Ambient Air Quality Monitoring Report: March Richards Bay Clean Air Association

Transcription

1 T0107 Ambient Air Quality Monitoring Report: March 2010 Prepared for the Richards Bay Clean Air Association AQ0002 March 2010 SGS SA: Environmental Services 1 of 76 6 Sookhai Place, Derby Downs, Westville, 3630 PO Box 416 Durban 3600 Tel: Fax: Internet: info@ecoserv.com

2 EXECUTIVE SUMMARY This is the Richards Bay Clean Air Association s (RBCAA) monthly ambient air quality report for March The ambient air monitoring system, maintained by SGS SA Environmental Services, is accredited to ISO 17025:2005 for the measurement of SO 2 by the South African National Accreditation Service (SANAS). The measurement of other pollutants reported does not fall within this accreditation. The applicable quality controls and measurement methods are listed in Appendix 1. South African limits and standards Air quality limits and thresholds are fundamental to effective air quality management, providing the link between the potential source of atmospheric emissions and the user of that air at the downwind receptor site. Ambient air quality limits indicate generally safe exposure levels for the majority of the population, including the very young and the elderly, throughout an individual s lifetime. Table A: South African limit values and standards Organisation Variable 10-min average Hourly average Daily average Monthly average Annual average NEMAQA [a] SO2 500 µg/m³ [c] 350 µg/m³ [d] 125 µg/m³ [e] - 50 µg/m³ [f] 191 ppb [c] 134 ppb [d] 48 ppb [e] - 19 ppb [f] NEMAQA [a] PM µg/m³ [e] - 50 µg/m³ [f] SANS [b] PM µg/m³ [e] - 40 µg/m³ [f] Notes: [a] SA Government Gazette (published 24 th December 2009) in terms of the National Environmental Management: Air Quality Act 39 of 2004 [b] SABS Draft South African National Standard SANS1929:2009 [c] Not to be exceeded more than 526 times in one year. [d] Not to be exceeded more than 88 times in one year. [e] Not to be exceeded more than 4 times in one year. [f] Not to be exceeded. SO 2 Exceedances There were no measured exceedances of the DEAT SO 2 National Standards. PM 10 Exceedances There were no measured exceedances of the SANS PM 10 Limit Values or DEAT PM 10 National Standards. 2 of 76

3 Dispersion Modelling Richards Bay Clean Air Association It must be noted that the HAWK Model predictions show areas that may have experienced exceedances within the month of March It is not practical to measure SO 2 concentrations in a dense grid and, as a result the HAWK Model is used as a predictive measure for determining the levels of SO 2 in Richards Bay. There may not be any measured exceedances during any month does not mean that there were no exceedances. The concentration maps are important in that they show the areas where no monitoring equipment exists, but may have experienced exceedances. The Model output is set to predict the maximum SO 2 concentrations and, therefore, the worst-case scenario, which may not always be the case in a particular area. Details of the model parameters are provided in Appendix 4. A limitation of dispersion models is their inability to adequately account for highly complex, rapidly varying spatial and temporal meteorological systems, such as calms, coastal fumigation, sea / land breeze recirculation and mountain and valley winds, particularly in complex terrain or near coastal boundaries. The US EPA considers the range of uncertainty to be -50% to 200% for models applied to gently rolling terrain. The accuracy improves with fairly strong wind speeds and during neutral atmospheric conditions. Dispersion modelling results can be compared with monitored values in order to improve the accuracy or calibrate models using percentiles. An investigation using July 2007 data compared the measured values to the 98 th, 99 th and 100 th percentile. The investigation concluded that the 99 th percentile more closely approximated measured values. The RBCAA has therefore decided to use the 99 th percentile across all averaging periods. 3 of 76

4 Figure A: Inter-annual comparison of RBCAA annual average SO 2 Richards Bay Clean Air Association Figure A is an inter-annual comparison of annual average SO 2. Since 2005 there has been a downward trend in measured annual average SO 2 concentrations (Arboretum 46%, Brackenham 68%, CBD 25%, Harbour West 52% (since 2006) and Scorpio 47%). The reduction in emissions is most likely related to a reduction in production which could be the result of a number of reasons, including load shedding, the increase in the cost of electricity and the downturn in the economy. We therefore strongly recommend that the emission inventory for Richards Bay, done in 2004, be revisited. In May 2008 Bayside Aluminium reduced its production and it s emissions by 53% (from 4454 tpa to 2102 tpa); the effects of this on measurements at, the closest stations (Harbour West and Scorpio) are noticeable. 4 of 76

5 Figure B: Wind rose for Arboretum, March 2010 Richards Bay Clean Air Association The average wind speed in March 2010 was 3.1 m/s with 8.79% calms. Predominant winds blew from two sectors: NNW to NE and S to SSW; most of the higher speed winds (>7.5 m/s) were from the sectors: S to SSW. 5 of 76

6 Figure C: March 2010 maximum predicted daily average SO 2 concentration (regional) Figure D: March 2010 maximum predicted daily average SO 2 concentration (local) 6 of 76

7 Maximum predicted daily average concentrations The Model predicted maximum daily average SO 2 concentrations greater than the DEAT SO 2 Daily Average National Standard (48 ppb) over the CBD, Felixton and Veldenvlei. The half-guideline includes parts of Alton, Arboretum, Arboretum Extension, Bayside Aluminium, Foskor, Hillside Aluminium, Mondi Richards Bay, the Port of Richards Bay, Richards Bay Minerals and Wildenweide. Figure E: March 2010 maximum daily average SO 2 concentration and prediction There were no measured exceedances of the DEAT SO 2 Daily Average National Standard (48 ppb). Daily average predicted values at all stations were within accepted dispersion modelling norms (-50% to 200%) except for Arboretum and Brackenham which were over predicted. Compared to the measurements, predicted values at all stations were higher. As mentioned in Section 3.3, there has been a significant downward trend in measured values since 2005; during this time there have only been small changes to the emission inventory (done in 2004) this is most likely the reason for the higher predictions at some stations. 7 of 76

8 SO 2 data There were no measured exceedances of the DEAT SO 2 National Standards. Table B: Maximum and monthly average SO 2 concentrations Maximum SO2 concentrations Station 10 Minute Average Hourly Average Daily Average Monthly Average % of guideline 22% 21% 16% 10% Arboretum (ppb) Date & time 2010/03/31 03: /03/31 01: /03/ /03 % of guideline 9% 8% 7% 4% Brackenham (ppb) Date & time 2010/03/31 03: /03/31 01: /03/ /03 % of guideline 33% 30% 39% 17% CBD (ppb) Date & time 2010/03/28 06: /03/31 01: /03/ /03 % of guideline 39% 43% 40% 31% Harbour West (ppb) Date & time 2010/03/16 11: /03/27 09: /03/ /03 % of guideline 51% 33% 21% 19% Scorpio (ppb) Date & time 2010/03/20 07: /03/20 07: /03/ /03 Trends for measured SO 2 concentrations are contained in Section 3. 8 of 76

9 TRS data There are no South African standards for total reduced sulphates (TRS). Table C: Maximum and monthly average TRS concentrations Maximum TRS concentrations Station 10 Minute Average Hourly Average Daily Average Monthly Average % of H2S odour threshold 511% 318% 56% 24% CBD (ppb) Date & time 2010/03/02 07: /03/02 07: /03/ /03 Trends for measured TRS concentrations are contained in Section 4. PM 10 data There were no measured exceedances of the SANS PM 10 Limit Values or DEAT PM 10 National Standards. Table D: Maximum and monthly average PM 10 concentrations Maximum PM10 concentrations Station 10 Minute Average Hourly Average Daily Average Monthly Average % of guideline % 60% Brackenham µg/m Date & Time 2010/03/06 14: /03/06 15: /03/ /03 % of guideline % 75% CBD µg/m Date & Time 2010/03/09 14: /03/09 14: /03/ /03 Trends for measured PM 10 concentrations are contained in Section 5. 9 of 76

10 Air quality complaints There were 8 air quality complaints received for the month of March 2010 (see Appendix 5). The historical count of complaints by month is reflected below. There were 23 complaints logged during the same period last year. Figure F: Comparison of number of air quality complaints per month Figure G: Air quality complaints by source 10 of 76

11 Network data capture and operation Data capture shows the percentage of the month where the station as a whole was operational; while the SO 2, PM 10, and TRS data capture indicates the percentage of valid data received from the respective analysers for the month. Data capture for March 2010 is shown in the table below. Table E: Ambient air quality data capture Data capture (%) for RBCAA system Station Data (%) SO2 (%) PM10 (%) TRS (%) Arboretum Brackenham CBD Harbour West Scorpio Average Notes: Target 80%, Good 90%, Excellent 95% Station, SO 2, PM 10 and TRS data capture for March 2010 was above target. 11 of 76

12 REPORT DETAILS REFERENCE AQ002 REPORT TITLE Monthly Report: March 2010 DATE SUBMITTED March 2010 CLIENT Sandy Camminga Richards Bay Clean Air Association PO Box Richards Bay 3900 Tel: (035) PREPARED BY: Lance Coetzee 6 Sookhai Place Derby Downs Westville Durban, 3630 Tel: (031) info@ecoserv.com SIGNED APPROVER Lance Coetzee Signed: STATUS NOTICE Signed: Mark Baird Draft This document is issued by the Company under its General Conditions of Service accessible at Attention is drawn to the limitation of liability, indemnification and jurisdiction issues defined therein. Any holder of this document is advised that information contained hereon reflects the Company s findings at the time of its intervention only and within the limits of Client s instructions, if any. The Company s sole responsibility is to its Client and this document does not exonerate parties to a transaction from exercising all their rights and obligations under the transaction documents. Any unauthorized alteration, forgery or falsification of the content or appearance of this document is unlawful and offenders may be prosecuted to the fullest extent of the law. 12 of 76

13 TABLE OF CONTENTS Description Page 1 INTRODUCTION 19 2 METEOROLOGY 21 3 MONITORING AND MODELLED RESULTS FOR SULPHUR DIOXIDE (SO 2 ) Ambient Air Quality Standards Compliance with Ambient Air Quality Standards and Maximums Monthly Average Information Daily Average Information Hourly Average Information minute Average Information Diurnal Trend Pollution Roses 49 4 MONITORED RESULTS FOR TOTAL REDUCED SULPHUR (TRS) Ambient Air Quality Standards Compliance with Ambient Air Quality Standards and Maximums Monthly Average Information Daily Average Information Hourly Average Information minute Average Information Diurnal Trend Pollution Roses 60 5 MONITORED RESULTS FOR FINE PARTICULATES (PM 10 ) Ambient Air Quality Standards Compliance with Ambient Air Quality Standards and Maximums Monthly Average Information Daily Average Information Hourly Average Information minute Average Information Diurnal Trend Pollution Roses 68 6 COMPLIANCE WITH GUIDELINES 70 7 AIR QUALITY COMPLAINTS Field Observations Distribution of Complaints by Source Distribution of Complaints by Region Distribution of Complaints by Type of 76

14 APPENDIX 1 Quality Assurance Statement APPENDIX 2 Meteorological data APPENDIX 3 Network data capture and operation Ambient Air Quality Data Capture Network Operation APPENDIX 4 Dispersion simulation inputs Source Emission Data Dispersion model settings APPENDIX 5 Air Quality Complaints Log APPENDIX 6 Case Studies Richards Bay Clean Air Association 14 of 76

15 LIST OF FIGURES Richards Bay Clean Air Association Description Page Figure 2.1: Wind roses for Arboretum (March 2010 and 2009) 21 Figure 2.2: Diurnal temperature profile March Figure 3.1: Long term monthly average SO2 concentrations 26 Figure 3.2: Monthly average SO2 concentration and prediction (March 2010) 27 Figure 3.3: Predicted monthly average SO2 concentration (regional) 29 Figure 3.4: Predicted monthly average SO2 concentration (local) 30 Figure 3.5: Maximum daily average SO2 concentration and prediction 32 Figure 3.6: Maximum predicted daily average SO2 concentration (regional) 33 Figure 3.7: Maximum predicted daily average SO2 concentration (local) 34 Figure 3.8: Daily average SO2 concentration 35 Figure 3.9: Maximum hourly average SO2 concentration and prediction 36 Figure 3.10: Maximum predicted hourly average SO2 concentration (regional) 37 Figure 3.11: Maximum predicted hourly average SO2 concentration (local) 38 Figure 3.12: Hourly average SO2 concentration at Arboretum 39 Figure 3.13: Hourly average SO2 concentration at Brackenham 40 Figure 3.14: Hourly average SO2 concentration at CBD 40 Figure 3.15: Hourly average SO2 concentration at Harbour West 41 Figure 3.16: Hourly average SO2 concentration at Scorpio 41 Figure 3.17: Maximum 10-minute average SO2 concentration and prediction 42 Figure 3.18: Maximum predicted 10-minute average SO2 concentration (regional) 43 Figure 3.19: Maximum predicted 10-minute average SO2 concentration (local) 44 Figure 3.20: 10-minute average SO2 concentration at Arboretum 45 Figure 3.21: 10-minute average SO2 concentration at Brackenham 46 Figure 3.22: 10-minute average SO2 concentration at CBD 46 Figure 3.23: 10-minute average SO2 concentration at Harbour West 47 Figure 3.24: 10-minute average SO2 concentration at Scorpio 47 Figure 3.25: Diurnal SO2 trends 48 Figure 3.26: SO2 pollution rose for Arboretum 49 Figure 3.27: SO2 pollution rose for Brackenham 50 Figure 3.28: SO2 pollution rose for CBD 51 Figure 3.29: SO2 pollution rose for Harbour West 52 Figure 3.30: SO2 pollution rose for Scorpio 53 Figure 4.1: Long term monthly average TRS concentrations 55 Figure 4.2: Daily average TRS at CBD 56 Figure 4.3: Hourly average TRS at CBD 57 Figure 4.4: 10-minute average TRS at CBD 58 Figure 4.5: Diurnal TRS trend at CBD of 76

16 Figure 4.6: TRS pollution rose for CBD 60 Figure 5.1: Long term monthly average PM10 concentrations 63 Figure 5.2: Daily average PM10 at Brackenham and CBD 64 Figure 5.3: Hourly average PM10 at Brackenham and CBD station 65 Figure 5.4: 10-minute average PM10 at Brackenham and CBD station 66 Figure 5.5: PM10 diurnal trend 67 Figure 5.6: Wind speed diurnal trend 67 Figure 5.7: PM10 pollution rose for Brackenham 68 Figure 5.8: PM10 pollution rose for CBD 69 Figure 6.1: SO2 exceedances per month Figure 6.2: SO2 exceedances per month Figure 6.3: SO2 exceedances per month Figure 6.4: SO2 exceedances per month Figure 7.1: Comparison of number of complaints per month 73 Figure 7.2: Distribution of complaints by source 74 Figure 7.3: Distribution of complaints by source YTD 74 Figure 7.4: Distribution of complaints by region 75 Figure 7.5: Distribution of complaints by region YTD 75 Figure 7.6: Distribution of complaints by type 76 Figure 7.7: Distribution of complaints by type YTD 76 Figure 7.8: Wind rose for Arboretum March Figure 7.9: Wind rose for Brackenham March Figure 7.10: Wind rose for Harbour West March Figure 7.11: Wind rose for Scorpio March of 76

17 LIST OF TABLES Richards Bay Clean Air Association Description Page Table 1.1: Ambient air quality standards for SO Table 1.2: Ambient air quality standards for PM Table 3.1: Ambient air quality standards for SO Table 3.2: SO2 Maximums Table 4.1: TRS Maximums Table 5.1: Ambient air quality standards for PM Table 5.2: PM10 Maximums Table 7.1: Ambient air quality data capture Table 7.2: Arboretum SO2 analyser zero and span checks Table 7.3: Arboretum station log Table 7.4: Arboretum status report Table 7.5: Brackenham SO2 analyser zero and span checks Table 7.6: Brackenham station log Table 7.7: Brackenham status report Table 7.8: CBD SO2 analyser zero and span checks Table 7.9: CBD station log Table 7.10: CBD status report Table 7.11: Harbour West SO2 analyser zero and span checks Table 7.12: Harbour West station log Table 7.13: Harbour West status report Table 7.14: Scorpio SO2 analyser zero and span checks Table 7.15: Scorpio station log Table 7.16: Scorpio status report Table 7.17: Source emission summary Table 7.18: Point source emission parameters Table 7.19: Area source emission parameters Table 7.20: Dispersion model meteorological parameters Table 7.21: Dispersion model setup parameters of 76

18 ABBREVIATIONS Richards Bay Clean Air Association Degrees C Degrees Celsius µg/m 3 Microgram per cubic metre CH 3 -S-CH 3 Dimethyl sulphide CH 3 S-H Methyl mercaptan CH 3 -S-S-CH 3 Dimethyl disulphide DEAT Department of Environmental Affairs and Tourism (RSA) E East ENE East north east ESE East south east g/s Grams per second K Kelvin m Metres m/s Metres per second N North NE North East NEMAQA National Environmental Management Air Quality Act NNE North north east NNW North north west NW North west PM 10 Fine particulate matter ppb Parts per billion RBCAA Richards Bay Clean Air Association S South SANAS South African National Accreditation Service SANS South African National Standards SE South east SO 2 Sulphur dioxide SSE South south east SSW South south west SW South west tpa Tons per annum TRS Total reduced sulphur US EPA United States Environmental Protection Agency W West WD Wind direction WNW West north west WS Wind speed WSW West south west 18 of 76

19 1 INTRODUCTION This report summarises the sulphur dioxide (SO 2 ), total reduced sulphur (TRS) and fine particulate (PM 10 ) monitoring data gathered by the RBCAA monitoring network for the month of March The monitoring network consists of five monitoring stations situated at Arboretum, Brackenham, CBD, Harbour West and Scorpio. The monitoring system, as maintained by SGS SA Environmental Services, is accredited by the South African National Accreditation Service (SANAS) for the measurement of SO 2. The applicable quality controls and measurement methods are listed in Appendix 1. The measured results pertain to instantaneous samples drawn from air passing the above fixed stations, and care should be taken when extrapolating these results to surrounding areas. All results are reported at standard temperature and pressure. Measured SO 2 concentrations over various time scales are compared to percentile concentrations predicted by the Hawk Air Pollution Dispersion Model. The Hawk Model SO 2 concentrations are based on ambient meteorological conditions and an emission inventory. Opinions, interpretations, meteorological data and Hawk Model findings presented in this report do not form part of the SANAS accreditation. Modelled SO 2 concentrations, using the Hawk Dispersion Model, are presented and results are compared to the monitored concentrations. 19 of 76

20 It is also the intention of this report to highlight certain incidents and exceedances of air quality standards. The National Environment Management Air Quality Act (NEMAQA), Schedule 2 Standards for SO 2 (Act 39 of 2004, published 24 February 2006) are listed in Table 1.1 below. Table 1.1: Ambient air quality standards for SO 2 Organisation Variable 10-min average Hourly average Daily average Monthly average Annual average NEMAQA [a] SO2 500 µg/m³ [c] 350 µg/m³ [d] 125 µg/m³ [e] - 50 µg/m³ [f] 191 ppb [c] 134 ppb [d] 48 ppb [e] 19 ppb [f] Notes: [a] SA Government Gazette (published 24 th December 2009) in terms of the National Environmental Management: Air Quality Act 39 of 2004 [c] Not to be exceeded more than 526 times in one year. [d] Not to be exceeded more than 88 times in one year. [e] Not to be exceeded more than 4 times in one year. [f] Not to be exceeded. Additional pollutants measured, as part of the RBCAA monitoring programme, include TRS and PM 10 at CBD station; the results of which are presented in Section 4 and 5 of this report. The NEMAQA, Schedule 2 Standards for PM 10 (Act 39 of 2004, published 24 February 2006) are listed in Table 1.2 below. Table 1.2: Ambient air quality standards for PM 10 Organisation Variable 10-min average Hourly average Daily average Monthly average Annual average NEMAQA [a] PM µg/m³ [e] - 50 µg/m³ [f] SANS [b] PM µg/m³ [e] - 40 µg/m³ [f] Notes: [a] SA Government Gazette (published 24 th December 2009) in terms of the National Environmental Management: Air Quality Act 39 of 2004 [b] SABS Draft South African National Standard SANS1929:2009 [e] Not to be exceeded more than 4 times in one year. [f] Not to be exceeded. 20 of 76

21 2 METEOROLOGY Figure 2.1: Wind roses for Arboretum (March 2010 and 2009) (a) Arboretum wind rose March 2010 The average wind speed in March 2010 was 3.1 m/s with 8.79% calms. Predominant winds blew from two sectors: NNW to NE and S to SSW; most of the higher speed winds (>7.5 m/s) were from the sectors: S to SSW. (b) Arboretum wind rose March of 76

22 The average wind speed in March 2009 was 2.9 m/s, with 14.87% calms. Predominant winds blew from two sectors: NNW to NE and S to SW; most of the higher speed winds (>7.5 m/s) were from the sector: S to SSW. Figure 2.2: Diurnal temperature profile March of 76

23 3 MONITORING AND MODELLED RESULTS FOR SULPHUR DIOXIDE (SO 2 ) In this section of the report, SO 2 concentrations measured at the fixed monitoring stations and SO 2 concentrations calculated by the Hawk Dispersion Model are compared. The Hawk Dispersion Model uses meteorological and topographical data, and an emission inventory to simulate the prevailing conditions in order to estimate the concentration of SO 2 at any given point within the area of interest. This requires the use of certain assumptions, resulting in a variation between the modelled and measured SO 2 concentrations presented. The concentration maps generated using the Hawk Model represent the cumulative concentrations predicted at receptor grid points by means of concentration isopleths, averaged over the required time period. The predicted concentrations in these dose maps may vary from actual concentrations. All modelled concentrations are reported at the 99 th percentile, unless otherwise stated. The national annual average standard of 19 ppb is the basis for comparison for monthly averaging, as there is no monthly average SO 2 standard. This results in the comparison of modelled and guideline SO 2 concentrations being more conservative. Limitations of dispersion models are their inability to account for highly complex, rapidly varying spatial and temporal meteorological systems such as calms, coastal fumigation, sea / land breeze recirculation, and mountain and valley winds, particularly in complex terrain or near coastal boundaries. The US EPA considers the range of uncertainty to be -50% to 200% for models applied to gently rolling terrain. The accuracy improves with fairly strong wind speeds and during neutral atmospheric conditions. Dispersion modelling results can be compared with monitored values in order to improve the accuracy or calibrate models using percentiles. 23 of 76

24 An investigation in July 2007 compared the measured values to the 98 th, 99 th and 100 th percentile. The investigation concluded that the 99 th percentile more closely approximated measured values. The RBCAA has therefore decided to use the 99 th percentile across all averaging periods. Previously, the 99 th percentile was used for monthly, daily and hourly averaging periods while the 100 th percentile for was used for 10-minute averaging periods. The extent of the effects on maximum 10-minute concentration maps will therefore appear greatly reduced. This does not indicate that there has been any reduction in emissions or improvement in air quality. 3.1 Ambient Air Quality Standards Ambient air quality standards for SO 2 are listed below. Table 3.1: Ambient air quality standards for SO 2 Organisation Variable 10-min average Hourly average Daily average Monthly average Annual average NEMAQA [a] SO2 500 µg/m³ [c] 350 µg/m³ [d] 125 µg/m³ [e] - 50 µg/m³ [f] 191 ppb [c] 134 ppb [d] 48 ppb [e] 19 ppb [f] Notes: [a] SA Government Gazette (published 24 th December 2009) in terms of the National Environmental Management: Air Quality Act 39 of 2004 [c] Not to be exceeded more than 526 times in one year. [d] Not to be exceeded more than 88 times in one year. [e] Not to be exceeded more than 4 times in one year. [f] Not to be exceeded. 24 of 76

25 3.2 Compliance with Ambient Air Quality Standards and Maximums There were no measured exceedances of the DEAT National Standards. Table 3.2: SO 2 Maximums Maximum SO2 concentrations Station 10 Minute Average Hourly Average Daily Average Monthly Average % of guideline 22% 21% 16% 10% Arboretum (ppb) Date & time 2010/03/31 03: /03/31 01: /03/ /03 % of guideline 9% 8% 7% 4% Brackenham (ppb) Date & time 2010/03/31 03: /03/31 01: /03/ /03 % of guideline 33% 30% 39% 17% CBD (ppb) Date & time 2010/03/28 06: /03/31 01: /03/ /03 % of guideline 39% 43% 40% 31% Harbour West (ppb) Date & time 2010/03/16 11: /03/27 09: /03/ /03 % of guideline 51% 33% 21% 19% Scorpio (ppb) Date & time 2010/03/20 07: /03/20 07: /03/ /03 25 of 76

26 3.3 Monthly Average Information Richards Bay Clean Air Association Long term monthly average SO 2 concentrations are shown below. Figure 3.1: Long term monthly average SO 2 concentrations 26 of 76

27 3.3.1 Monthly average concentration and prediction The monthly average SO 2 measured at each of the RBCAA stations, and the Hawk predicted average for the month are shown below. The monthly average for the same period the previous year (where available) is also provided. Figure 3.2: Monthly average SO 2 concentration and prediction (March 2010) When compared to the previous year, monthly average SO 2 concentrations measured at Scorpio were lower and at Arboretum, Brackenham, CBD and Harbour West were similar (within 2.0 ppb or 10%). There were no measured exceedances of the DEAT SO 2 Annual Average National Standard (19 ppb). 27 of 76

28 Monthly average predicted values at all stations were within accepted dispersion modelling norms (-50% to 200%) except for Brackenham which was over predicted. Compared to the measurements, predicted values at all stations were higher. There has been a significant downward trend in measured values since 2005; during this time there have only been small changes to the emission inventory (done in 2004) this is most likely the reason for the high predictions. It is therefore recommended that the emission inventory be updated. 28 of 76

29 3.3.2 Predicted monthly average concentration Figure 3.3: Predicted monthly average SO 2 concentration (regional) 29 of 76

30 Figure 3.4: Predicted monthly average SO 2 concentration (local) 30 of 76

31 The model predicted monthly average concentrations greater than the DEAT SO 2 Annual Average Standard (19 ppb) over Bayside Aluminium. The half-guideline includes parts of the CBD, Felixton, Foskor, Hillside Aluminium, Mondi Richards Bay, the Port of Richards Bay, Southern Sanctuary and Veldenvlei. 31 of 76

32 3.4 Daily Average Information Richards Bay Clean Air Association Maximum daily average concentration and prediction Figure 3.5: Maximum daily average SO 2 concentration and prediction There were no measured exceedances of the DEAT SO 2 Daily Average National Standard (48 ppb). Daily average predicted values at all stations were within accepted dispersion modelling norms (-50% to 200%) except for Arboretum and Brackenham which were over predicted. Compared to the measurements, predicted values at all stations were higher. As mentioned in Section 3.3, there has been a significant downward trend in measured values since 2005; during this time there have only been small changes to the emission inventory (done in 2004) this is most likely the reason for the higher predictions at some stations. 32 of 76

33 3.4.2 Maximum predicted daily average concentration Figure 3.6: Maximum predicted daily average SO 2 concentration (regional) 33 of 76

34 Figure 3.7: Maximum predicted daily average SO 2 concentration (local) 34 of 76

35 The Model predicted maximum daily average SO 2 concentrations greater than the DEAT SO 2 Daily Average National Standard (48 ppb) over the CBD, Felixton and Veldenvlei. The half-guideline includes parts of Alton, Arboretum, Arboretum Extension, Bayside Aluminium, Foskor, Hillside Aluminium, Mondi Richards Bay, the Port of Richards Bay, Richards Bay Minerals and Wildenweide Daily average trend Figure 3.8: Daily average SO 2 concentration 35 of 76

36 3.5 Hourly Average Information Maximum hourly average concentration and prediction Figure 3.9: Maximum hourly average SO 2 concentration and prediction There were no measured exceedances of the DEAT SO 2 Hourly Average National Standard (134 ppb). Hourly average predicted values at all stations were within accepted dispersion modelling norms (-50% to 200%) except for Arboretum and Brackenham which were over predicted. Compared to the measurements predicted values at all stations were higher. As mentioned in Section 3.3, there has been a significant downward trend in measured values since 2005; during this time there have only been small changes to the emission inventory (done in 2004) this is most likely the reason for the higher predictions at some stations. 36 of 76

37 3.5.2 Maximum predicted hourly average concentration Figure 3.10: Maximum predicted hourly average SO 2 concentration (regional) 37 of 76

38 Figure 3.11: Maximum predicted hourly average SO 2 concentration (local) Richards Bay Clean Air Association 38 of 76

39 The Model predicted maximum daily average SO 2 concentrations greater than the DEAT SO 2 National Standard (134 ppb) over Arboretum, Arboretum Extension, Bayside Aluminium, the CBD, Felixton, Mondi Richards Bay, the Port of Richards Bay, the Southern Sanctuary, Veldenvlei and Wildenweide. The half-guideline includes parts of Alton, Birdswood, Brackenham, Foskor, Hillside Aluminium, Richards Bay Minerals and TATA Steel Hourly average trend Figure 3.12: Hourly average SO 2 concentration at Arboretum 39 of 76

40 Figure 3.13: Hourly average SO 2 concentration at Brackenham Richards Bay Clean Air Association Figure 3.14: Hourly average SO 2 concentration at CBD 40 of 76

41 Figure 3.15: Hourly average SO 2 concentration at Harbour West Richards Bay Clean Air Association Figure 3.16: Hourly average SO 2 concentration at Scorpio 41 of 76

42 minute Average Information Maximum 10-minute average concentration and prediction Figure 3.17: Maximum 10-minute average SO 2 concentration and prediction There were no measured exceedances of the DEAT SO 2 10-minute Average National Standard (191 ppb). Predicted 10-minute average values for all stations were within normal dispersion modelling norms (-50% to 200%) except for Brackenham which was over predicted. Compared to the measurements, predicted values at Scorpio were similar (within 10%) and at Arboretum, Brackenham, CBD and Harbour West higher. As mentioned in Section 3.3, there has been a significant downward trend in measured values since 2005; during this time there have only been small changes to the emission inventory (done in 2004) this is most likely the reason for the higher predictions at some stations. 42 of 76

43 3.6.2 Maximum predicted 10-minute concentration Figure 3.18: Maximum predicted 10-minute average SO 2 concentration (regional) 43 of 76

44 Figure 3.19: Maximum predicted 10-minute average SO 2 concentration (local) Richards Bay Clean Air Association 44 of 76

45 The model predicted maximum 10-minute average SO 2 concentrations greater than the DEAT 10-minute National Standard (191 ppb) over Arboretum, Arboretum Extension, Bayside Aluminium the CBD, Mondi Richards Bay and Veldenvlei. The half-guideline includes parts of Alton, Birdswood, Felixton, Foskor, Hillside Aluminium, the Port of Richards Bay, Richards Bay Minerals, the Southern Sanctuary and Wildenweide. Figure 3.20: 10-minute average SO 2 concentration at Arboretum 45 of 76

46 Figure 3.21: 10-minute average SO 2 concentration at Brackenham Richards Bay Clean Air Association Figure 3.22: 10-minute average SO 2 concentration at CBD 46 of 76

47 Figure 3.23: 10-minute average SO 2 concentration at Harbour West Richards Bay Clean Air Association Figure 3.24: 10-minute average SO 2 concentration at Scorpio 47 of 76

48 3.7 Diurnal Trend Richards Bay Clean Air Association Diurnal SO 2 trends for the RBCAA network are shown below. The peak at Harbour West can be associated with a sulphur fire on one on Foskor s conveyors. Figure 3.25: Diurnal SO 2 trends 48 of 76

49 3.8 Pollution Roses Figure 3.26: SO 2 pollution rose for Arboretum Most of the higher concentrations (>10 ppb) measured at Arboretum came from the sector: SSW to SW. Foskor and Bayside Aluminium are to the SW and Hillside Aluminium to the WSW, Mondi Richards Bay to the W and TATA Steel to the WNW. 49 of 76

50 Figure 3.27: SO 2 pollution rose for Brackenham Most of the higher concentrations (>10 ppb) measured at Brackenham came from two sectors: SSE to S and WSW. Foskor is to the S, Hillside and Bayside Aluminium to the SSW and Mondi Richards Bay and TATA Steel to the WSW. 50 of 76

51 Figure 3.28: SO 2 pollution rose for CBD Most of the higher concentrations (>10 ppb) measured at CBD came from the sector: S to SSW. Foskor is to the SSW, Bayside Aluminium to the SW, Hillside Aluminium to the WSW, Mondi Richards Bay to the W and TATA Steel to the WNW. 51 of 76

52 Figure 3.29: SO 2 pollution rose for Harbour West Most of the higher concentrations (>10 ppb) measured at Harbour West came from two sectors: N to NNE and SW to WSW. Foskor is to the NNE, the Port of Richards Bay to the E, Hillside Aluminium and TATA Steel to the N, Bayside Aluminium to the W, Mondi Richards Bay to the WNW and Richards Bay Coal Terminal to the SW. 52 of 76

53 Figure 3.30: SO 2 pollution rose for Scorpio Most of the higher concentrations (>10 ppb) measured at Scorpio came three sectors: NNW to NNE, S and SW. Foskor is to the S, Hillside Aluminium to the NW, Bayside Aluminium to the SW, Mondi Richards Bay to the W and TATA Steel to the NNW. 53 of 76

54 4 MONITORED RESULTS FOR TOTAL REDUCED SULPHUR (TRS) Total Reduced Sulphurs (TRS) are measured at CBD station. Total reduced sulphur compounds, often associated with rotten egg or cooked cabbage odour, refer to a gaseous mixture of compounds consisting mainly of hydrogen sulphide (H 2 S), methyl mercaptan (CH 3 S-H), dimethyl sulphide (CH 3 -S-CH 3 ) and dimethyl disulphide (CH 3 -S- S-CH 3 ). While there are other ambient TRS compounds, these four are the most common, abundant and the ones generally referred to in discussions about TRS. Once released into the atmosphere, oxidation products of TRS compounds, such as sulphuric acid, contribute to the acidity of the environment. The most commonly reported health concerns related to TRS substances are nausea and headaches, although each component has its own characteristics and effects. 4.1 Ambient Air Quality Standards There are no guidelines or standards for TRS; however the odour threshold for H 2 S is 4.5ppb. 4.2 Compliance with Ambient Air Quality Standards and Maximums Table 4.1: TRS Maximums Maximum TRS concentrations Station 10 Minute Average Hourly Average Daily Average Monthly Average % of H2S odour threshold 511% 318% 56% 24% CBD (ppb) Date & time 2010/03/02 07: /03/02 07: /03/ /03 54 of 76

55 4.3 Monthly Average Information Richards Bay Clean Air Association Long term monthly average TRS concentrations are shown below. Figure 4.1: Long term monthly average TRS concentrations 55 of 76

56 4.4 Daily Average Information Richards Bay Clean Air Association Daily Average Trend The daily average TRS trend at CBD is shown below. Figure 4.2: Daily average TRS at CBD 56 of 76

57 4.5 Hourly Average Information Richards Bay Clean Air Association Hourly Average Trend The hourly average TRS trend at CBD is shown below. Figure 4.3: Hourly average TRS at CBD 57 of 76

58 minute Average Information Minute Average Trend The 10-minute average TRS trend at CBD is shown below. Figure 4.4: 10-minute average TRS at CBD 58 of 76

59 4.7 Diurnal Trend Richards Bay Clean Air Association The diurnal TRS trend at CBD network is shown below. Figure 4.5: Diurnal TRS trend at CBD 59 of 76

60 4.8 Pollution Roses Richards Bay Clean Air Association Figure 4.6: TRS pollution rose for CBD Most of the higher concentrations (>10 ppb) measured at CBD came from the two sectors: ENE and S to SW. Foskor is to the SSW, Bayside Aluminium to the SW, Hillside Aluminium to the WSW, Mondi Richards Bay to the W and TATA Steel to the WNW. 60 of 76

61 5 MONITORED RESULTS FOR FINE PARTICULATES (PM 10 ) PM 10 refers to the measurement of particulate matter of less than 10 microns. The TEOM instruments at the Brackenham and CBD stations measure PM 10 data continuously. The instrument at Brackenham was removed on the 17 th of November to be installed into one of the new mobile monitoring stations. 5.1 Ambient Air Quality Standards Ambient air quality standards for PM 10 are listed below. Table 5.1: Ambient air quality standards for PM 10 Organisation Variable 10-min average Hourly average Daily average Monthly average Annual average NEMAQA [a] PM µg/m³ [e] - 50 µg/m³ [f] SANS [b] PM µg/m³ [e] - 40 µg/m³ [f] Notes: [a] SA Government Gazette (24 th December 2009) in terms of the National Environmental Management: Air Quality Act 39 of 2004 [b] SABS Draft South African National Standard SANS1929:2009 [e] Not to be exceeded more than 4 times in one year. [f] Not to be exceeded. 61 of 76

62 5.2 Compliance with Ambient Air Quality Standards and Maximums There were no measured exceedances of the SANS PM 10 National Daily Limit Values or DEAT PM 10 National Standards. Table 5.2: PM 10 Maximums Maximum PM10 concentrations Station 10 Minute Average Hourly Average Daily Average Monthly Average % of guideline % 60% Brackenham CBD µg/m Date & Time 2010/03/06 14: /03/06 15: /03/ /03 % of guideline % 75% µg/m Date & Time 2010/03/09 14: /03/09 14: /03/ /03 62 of 76

63 5.3 Monthly Average Information Richards Bay Clean Air Association Long term monthly average PM 10 concentrations are shown below. Figure 5.1: Long term monthly average PM 10 concentrations 63 of 76

64 5.4 Daily Average Information Richards Bay Clean Air Association Daily Average Trend Figure 5.2: Daily average PM 10 at Brackenham and CBD 64 of 76

65 5.5 Hourly Average Information Hourly Average Trend Figure 5.3: Hourly average PM 10 at Brackenham and CBD station 65 of 76

66 minute Average Information Richards Bay Clean Air Association Minute Average Trend Figure 5.4: 10-minute average PM 10 at Brackenham and CBD station 66 of 76

67 5.7 Diurnal Trend Richards Bay Clean Air Association The diurnal trend for PM 10 at CBD and Brackenham stations is shown in below. There is a correlation between PM 10 concentration and wind speed. Figure 5.5: PM 10 diurnal trend Figure 5.6: Wind speed diurnal trend 67 of 76

68 5.8 Pollution Roses Richards Bay Clean Air Association Figure 5.7: PM 10 pollution rose for Brackenham Most of the higher concentrations (>100 µg/m 3 ) measured at Brackenham came from two sectors: ENE to E and SSW. Foskor is to the South, Hillside and Bayside Aluminium to the SSW, TATA Steel and Mondi Richards Bay to the SW and Richards Bay Coal Terminal and the Port of Richards Bay to the SSE. 68 of 76

69 Figure 5.8: PM 10 pollution rose for CBD Richards Bay Clean Air Association Most of the higher concentrations (>100 µg/m 3 ) measured at CBD came from the sector: NNW to ENE. Foskor is to the South, Hillside and Bayside Aluminium to the SSW, TATA Steel and Mondi Richards Bay to the SW and Richards Bay Coal Terminal and the Port of Richards Bay to the SSE. 69 of 76

70 6 COMPLIANCE WITH GUIDELINES Figures 6.1 to 6.4 show total numbers of SO 2 standard exceedances per month measured at the RBCAA monitoring stations for 2006 to There have been no exceedances during Figure 6.1: SO 2 exceedances per month of 76

71 Figure 6.2: SO 2 exceedances per month 2008 Figure 6.3: SO 2 exceedances per month of 76

72 Figure 6.4: SO 2 exceedances per month 2006 Richards Bay Clean Air Association 72 of 76

73 7 AIR QUALITY COMPLAINTS 7.1 Field Observations There were 8 air quality complaints received for the month of March 2010 (see Appendix 5). The historical count of complaints by month is reflected below. There were 23 complaints logged during the same period last year. Figure 7.1: Comparison of number of complaints per month 73 of 76

74 7.2 Distribution of Complaints by Source Figure 7.2: Distribution of complaints by source Figure 7.3: Distribution of complaints by source YTD 74 of 76

75 7.3 Distribution of Complaints by Region Figure 7.4: Distribution of complaints by region Richards Bay Clean Air Association Figure 7.5: Distribution of complaints by region YTD 75 of 76

76 7.4 Distribution of Complaints by Type Figure 7.6: Distribution of complaints by type Richards Bay Clean Air Association Figure 7.7: Distribution of complaints by type YTD 76 of 76

77 APPENDIX 1 Quality Assurance Statement The SO 2 concentrations reported are determined by a United States Environmental Protection Agency (US EPA) equivalent method EQSA All SO 2 measurements allow for a maximum precision error of 10% of the reported value. A tolerance around the zero point of plus or minus 5 ppb is allowed. All effort is made to reduce the error to a minimum. In terms of quality assurance standards, data collection must be above 80% to be valid for statistical analysis. Test Range Action Zero Span Zero 0 to 2 ppb Leave as is. -2 to 0 ppb Set to zero. -5 to -2 ppb and 2 to 5 ppb Adjust data set to re-zero all data Outside above limits Invalidate and recalibrate. Span Plus or minus 3% deviation. -10 to -3% and 3 to 10% deviation. Outside above limits Invalidate and recalibrate. If specific reason can be identified for deviation, data may be adjusted. Leave as is. Scale data set by opposite corresponding percentage. If specific reason can be identified for deviation, data may be adjusted. Note that the system is accredited for the measurement of SO 2 only. The accreditation does not include the measurement of TRS, PM 10, or meteorological variables (e.g. wind, temperature). All opinions, interpretations and Hawk Model findings detailed in this report do not form part of the accreditation.

78 APPENDIX 2 Meteorological data Richards Bay: Short term climate data Temperature ( C) Month Lowest Highest Average Recorded Recorded Daily Minimum Daily Maximum Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar

79 Richards Bay: Short term climate data Wind Speed (m/s) Month Calms (%) Lowest Highest Daily Daily Average Recorded Recorded Minimum Maximum Jan % Feb % Mar % Apr % May % Jun % Jul % Aug % Sep % Oct % Nov % Dec % Jan % Feb % Mar % Apr % May % Jun % Jul % Aug % Sep % Oct % Nov % Dec % Jan % Feb % Mar % Apr % May % Jun % Jul % Aug % Sep % Oct % Nov % Dec % Jan % Feb % Mar %

80

81 Figure 7.8: Wind rose for Arboretum March 2010 The average wind speed in March 2010 was 3.1 m/s with 8.79% calms. Predominant winds blew from two sectors: NNW to NE and S to SSW; most of the higher speed winds (>7.5 m/s) were from the sectors: S to SSW.

82 Figure 7.9: Wind rose for Brackenham March 2010 The average wind speed in March 2010 was 2.9 m/s with 10.32% calms. Predominant winds blew from two sectors: N to NE and SSW; most of the higher speed winds (>7.5 m/s) were from the sector: SSW.

83 Figure 7.10: Wind rose for Harbour West March 2010 Richards Bay Clean Air Association The average wind speed in March 2010 was 3.5 m/s with 6.24% calms. Predominant winds blew from two sectors: N to ENE and SSW to SW; most of the higher speed winds (>7.5 m/s) were from two sectors: ENE and SSW to SW.

84 Figure 7.11: Wind rose for Scorpio March 2010 The average wind speed in March 2010 was 2.7 m/s with 7.371% calms. Predominant winds blew from two sectors: NNE to ENE and SSW to WSW; most of the higher speed winds (>7.5 m/s) were from the sector: SW.

85 Richards Bay: Long term climate data Period: This climatological information is the normal values and, according to World Meteorological Organisation (WMO) prescripts, based on monthly averages for the 30-year period Month Highest Recorded Temperature ( C) Average Daily Maximum Average Daily Minimum Lowest Recorded Average Monthly (mm) Precipitation Average Number of days with >= 1mm Highest 24 Hour Rainfall (mm) January February March April May June July August September October November December Year Long term data courtesy of

86 APPENDIX 3 Network data capture and operation Ambient Air Quality Data Capture Data capture shows the percentage of the month where the station as a whole was operational, while the SO 2, PM 10, and TRS data capture indicate the percentage of valid data received from the respective analysers for the month. Data capture for March 2010 is shown in the table below. Table 7.1: Ambient air quality data capture Data capture (%) for RBCAA system Station Data (%) SO2 (%) PM10 (%) TRS (%) Arboretum Brackenham CBD Harbour West Scorpio Average Notes: Target 80%, Good 90%, Excellent 95% Station, SO 2, PM 10 and TRS data capture for March 2010 was above target.

87 Network Operation General The SO 2 analyzer repaired by C&M Consulting Engineers installed at Scorpio monitoring station had an offset of 5 ppb, this was set back to 0, and the background fill was switched back on. Both the Mobile monitoring stations was received on 10 March 2010 and was taken to St Lucia and Mtunzini for the set up of the PM 10 Monitors the following day. The method of analyzing for TRS changed on 10 March 2010 with the installation of a SO X scrubber on the sample inlet line. On 16 March 2010 the SGS technician came to check the calibrations of the PM 10 monitors and found that the St Lucia monitor had a flow control problem, and the analyzer was removed and sent to the suppliers for repairs. The St Lucia and Mtunzini met mast and equipment was commissioned on 17 and 18 March 2010 respectively. The St Lucia monitoring station s communication router was removed on 26 March 2010; a new router will be installed to solve the communication problem. The spare (old Scorpio) SO 2 Analyzer was received back on 30 March 2010 after it was repaired by SI Analytics. Inteltronics calibrated all the met stations on 31 March and 1 April 2010 except for the RBM met station. The RBM station will be calibrated in due course as soon as Inteltronics access permits have been issued.