australian) National Pollutant Inventory

O3 Ozone

PM Particulate matter

PM10 Particulate matter with diameter of less than 10 µm

PM2.5 Particulate matter with diameter of less than 2.5 µm

SAAQIS South African Air Quality Information System

SLR SLR Consulting (South Africa)(Pty) Ltd.

SO2 Sulfur dioxide

TSP Total Suspended Particulates

TVOCs Total Volatile Organic Compounds

US EPA United States Environmental Protection Agency

UTM Universal Transverse Mercator (projection)

VTAPA Vaal Triangle Airshed Priority Area

WHO World Health Organization

µ micro

°C Degrees Celsius

Note: The spelling of “sulfur” has been standardised to the American spelling throughout the report. "The International Union of Pure and Applied Chemistry, the international professional organisation of chemists that operates under the umbrella of UNESCO, published, in 1990, a list of standard names for all chemical elements. It was decided that element 16 should be spelled “sulfur”. This compromise was to ensure that in future searchable data bases would not be complicated by spelling variants. (IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.doi: 10.1351/goldbook)"

http://goldbook.iupac.org/

http://goldbook.iupac.org/


Report No.: 17SLR25 Report Version: Rev 2 vii

Glossary

Air-shed An area, bounded by topographical features, within which airborne contaminants can be retained for an extended period

Algorithm A mathematical process or set of rules used for calculation or problem-solving, which is usually undertaken by a computer

Atmospheric dispersion model A mathematical representation of the physics governing the dispersion of pollutants in the atmosphere

Atmospheric stability A measure of the propensity for vertical motion in the atmosphere

Baseline Information gathered at the beginning of a study which describes the environment prior to development of a project and against which predicted changes (impacts) are measured.

Calm / stagnation A period when wind speeds of less than 0.5 m/s persist

Cartesian grid A co-ordinate system whose axes are straight lines intersecting at right angles

Causality The relationship between cause and effect

Cumulative Impacts Direct and indirect impacts that act together with current or future potential impacts of other activities or proposed activities in the area/region that affect the same resources and/or receptors.

Construction Phase The stage of project development comprising site preparation as well as all construction activities associated with the development.

Convection Vertical movement of air generated by surface heating

Convective boundary layer The layer of the atmosphere nearest to the surface containing convective air movements

Diffusion Clean air mixing with contaminated air through the process of molecular motion. Diffusion is a very slow process compared to turbulent mixing.

Dispersion The lowering of the concentration of pollutants by the combined processes of advection (turbulent mixing) and diffusion

Environmental Authorisation Permission granted by the competent authority for the applicant to undertake listed activities

in terms of the NEMA EIA Regulations, 2014.

Environmental Impact Assessment A process of evaluating the environmental and socio-economic consequences of a proposed

course of action or project.

Environmental Impact Assessment

Report

The report produced to relay the information gathered and assessments undertaken during

the Environmental Impact Assessment.

Environmental Management Programme A description of the means (the environmental specification) to achieve environmental

objectives and targets during all stages of a specific proposed activity.

Impact A change to the existing environment, either adverse or beneficial, that is directly or indirectly

due to the development of the project and its associated activities.

Mitigation measures Design or management measures that are intended to minimise or enhance an impact,

depending on the desired effect. These measures are ideally incorporated into a design at an

early stage.

Operational Phase The stage of the works following the Construction Phase, during which the development will

function or be used as anticipated in the Environmental Authorisation.

Specialist study A study into a particular aspect of the environment, undertaken by an expert in that

discipline.

Stakeholders All parties affected by and/or able to influence a project, often those in a position of authority

and/or representing others.


Report No.: 17SLR25 Report Version: Rev 2 1


1 INTRODUCTION

1.1 Background

The development of a maize wet mill is proposed near Vereeniging, Gauteng. The wet mill will produce up to five liquid

products and, potentially, four dry products. Airshed Planning Professionals (Pty) Ltd was appointed by SLR Consulting

(South Africa) (Pty) Ltd (SLR) to undertake an Air Quality Impact Assessment (AQIA) as part of the Environmental Impact

Assessment (EIA) to identify key aspects that may have significant air quality impacts during the various project phases. As

such the report conforms to the amended regulated format requirements for specialist reports as per the Appendix 6 of EIA

Regulations (Government Gazette No. 40772, 7 April 2017). This report covers the air quality impact assessment for the

proposed maize wet mill.

The locality of proposed maize wet mill, in relation to the surrounding activities is shown in Figure 1-1.

1.2 Terms of Reference

The specific terms of reference for the overall project are as follows:

• identify and describe the existing air quality of the project area, as well as climatic patterns and features (i.e. the

baseline);

• assess (model) the impact on air quality (specifically particulate matter) and human health and biota resulting from

the proposed facility (including impacts associated with the construction, operational, decommissioning and post-

closure phases of the project);

• identify and describe potential cumulative air quality impacts resulting from the proposed project in relation to

proposed and existing developments in the surrounding area;

• recommend mitigation measures to minimise impacts and/or optimise benefits associated with the project; and

• recommend a monitoring campaign to ensure the correct implementation and adequacy of recommenced

mitigation measures, if applicable.



Figure 1-1: Local setting of the proposed facility



2 METHODOLOGY

The air quality study includes both baseline and predicted impact assessment. The baseline characterisation includes the

following enabling tasks:

• Identification of existing sources of emission and characterization of ambient air quality in the study area using

data from the nearest continuous air quality monitoring station (AQMS) and a qualitative interpretation of dominant

sources in the vicinity.

o A short-term on-site monitoring campaign was conducted during April and May to contextualise the on-

site baseline in relation to the baseline conditions at the nearest AQMS.

• It is important to have a good understanding of the meteorological parameters governing the rate and extent of

dilution and transportation of air pollutants that are generated by the proposed project. The primary meteorological

parameters for air pollutant dispersion include wind speed, wind direction and ambient temperature. Other

meteorological parameters that influence the air concentration levels include rainfall (washout) and a measure of

atmospheric stability. The latter quantities are normally not measured and are derived from other parameters such

as the vertical height temperature difference or the standard deviation of wind direction. The depth of the

atmosphere in which the pollutants can mix is similarly derived from other meteorological parameters by means of

mathematical parameterizations.

o The Sharpeville AQMS (managed by the Department of Environmental Affairs) in Sharpeville

(approximately 5 km south-west of the project site) measures wind speed, wind direction, temperature,

rainfall, relative humidity and barometric pressure; as well as a suite of atmospheric air pollutant

concentrations.

o Although long-term (2007 to 2017) data is available the assessment focussed on the period 2014 to

2016, in order to align with the period simulated in the dispersion modelling.

• Potential air pollution sensitive receptors within the study area were identified and georeferenced for detailed

analysis of the impact assessment calculations.

The impact assessment followed with the tasks below:

• The dispersion modelling was executed as per The Regulations Regarding Air Dispersion Modelling (Government

Gazette No 37804 vol. 589; published 11 July 2014). Three Levels of Assessment are defined in the Regulations.

Level 2 was deemed adequate. These are described under Section 4.3.

• Preparation of the model control options and input files for the AERMOD dispersion modelling suite. This included

the compilation of:

o terrain information (topography, land use, albedo and surface roughness);

o source layout; and

o grid and receptor definitions.

• Preparation of hourly average meteorological data for the wind field and atmospheric dispersion model.

• Preparation of an emissions inventory (particulates) for the proposed operations, including:

o Boiler emission (point sources)

o Maize handling operations (volume sources)

o Fugitive sources1:

▪ Vehicle particulate entrainment (area sources);

1 Fugitive particulate matter (PM) emissions will be released to atmosphere during these activities. Fugitive emissions refer to emissions

that are spatially distributed over a wide area and not confined to a specific discharge point as would be the case for process related

emissions (IFC, 2007).



o Emission limits and emission factors were used to quantify emission rates based on design process

rates.

• Using the emissions inventory, simulations were conducted using the AERMOD dispersion modelling suite, which

calculated ambient air pollutant concentrations.

• The legislative and regulatory context, including emission limits and guidelines, ambient air quality guidelines and

dustfall classifications were used to assess the impact and recommend additional emission controls, mitigation

measures and air quality management plans to maintain the impact of air pollution to acceptable limits in the study

area. The model results were analysed against the NAAQS and NDCR.

2.1 Analysis

2.1.1 AERMOD Modelling Suite

As per the National Code of Practice for Air Dispersion Modelling use was made of the US EPA approved AERMOD

atmospheric dispersion modelling suite for the simulation of ambient air pollutant concentrations and dustfall rates.

AERMOD is a gaussian plume model, which are best used for near-field applications where the steady-state meteorology

assumption is most likely to apply. The AERMOD model is one of the most widely used gaussian plume model. AERMOD is

a Gaussian plume model best used for near-field applications where the steady-state meteorology assumption is most likely

to apply. AERMOD is a model developed with the support of the AMS/EPA Regulatory Model Improvement Committee

(AERMIC), whose objective has been to include state-of the-art science in regulatory models (Hanna, Egan, Purdum, &

Wagler, 1999). AERMOD is a dispersion modelling system with three components, namely: AERMOD (AERMIC Dispersion

Model), AERMAP (AERMOD terrain pre-processor), and AERMET (AERMOD meteorological pre-processor).

AERMOD is an advanced new-generation model designed to simulate pollution concentrations from continuous point, flare,

area, line, and volume sources. AERMOD offers advanced algorithms for plume rise and buoyancy, and the computation of

vertical profiles of wind, turbulence and temperature. However, retains the single straight-line trajectory limitation. AERMET

is a meteorological pre-processor for AERMOD. Input data can come from hourly cloud cover observations, surface

meteorological observations and twice-a-day upper air soundings. Output includes surface meteorological observations and

parameters and vertical profiles of several atmospheric parameters. AERMAP is a terrain pre-processor designed to simplify

and standardise the input of terrain data for AERMOD. Input data includes receptor terrain elevation data. The terrain data

may be in the form of digital terrain data. The output includes, for each receptor, location and height scale, which are

elevations used for the computation of air flow around hills. A disadvantage of the model is that spatial varying wind fields,

due to topography or other factors cannot be included. Input data types required for the AERMOD model include: source

data, meteorological data (pre-processed by the AERMET model), terrain data and information on the nature of the receptor

grid.

The AERMOD modelling suite consists of several components, as summarised in Table 2-1; however, only AERMOD

contains the simulation engines to calculate the dispersion and removal mechanisms of pollutants released into this

boundary layer. The other codes are mainly used to assist with the preparation of input and output data. Table 2-1 also

includes the development versions of each of the codes used in the investigation.

Table 2-1:Summary description of AERMOD model suite with versions used in the investigation

Module Interface Version Executable Description

AERMOD Breeze v8.0.0.33 (US) EPA 16216r Gaussian plume dispersion model.

AERMET Breeze v7.8.0.2 (US) EPA 16216 Meteorological pre-processor for creating AERMOD compatible



Module Interface Version Executable Description

formats.

AERMAP Breeze v8.0.0.33 (US) EPA 11103 Topographical pre-processor for creating digital elevation data in a format compatible with the AERMOD control file.

The execution phase (i.e. dispersion modelling and analyses) involves gathering specific information regarding the emission

source(s) and site(s) to be assessed, and subsequently the actual simulation of the emission sources and determination of

impact significance. The information gathering included:

Source information: emission rate, source extents and release height;

Site information: site layout, terrain information, and land use data;

Meteorological data: a minimum of wind speed, wind direction, temperature, and sensible heat flux or Monin-

Obukhov length; and

Receptor information: locations using discrete receptors and/or gridded receptors.

2.1.1 Meteorological Requirements

An understanding of the atmospheric dispersion potential of the area is essential to an air quality impact assessment. In the

absence of on-site surface and upper air (sounding) meteorological data required for atmospheric dispersion modelling,

surface parameters measured at the Sharpeville AQMS for the period 2014 to 2016 were used and upper air profiles

estimated by AERMET. The data set is considered representative of the site due to the close proximity and lack of

significant topographical features.

2.1.2 Topographical and Land Use Data

The terrain near the proposed facility is flat or gently sloping (less than 10%), and therefore does not meet the

recommendation to include terrain.

2.1.3 Receptor Grid

The dispersion of pollutants expected to arise from the proposed operations was simulated for an area covering 12.5 km

(east-west) by 12.5 km (north-south). The area was divided into a grid matrix with a resolution of 100 m. AERMOD

calculates ground-level concentrations and dustfall rates at each grid point. The grid details used in dispersion modelling are

given in Table 2-2.

Table 2-2:Simulation domain

Parameter Simulation domain

South-western corner of simulation domain 583 622 m (Easting); 7 043 783 m (Northing)

Domain size 12.5 x 12.5 km

Projection Grid: UTM Zone 35S, Datum: WGS-84

Resolution 100 m

2.1.4 Dispersion results



The dispersion model uses the specific input data to run various algorithms to estimate the dispersion of pollutants between

the source and receptor. The model output is in the form of a simulated time-averaged concentration at the receptor. These

simulated concentrations are added to suitable background concentrations and compared with the relevant ambient air

quality standard or guideline. The post-processing of air concentrations at discrete receptors as well as the regular grid

points include the calculation of the frequency of exceedance of NAAQ limit concentrations, which corresponds to the

requirements of the NAAQS.

Ground level concentration isopleths plots presented in this report depict interpolated values from the concentrations

simulated by AERMOD for each of the receptor grid points specified. Plots reflecting hourly and daily averaging periods

contain the frequency that the simulated ground level concentrations exceed the National Ambient Air Quality (NAAQ) limit

concentration, for those averaging periods, over an annual period. Typically, the National Ambient Air Quality Standards

(NAAQS) apply to areas where the Occupational Health and Safety regulations do not apply, thus outside the proposed

facility property boundary. Ambient air quality guidelines and standards are therefore not occupational health indicators but

applicable to areas where the public has access i.e. off-site.

2.1.5 Uncertainty of Modelled Results

There will always be some error in any geophysical model; however, modelling is recognised as a credible method for

evaluating impacts, 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.

The stochastic uncertainty includes all errors or uncertainties in data such as source variability, observed concentrations,

and meteorological data. Even if the field instrument accuracy is excellent, there can still be large uncertainties due to

unrepresentative placement of the instrument (or taking of a sample for analysis). Model evaluation studies suggest that the

data input error term is often a major contributor to total uncertainty. Even in the best tracer studies, the source emissions

are known only with an accuracy of ±5%, which translates directly into a minimum error of that magnitude in the model

predictions. It is also well known that wind direction errors are the major cause of poor agreement, especially for relatively

short-term predictions (minutes to hourly) and long downwind distances. All the above factors contribute to the inaccuracies

not even associated with the mathematical models themselves.

A disadvantage of AERMOD is that spatial varying wind fields, due to topography or other factors cannot be included.

Although the model has been shown to be an improvement on the ISC model, especially short-term predictions, the range of

uncertainty of the model predictions is -50% to 200%. The accuracy improves with fairly strong wind speeds and during

neutral atmospheric conditions.

2.2 Impact Assessment

Potential impacts of the proposed project were identified based on the project description, review of other studies for similar

projects and professional experience. The significance of the impacts was assessed using the provided SLR impact rating

methodology (Appendix D). The significance of an impact is defined as a combination of the consequence of the impact

occurring and the probability that the impact will occur. The impact significance was rated for normal operations, assuming

the effective implementation of design mitigation measures, and for the additionally mitigated operations.



2.3 Mitigation and Management Recommendations

Where required additional mitigation and optimisation measures that can be implemented effectively to reduce or enhance

the significance of impacts were identified and the impact quantified.

2.4 Assumptions, Limitations and Exclusions

The study is based on a number of assumptions and is subject to certain limitations, which should be borne in mind when

considering information presented in this report. The validity of the findings of the study is not expected to be affected by

these assumptions and limitations:

1. All project information required to calculate emissions for proposed operations were provided by the applicant or

its design engineers.

2. The baseline air quality is based on the data from the Sharpeville AQMS which is located approximately 5 km

south-west of the proposed facility. The sources of air pollutants near the AQMS may differ from those near the

proposed site.

3. The impact of the construction and operational phases were determined qualitatively and assumed, along with

decommissioning phase impacts, to be equal or less significant than construction phase impacts. Mitigation and

management measures recommended are provided for the construction and decommissioning. No impacts are

expected post-closure provided the rehabilitation of final land forms is successful.

4. Particulate matter, with reference to Total Particulate Matter (TSP); PM10 (Particulate matter with an aerodynamic

dimeter less than 10 µm) and PM2.5 (particulate matter with an aerodynamic dimeter less than 2.5 µm) and sulfur

dioxide (SO2) are the main pollutants of concern from the proposed operations. Oxides of nitrogen (NOX), from

coal combustion, were also quantified and assessed.

5. The following pollutants were not quantified:

a. Sulfite emissions may result from the maize steeping process; however, emission factors are not

available to quantify emissions from these process steps. Control systems have been planned in order

to minimise emissions and prevent occupational exposure.

b. Refining of maize sugars into liquid product streams may also results in emissions of chloride and

volatile organic compounds. These emission streams will be fitted with off-gas scrubbing systems to

minimise emissions.

6. Emissions:

a. The quantification of sources of emission was restricted to the proposed operations using design

parameters available. Baseline (i.e. predevelopment) air quality was assessed using a three-year data

set from a nearby Air Quality Monitoring Station (AQMS) and a short on-site monitoring campaign.

b. Process particle size, moisture and silt content data were not available and therefore default values

described in the emission factor literature were used.

c. Emissions of malodourous compounds from the maize wet mill and associated waste water treatment

facility were not quantified due to the detailed information required to quantify emissions (which was not

available at this stage). However, these are not likely to be significant sources of malodourous

emissions. Other processes resulting in malodourous emissions in the vicinity are likely to mask impacts

from the proposed maize wet mill and waste water treatment facility.

7. The assessment conservatively assessed the impact of coal use only. The use of other fuels, such as methane

recovered from the waste water treatment plant, combusted in the boilers would reduce the impact of the plant on

ambient concentrations of particulates, SO2 and NOX.

Other assumptions made in the report are explicitly stated in the relevant sections.



3 PROJECT DESCRIPTION

The proposed maize wet mill will manufacture glucose and starch products from maize and corn oil and feed as by-products

(Figure 3-1). Maize will be delivered by haul truck and moved to four storage silos where dust removal systems will have

been fitted to minimise particulate emissions. The corn cleaning process will remove dust and broken corn and foreign

material, including a dust removal system, and send the corn to the steep house. The steeping of corn is a cleaning and

preparatory step for the corn wet milling process, including three grinding steps, as well as germ separation and dewatering.

Solid product (gluten, and fibre) is dewatered and dried where drying is via indirect heat and excess air is filtered prior to

venting to the atmosphere. Starch is fed to the conversion process where enzymatic reactions, carbon treatment,

demineralisation and isomerisation reactions convert the starch to produce glucose. Glucose is concentrated using

evaporators. Products are then moved to storage in preparation for shipping.

Figure 3-1: Maize wet mill process flow diagram

The atmospheric pollutants of concern associated with maize wet mills are: particulate matter (PM) from grain storage and

handling operations; total volatile organic compounds (TVOCs) from grain drying and starch production; sulfur dioxide (SO2)

from maize wet milling operations. The focus of this report is on the PM emissions, boiler combustion emissions (SO2, NO2,

and PM), process TVOC emissions, and PM emissions associated with vehicle entrainment on haul and access roads.

Malodourous compounds can also be released during the maize wet milling and syrup refining processes. Potentially

malodourous emissions could result from a number of process steps (Table 3-1). Emissions of malodourous compounds

from the maize wet mill and associated waste water treatment facility were not quantified due to the detailed information

required to quantify emissions (which was not available at this stage). However, these are not likely to be significant sources

of malodourous emissions, especially if control systems are included in the engineering design and operation of the mill.

Other processes resulting in malodourous emissions in the vicinity, including a large scale municipal waste water treatment

works and an abattoir with a rendering plant, are likely to mask impacts from the proposed maize wet mill and waste water

treatment facility.



Table 3-1: Potential malodours emissions from the proposed maize wet mill

Malodour Emission Source Compounds and odour

characteristic Cause of malodours Control of malodours

Maize steeping process SO2 pungent odour in slurries Sulfite used in the steeping

process steps

Enclosure and venting of

process equipment. Wet

scrubbing of extracted process

gases.

Germ driers A toasted smell not usually

considered objectionable

Gluten driers Burnt odour and blue-brown

haze

Temperatures above 423°C

promote smouldering in drying

equipment.

Drying temperature kept below

423°C.

Feed (germ and fibre) driers

Blue haze.

Acrid odours when TVOC

profiles contain acetic acid and

acetaldehyde.

Rancid odours when TVOC

profiles contain butyric and

valeric acids.

Fruity smells from a range of

aldehyde compounds.

Where steep-water (contain

sulfurous compounds) is

present in the feed can result

in unacceptable odours. Drying

temperatures above 423°C.

Drying temperature kept below

423°C.

Ionizing wet-collectors, with

possible addition of an alkaline

wash before and after ionizing.

Cooling of dryer exhaust to

condense out water vapour

can be sent to a water

treatment facility for reuse.

Waste water treatment facility

Various malodours compounds

including hydrogen sulfide

(H2S)

High sulfurous and organic

compound concentrations and

slurries and waste water

Chemical control to minimise

formation of H2S and other

malodours compounds.



4 APPLICABLE LEGISLATION

Prior to assessing the impact of proposed activities on human health and the environment, reference needs to be made to

the air quality regulations governing the calculation and impact of such operations, including reporting requirements,

emission standards, ambient air quality standards and dust control regulations. Air quality guidelines and standards are

fundamental to effective air quality management, providing the link between the source of atmospheric emissions and the

user of that air at the downstream receptor site. The ambient air quality standards and guideline values indicate safe daily

exposure levels for the majority of the population, including the very young and the elderly, throughout an individual’s

lifetime. Air quality guidelines and standards are normally given for specific averaging or exposure periods.

This section summarises legislation relevant to the proposed project, including: registration of Controlled Emitters, the

National Atmospheric Emission Reporting Regulations, Regulations regarding Air Dispersion Modelling, NAAQS and

National Dust Control Regulations (NDCR).

4.1 Controlled Emitters

A liquid or solid fuel boiler can be classified in one of four categories under NEM:AQA:

• A listed activity (Subcategory 1.2 – Liquid Fuel Combustion Installations, Subcategory 1.1 – Solid Fuel

Combustion Installations) as per Section 21 of NEM:AQA, applicable to all liquid and solid fuel combustion

installations used primarily for steam raising or electricity generation with a design capacity equal to or greater

than 50 MW heat input per unit, based on the lower calorific value of the fuel used.

• A controlled emitter as per Section 23(1) of NEM:AQA, applicable to any boiler with a design capacity equal to

10 MW but less than 50 MW net heat input per unit, based on the lower calorific value used.

• Unclassified under NEM:AQA, applicable to boilers with a design capacity less than 10 MW heat input per unit,

based on the lower calorific value used.

• Or, in the case where a waste is co-fed with conventional fuels, a listed activity (Subcategory 1.6 – Waste Co-

feeding combustion installations) as per Section 23(1) of NEM:AQA, applicable to all combustion installations co-

feeding waste with conventional fuels in processes primarily used for steam raising or electricity generation.

Based on estimated coal use per boiler (2.1 tonnes per hour), the proposed boilers will have a design capacity greater than

10 MW but less than 50 MW net heat input (15.75 MW per boiler) and will therefore require registration with the local

authority as a controlled emitter. Minimum emission standards apply for particulates (PM) and sulfur dioxide (SO2) (Table

4-1). It is understood that the boiler design will comply with the emission standards (Table 4-1).

Table 4-1: Minimum Emission Standards for Solid Fuel-fired Small Boilers

Description: Small boilers fuelled with solid fuels

Application: All small boilers fuelled with hydrocarbon based solid fuel, excluding biomass

Substance or Mixture of Substances Plant

Status

Emission concentration limit

(mg/Nm³ under normal conditions

of 273 Kelvin; 101.3 kPa; and, 10%

O2)

Design emission concentration

(mg/Nm³ under normal conditions

of 273 Kelvin; 101.3 kPa; and,

6% O2) Common Name Chemical

Symbol

Particulate matter PM New

120 150 [110 mg/Nm³ at 10% O2]

Sulfur dioxide SO2 2 800 2 000 [1 463 mg/Nm³ at 10% O2]



Based on the combined installed capacity of the proposed boilers (8 x 15.75 MW = 126 MW), as well as the location of the

proposed plant within an air quality priority area (Section 4.6), it is proposed that the operation of the boiler plant be

managed such that it meets the minimum emission standards for the listed activity (Section 21 Subcategory 1.1 – Solid Fuel

Combustion Installations) (Table 4-2). Compliance with the minimum emission standards for Subcategory 1.1 installations

was assessed as part of the additional mitigation scenario (Section 8).

Table 4-2: Minimum Emission Standards for Subcategory 1.1: Solid Fuel Combustion Installations

Description: Solid fuel combustion installations used primarily for steam raising or electricity generation.

Application: All installations with design capacity equal to or greater than 50 MW heat input per unit, based on the

lower calorific value of the fuel used.

Substance or Mixture of Substances

Plant Status

Emission concentration limit

(mg/Nm³ under normal conditions of

273 Kelvin; 101.3 kPa; and, 10% O2) Common Name Chemical Symbol

Particulate matter PM

New

50

Sulfur dioxide SO2 500

Oxides of nitrogen NOx (expressed as NO2) 750

4.2 Atmospheric Emissions Reporting Regulations

The National Atmospheric Emission Reporting Regulations (Government Gazette No. 38633) came into effect on 2 April

2015. The purpose of the regulations is to regulate the reporting of data and information from an identified point, non-point

and mobile sources of atmospheric emissions to an internet-based National Atmospheric Emissions Inventory System

(NAEIS). The NAEIS is a component of the South African Air Quality Information System (SAAQIS). Its objective is to

provide all stakeholders with relevant, up to date and accurate information on South Africa's emissions profile for informed

decision making.

Emission sources and data providers are classified according to groups. As the proposed operations would be classified

under Group B (“Controlled emitter declared in terms of section 23 of the Act”) emission reports from this group must be

made in the format required for NAEIS and if applicable should be in accordance with the registration of the controlled

emitters.

As per the regulations, the facility owner / operator and/or their data provider should be registered on the NAEIS system as

they are currently operating. Data providers must inform the relevant authority of changes if there are any:

• Change in registration details;

• Transfer of ownership; or

• Activities being discontinued.

A data provider must submit the required information for the preceding calendar year to the NAEIS by 31 March of each

year. Records of data submitted must be kept for a period of 5 years and must be made available for inspection by the

relevant authority.

The relevant authority must request, in writing, a data provider to verify the information submitted if the information is

incomplete or incorrect. The data provider then has 60 days to verify the information. If the verified information is incorrect or



incomplete the relevant authority must instruct a data provider, in writing, to submit supporting documentation prepared by

an independent person. The relevant authority cannot be held liable for cost of the verification of data. A person guilty of an

offence in terms of section 13 of these regulations is liable for penalties.

4.3 Atmospheric Dispersion Modelling Regulations

Air dispersion modelling provides a cost-effective means for assessing the impact of air emission sources, the major focus of

which is to determine compliance with the relevant ambient air quality standards. Dispersion modelling provides a versatile

means of assessing various emission options for the management of emissions from existing or proposed installations.

Regulations regarding Air Dispersion Modelling were promulgated in Government Gazette No. 37804 vol. 589; 11 July 2014,

(Government Gazette, 2014) and recommend a suite of dispersion models to be applied for regulatory practices as well as

guidance on modelling input requirements, protocols and procedures to be followed. The Regulations regarding Air

Dispersion Modelling are applicable –

(a) in the development of an air quality management plan, as contemplated in Chapter 3 of the NEM:AQA;

(b) in the development of a priority area air quality management plan, as contemplated in Section 19 of the

NEM:AQA;

(c) in the development of an Atmospheric Impact Report (AIR), as contemplated in Section 30 of the NEM:AQA; and,

(d) in the development of a specialist air quality impact assessment study, as contemplated in Chapter 5 of the

NEM:AQA.

Three Levels of Assessment are defined in the Regulations. The three levels are:

• Level 1: where worst-case air quality impacts are assessed using simpler screening models

• Level 2: for assessment of air quality impacts as part of license application or amendment processes, where

impacts are the greatest within a few kilometres downwind (less than 50km)

• Level 3: require more sophisticated dispersion models (and corresponding input data, resources and model

operator expertise) in situation:

o where a detailed understanding of air quality impacts, in time and space, is required;

o where it is important to account for causality effects, calms, non-linear plume trajectories, spatial

variations in turbulent mixing, multiple source types & chemical transformations;

o when conducting permitting and/or environmental assessment process for large industrial developments

that have considerable social, economic and environmental consequences;

o when evaluating air quality management approaches involving multi-source, multi-sector contributions

from permitted and non-permitted sources in an air-shed; or,

o when assessing contaminants resulting from non-linear processes (e.g. deposition, ground-level O3,

particulate formation, visibility).

The first step in the dispersion modelling exercise requires a clear objective of the modelling exercise and thereby gives

clear direction to the choice of the dispersion model most suited for the purpose. Accordingly, Level 2 was deemed

appropriate.

4.4 South African National Ambient Air Quality Standards

National Ambient Air Quality Standards (NAAQS) were determined based on international best practice for inhalable

particulate matter (PM2.5), thoracic particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide

(CO), ozone, lead and benzene. The NAAQS permit a frequency of exceedance (FOE) of 1% per year (88 hours or 4 days

per year) for 1-hour and 24-hour average concentrations of some pollutants. Simulated ambient air pollutant concentrations



were assessed against NAAQS (Table 4-3), where PM2.5; PM10; SO2; and, NO2 were the criteria pollutants of concern in this

assessment.

Table 4-3: National Ambient Air Quality Standards for pollutants of concern in this assessment

Pollutant Averaging

Period Concentration

(μg/m³) Concentration

(ppb)

Permitted Frequency of Exceedance

(FOE) Compliance Date

PM2.5

24 hours 40 - 4 Enforceable between 1 January 2016 to 31 December 2029 1 year 20 - -

24 hours 25 - 4 Enforceable from 1 January 2030

1 year 15 - -

PM10 24 hours 75 - 4

Currently enforceable 1 year 40 - -

SO2

1 hour 350 134 88

Currently enforceable 24 hours 125 48 4

1 year 50 19 -

NO2 1 hour 200 106 88

Currently enforceable 1 year 40 21 -

Benzene 5 1.6 - Currently enforceable

4.5 National Dust Control Regulations

The National Dust Control Regulations (NDCR) were gazetted on 1 November 2013 (No. 36974). The purpose of the

regulations is to prescribe general measures for the control of dust in all areas including residential and light commercial

areas. The standard for acceptable dustfall rate is set out in Table 4-4. The method to be used for measuring dustfall rate

and the guideline for locating sampling points shall be ASTM D1739: 1970, or equivalent method approved by any

internationally recognized body.

Table 4-4: Acceptable dust fall rates

Restriction Area Dust-fall rate (D) (mg/m²/day, 30-

day average) Permitted frequency of exceeding dust fall rate

Residential D < 600 Two within a year, not sequential months.

Non-residential 600 < D < 1 200 Two within a year, not sequential months

Note: The method to be used for measuring dustfall rate and the guideline for locating sampling points shall be ASTM D1739: 1970, or

equivalent method approved by any internationally recognized body

4.6 The Vaal Triangle Airshed Priority Area

The proposed location of the maize wet mill is within the Vaal Triangle Airshed Priority Area: an area of already

compromised air quality. The spatial extent of the priority area includes: Regions D and G of the City of Johannesburg; the

Emfuleni Local Municipality; the Midvaal Local Municipality; and, the Metsimaholo Local Municipality.

The Vaal Triangle is a highly industrialised area housing numerous industries, a coal fired power station, and various smaller

industrial and commercial activities in addition to a few collieries and quarries giving rise to noxious and offensive gasses.

The Vaal Triangle is also home to a number of large informal settlements mainly using coal and wood as fuel source. This in

return impacts directly on the health and well-being of the people residing there. Other sources of concern contributing to the



pollution mixture within the area include vehicle tailpipe emissions, biomass burning, water treatment works and landfill

areas, agricultural activities and various other fugitive sources.

An Air Quality Management Plan (AQMP), providing detailed intervention strategies, was developed for the Vaal Triangle

Priority area between 2007 and 2009, with the final plan published 29 May 2009 (Government Gazette No. 32254). It should

be noted that the development of this plan preceded the publication of National Ambient Air Quality Standards (Government

Gazette No. 32816, 24 December 2009) and Minimum Emission Standards (Government Gazette No. 33064, 31 March

2010 and revised on 23 November 2013, No. 37054).

The 2009 Vaal Triangle Priority Area AQMP is currently under revision to determine the improvement, if any that resulted

from the implementation of the 2009 AQMP and to provide new/ additional reductions strategies.

The proposed site is located centrally within the Priority Area and has several important implications for this operation. New

developments which are associated with atmospheric emissions, and hence the potential for contributing to air pollutant

concentrations, are subject to intense scrutiny by national air pollution control officers. Emphasis is being placed on ensuring

that best practice control measures are being proposed for implementation and that the development will not substantially

add to the existing air pollution burden in the region. Existing industries with significant emissions are likely to be expected to

implement emission reduction programmes and air quality management measures for other significant sources (e.g.

household fuel burning) will be sought and implemented.

Operating in the Priority Area will require stringent compliance with NEM:AQA from construction phase; including, but not

limited to: a facility-specific air quality management plan (AQMP) using best available technology emissions controls

(engineering design) and best practice on-site control of fugitive emissions. A complaints register will be required from on-

set of the construction phase.

4.7 International Finance Corporation Environmental, Health and Safety Guidelines

The technical reference documents published in the International Finance Corporation (IFC) Environmental, Health and

Safety (EHS) Guidelines provide general and industry specific examples of Good International Industry Practice (GIIP). The

General EHS Guidelines are designed to be used together with the relevant Industry Sector EHS Guidelines.

The EHS Guidelines’ general approach to air quality (IFC, 2007) states that projects should prevent or minimize impacts by

ensuring that:

• Emissions do not result in pollutant concentrations that reach or exceed the relevant national ambient air quality

guidelines and standards, or in their absence, the current World Health Organisation (WHO) Air Quality Guidelines

(AQG) or other internationally recognised sources;

• Emissions do not contribute a significant portion to the attainment of relevant ambient AQG or standards. The

Guideline suggests 25% of the applicable ambient air quality standards to allow additional, future development in

the same airshed.

The General EHS Guidelines state that at project level, impacts should be estimated through qualitative or quantitative

assessments using baseline air quality assessments and atmospheric dispersion models. The dispersion model should be

internationally recognised and able to consider local atmospheric, climatic and air quality data as well as the effects of

downwash, wakes or eddy effects generated by structures and terrain features (IFC, 2007).

The General EHS Guidelines also provides guidance with respect to:

• projects located in degraded airsheds or ecologically sensitive areas;



• points sources and stack heights;

• emissions from small combustion facilities (3 to 50 MW (thermal) rated heat input capacity);

• fugitive sources;

• ozone depleting substances;

• land based mobile sources;

• greenhouse gases;

• monitoring; and

• air emissions prevention and control technologies.



5 AIR QUALITY BASELINE

5.1 Affected Environment

The maize wet mill is proposed for development near the Leeuwkuil area of Vereeniging, in the Emfuleni Local and

Sedibeng District Municipalities. The proposed site is close to existing residential areas (both formal and informal) and

industrial activities. Formal residential areas occur to the north (Correctional Services Facility – the closest being the staff

accommodation) and to the east of the R59 (Leeuhof). Informal residences include the occupation of an abandoned building

to the west of the proposed site, and informal housing for cattle herders to the south of the proposed site. Industrial activities

near to the proposed site include: workshops and warehousing to the north and west; a fresh produce market to the west;

wheat mill plant to the north; engineering and fabrication facilities to the north; Leeuwkuil waste water treatment works to the

south; and an abattoir and rending plant to the south east. The proposed site is located centrally within the Vaal Triangle

Airshed Priority Area (VTAPA); an area of already compromised air quality.

The National Ambient Air Quality Standards (NAAQS) (Section 4.4) are based on human exposure to specific criteria

pollutants and as such, receptors were identified where the public is likely to be unwittingly exposed. NAAQS are

enforceable outside of the property of the proposed facility, therefore the receptors identified (Figure 5-1) included the

nearby hospitals, schools, air quality monitoring station (AQMS), as well as nearby industrial, commercial, and residential

areas (Table 5-1).

Table 5-1: Distance to nearby air quality sensitive receptors

Receptor details Distance from centre of

proposed site (m) Direction from proposed site

Leeuhof Residential Area 262 E

Dept of Correctional Services, including staff accommodation 398 N

Roads agency 405 NW

SAB depot 426 SSW

Telkom office / stores / workshop 427 NW

Preschool (located on Lager Road) 525 SW

Single residence (building appears to be occupied) 535 W

Fresh Produce Market 879 W

Eureka School 1 120 SE

School hostel (General Smuts High School) 1 136 SE

Transnet 1 477 NW

Leeuwkuil Waste-water Treatment Works 1 522 SW

Rood Gardens A.H. 1 538 NW

General Smuts High School 1 595 SE

Vereeniging Gymnasium 1 658 E

Informal cattle post housing 1 748 SSW

Selborne Primary School 2 044 SE

Isizwe-Setjhaba Secondary School 2 083 NW

Medi-Clinic Vereeniging 2 089 SE

Phoenix High School 2 302 ENE

Care Cure 2 356 SE

Medi Zone Three Rivers 2 429 SE

Emmanuel Primary School 2 865 SSW

Kopanong Hospital 3 690 NE

Mohloli Secondary School 4 375 SW

Titima Primary School 4 409 SW

Sharpeville Air Quality Monitoring Station 5 028 SW



Figure 5-1: Location of the proposed project in relation to surroundings



5.2 Atmospheric Dispersion Potential

Meteorological mechanisms govern the dispersion, transformation, and eventual removal of pollutants from the atmosphere.

The analysis of hourly average meteorological data is necessary to facilitate a comprehensive understanding of the

dispersion potential of the site. The horizontal dispersion of pollution is largely a function of the wind field. The wind speed

determines both the distance of downward transport and the rate of dilution of pollutants.

Hourly sequential near-site meteorological and ambient air quality monitoring data was accessed for the 2014 to 2016

period from the Sharpeville air quality monitoring station (AQMS) which is located approximately 4.5 km south-west of the

proposed project site. The station records concentrations as a result of surrounding emissions including: domestic fuel

burning, as well as industrial emissions. This data was used in dispersion modelling and is discussed below.

5.2.1 Local Wind Field

The vertical dispersion of pollution is largely a function of the wind field. The wind speed determines both the distance of

downward transport and the rate of dilution of pollutants. The generation of mechanical turbulence is similarly a function of

the wind speed, in combination with the surface roughness.

The wind roses for Sharpeville (Figure 5-2 and Figure 5-3) comprise 16 spokes, which represent the directions from which

winds blew during the period. The colours reflected the different categories of wind speeds with the dotted circles indicating

the frequency of occurrence, and each circle representing a 3% frequency of occurrence.

The period wind field for Sharpeville (Figure 5-2) shows that the wind flow is dominated by north-westerly winds, followed by

winds from the north-east. Calm conditions occurred 8.5% of the period summarised. Day-time winds are more frequently

higher than 5 m/s, and predominantly from the west and north-west. Night-time (18:00 to 05:00) shows more calm conditions

(12.7%) with winds equally dominant from the north-east and north-west.

The seasonal wind field for Sharpeville shows winds usually from the north-east and north-west during autumn and winter

with winds from the north-east more dominant during summer. Spring-time winds show a predominance of north-westerly

winds with the winds more frequently above 5 m/s. Winter has the highest frequency of calms at 14%, while spring shows

the most infrequent calm conditions (3.9%).



Figure 5-2: Period, day-time and night-time wind roses for Sharpeville AQMS, 2014-2017

Figure 5-3: Seasonal wind roses for Sharpeville AQMS, 2014-2017



5.2.2 Ambient Temperature

The air temperature is important for determining the development of the mixing and inversion layers. Monthly temperatures

statistics for hourly data recorded at the Sharpeville AQMS (2013 to 2015) show that minimum temperatures can drop below

0°C between June and September, while maximum temperatures exceed 30°C between August and April (Table 5-2). The

period reported for the Sharpeville AQMS is within the range of the long-term average for the area; however, the maximum

for Sharpeville (39.1°C) is higher than the long-term average for the period 1950 to 2000. While elevated air temperatures

can assist with pollutant dispersion, heat waves (area average is 4 heat waves per year) can be associated with periods of

poor dispersion. Similarly, cold temperatures in winter are generally associated with near-surface inversion layers and poor

dispersion conditions.

Table 5-2: Minimum, average and maximum temperature per month from the Sharpeville AQMS (2014 - 2016), and

long-term (1950 to 2000) statistics at the same location

Temperature Month of Year Long-term

(1950 – 2000)(a) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Minimum 8.2 3.0 7.0 1.1 -1.7 -5.7 -5.0 -3.8 -1.2 2.9 5.9 9.1 -6.4

Average 21.8 21.7 20.0 17.1 13.9 10.8 10.4 13.8 18.5 20.2 20.9 21.7 16.8

Maximum 39.1 34.6 33.2 31.7 29.1 26.4 24.6 30.4 32.7 35.3 36.4 36.7 35.9

Notes: (a) Schulze et al. (2008)

Figure 5-4: Diurnal temperature profile for Sharpeville AQMS, 2014-2017

5.3 Existing Air Quality – Sharpeville AQMS

Several AQMS are located across the VTAPA and are owned and managed by both National and District government

departments, as well as industry partners. The closest station to the proposed facility is the Sharpeville station. Verified data



for the period 1 January 2014 to 31 December 2016 were made available for this study and a summary of measured

parameters is provided in Table 5-3. Non-compliance with the applicable NAAQS was recorded for: annual average NO2

concentration in 2015; and, PM10 and PM2.5 daily and annual concentrations for all years summarised. The pollutants of

concern for the facility (PM2.5, PM10, SO2, and NO2) are discussed below.

Table 5-3: Summary of the ambient measurements at Sharpeville for the period 2014 - 2016

Period Data Availability Hourly

Annual Average No of recorded hourly exceedances 99th Percentile

SO2 (units: ppb)

2014 96% 73.5 8.8 8

2015 87% 51.8 7.3 15

2016 80% 48.5 5.8 3

Average 57.9 7.3

NO2 (units: ppb)

2014 97% 50.6 15.1 1

2015 86% 83.3 23.3 15

2016 86% 55.7 15.8 -

Average 63.2 18.1

Period Data Availability Daily

Annual Average No of recorded daily exceedances 99th Percentile

PM2.5 (units: µg/m3)

2014 99% 112.5 38.3 34

2015 88% 97.9 36.5 27

2016 53% 77.2 31.6 43

Average 95.9 35.5

PM10 (units: µg/m3)

2014 99% 173.8 64.8 25

2015 89% 153.6 62.8 83

2016 86% 234.8 95.9 185

Average 187.4 74.5

SO2 (units: ppb)

2014 96% 35.7 8.8 -

2015 87% 35.9 7.3 2

2016 80% 28.4 5.8 -

Average 33.3 7.3

5.3.1 Particulate Matter (PM2.5 and PM10)

Exceedances of the NAAQ limit concentration for PM2.5 was exceeded between 27 (2015) and 43 (2016) days during the

assessment period (Table 5-3). Annual average concentrations also exceeded the NAAQS for all three years, despite low

data availability in 2016. Between 2014 and 2016, daily PM10 concentrations exceeded the NAAQ limit concentration a

maximum of 185 days (in 2016) and a minimum of 25 days (2014). Annual average concentrations exceeded NAAQS during

all three years with a maximum of 95.9 μg/m3 during 2016 (Table 5-3).

An analysis of the observed PM2.5 and PM10 concentrations at the Sharpeville AQMS involved categorising the concentration

values into wind speed and direction bins for different concentrations. The information is most easily visualised as polar

plots, where the centre of the polar plot refers to the location of the monitoring station (Figure 5-5). These polar plots

(Carslaw and Ropkins, 2012; Carslaw, 2013) provide an indication of the directional contribution as well as the dependence

of concentrations on wind speed. The directional display is fairly obvious, i.e. when higher concentrations are shown to

occur in a certain sector, e.g. north-easterly for PM10 (Figure 5-5b), it is understood that most of the high concentrations

occur when winds blow from that sector. The presence of a high concentration pattern which is more symmetrical around the



centre of the plot is an indication that the contributions are near-equally distributed, and occur under calm-wind conditions,

as for PM2.5 (Figure 5-5a). Local sources contribute to PM2.5 concentrations at low wind speeds, including domestic fuel

burning, informal waste burning, and vehicle entrainment on unpaved roads. While local sources also contribute to PM10

concentrations, the highest PM10 concentrations are associated with wind speeds above 6 m/s and originate to the north and

north-east.

(a) PM2.5 (b) PM10

Figure 5-5: Daily PM2.5 and PM10 (µg/m3) polar plots for Sharpeville

5.3.2 Sulfur Dioxide (SO2)

Ambient SO2 concentrations monitored at Sharpeville were compliant with the hourly, daily and annual NAAQS between

2014 and 2016 (Table 5-3), and maximum concentrations were recorded during 2014.

Sources of SO2 near the Sharpeville station include a source to the south east contributing the highest concentrations at

wind speeds between 1 and 4 m/s; lower concentrations from the south-east and east contribute at wind speeds greater

than 4 m/s (Figure 5-6). A contribution from the north-west also contributes at all wind speeds.



(a) SO2

Figure 5-6: Hourly SO2 (ppb) polar plot for Sharpeville

5.3.3 Nitrogen Dioxide (NO2)

The highest NO2 concentrations were recorded during 2015 at the Sharpeville station, where the annual average

concentration was exceeded NAAQS (Table 5-3). Compliance with hourly and annual NAAQS were recorded for 2014 and

2016.

Sources contributing to NO2 concentrations at Sharpeville originate to the north-west and north-north-east of the station at

wind speeds above 8 m/s (Figure 5-7). Local sources contribute at low speeds and could be associated with vehicle activity

and domestic fuel burning.



(a) NO2

Figure 5-7: Hourly mean NO2 (ppb) polar plot for Sharpeville

5.4 Existing Air Quality – On-site Measurement Campaign

A short-term on-site air quality monitoring campaign was conducted between 24th April and 22nd May 2018. The campaign

included: PM10 and PM2.5 monitoring using TAS MiniVol samplers; and passive-diffusive monitoring of SO2, and NO2.

5.4.1 Fine Particulates

Particulate matter with aerodynamic diameters less than 10 μm and 2.5 μm (or PM10 and PM2.5) was sampled using a TAS

MiniVol sampler - a filter-based, low volume sampler. The MiniVol samplers were set within the boundary of the SAB

distribution depot – away from major on-site activities likely to result in particulate emissions - as this was the most secure

location in the area and it provided easy access to the on-site employees who were trained to operate the samplers. The

fine particulate fractions were sampled on weekdays, and on one weekend during the campaign. Some interruptions to the

sampling frequency occurred due to public holidays and availability of staff on those days. It is therefore possible that peak

or low ambient PM concentrations were not recorded. The filters removed from the samplers were placed in sealed

containers and sent to Biograde Laboratory Services (Pretoria) for gravimetric analysis.

During the short-term on-site campaign, daily PM10 NAAQ limit concentration (75 μg/m3) was exceeded on six days (Table

5-4). The comparison with the Sharpeville AQMS daily averages over the same period shows good correlation; where four

days of exceedances co-occur at both locations. The days of exceedance are not associated with above average wind

speeds and overnight temperatures were relatively low, suggesting poor dispersion conditions for accumulated particulates.

Only one exceedance of the current daily PM2.5 NAAQ limit concentration was recorded during the on-site monitoring

campaign (Table 5-5). The comparison with the PM2.5 measured at the Sharpeville station is poor, where 15 days were

recorded to exceed the NAAQ limit concentration. This suggests a very localised source of PM2.5 relative to the Sharpeville

station. The day with the highest measured PM2.5 concentration at the on-site monitoring did, however, correspond with the

highest concentration measured at Sharpeville station. The long-term average PM10 and PM2.5 concentrations at the

Sharpeville station may be conservative relative to those at site.



Table 5-4: On-site ambient PM10 concentrations measured during April – May 2018 (red shading indicates

exceedance of the NAAQ limit concentration)

Date Day of week Hours exposed On-site daily PM10

concentration (μg/m3)

Sharpeville daily PM10 concentration

(μg/m3)

25/04/2018 Wednesday 24.4 79.7 62.3

26/04/2018 Thursday 32.3 1.6 63.3

30/04/2018 Monday 35.6 44.2 66.8

02/05/2018 Wednesday 26.0 40.3 53.3

03/05/2018 Thursday 21.7 48.7 51.9

04/05/2018 Friday 23.8 No data 41.7

07/05/2018 Monday 23.6 53.8 75.7

08/05/2018 Tuesday 24.4 111.4 88.3

09/05/2018 Wednesday 23.8 123.6 136.3

10/05/2018 Thursday 23.8 78.7 89.2

11/05/2018 Friday 23.1 102.4 91.1

12/05/2018 Saturday 24.2 38.8 77.8

13/05/2018 Sunday 23.2 48.8 59.0

14/05/2018 Monday 23.6 2.1 47.0

15/05/2018 Tuesday 24.1 2.1 26.2

16/05/2018 Wednesday 23.4 2.1 26.9

17/05/2018 Thursday 31.1 82.1 60.3

18/05/2018 Friday 17.0 2.8 77.3

21/05/2018 Monday 23.8 2.1 46.1

22/05/2018 Tuesday 20.5 2.4 47.2

Table 5-5: On-site ambient PM2.5 concentrations measured during April – May 2018 (red shading indicates

exceedance of the current NAAQ limit concentration)

Date Day of week Hours exposed On-site daily PM2.5

concentration (μg/m3)

Sharpeville daily PM2.5 concentration

(μg/m3)

24/04/2018 Tuesday 24.0 27.89 49.3

25/04/2018 Wednesday 24.4 23.37 36.3

26/04/2018 Thursday 59.2 23.94 41.2

30/04/2018 Monday 39.3 12.57 43.8

02/05/2018 Wednesday 26.0 16.91 38.1

03/05/2018 Thursday 21.7 2.28 44.8

04/05/2018 Friday 23.8 2.11 35.4

07/05/2018 Monday 23.9 16.80 48.0

08/05/2018 Tuesday 24.3 23.46 54.8

09/05/2018 Wednesday 23.9 47.59 91.8

10/05/2018 Thursday 29.8 16.14 57.2

11/05/2018 Friday 23.0 30.39 56.2

12/05/2018 Saturday 24.3 2.07 50.4

13/05/2018 Sunday 24.6 25.94 42.6

14/05/2018 Monday 23.5 2.13 31.1

15/05/2018 Tuesday 24.3 2.07 19.1

16/05/2018 Wednesday 23.4 2.14 23.9

17/05/2018 Thursday 31.2 6.64 42.6

18/05/2018 Friday 16.8 2.83 45.7



5.4.2 Passive-Diffusive Sampling

Radiello® passive diffusive tubes were used to sample SO2 and NO2 concentrations. Passive diffusive sampling relies on

the diffusion of analytes through a diffusive surface onto an adsorbent. After sampling, the analytes are chemically desorbed

by solvent extraction or thermally desorbed and analysed. Passive sampling does not involve the use of pumping systems

and does not require electricity. The concentration of analytes adsorbed during the exposure period can be calculated to

time-frames comparable with the NAAQS.

Passive diffusive samplers were placed at eye level at four locations around the proposed maize wet mill site: at the SAB

depot; at the Roads Agency site; at the Correctional Services Facility (near the staff accommodation); and, at a substation

on the eastern side of the proposed property near the R59 (Figure 5-1). The manufacturer approved rain shelter was

attached to a post to ensure protection against adverse weather conditions, while allowing adequate ventilation. Supporting

plates were assembled and operated according to manufacturer instructions. Exposure time was 14 days, within the period

recommended by the manufacturer (14 to 16 days). Two exposure periods were used during the on-site ambient monitoring:

(1) 24th April to 8th May 2018; and, (2) 8th May to 22nd May 2018. The analytical methods and calculations depend on the

pollutant according to the manufacturer specification sheets, where analysis was conducted by Biograde Laboratory

Services, Pretoria.

Figure 5-8: Location of passive diffusive samplers for SO2 and NO2 monitoring

To compare the 1-month (two 14-day contiguous sampling campaign) average sampled concentrations to long term (annual

average) NAAQS, equivalent annual average concentrations were extrapolated. For extrapolating time averaging periods of

from 24 hours to 1 year, Beychock (2005), recommends the following equation:

𝐶𝑥𝐶𝑝

= (𝑡𝑝

𝑡𝑥)0.53

where:

Cx and Cp are concentrations over any two averaging periods between 24 hours and 1 year;



tx and tp are corresponding averaging times in days.

Although mathematical extrapolations exist for averaging periods shorter than 24 hours, these extrapolations cannot be

used to determine the number of exceedances of the specified NAAQS limit values for 1-hour and 24-hour averaging

periods. It is therefore not appropriate for assessing compliance with short term NAAQS.

Calculated annual SO2 concentrations, based on the passive sampling, were compliant with the annual National Ambient Air

Quality Standard (NAAQS) (Table 5-6). The site with the highest campaign concentration was the Correctional Services site

(during Campaign 1), and the substation (during Campaign 2). Annualised NO2 concentration, based on the two contiguous

14-day exposure period, are likely to be compliant the annual NO2 standard (Table 5-6). The location with the highest

campaign concentrations was the substation, where concentrations could be associated with vehicle exhaust emissions

along the R59.

The concentrations of SO2 near the proposed maize wet mill are lower than concentrations measured at Sharpeville during

the same 14-day campaigns periods (Table 5-6). However, there is a better correlation between on-site measurements and

Sharpeville AQMS measurements of NO2. Both SO2 and NO2 annual concentrations on-site are lower than the long-term

average concentrations at Sharpeville. This is possibly related to the on-site campaign length (one month) and timing (prior

to the known winter-time peak concentrations measured at Sharpeville). The Sharpeville station is therefore representative

of the SO2 and NO2 concentrations in the area, include the proposed location of the maize wet mill.

Table 5-6: Ambient SO2 and NO2 concentrations measured near the proposed site of the maize wet mill (all units:

μg/m3)

Location

On-site 14-day exposure period concentration

Sharpeville 14-day exposure period concentration

Calculated on-site annual

concentration(a)

Sharpeville long-term average

concentration(b) Campaign 1 Campaign 2 Campaign 1 Campaign 2

SO2

SAB Depot 8.15 3.01

26.19 19.91

0.99

7.5 Roads Agency 5.22 1.40 0.59

Correctional Services 8.55 4.27 1.14

Substation 7.84 13.70 1.91

NO2

SAB Depot 20.84 14.20

28.52 33.41

3.11

16.2 Roads Agency 18.93 9.34 2.51

Correctional Services 21.73 20.79 3.78

Substation 23.03 23.25 4.11

Notes: (a) Calculated on-site annual concentrations are based on the two 14-day passive monitoring campaigns (b) The long-term average concentrations at Sharpeville are based on annual averages from 2007 to 2016



6 IMPACT ASSESSMENT: CONSTRUCTION PHASE

6.1 Emissions Inventory for Construction Phase

During the construction phase the following activities are likely to occur:

• Site establishment of construction phase facilities;

• Clearing of vegetation, stripping and stockpiling of soil resources and earthworks;

• Collection, storage and removal of construction related waste;

• Construction of all infrastructure required for the operational phase; and

• Operation of mechanical equipment, including haul trucks moving equipment and materials to- and from site.

6.2 Assessment of Impact

It is not anticipated that the various construction activities would result in higher PM2.5 and PM10 ground level concentrations

and dustfall rates than the operational phase activities. The temporary nature of the construction activities would likely

reduce the significance of the potential impacts. The main pollutants of concern would likely be PM. A qualitative

assessment of construction operations from the PM10, PM2.5 and TSP impacts perspective is discussed below.

Two potential direct construction phase impacts on the air quality of the area were identified:

• A1: Potential impact on human health from increased pollutant concentrations associated with construction

activities;

• A2: Increased nuisance dustfall rates associated with construction activities;

6.2.1 Potential Impact A1: Potential for impacts on human health from increased pollutant concentrations associated

with general construction activities

The sources of emissions would include site establishment in proposed operating areas; vegetation clearing; stripping and

stockpiling of topsoil and other earthworks; collection, storage and removal of construction related waste; the construction of

all required infrastructure; and the operation of mechanical equipment. It is unlikely that the long-term and short-term

NAAQS will be exceeded at air quality sensitive receptors (AQSRs) without mitigation in place. The construction operations

are likely to last approximately two years.

Unmitigated PM10 and PM2.5 emissions in the project area will probably result in a minor deterioration impact on human

health in the short-term in a localised area. The significance of the construction phase is likely to be LOW without mitigation,

and VERY LOW with mitigation applied.

6.2.2 Potential Impact A2: Increased nuisance dustfall rates associated with general construction activities

The sources of emissions would include site establishment in proposed operating areas; vegetation clearing; stripping and

stockpiling of topsoil and other earthworks; collection, storage and removal of construction related waste; the construction of

all required infrastructure; and the operation of mechanical equipment. It is unlikely that the NDCR limit for residential areas

will be exceeded at AQSRs (with and without mitigation). The construction operations are likely to last approximately two

years.

Unmitigated TSP emissions in the project area will possibly result in a minor deterioration impact on human health in the

short-term in a localised area. The significance of the construction phase is likely to be LOW without mitigation, and VERY

LOW with mitigation applied.



Table 6-1: Health risk impact significance summary table for the construction operations

Intensity Duration Spatial Extent Consequence Probability Significance

Without mitigation L L M Low Probable Low

Recommended mitigation measures:

Reduction of fugitive PM emissions through the watering of roads, stockpiles and inactive open areas and the use of screens.

Reductions of vehicle exhaust emissions using best quality diesel; and inspection and maintenance programs.

With mitigation L L L Low Possible Very Low

Table 6-2: Nuisance impact significance summary table for the construction operations

Intensity Duration Spatial Extent Consequence Probability Significance

Without mitigation L L M Low Probable Low

Recommended mitigation measures:

Reduction of fugitive PM emissions through the watering of roads, stockpiles and inactive open areas and the use of screens.

Reductions of vehicle exhaust emissions using best quality diesel; and inspection and maintenance programs.

With mitigation L L L Low Possible Very Low



7 IMPACT ASSESSMENT: OPERATIONAL PHASE – DESIGN MITIGATED

7.1 Emissions Inventory

The establishment of a comprehensive emissions inventory formed the basis for the assessment of the air quality impacts

from the proposed operations on the receiving environment. Operations occur within the three building areas and the

engineering designs include extraction systems to evacuate fugitive emissions from the process buildings. The following

sections describe the location and parameters of the individual sources associated with the proposed project.

7.1.1 Point Sources

Eight boilers – two flues per chimney stack – are proposed. Five boilers are proposed to operate simultaneously, with three

additional boilers used for rotational maintenance. The parameters (Table 7-1) and pollutant emission rates (Table 7-2) used

in dispersion modelling setup are summarised below. Emissions from the boilers were calculated using the maximum

allowable emission concentrations (Table 7-3).

Particulate and volatile organic compound (VOC) emissions from grain and dry solid product handling steps, from receiving

through to dispatch, will be vented to the atmosphere via point sources after emissions control systems (Chimneys 5 to 17).

The parameters (Table 7-1) and pollutant emission rates (Table 7-2) used in dispersion modelling setup are summarised

below. Emissions from the particulate control systems were calculated using the maximum emission concentrations as

provided by the design engineers (Table 7-3).



Table 7-1: Parameters for point sources of atmospheric pollutant emissions at the proposed facility

Point Source code

Source name Latitude

(decimal degrees) Longitude

(decimal degrees)

Height of Release Above

Ground (m) (a)

Height Above Nearby

Building (m)

Diameter at Stack Tip / Vent

Exit (m) (a)

Actual Gas Exit Temperature (°C) (a)

Actual Gas Volumetric Flow

(m³/hr) (a)

Actual Gas Exit Velocity

(m/s) (a)

STK1(d) Boiler stack 1 -26.66233 27.90709 38 23 1.5 120 84 611 13.3




CH5 Germ Silo Filter -26.662516 27.907387 29 1.0(b) 40 14 137 5.0

CH6 Fibre Silo Filter -26.662509 27.907457 29 1.0(b) 40 14 137 5.0

CH7 Gluten Silo Filter -26.662496 27.907532 29 1.0(b) 40 14 137 5.0

CH8 Broken Silo Filter -26.663287 27.908396 15 1.0(b) 40 14 137 5.0

CH9 Corn discharge dust

suction filter A -26.663716 27.908747 10 1.0(b) 25(c) 42 412 15.0


suction filter B -26.663347 27.908687 10 1.0(b) 25(c) 42 412 15.0

CH11 Germ cooler -26.662253 27.907967 29 1.0(b) 20 14 137 5.0

CH12 Gluten Dust

Collector -26.662356 27.907973 14.5 1.0(b) 20 14 137 5.0

CH13 Fibre Transfer Line

Air Filter -26.662459 27.908006 29 1.0(b) 20 14 137 5.0

CH15 Chemical Area

Scrubber -26.661163 27.908196 15 1.0(b) 20 14 137 5.0

CH16 Precoat Silo Air Filter -26.661838 27.908111 15 1.0(b) 20 28 274 10.0

CH17 CSL Evaporator -26.662728 27.907851 30 1.0(b) 20 22 619 8.0

Notes: (a) Parameters assumed based on design specifications (b) Assumed diameter (detail provided “less than 2 m”) (c) Exit temperature at ambient (25°C assumed) (d) Assumed to contain the off-gas flues from two boilers



Table 7-2: Atmospheric pollutant emission rates for the proposed facility

Point Source code Pollutant Name Maximum release rate

Emissions Hours Type of Emissions (mg/Nm³) (mg/Am³)(a) (g/s) Averaging period

STK1 to STK4

PM 120 69.9 1.64

Hourly 8 760 Continuous SO2 2 800 1631.0 38.33

NOX 642 531 12.49

CH5 PM <321 234.75 0.92 Hourly 8 760 Continuous










CH16 PM <300 234.36 1.47

Hourly 8 760 Continuous TVOCs <241 188.27 1.18

CH17 PM <300 234.36 1.47

Hourly 8 760 Continuous TVOCs <280 218.73 1.37

Notes: (a) Actual emission concentrations (mg/Am³) were estimated based on the proposed stack design (stack diameter) and emission parameters (exit temperature, velocity, and pressure). This may vary under actual

operational conditions.

Table 7-3: Point Source Emission Estimation Information

Point Source code Basis for Emission Rates

STK1 to STK4 PM and SO2 emissions: based on minimum emission standards for coal combusting installations between 10 MW and 50 MW per boiler (Section 23 of the NEM:AQA, Table 4-1)

STK1 to STK4 NOX emissions: based on Australian National Pollutant Inventory emission factors for boilers using pulverised coal (NPI, 2011)

CH5 to CH17 PM and TVOC emissions: based on emission concentrations and stack parameters provided by project design engineers.



7.1.2 Fugitive Sources

Fugitive sources (Table 7-4 and Table 7-5) include: coal handling; and, the paved access road along which vehicle

entrainment of particulates is likely to occur. Published emission factors were used to estimate emissions from the materials

handling activities (Table 7-6). Emissions due to vehicle entrainment of particulates along the paved access road were also

quantified (Table 7-6).

Table 7-4: Area, volume and/or line source parameters

Source code

Source Description

Latitude (decimal

degrees) of SW corner

Longitude (decimal



Ground (m)

Length of Area (m)

Width of Area (m)

Angle of Rotation

from True North (°)

MHC Coal loading operations

-26.66283 27.90704 3 3 3 -

CR1

Coal delivery route

-26.66099 27.90280

0.5

371.5

4.5

22.7

CR2 -26.66226 27.90625 95.8 -6.0

CR3 -26.66216 27.90721 85.4 83.6

CR4 -26.66293 27.90731 41.4 -12.4

CR5 -26.66285 27.90771 97.6 -98.3

CR6 -26.66198 27.90757 127.2 170.6

CR7 -26.66217 27.90631 373.6 -158.1

MZR1

Maize delivery route

-26.66099 27.90280 374.9 24.2

MZR2 -26.66236 27.90624 126.6 77.8

MZR3 -26.66347 27.90652 124.2 -6.3

MZR4 -26.66334 27.90776 74.5 75.3

MZR5 -26.66399 27.90796 93.0 -9.7

MZR6 -26.66384 27.90888 77.3 -101.7

MZR7 -26.66316 27.90871 215.1 173.2

MZR8 -26.66340 27.90657 128.5 -101.3

MZR9 -26.66227 27.90631 377.7 -156.6

BPR1

Product delivery route

-26.66093 27.90281 166.9 23.6

BPR2 -26.66152 27.90435 90.6 -35.3

BPR3 -26.66104 27.90509 105.4 24.6

BPR4 -26.66143 27.90606 12.7 -51.3

BPR5 -26.66134 27.90614 33.9 78.2

BPR6 -26.66164 27.90621 31.5 75.7

BPR7 -26.66192 27.90629 92.8 -3.9

BPR8 -26.66185 27.90722 16.8 69.2

BPR9 -26.66199 27.90728 24.8 -9.7

BPR10 -26.66196 27.90753 107.7 79.2

BPR11 -26.66291 27.90774 45.3 170.5

BPR12 -26.66298 27.90729 110.7 -96.4

BPR13 -26.66199 27.90716 94.4 171.9

BPR14 -26.66211 27.90622 45.7 -97.4

BPR15 -26.66170 27.90616 28.0 -109.3

BPR16 -26.66147 27.90606 104.7 -155.3

BPR17 -26.66108 27.90510 93.5 145.4

BPR18 -26.66156 27.90434 167.5 -157.6



Table 7-5: Fugitive source emissions

Area Source code

Pollutant Name

Design mitigated

emission rate (g/s)

Emission Hours Type of

Emission

Wind Dependent

(yes/no)

MHC

Particulates (total suspended particulates) 3.19X10-3 8760 per year Continuous No

Particulates (PM10) 1.51X10-3 8760 per year Continuous No

Particulates (PM2.5) 1.66X10-3 8760 per year Continuous No

CR1 to CR7




MZR1 to MZR9




BPR1 to BPR18




Table 7-6: Area Source Emission Estimation Information

Area Source code

Basis for Emission Rates

MHC

Australian National Pollutant Inventory Emissions Estimation Techniques Manual Mining (NPI, 2012) using batch plant capacity of 10.3 tonnes per hour.

• 75% control efficiency accounts for enclosure of coal handling activities in a structure of three sides

• Coal handling is a wind dependent source and long-term average wind-speed at the Sharpeville AQMS (2.6 m/s) was used in the estimation of emissions.

CR1 to CR7 US EPA AP 42, 5th Edition, Volume I, Chapter 13: Miscellaneous Sources, 13.2.1 Paved Roads (2011) using the default

silt content of 0.6 g/m2 for low vehicle volume (<500) facilities. Assuming:

• 30 tonne trucks carrying 49 tonnes of coal per day; 2 000 tonnes per day of raw maize feed; 1 712 tonnes per day of dry product; 664 trips per hour (product and raw materials).

• 24 hours per day, 365 days per year.

MZR1 to

MZR9

BPR1 to

BPR18



7.1.3 Emission Source Summary

Emissions associated with the normal operation of the maize wet mill facility were estimated as described in Section 4.

Annual total emissions are summarised in Table 7-7. The emission control system point sources were quantified to be the

largest contributing sources to the particulate fractions, while the boilers were the sources of SO2 and NOx. Neither emission

factors nor particulate size distributions are provided for in the US EPA AP-42 for Corn Wet Mill emissions estimation

chapter for size fractions other than TSP. The TSP emission rates were therefore conservatively assumed to apply to PM10

and PM2.5.

Table 7-7: Annual pollutant emission rates (by source group) [units: t/a]

Source group PM2.5 PM10 TSP SO2 NOX TVOCs

Boilers 155 155 155 3 627 984

Coal Handling 0.01 0.05 0.10 - -

Wet Mill and refinery emission control systems 434 434 434 - - 80.6

Paved roads 2 8 42 - -

Dispersion modelling was completed for the operational phase of the proposed facility including design mitigation measures.

7.2 Assessment of Impact –Operational Phase with Design Mitigation Measures

The results of the simulation of the operational phase of the proposed facility on ambient air quality are discussed in this

section. Isopleth plots are only included where exceedances of assessment criteria were simulated. The simulation results

are for the proposed facility only and do not include any other source contributions in the area.

7.2.1 Respirable Particulate Matter (PM2.5)

The simulated PM2.5 concentrations as a result of the proposed facility show off-site exceedances of the 2016 daily standard

for up to 1 500 m and exceedances of the 2030 daily standard for up to 3 500 m off-site (Figure 7-1). Simulated annual

PM2.5 concentrations could be non-compliant with the 2016 NAAQS by up to 330 m and non-compliant with the 2030

NAAQS up to 460 m off-site (Figure 7-2). The IFC ‘good practice’ contribution guideline (25% of annual NAAQS) is not met

up to 2 500 m off-site (Figure 7-3).



Figure 7-1: Simulated area of exceedance of the daily PM2.5 NAAQ limit concentration

Figure 7-2: Simulated annual PM2.5 concentrations



Figure 7-3: Simulated annual PM2.5 concentrations – with IFC contribution guidelines

7.2.2 Inhalable Particulate Matter (PM10)

Simulated daily PM10 concentrations show potential off-site exceedances of the daily NAAQS by up to 1 000 m (Figure 7-4).

The simulated annual average PM10 concentrations may also exceed NAAQS off-site by up to 200 m (Figure 7-5). The IFC

guideline is not met due to off-site exceedances of the NAAQS (exceeded by up to 1 000 m).



Figure 7-4: Simulated area of exceedance of the daily PM10 NAAQ limit concentration

Figure 7-5: Simulated annual PM10 concentrations



7.2.3 Fallout Dust

Dustfall deposition rates were estimated based on emissions from the operational phase of the project. The simulated TSP

concentrations were converted to deposition rates by assuming a settling velocity of 3.24 x 10-2 m/s (based on a 30 μm

particle with a density of 1.2 g/cm3).

The impact of the proposed project on the environment was assessed with respect to nuisance dustfall. Emissions of the

particle size fraction likely to result in elevated dustfall rates were from the maize and maize product handling, as well as

vehicle entrainment of particulates along the access road used to haul raw materials and product. Compliance with the

NDCR for residential areas was simulated across the domain with a maximum daily dustfall rate, because of the project, of

135 mg/m2.day.


Simulated hourly (Figure 7-6) and daily (Figure 7-7) SO2 concentrations show potential off-site exceedances of the

applicable NAAQS by up to 400 m (Figure 7-4). The simulated annual average SO2 concentrations are not likely to exceed

NAAQS, where the domain maximum simulated concentration was 47.9 µg/m3. The estimation of emissions assumed that

all boilers would operate at the minimum emission standard for SO2. Off-site exceedances are less likely if the boilers

operate below the emission standard.

Figure 7-6: Simulated area of exceedance of the hourly SO2 NAAQ limit concentration



Figure 7-7: Simulated area of exceedance of the daily SO2 NAAQ limit concentration


The simulated hourly NOX concentrations were compliant with the hourly limit concentration, assuming all NOX converts to

NO2, such that the maximum simulated NO2 concentration was 108 μg/m³.

Annual NO2 concentrations were converted from NOX to NO2 using the Ambient Ratio Method for Tier 2 assessments

recommended in the Regulations Regarding Air Dispersion Modelling (Government Gazette No. 37804 vol. 589; 11 July

2014) and based on the national ratio of NO2:NOX=0.8. Simulated annual NO2 concentrations complied with the annual

NAAQS where the domain maximum simulated concentration was 5.7 μg/m³).

7.2.6 Total Volatile Organic Compounds (TVOCs)

The simulated annual average TVOC concentrations were conservatively assumed to be benzene to compare with the

NAAQS (Table 4-3). Exceedances of the benzene NAAQS are possible up to 300 m from site (Figure 7-8). It is likely that the

TVOC profile will contain compounds other than benzene. The European Collaborative Action (1992) provides a comfort range

for TVOCs – less than 200 µg/m3 - based on toxicological work on mucous membrane irritation (Mølhave, 1990). The maximum

simulated TVOC concentration in the domain was 50 µg/m3, and therefore compliant with the comfort level.



Figure 7-8: Simulated area of exceedance of the annual benzene NAAQS



8 IMPACT ASSESSMENT: OPERATIONAL PHASE – ADDITIONAL MITIGATION

8.1 Emissions Inventory

Based on the location of the proposed facility within an airshed of already compromised air quality, additional mitigation

measures are recommended for implementation during the operation phase to minimise the impact on ambient air quality.

Additional mitigation included: the release of boiler emissions through a single chimney stack, with controls on particulates

and SO2 emissions; particulate emission controls to the grain and solid product handling systems; and regular sweeping of

the paved access road to reduce potential of particulate entrainment by raw material and product haul vehicles.

8.1.1 Point Sources

Design and management of the boilers is recommended to be compliant with the solid-fuel combustion installations with

capacities greater than 50 MW (as per Subcategory 1.1 in Section 21 of the NEM:AQA). The recommended design should

have the five operational boilers vent via a single 38 m stack such that the combined emissions are compliant with new plant

emission standards. To achieve the stringent emission limit concentrations, the boiler plant design will need to include: filter

bags or cyclones to minimise particulate emissions, and a scrubber to reduce SO2 and NOx emissions. The use of low

sulfur-content coal would also reduce SO2 emissions. Mitigation of particulate emissions is recommended on the extraction

systems evacuating grain and solid product handling via filters (with a control efficiency of 85%); as well as mechanical

sweeping of the access road using vacuum and broom mechanical sweepers to achieve 80% control efficiency.

The parameters (Table 8-1) and pollutant emission rates (Table 8-2 used in dispersion modelling setup, for the additionally

mitigated scenario, are summarised below. Emissions from the boilers were calculated using the maximum emission limit

concentrations (Table 8-3). Emissions from the particulate control systems were calculated using the maximum emission

concentrations as provided by the design engineers with additional 85% control efficiency (Table 8-3).



Table 8-1: Parameters for point sources of atmospheric pollutant emissions at the proposed facility – with additional mitigation

Point Source code

Source name Latitude

(decimal degrees) Longitude

(decimal degrees)


Ground (m) (a)

Height Above Nearby

Building (m)

Diameter at Stack Tip / Vent

Exit (m) (a)

Actual Gas Exit Temperature (°C) (a)

Actual Gas Volumetric Flow

(m³/hr) (a)

Actual Gas Exit Velocity

(m/s) (a)

STK1(d) Boiler stack 1 -26.66233 27.90709 38 23 1.73 120 211 527 25

CH5 Germ Silo Filter -26.662516 27.907387 29 1.0(b) 40 14 137 5.0

CH6 Fibre Silo Filter -26.662509 27.907457 29 1.0(b) 40 14 137 5.0

CH7 Gluten Silo Filter -26.662496 27.907532 29 1.0(b) 40 14 137 5.0

CH8 Broken Silo Filter -26.663287 27.908396 15 1.0(b) 40 14 137 5.0


suction filter A -26.663716 27.908747 10 1.0(b) 25(c) 42 412 15.0


suction filter B -26.663347 27.908687 10 1.0(b) 25(c) 42 412 15.0

CH11 Germ cooler -26.662253 27.907967 29 1.0(b) 20 14 137 5.0

CH12 Gluten Dust

Collector -26.662356 27.907973 14.5 1.0(b) 20 14 137 5.0

CH13 Fibre Transfer Line

Air Filter -26.662459 27.908006 29 1.0(b) 20 14 137 5.0

CH15 Chemical Area

Scrubber -26.661163 27.908196 15 1.0(b) 20 14 137 5.0

CH16 Precoat Silo Air Filter -26.661838 27.908111 15 1.0(b) 20 28 274 10.0

CH17 CSL Evaporator -26.662728 27.907851 30 1.0(b) 20 22 619 8.0

Notes: (a) Parameters assumed based on design specifications (b) Assumed diameter (detail provided “less than 2 m”) (c) Exit temperature at ambient (25°C assumed) (d) Assumed to contain the off-gas flues from five boilers



Table 8-2: Atmospheric pollutant emission rates for the proposed facility – with additional mitigation

Point Source code Pollutant Name Additionally mitigated release rate

Emissions Hours Type of Emissions (mg/Nm³) (mg/Am³)(a) (g/s) Averaging period

STK1

PM 50 29.12 1.71

Hourly 8 760 Continuous SO2 500 291.24 17.11

NOX 750 1630.96 25.67











CH16 PM <45 35.15 0.22

Hourly 8 760 Continuous TVOCs No additional mitigation recommended (emission rates as per Section 7)

CH17 PM <45 35.15 0.22

Hourly 8 760 Continuous TVOCs No additional mitigation recommended (emission rates as per Section 7)

Notes: (b) Actual emission concentrations (mg/Am³) were estimated based on the proposed stack design (stack diameter) and emission parameters (exit temperature, velocity, and pressure). This may vary under actual

operational conditions.

Table 8-3: Point Source Emission Estimation Information

Point Source code Basis for Emission Rates

STK1 PM, NOX, SO2 emissions: based on minimum emission standards for coal combusting installations of 50 MW per boiler (Subcategory 1.1 Section 21 of the NEM:AQA, Table 4-2)

CH5 to CH17 PM and TVOC emissions: based on emission concentrations and stack parameters provided by project design engineers.



8.1.2 Fugitive Sources

Fugitive sources (Table 8-4 and Table 8-5) include: coal handling; and, the paved access road along which vehicle

entrainment of particulates is likely to occur. Published emission factors were used to estimate emissions from the materials

handling activities (Table 8-6). Emissions due to vehicle entrainment of particulates along the paved access road were also

quantified assuming an 80% control efficiency of a mechanical sweeper using a vacuum and broom system (Table 8-6).

Table 8-4: Area, volume and/or line source parameters – with additional mitigation

Source code

Source Description

Latitude (decimal


Longitude (decimal



Ground (m)

Length of Area (m)

Width of Area (m)

Angle of Rotation

from True North (°)

MHC Coal loading operations

-26.66283 27.90704 3 3 3 -

CR1

Coal delivery route

-26.66099 27.90280

0.5

371.5

4.5

22.7

CR2 -26.66226 27.90625 95.8 -6.0

CR3 -26.66216 27.90721 85.4 83.6

CR4 -26.66293 27.90731 41.4 -12.4

CR5 -26.66285 27.90771 97.6 -98.3

CR6 -26.66198 27.90757 127.2 170.6

CR7 -26.66217 27.90631 373.6 -158.1

MZR1

Maize delivery route

-26.66099 27.90280 374.9 24.2

MZR2 -26.66236 27.90624 126.6 77.8

MZR3 -26.66347 27.90652 124.2 -6.3

MZR4 -26.66334 27.90776 74.5 75.3

MZR5 -26.66399 27.90796 93.0 -9.7

MZR6 -26.66384 27.90888 77.3 -101.7

MZR7 -26.66316 27.90871 215.1 173.2

MZR8 -26.66340 27.90657 128.5 -101.3

MZR9 -26.66227 27.90631 377.7 -156.6

BPR1

Product delivery route

-26.66093 27.90281 166.9 23.6

BPR2 -26.66152 27.90435 90.6 -35.3

BPR3 -26.66104 27.90509 105.4 24.6

BPR4 -26.66143 27.90606 12.7 -51.3

BPR5 -26.66134 27.90614 33.9 78.2

BPR6 -26.66164 27.90621 31.5 75.7

BPR7 -26.66192 27.90629 92.8 -3.9

BPR8 -26.66185 27.90722 16.8 69.2

BPR9 -26.66199 27.90728 24.8 -9.7

BPR10 -26.66196 27.90753 107.7 79.2

BPR11 -26.66291 27.90774 45.3 170.5

BPR12 -26.66298 27.90729 110.7 -96.4

BPR13 -26.66199 27.90716 94.4 171.9

BPR14 -26.66211 27.90622 45.7 -97.4

BPR15 -26.66170 27.90616 28.0 -109.3

BPR16 -26.66147 27.90606 104.7 -155.3

BPR17 -26.66108 27.90510 93.5 145.4

BPR18 -26.66156 27.90434 167.5 -157.6



Table 8-5: Fugitive source emissions – with additional mitigation

Area Source code

Pollutant Name Additionally

mitigated emission rate (g/s)

Emission Hours

Type of Emission

Wind Dependent

(yes/no)

MHC

Particulates (total suspended particulates) No additional mitigation

recommended (emission rates as

per Section 7)

8760 per year Continuous No

Particulates (PM10) 8760 per year Continuous No

Particulates (PM2.5) 8760 per year Continuous No

CR1 to CR7




MZR1 to MZR9




BPR1 to BPR18




Table 8-6: Area Source Emission Estimation Information

Area Source code

Basis for Emission Rates

MHC

Australian National Pollutant Inventory Emissions Estimation Techniques Manual Mining (NPI, 2012) using batch plant capacity of 10.3 tonnes per hour.

• 75% control efficiency accounts for enclosure of coal handling activities in a structure of three sides

• Coal handling is a wind dependent source and long-term average wind-speed at the Sharpeville AQMS (2.6 m/s) was used in the estimation of emissions.

CR1 to CR7 US EPA AP 42, 5th Edition, Volume I, Chapter 13: Miscellaneous Sources, 13.2.1 Paved Roads (2011) using the default

silt content of 0.6 g/m2 for low vehicle volume (<500) facilities. Assuming:

• 30 tonne trucks carrying 49 tonnes of coal per day; 2 000 tonnes per day of raw maize feed; 1 712 tonnes per day of dry product; 664 trips per hour (product and raw materials).

• 24 hours per day, 365 days per year

• Mitigation using mechanical sweepers with vacuums and brooms assumed to achieve 80% control efficiency.

MZR1 to

MZR9

BPR1 to

BPR18



8.1.3 Emission Source Summary – With Additional Mitigation

Annual total emissions from the maize wet mill facility, assuming additional mitigation measures are implemented, are

summarised in Table 8-7. The emission control system point sources were quantified to be the largest contributing sources

to the particulate fractions, while the boilers were the only sources of SO2 and NOx. As for the Design Mitigated Scenario,

TSP emission rates from the wet mill were conservatively assumed to apply to PM10 and PM2.5.

Table 8-7: Annual pollutant emission rates (by source group) [units: t/a]

Source group PM2.5 PM10 TSP SO2 NOX TVOCs

Boilers 54 54 54 540 394 -

Coal Handling 0.01 0.05 0.10 - - -

Wet Mill and refinery emission control systems 79 79 79 - - 80.6

Paved roads 0.4 1.5 7.8 - - -

8.2 Assessment of Impact –Operational Phase with Additional Mitigation

The results of the simulation of the operational phase of the proposed facility with the recommended additional mitigation

measures. Isopleth plots are only included where exceedances of assessment criteria were simulated. The simulation

results are for the proposed facility only and do not include any other source contributions in the area.

8.2.1 Respirable Particulate Matter (PM2.5)

The simulated PM2.5 concentrations as a result of additionally mitigated emissions show off-site exceedances of the 2016

daily standard for up to 80 m and exceedances of the 2030 daily standard for up to 135 m off-site (Figure 8-1). The area

impacted by elevated daily average PM2.5 concentrations is substantively smaller after additional mitigation were applied to

design mitigated emission rates. Simulated annual PM2.5 concentrations were compliant with the 2016 and 2030 NAAQS off-

site. The IFC guideline (25% contribution to NAAQS) could be exceeded up to 300 m off-site (Figure 8-2).



Figure 8-1: Simulated area of exceedance of the daily PM2.5 NAAQ limit concentration

Figure 8-2: Simulated annual PM2.5 concentrations – additionally mitigated operations with IFC contribution

guidelines



8.2.2 Inhalable Particulate Matter (PM10)

Domain maximum simulated daily PM10 concentrations (78.5 µg/m³) exceeded daily NAAQ limit, however there were fewer

than four days per year where exceedances were simulated (domain maximum: 1 day per year). The simulated annual

average PM10 concentrations was compliant with NAAQS (domain maximum was 22.9 µg/m³). Simulated annual average

PM10 concentrations did not meet the IFC guideline (25% contribution to NAAQS) up to 100 m off-site; however,

exceedances of the guideline were not exceeded at the nearby receptors (Figure 8-3).

Figure 8-3: Simulated annual PM10 concentrations – additionally mitigated operations

8.2.3 Fallout Dust

Dustfall deposition rates were estimated based on the method described for the design mitigated scenario (Section 7.2.3).

Compliance with the NDCR for residential areas was simulated across the domain, for the additionally mitigated scenario

where the with a maximum daily dustfall rate was simulated at 135 mg/m2.day. Additional mitigation measures would

therefore not make a material difference to the already compliant dustfall rates.


Simulated hourly (domain maximum concentration: 71.4 µg/m³) and daily (domain maximum concentration: 28.2 µg/m³) SO2

concentrations will comply with NAAQS if additional mitigation is implemented. The domain maximum simulated annual



average SO2 concentrations was 4.0 µg/m3, representing 8% of the NAAQS and therefore also meets the IFC contribution

limit.


The simulated hourly NOX concentrations were compliant with the hourly limit concentration, assuming all NOX converts to

NO2, such that the maximum simulated NO2 concentration was 107.1 μg/m³.

Annual NO2 concentrations were converted from NOX to NO2 using the Ambient Ratio Method for Tier 2 assessments

recommended in the Regulations Regarding Air Dispersion Modelling (Government Gazette No. 37804 vol. 589; 11 July

2014) and based on the national ratio of NO2:NOX=0.8. Simulated annual NO2 concentrations complied with the annual

NAAQS where the domain maximum simulated concentration was 4.3 μg/m³; a contribution of 11% of the annual NAAQS,

meeting the IFC contribution of 25% or less.

8.2.6 Total Volatile Organic Compounds (TVOCs)

No additional mitigation was recommended for TVOC emissions, therefore the results as per Section 7.2.6 are applicable.



8.3 Impact Significance Rating for Design and Additional Mitigated Scenarios

Table 8-8: Health risk impact significance summary table for the proposed facility – particulates (PM2.5 and PM10)

Severity Duration Spatial Scale Consequence Probability Significance

With design mitigation H H H High Probable High

Recommended management and mitigation measures: Reduction of fugitive PM emissions through the sweeping of roads; boiler plant managed as listed activity; and, installation of extraction units with fabric filters on the grain processing plant. Monitoring of ambient PM2.5 and PM10 at the property boundary during short campaigns at least twice per year.

With additional mitigation L H L Medium Possible Low

Table 8-9: Health risk impact significance summary table for the proposed facility – SO2


With design mitigation H H H High Possible Medium

Recommended management and mitigation measures: Reduction of SO2 emissions from boilers by using low-sulfur coal; boiler plant managed as listed activity; regular monitoring of SO2 emissions to ensure operation below minimum emission standards. Monitoring of ambient SO2 at the property boundary during short campaigns at least twice per year.

With additional mitigation VL H VL Low Probable Low

Table 8-10: Health risk impact significance summary table for the proposed facility – NO2


With design mitigation M H M Medium Probable Medium

Recommended management and mitigation measures: Regular monitoring of NO2 emissions from boiler stacks; boiler plant managed as listed activity; monitoring of ambient NO2 at the property boundary during short campaigns at least twice per year.

With additional mitigation VL H VL Low Probable Low

Table 8-11: Health risk impact significance summary table for the proposed facility - TVOCs


With design mitigation L H L Low Possible Medium

Recommended management measures: Passive monitoring of TVOCs during regular short-term campaigns. Periodic emissions measurements campaigns. .



Table 8-12: Nuisance dustfall impact significance summary table for the proposed facility


With design mitigation L M L Low Possible Low

Recommended management and mitigation measures:

Reduction of fugitive PM emissions through the sweeping of roads; and, installation of extraction units with fabric filters on the grain processing plant.

With additional mitigation L M L Low Possible Low



9 IMPACT ASSESSMENT: CUMULATIVE

The cumulative impact of the proposed facility and the existing baseline was estimated using annual averaging period for

the pollutants of concern for both the on-site estimated annual average concentrations as well as the Sharpeville AQMS.

The cumulative annual average concentrations suggest that the proposed facility will not result in exceedances of annual

standard for SO2 or NO2 (Table 9-1). Although the on-site baseline PM2.5 concentrations were compliant with the NAAQS,

the simulated incremental annual concentrations suggest non-compliance with NAAQS after development. PM10

concentrations, using either on-site estimated averages or the Sharpeville AQMS averages, are already non-compliant with

NAAQS. (Table 9-1). The proposed facility will further add particulates to both the PM2.5 and PM10 fractions (Table 9-1).

It is understood that a glass bottle manufacturing facility is proposed for development near to the maize wet mill facility. The

cumulative impact of the two facilities, being near each other, is also summarised in Table 9-1. Potential non-compliance

with the PM2.5 and PM10 annual NAAQS is possible if both facilities are developed, mainly as a result of the on the already

elevated pre-development particulate concentrations (Table 9-1).



Table 9-1: Cumulative annual average pollutant concentrations (bold text indicates non-compliance with NAAQS)

Pollutant

Annual average concentration (μg/m³)

NAAQS On-site estimated(a) Sharpeville AQMS Long-term Average

Measured(b)

Simulated incremental(c)

(at site boundary)

Cumulative (proposed facility

only)(d)

Cumulative (proposed facility

only)(e)

Cumulative (both facilities)(f)

Cumulative (both facilities)(g)

PM2.5 15(h) 10.6 35.4 13.4 24.0 48.8 29.1 53.9

PM10 40 45.0 73.9 15.5 60.5 89.4 72.5 101.4

SO2 50 1.16 7.5 3.7 4.9 11.2 7.9 14.2

NO2 40 3.38 16.2 5.6 9.0 21.8 11.4 24.2

Notes:

(a) Based on average daily ratio between on-site measured concentrations and Sharpeville AQMS daily measured. (b) Based on the Sharpeville AQMS long-term average for the period 1 January 2007 to 31 December 2016. (c) From dispersion modelling reported in Section 8.2 Proposed facility only (additionally mitigated operations). Simulated maximum concentration at site boundary. (d) Estimated annual at facility (a) plus simulated incremental (c). (e) Sharpeville long-term average (b) plus simulated incremental (c). (f) Estimated annual at facility (a) plus simulated incremental (c) plus mitigated annual incremental at the glass bottle manufacturing facility. (g) Sharpeville long-term average (b) plus simulated incremental (c) mitigated annual incremental at the glass bottle manufacturing facility. (h) Applicable after 1 January 2030



10 IMPACT ASSESSMENT: NO GO OPTION

10.1 Baseline State of the Air Quality

Should the no go option be embarked on, only the existing activities will occur in the area without the addition of the

proposed facility. However, due to the current activities in the vicinity (including farming operations, vehicle entrainment on

roads, wind-blown dust from open areas, vehicle exhaust, household fuel burning and biomass burning) the PM2.5, PM10, and

occasionally NO2 annual average concentrations already exceed the annual NAAQSs (Table 10-1).

Table 10-1: Impact significance summary table for the no-go option

Impact Severity Duration Spatial Extent Consequence Probability Significance

Non-go option (baseline) H H VH Very High Probable Very High



11 AIR QUALITY MANAGEMENT MEASURES

Based on the findings of the impact assessment, the following mitigation, management and monitoring recommendations

are made.

11.1 Air Quality Management Objectives

The main objective of the proposed air quality management measures for the project is to ensure that operations at the

facility cumulatively result in ambient air concentrations that are within the relevant ambient air quality criteria off-site. To

define site specific management objectives, the main sources of pollution needed to be identified.

11.1.1 Source Specific Management and Mitigation Measures

Fugitive emissions from the maize handling and dry solid product handling and vehicle entrainment of particulates from

paved road surfaces are the main sources of pollution from the proposed project.

11.1.1.1 Fine particulate control options

Main techniques adopted to reduce fine particulate emissions include source extent reduction, source improvement and

surface treatment methods:

• Source extent reduction:

o Dust spillage prevention and/or removal;

o Tarpaulin covers on haul trucks;

o Strict speed limits for haul trucks on plant roads and access roads, and,

o Regular washing of haul trucks.

• Source Improvement:

o Effective particulate extraction and removal systems especially on maize receiving, maize cleaning, and

product driers (control efficiency of 85%). These could include, for example, cyclones and/or fabric

filters.

o An effective particulate removal system may be needed to control emissions from the boiler plant, if the

aim is to achieve compliance with the minimum emissions standards for Subcategory 1.1 listed activities.

o Regular cleaning and maintenance of particulate extraction and removal systems.

o Enclosed storage of waste particulates from fabric filters, if not recirculated into the process.

• Surface treatment:

o Using a mechanical vacuum and broom sweeper on paved road surfaces (control efficiency 80%);

o Regular sweeping of loading areas, paved roads etc. would minimise the potential for windblown dust

entrainment or entrainment by haul trucks.

The above measures must be applied to the operations to ensure exposed areas are kept free of dry fine materials.

11.1.2 Source Monitoring

It should be noted that the data provider will be expected to report annual emissions from the boilers on the NAEIS system.

It is also recommended that annual or biennial emissions monitoring be conducted on all main process control system

chimneys. In addition to annual point source monitoring campaigns, dustfall monitoring near fugitive sources can be an

effective mechanism in determining the main emission sources. A network of eight dustfall monitoring units is suggested:



four to be located downwind of the major materials handling points and four at cardinal wind direction points on the

boundary.

11.1.3 Ambient Air Quality Monitoring

Ambient air quality monitoring can serve to meet various objectives, such as:

• Compliance monitoring;

• Validate dispersion model results;

• Use as input for health risk assessment;

• Assist in source apportionment;

• Temporal trend analysis;

• Spatial trend analysis;

• Source quantification; and,

• Tracking progress made by control measures.

It is recommended that, as a minimum continuous dustfall sampling be conducted as part of the project’s air quality

management plan. Short-term ambient monitoring campaigns are recommended at least twice annually for PM2.5, PM10, SO2

and TVOCs Low-flow filter-based sampling is recommended for PM2.5 and PM10. Passive sampling methodology would be

appropriate for SO2 and TVOC monitoring.

11.1.3.1 Dustfall Sampling

The ASTM method covers the procedure of collection of dustfall and its measurement and employs a simple device

consisting of a cylindrical container (not less than 150 mm in diameter) exposed for one calendar month (30 ±2 days). Even

though the method provides for a dry bucket, de-ionised (distilled) water can be added to ensure the dust remains trapped in

the bucket. The bucket stand includes wind shield at the level of the rim of the bucket to provide an aerodynamic shield. The

bucket holder is connected to a 2 m galvanized steel pole, which is either planted and cemented or directly attached to a

fence post (Figure 11-1). This allows for a variety of placement options for the fallout samplers. Two buckets are usually

provided for each dust bucket stand. Thus, after the first month, the buckets get exchanged with the second set.

Collected sampled are sent to an accredited laboratory for gravimetric analysis. At the laboratory, each sample will be rinsed

with clean water to remove residue from the sides, and the contents filtered through a coarse filter (>1 mm) to remove

insects and other course organic detritus. The sample is then filtered through a pre-weighed paper filter to remove the

insoluble fraction. This residue and filter are dried, and gravimetrically analysed to determine total dustfall.



Figure 11-1: Dustfall collection unit example

11.1.3.2 Air Quality Monitoring

Radiello® passive diffusive tubes are recommended for the sampling of pollutant concentrations at the proposed maize wet

mill during short-term campaigns. Monitoring at the nearest receptors and approximately four locations on the facility

boundary is recommended. Passive diffusive sampling relies on the diffusion of analytes through a diffusive surface onto an

adsorbent. After sampling, the analytes are chemically desorbed by solvent extraction or thermally desorbed and analysed.

Passive sampling does not involve the use of pumping systems and does not require electricity. The concentration of

analytes adsorbed during the exposure period can be calculated to time-frames comparable with the NAAQS; international

inhalation health-effect screening levels; as well as odour detection threshold concentrations. This methodology is proposed

for SO2, TVOCs, and potentially odourous compounds, for example hydrogen sulfide (H2S) and ammonia (NH3). Passive

sampling is a cost-effective method to monitor air quality at multiple locations.

11.2 Record-keeping, Environmental Reporting and Community Liaison

11.2.1 Periodic Inspections and Audits

Periodic inspections and external audits are essential for progress measurement, evaluation and reporting purposes. It is

recommended that site inspections and progress reporting be undertaken at regular intervals (at least quarterly), with annual

environmental audits being conducted. Annual environmental audits should be continued at least until closure. Results from

site inspections and monitoring efforts should be combined to determine progress against source- and receptor-based

performance indicators. Progress should be reported to all interested and affected parties, including authorities and persons

affected by pollution.

The criteria to be considered in the inspections and audits must be made transparent by way of minimum requirement

checklists included in the management plan. Corrective action or the implementation of contingency measures must be

proposed to the stakeholder forum if progress towards targets is indicated by the quarterly/annual reviews to be

unsatisfactory.



11.2.2 Liaison Strategy for Communication with I&APs

Stakeholder forums provide possibly the most effective mechanisms for information dissemination and consultation.

Management plans should stipulate specific intervals at which forums will be held and provide information on how people will

be notified of such meetings. For operations for which operational facilities are near (within 3 km) of community areas, it is

recommended that such meetings be scheduled and held at least on a bi-annual basis. A complaints register must be kept,

from commencement with construction activities.

11.2.3 Financial Provision

The budget should provide a clear indication of the capital and annual maintenance costs associated with particulate control

measures, emissions monitoring campaigns, and ambient monitoring plans Costs related to inspections, audits,

environmental reporting and I&AP liaison should also be indicated where applicable. Provision should also be made for

capital and running costs associated with emission control contingency measures and for security measures. The financial

plan should be audited by an independent consultant, with reviews conducted on an annual basis.



12 FINDINGS AND RECOMMENDATIONS

12.1 Main Findings

An air quality impact assessment was conducted for activities associated with the proposed maize wet mill. The main

objective of this study was to establish baseline air quality in the study area and to quantify the extent to which ambient

pollutant levels will change due to the proposed operations. The baseline and impact study then informed the air quality

management and mitigation measures recommended as part of the Air Quality Management Plan (AQMP). This section

summarises the main findings of the baseline and impact assessments.

The main findings of the baseline assessment are:

• Several AQSRs are located near to the proposed property, the closest of which is the staff accommodation of the

Department of Correctional services.

• The main sources likely to contribute to baseline pollutant concentrations include industrial operations, vehicle

entrained dust from local roads, vehicle exhaust, household fuel burning, biomass burning, and windblown dust

from unvegetated areas.

• The area is dominated by winds from the north-east and north-west. Wind speeds above 7 m/s are more common

from the north-west. Calm conditions (wind speeds less than 1 m/s) occurred less than 10% of the period of

assessment.

The main findings of the impact assessment are as follows:

• Only the operational phase air quality impacts were quantified since construction and decommissioning phase

impacts will likely be similar and less significant than the operational phase impacts.

• Pollutants of concern include particulate matter (PM), SO2 and NO2 where PM emissions from maize handling and

vehicle entrainment from haul trucks were quantified to be the most significant during the operational phase.

• Construction phase:

o The significance of construction related inhalation health and nuisance impacts are likely “low” risk

without mitigation, and “very low“ with mitigation.

• Operational phase:

o PM10 and PM2.5 concentrations were simulated to be in non-compliance over the short- (up to 3 500 m

off-site) and long-term (up to 460 m off-site).

▪ Compliance with PM10 and PM2.5 NAAQS can be achieved by implementation of the

recommended mitigation measures.

▪ With additional mitigation, the IFC contribution guideline can be met within 300 m of the facility

for PM2.5 and 100 m for PM10.

o Simulated SO2 concentrations were in non-compliance with the hourly, daily, and annual standards

beyond the boundary, if the boilers operate at the emission standards.

▪ Compliance with SO2 NAAQS can be achieved by implementation of the recommended

mitigation measures.

▪ Annual average SO2 concentrations meet the IFC contribution guideline (25% of NAAQS)

o Simulated NO2 concentrations, under both the design and additionally mitigated scenarios, were

compliant with the hourly and annual NAAQS.

▪ Annual average NO2 concentrations meet the IFC contribution guideline (25% of NAAQS)

o Dustfall rates are below the NDCR limits for residential areas and non-residential areas off-site.



o Simulated TVOC concentrations may exceed the annual benzene NAAQS if all TVOCs are assumed to

be benzene. The TVOC profile is likely to include many compounds and therefore compliance with the

benzene standard is expected.

o The significance of operations related inhalation health impacts is likely to have a “medium” significance

with design mitigation; and or “low” with additional mitigation measures.

o The significance of operations related to nuisance impacts, associated with dustfall and odours, is likely

to have a “low” significance with design and additional mitigation.

12.2 Air Quality Recommendations

To ensure the lowest possible impact on AQSRs and environment it is recommended that the air quality management plan

as set out in this report should be adopted. This includes:

• design and management of the boiler plant as per the Subcategory 1.1 listed activity;

• mitigation of potential fugitive emissions from the maize and dry maize-product handling resulting in the

management of associated air quality impacts;

• mitigation of vehicle entrainment emissions from the paved access roads using a mechanical sweeper; strict

enforcement speed limits (maximum 20 km/h on access roads); covers for vehicles; and regular clean-ups of road

spillages;

• emissions monitoring in accordance with the reporting requirements for Section 23 controlled emitters;

• emissions monitoring of maize wet mill control system chimneys;

• ambient air quality monitoring;

• dustfall monitoring; and

• implementation of the reporting procedures.

Based on these findings, it is the specialist opinion that the project would not have a significant impact on the surrounding environment

and could be authorised.



13 REFERENCES

Beychock, M. R. (2005). Fundamentals of Stack Gas Dispersion (4th Edition ed.).

European Collaborative Action. (1992). . "lndoor Air Quality and Its Impact on Man ". Report No. 11: Guidelines for

Ventilation Requirements in Buildings. Luxembourg: Office for Publications of the European Communities.

Government Gazette. (2014, July 11). Regulations Regarding Air Dispersion Modelling. Regulations Prescribing the Format

of the Atmospheric Impact Report, 37804.

Hanna, S. R., Egan, B. A., Purdum, J., & Wagler, J. (1999). Evaluation of ISC3, AERMOD, and ADMS Dispersion Models

with Observations from Five Field Sites.

IFC. (2007). General Environmental, Health and Safety Guidelines. World Bank Group.

Kornelius, G., & Kwata, M. (2010). Comparison of Different Versions of ASTM 1739 for the Measurement of Dust Deposition

in the South African Mining Sectors. Pretoria: Environmental Engineering Group, Department of Chemical

Engineering , University of Pretoria .

Mølhave, L. (1990). Volatile Organic Compounds, Indoor Air Quality and Health. Indoor Air, 15-33.

NPI. (2011). Emissions Estimation Technique Manual for Combustion in Boilers. Version 3.6. Canberra: Australian

Government Department of Sustainability, Environment, Water, Population and Communities.

NPI. (2012). Emission Estimation Technique Manual for Mining. Version 3.1. Canberra: Australian Government Department

of Sustainability, Environment, Water, Population and Communities.



14 APPENDIX A: AUTHORS’ CURRICULUM VITAE



15 APPENDIX B: COMPETENCIES FOR PERFORMING AIR DISPERSION MODELLING

All modelling tasks were performed by competent personnel. Table 15-1 is a summary of competency requirements. Apart

from the necessary technical skills required for the calculations, personnel competency also include the correct attitude,

behaviour, motive and other personal characteristic that are essential to perform the assigned job on time and with the

required diligence as deemed necessary for the successful completion of the project.

The project technical team included a principal engineer with relevant experience of 30 years and one senior scientist with

12 years relevant experience. The principal engineer also managed and directed the project.

Verification of modelling results was conducted by the principal engineer. The latter function requires a thorough knowledge

of the

• meteorological parameters that influence the atmospheric dispersion processes and

• atmospheric chemical transformations that some pollutants may undergo during the dispersion process.

In addition, the project team included one junior staff member.

Table 15-1: Competencies for Performing Air Dispersion Modelling

Competency Task, Knowledge and Experience

Context Communication with field workers, technicians, laboratories, engineers and scientists and project managers during the process is important to the success of the model

Familiar with terminology, principles and interactions

Record keeping is important to support the accountability of the model - Understanding of data collection methods and technologies

Knowledge Meteorology:

Obtain, review and interpret meteorological data

Understanding of meteorological impacts on pollutants

Ability to identify and describe soil, water, drainage and terrain conditions

Understanding of their interaction

Familiarity with surface roughness`

Ability to identify good and bad data points/sets

Understanding of how to deal with incomplete/missing meteorological data

Atmospheric Dispersion models

Select appropriate dispersion model

Prepare and execute dispersion model

Understanding of model input parameters

Interpret results of model

Chemical and physical interactions of atmospheric pollutants

Familiarity with fate and transport of pollutants in air

Interaction of primary pollutants with other substances (natural or industrial) to form secondary pollutants

Information relevant to the model

Identify potential pollution (emission) sources and rates

Gather physical information on sources such as location, stack height and diameter

Gather operating information on sources such as mass flow rates, stack top temperature, velocity or volumetric flow rate

Calculate emission rates based on collected information

Identify land use (urban/rural)



Competency Task, Knowledge and Experience

Identify land cover/terrain characteristics

Identify the receptor grid/site

Legislation, regulations and guidelines regarding National Environment Management: Air Quality Act (Act No 39 of 2004), including

Minimum Emissions Standards (Section 21 of Act)

National Ambient Air Quality Standards

Regulations regarding Air Dispersion Modelling

Atmospheric Impact Report (AIR)

Abilities Ability to read and understand map information

Ability to prepare reports and documents as necessary

Ability to review reports to ensure accuracy, clarity and completeness

Communication skills

Team skills



16 APPENDIX C: COMMENTS/ISSUES RAISED

No I&AP’s comments have been provided.



17 APPENDIX D: IMPACT SIGNIFICANCE METHODOLOGY

PART A: DEFINITIONS AND CRITERIA*

Definition of SIGNIFICANCE Significance = consequence x probability

Definition of CONSEQUENCE Consequence is a function of intensity, spatial extent and duration

Criteria for ranking of the

INTENSITY of

environmental impacts

VH Severe change, disturbance or degradation. Associated with severe consequences. May

result in severe illness, injury or death. Targets, limits and thresholds of concern continually

exceeded. Substantial intervention will be required. Vigorous/widespread community

mobilization against project can be expected. May result in legal action if impact occurs.

H Prominent change, disturbance or degradation. Associated with real and substantial

consequences. May result in illness or injury. Targets, limits and thresholds of concern

regularly exceeded. Will definitely require intervention. Threats of community action. Regular

complaints can be expected when the impact takes place.

M Moderate change, disturbance or discomfort. Associated with real but not substantial

consequences. Targets, limits and thresholds of concern may occasionally be exceeded.

Likely to require some intervention. Occasional complaints can be expected.

L Minor (Slight) change, disturbance or nuisance. Associated with minor consequences or

deterioration. Targets, limits and thresholds of concern rarely exceeded. Require only minor

interventions or clean-up actions. Sporadic complaints could be expected.

VL Negligible change, disturbance or nuisance. Associated with very minor consequences or

deterioration. Targets, limits and thresholds of concern never exceeded. No interventions or

clean-up actions required. No complaints anticipated.

VL+ Negligible change or improvement. Almost no benefits. Change not measurable/will remain in

the current range.

L+ Minor change or improvement. Minor benefits. Change not measurable/will remain in the

current range. Few people will experience benefits.

M+ Moderate change or improvement. Real but not substantial benefits. Will be within or

marginally better than the current conditions. Small number of people will experience

benefits.

H+ Prominent change or improvement. Real and substantial benefits. Will be better than

current conditions. Many people will experience benefits. General community

support.

VH+ Substantial, large-scale change or improvement. Considerable and widespread

benefit. Will be much better than the current conditions. Favourable publicity and/or

widespread support expected.

Criteria for ranking the

DURATION of impacts

VL Very short, always less than a year. Quickly reversible

L Short-term, occurs for more than 1 but less than 5 years. Reversible over time.

M Medium-term, 5 to 10 years.

H Long term, between 10 and 20 years. (Likely to cease at the end of the operational life of the

activity)

VH Very long, permanent, +20 years (Irreversible. Beyond closure)

Criteria for ranking the

EXTENT of impacts

VL A part of the site/property.

L Whole site.

M Beyond the site boundary, affecting immediate neighbours

H Local area, extending far beyond site boundary.

VH Regional/National



PART B: DETERMINING CONSEQUENCE

EXTENT

A part of the

site/property

Whole site Beyond the

site, affecting

neighbours

Local area,

extending far

beyond site.

Regional/

National

VL L M H VH

INTENSITY = VL

DURATION

Very long VH Low Low Medium Medium High

Long term H Low Low Low Medium Medium

Medium term M Very Low Low Low Low Medium

Short term L Very low Very Low Low Low Low

Very short VL Very low Very Low Very Low Low Low

INTENSITY = L

DURATION

Very long VH Medium Medium Medium High High

Long term H Low Medium Medium Medium High

Medium term M Low Low Medium Medium Medium

Short term L Low Low Low Medium Medium

Very short VL Very low Low Low Low Medium

INTENSITY = M

DURATION

Very long VH Medium High High High Very High

Long term H Medium Medium Medium High High

Medium term M Medium Medium Medium High High

Short term L Low Medium Medium Medium High

Very short VL Low Low Low Medium Medium

INTENSITY = H

DURATION

Very long VH High High High Very High Very High

Long term H Medium High High High Very High

Medium term M Medium Medium High High High

Short term L Medium Medium Medium High High

Very short VL Low Medium Medium Medium High

INTENSITY = VH

DURATION

Very long VH High High Very High Very High Very High

Long term H High High High Very High Very High

Medium term M Medium High High High Very High

Short term L Medium Medium High High High

Very short VL Low Medium Medium High High

VL L M H VH

A part of the

site/property

Whole site Beyond the

site, affecting

neighbours

Local area,

extending far

beyond site.

Regional/

National

EXTENT



PART C: DETERMINING SIGNIFICANCE

PROBABILITY

(of exposure to

impacts)

Definite/

Continuous VH Very Low Low Medium High Very High

Probable H Very Low Low Medium High Very High

Possible/

frequent M Very Low Very Low Low Medium High

Conceivable L Insignificant Very Low Low Medium High

Unlikely/

improbable VL Insignificant Insignificant Very Low Low Medium

VL L M H VVH

CONSEQUENCE

PART D: INTERPRETATION OF SIGNIFICANCE

Significance Decision guideline

Very High Potential fatal flaw unless mitigated to lower significance.

High It must have an influence on the decision. Substantial mitigation will be required.

Medium It should have an influence on the decision. Mitigation will be required.

Low Unlikely that it will have a real influence on the decision. Limited mitigation is likely to be required.

Very Low It will not have an influence on the decision. Does not require any mitigation

Insignificant Inconsequential, not requiring any consideration.

*VH = very high, H = high, M= medium, L= low and VL= very low and + denotes a positive impact.

air quality specialist report for a proposed maize wet mill ......air quality specialist report for...

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