Media Release: Garden Route District Municipality establishes a dispersion modelling function
For Immediate Release 10 June 2021
The Garden Route District Municipality (GRDM) recently procured the Enviman AERMOD (Air Quality Dispersion Modelling) software programme that enables the GRDM Air Quality Unit to conduct dispersion modelling studies. This is a new initiative to expand the scope of work of the GRDM Air Quality Officers.
According to Dr Johann Schoeman, GRDM Manager: Air Quality: “Air dispersion modelling is defined as a series of mathematical simulations of how air pollutants disperse in the ambient atmosphere. It is performed with computer programs that solve the mathematical equations and algorithms which simulate the dispersion of pollutants.”
Dr Schoeman says AERMOD is also listed as an approved dispersion model in the Regulations that governs Dispersion Modelling, 2014, Government Notice R533. Thus, the program allows for creating air quality maps for comparison against national guidelines and limit values.
The application of this software will assist the Air Quality unit in dealing with air quality complaints. It predicts the emissions and effect of a specific source on a particular residency, depending on real-time weather data availability. For example, suppose a person phones the GRDM to complain about the smoke from a stack of Facility X. In that case, the GRDM can execute a theoretical predication of the dispersion by entering the real-time weather data and stack parameters, and the model will determine the concentrations at the complainant’s residency. GRDM can then determine if the complaint is indeed justified by comparing it with the National Ambient Air Quality standards.
The GRDM can also determine the air quality impact of area sources such as landfill sites on communities. The below dispersion model for Methane was done for the proposed GRDM Landfill site in Mossel Bay, based on the predicted landfill volumes during year one and the historical weather data for Mossel Bay over the last three years.
The programme can also determine various percentile equations to determine a specific source’s worst-case scenario on a community. The 99 percentile, for example, predicts the highest concentration of a pollutant for 1% of the year. This is demonstrated in the picture below.
Feature image: Average hourly period concentrations for Methane from the proposed Landfill site in Mossel Bay computed over a year. As can be seen in both examples, the methane concentrations are insignificant and will not cause any harm to the community.Â
Media Release: Garden Route at the top of its game in controlling air quality
For immediate release
26 March 2021
Garden Route district continues to achieve 100% submission of NAEIS reports
The “National Atmospheric Emission Inventory System” or “NAEIS” is an internet-based emissions reporting system, which is a component of the South African Atmospheric Emission Licencing and Inventory System (SAAELIP) portal. NAEIS allows for regulated industries, as well as authorities to report atmospheric emissions from all sectors for compiling a national atmospheric emission inventory profile. NAEIS is legislated through the National Emission Reporting regulations that prescribe NAEIS reporting.
“Emission inventory means an accounting of the amount of pollutants discharged into the atmosphere and it contains the total emissions for one or more specific greenhouse gases and air pollutants originating from all sources in a certain geographical area and within a specified time span, said Dr Johann Schoeman, Manager: District Air Quality Control.NAEIS is a web-based atmospheric emissions monitoring and reporting system that is aimed at providing accurate, current and complete information. It includes all significant sources of identified atmospheric emissions, including greenhouse gas emissions from South Africa. NAEIS uses a single national reporting system of atmospheric emissions, which includes:
Informing policy formulation;
Meeting obligations as a country, under the United Framework Convention on Climate Change and any other international treaties to which it is bound; and
The establishment and upkeep of a National Emission Inventory Profile.
To comply with the reporting regulations, facilities must report emissions from each preceding year. This is made possible when the NAEIS system is opened for reporting from 1 January to 31 March annually. To ensure that this is done, the GRDM Air Quality unit arranged training sessions for its industries since the inception of NAEIS reporting in 2015 to assist stakeholders with reporting on the NAEIS system. Since the start, the Garden Route district collectively achieved a 100% submission of NAEIS reports although the National target currently stands at 90%.
This 100% submission rate is achieved through relentless assistance to our industry. “We guide the industry through special NAEIS completion target-group sessions, appointments and personal assistance,’ said Dr Schoeman.
“Most of the larger industries also have the capacity to appoint consultants to assist them with NAEIS reporting. We therefore focus on the smaller industries that do not have the capacity to do the reporting.”
Dr Schoeman further explained: “Within the Garden Route district, we have 37 facilities that have to report on NAEIS. With a week remaining, we already achieved a 70% submission rate with 26 Facilities that already submitted their NAEIS reports. We are in the process of reminding and assisting those that are busy with their NAEIS reports to do their submissions before 31 March 2021.”
The GRDM’s Air Quality section is sure that another 100% submission rate will be achieved for 2021. The Covid-19 pandemic made it challenging for both Industry, as well as the Air Quality Officers, because additional to compliance with Covid-19 protocols were added to daily tasks. Despite these challenges, the GRDM used innovative means to achieve its goals and objectives. After the NAEIS reporting cycle, authorities have to audit the NAEIS report, after which the National Department does National verifications.
Media Statement: Oil smell and possible oil pollution in Dana Bay
For Immediate Release 10 February 2021
Community members recently raised concerns via social media regarding possible oily residue in the Blinde River and areas reeking of oil in Dana Bay. An inspection was subsequently done at the Blinde River on 10 February 2021 at around 13:15. Results of the inspection indicate that the blackish residue is most likely from algae growth in the river.
Algae often loosens up and decomposes alongside river banks and is in this case visibly darker in colour, similar to oil residue. PetroSA, who also visited the Blind River also confirmed this finding. However, samples were taken and sent for lab tests to confirm this statement. Furthermore, it was also confirmed that there was no oily smell from the black algae residue in the River or in Dana Bay.
The oily smell during the night is most likely residing from the PetroSA Gas To Liquids (GTL) refinery and specifically from an oil spill that occurred at the end of 2020 in two storm water ponds located adjacent to the N2. This incident was subsequently communicated to community members.
The respective case officers from National and Provincial level have been informed and are currently busy with applicable administrative action to resolve this issue. Over the short term, a solution is to clean the affected ponds, which is already underway. While the long-term solution is to upgrade the applicable unit to prevent spillages going forward. Further details about such clean-up operations need to be directed to the relevant authority, i.e. PetroSA.
The fact that the smells are more eminent during early morning hours is just that at that time of the morning, weather conditions are normally stable with dispersion conditions favouring air pollution. As soon as the temperature rises and the wind picks up, the smells gets dispersed.
Provincial air quality monitoring stations are located in George, Mossel Bay and Oudtshoorn. The concentrations of pollutants measured at the Mossel Bay station continues to comply with the National Ambient Air Quality Standards. Furthermore, the listed activities in the Garden Route are monitored through their respective Atmospheric Emission Licences and any non-compliance will continue to be addressed through administrative action.
Mossel Bay residents are further informed that PetroSA management has opted in for an open line of communication with the public. Residents are therefore urged to contact the PetroSA Shift Manager at 044- 601 2531 to lodge a complaint which will be subsequently investigated.
The public is also welcome to contact the District Air Quality office for any applicable air quality complaints under the GRDM jurisdiction. The office number is 044-693 0006 during normal office hours (Monday – Thursday, 07:30 – 16:30; Fridays from 07:30 – 13:30).
Dr Johann Schoeman
Manager: District Air Quality Control jschoeman@gardenroute.gov.za
Tel: +27 (0)44 693 0006 | +27 (0)84 317 9167
Media Release: Ambient Air Quality Monitoring conducted in Louis Fourie Road Mossel BayÂ
For immediate release
25 January 2021
The stretch of the Louis Fourie Road between Hartenbos and Mossel Bay was identified as an Air Quality hotspot in the Garden Route District Municipality’s (GRDM) 3rd Generation Air Quality Management Plan (AQMP),  as a result of mobile emissions. This declaration was made based on estimate emissions, making use of traffic counts and international-based emission factors from the United States Environmental Protection Agency (USEPA).
According to Dr Schoeman, GRDM Manager: Air Quality: “Based on the traffic counts obtained from the South African National Roads Agency Ltd (SANRAL), the highest traffic density in the Garden Route district is most probably experienced along the R102 provincial road between Hartenbos and Mossel Bay through the Voorbaai area. A total number of 9.5 million vehicles were counted during 2018”.
It is recommended in the AQMP that ambient air quality monitoring be undertaken to verify the estimated emissions and compliance with the National Ambient Air Quality Standards.
From 5 January 2021 to 11 January 2021, the GRDM District Air Quality Unit commissioned its Zephyr mobile Air Quality monitoring station on Louis Fourie Road in Mossel Bay to verify the estimated emissions in the AQMP. Monitoring work was also intended to determine whether the stretch of road is indeed a hotspot.
“The results indicated periods of exceedances of the 24-hour average concentrations for both Sulphur dioxide (SO2) as well as Oxides of Nitrogen (NOx), 24-hour average concentrations as specified in the National Ambient Air Quality Standards,” said Dr Schoeman. According to Dr Schoeman, the Zephyr monitoring station does not make use of reference methods for sampling, hence it is calibrated, and the results are highly accurate and therefore the perfect tool for screening purposes. The Zephyr was imported from the UK, who is using it extensively for more than five years to determine the impact of vehicle emissions in the greater Londen.
The exercise helps in creating awareness and to demonstrate that non-industrial activities also have an impact on ambient air quality. The results will be discussed with Mossel Bay local municipality, which can be used as supplementary motivation to improve traffic flow along Louis Fourie road with the Provincial Roads directorate.
Media Statement: Odour complaints in Mossel Bay receiving attention
For Immediate Release 8 October 2020
As part of an investigation about the offensive odour complaints in Mossel Bay, the Garden Route District Municipality (GRDM) Air Quality (AQ) and PetroSA convened a two-weekly meeting on odours in communities. The latest odours originate most likely from an oily effluent spill in the two storm-water dams on the refinery site. This incident was reported to the authorities and discussed in length at an engagement, followed by a media statement by PetroSA which addressed details of the incident. As part of the action list emanating from the meeting, GRDM visited the site and incident on the 6 October 2020. During the site visit the GRDM AQ Unit was joined by Mr Rudzani Makahane, Water Use Officer of the Breede-Gouritz Catchment Management Agency.
The oil spill into the storm water system was confirmed as signs of oil residue was visible in both the storm water ponds and the Blind River. There was a distinct pungent smell of hydrocarbons present at the ponds. Although, the GRDM is the Air Quality Licencing Authority for PetroSA, and offensive odours form part of air pollution, the primary origin of the odour is storm water. Thus, the primary source must be addressed in order to mitigate the air quality offensive odours (secondary matter).
Media Release: Third Generation Western Cape Air Quality Management Plan Review
For Immediate Release
28 August 2020
The Western Cape Government, through the Department of Environmental Affairs and Development Planning (DEA&DP), implements systems and provides an oversight role in the province with respect to air quality management. In line with Section 15 (1) of the National Environmental Management: Air Quality Act (Act 39 of 2004) (NEM: AQA) Provinces and Municipalities are required to develop Air Quality Management Plans to manage air quality in their regions. For it to be effective, the AQMP needs to be reviewed every 5 years to establish whether the identified goals and targets have been effectively implemented.
In accordance with the NEM: AQA requirements, a Western Cape Air Quality Management Plan (AQMP) was first developed in 2010 to manage air quality in the Province. The 2010 Western Cape AQMP outlined the air quality management planning, monitoring and regulatory interventions, inclusive of assessing air quality impacts and characterizing the sources of pollution within the Western Cape Province.
The 2nd Generation Western Cape AQMP was built upon the strengths and successes of the 2010 Western Cape AQMP and was informed via formal Public Participation Process workshops during 2015 and adopted in 2016. The 2nd Generation AQMP mainly focused on strengthening the linkages between Air Quality Management and Climate Change Response, as well as spatial planning for growth and development in the Western Cape Province.
The 2nd Generation AQMP upholds the vision and the mission of the 2010 Western Cape AQMP which are as follows:
VISION
“Clean and healthy air for all in the Western Cape”
MISSION
“To ensure the effective and consistent implementation of sustainable air quality management practices, by all spheres of government, relevant stakeholders and civil society to progressively achieve and efficiently maintain clean and healthy air in the Western Cape”
GOALS
Four goals of the AQMP support the vision and mission, with each goal addressing the different aspects of the vision and are underpinned by objectives to achieve them. These are:
Goal 1 Ensure effective and consistent air quality management, linked to Climate Change Response
Goal 2 Continually engage with stakeholders to raise awareness with respect to Air Quality Management and Climate Change Response
Goal 3 Ensure effective and consistent compliance monitoring and enforcement
Goal 4 Support Air Quality and Climate Change Response programmes, including promoting and facilitating the reduction of Greenhouse gas emissions.
Following 5 years of the implementation of the 2nd Generation AQMP (2016-2020), the DEA&DP is extending an invitation and calling on all Interested and Affected Parties (I&AP’s) and authorities in the different regions of the Province to review the 2nd Generation AQMP. This first phase of the public participation review process will run from 3 August to 3 September 2020.
The review is to, inter alia:
Assess progress made in air quality management in the Province;
Establish whether the identified goals and targets have been effectively implemented;
Establish whether the goals and targets were still valid in terms of new developments and economic growth in the province; and
Identify potential air quality risks and interventions that can be translated into new goals and objectives, where required.
All I&APs and authorities are invited to participate in the first phase of the Public Participation Process, which will contribute towards the development of the 3rd Generation Western Cape AQMP.
Due to the current novel Coronavirus (COVID-19) Pandemic, the Public Participation Process (PPP) cannot be undertaken through the known conventional methods. In compliance to the National Disaster Management Regulations, which prohibit social gatherings, the PPP will be conducted via two sets of questionnaires to the public and industry, respectively. The I&AP’s and authorities will be engaged through alternative platforms to ensure that the Public Participation Process of the 2nd Generation AQMP is far-reaching.
The links to the background document & questionnaires will be made available on the WCG website, Facebook and Twitter.
Please click on the links below to access and complete the questionnaire.
English: https://forms.gle/qqFs7MVGXoZHuZwt8
Afrikaans: https://forms.gle/mbLbV1R6RUwxFFWp9
If you have any queries and should you wish to engage with the DEA&DP through any other virtual means (e.g. via MS Teams, Skype, Zoom), kindly contact:
Sally Benson: Sally.Benson@westerncape.gov.za
Media Release: New Mobile Air Quality Sensor for the Garden Route
For Immediate Release 22 July 2020
The Garden Route District Municipality procured a new ambient air quality sensor for monitoring ambient air quality. The Zephyr® is a compact and lightweight ambient air pollution sensor that accurately measures harmful gases and particle matter.
​“Zephyr® sensors provide detailed air quality measurements in real-time to help identify pollution hotspots at a localised level such as busy road junctions, industrial activities and at area sources such as sewerage works, pumps station and stockpiles,” said Dr Johann Schoeman, GRDM Manager Air Quality Management. The district might procure more sensors over time to be able to easily deploy district-wide analysis and optimisation of pollution-lowering initiatives. Ambient monitoring is a legislative requirement for District and Local municipalities and one of the objectives of the Garden Route 3rd Generation Air Quality Management Plan.
​Every unit is GPS enabled and can be used as a static or mobile sensor for while walking, cycling or driving.
Pollutants being measured
How it works
1. Power: Via a solar panel or DC power supply
2. Zephyr: Measures pollutants in the air in real-time
3. GSM: Built-in connection captures and sends data
4. SQL Database: Raw data is stored and calibrated
5. Upload Server: Data is authenticated and converted
6. Data access: Access and download your Zephyr data
7. MyAir: Access data via your online dashboard
8. API: Integrate data into an existing system
Every Zephyr® air quality sensor is calibrated prior to dispatch and its calibration performance is tested against reference standard analysers. Furthermore, every Zephyr® comes standard with a calibration certificate.
While the sensor is deployed, real time measurements can be accessed by the District Air Quality officers via a laptop, personal computer or cellular phone. This is extremely helpful especially when dealing with air quality complaints. Data is viewable in various formats such as excel spreadsheets, graphic formats or a dashboard. It can also be viewed as a snapshot, providing the user with  an overall view of the air quality in the current location, based on USEPA Air Quality indexes. GRDM already requested Earthsense, the manufacturer of Zephyr®, to adopt the index for our local conditions and to tweak the programme for South African National Ambient Air Quality Standards.
The sensor is currently located in the Mossel Bay region where it is used as a tool to assist with an air quality complaint. The Garden Route has various air quality hot-spots, as identified in the AQMP. Therefore, the sensor will be moved around in the District to obtain the necessary air quality status of each of the hot spots. This data is essential in order to mitigate and improve the general air quality of the region.
It is also the District’s goal to expand the ambient monitoring network so that each town has its own Zephyr® to assist in achieving the GRDM Air Quality vision “To have air quality worthy of the name Garden Route”.
For any further information, please contact Dr Johann Schoeman on: jschoeman@gardenroute.gov.za or 044 803 1300.
Media Release: Effects of the National Lockdown on Air Quality within the Garden Route District
For Immediate Release 5 May 2020
The major outdoor (ambient) air pollution contributors in the Garden Route district include industrial activities, vehicle emissions and wood burning for household purposes. Due to the current lock-down, only around 20% of these industries have rendered essential services, while vehicle movement decreased by estimate of between 10 and 25%.
According to the World Health Organisation (2013), ambient air pollution, as annual PM2.5, accounted for 3.1 million deaths and around 3.1% of global disability-adjusted life years and the health effects includes respiratory and cardiovascular morbidity, such as aggravation of asthma and respiratory symptoms.
The lockdown has resulted in a reduction of some air pollutants across the district, but not all pollutants react as immediate as others, for instance, carbon monoxide is known to remain in the atmosphere for a couple of years. It is however estimated that there is a 6% global reduction in carbon dioxide emissions due to countries partially shutting down their economies.
As the cooler winter months, approaches some domestic emissions may increase in the informal residential areas, for example, particulate emissions from woodstoves and fires that are used for household purposes. According to experts, economic recovery will receive priority after the lockdown, even if it is to the detriment of the environment. It is therefore vital that authorities involved in air quality management must continue to strive towards a reduction in emissions.
Air quality in George appears to indicate a general decreasing trend in air pollution between 1 March and 27 April 2020 as seen in figures one and two. These results have undergone quality assurance and are compared with time average concentration limits in the National Ambient Air Quality Standards for each criteria pollutant to determine any exceedances or non-compliances with standards.
Demonstrates a decrease in SO2 levels in George, 6µg/m3 to 4µg/m3Demonstrates a decrease in O3 levels in George, from 12µg/m3 to 2.5 µg/m3
During the development of the GRDM 3rd Generation Air Quality Management Plan, ambient air quality modelling was undertaken in most of the towns in the district. Emissions from industrial activities and traffic were estimated and modelled to identify any possible air quality hotspots for further monitoring. Below are images of dispersion modelling with an estimated 10% of the vehicle data count before the national lock down in Knysna Central Business District and ambient emission with only one listed activity in operation during the NLD in Oudtshoorn.
Knysna Main Road before lock-down. 99-percentile NO2 concentrations along Main Road, Knysna Centre Burgundy coloured regions show areas where the air quality standard may potentially be exceeded
Knysna Main Road during lock-down (estimated 10% of total vehicle movement before lock down). 99-percentile NO2 concentrations along Main Road, Knysna Centre Blue colour show demonstrates a decrease in NO2 emissions.
Before lock-down, 99-percentile daily average PM10 concentrations in the vicinities of PSP Timbers and Johnson Bricks, Oudtshoorn Burgundy coloured regions show areas where the air quality standard may potentially be exceeded
Oudtshoorn PM10 average concentration during NLD
The impact of industrial activities and vehicle emission are estimated by making use of emission factors obtained from the United States Environmental Protection Agency (USEPA) and modelled by making use of dispersion modelling software.
The Department of Environment, Forestry and Fisheries has developed a country-specific Air Quality Index (AQI) in line with best international practices to simplify the reporting of air quality to the general public. This data can be viewed live by the general public at www.saaqis.environment.gov.za. The AQI is derived from six (i.e. PM10, PM2.5, CO, O3, SO2 and NO2) criteria pollutants, for good air quality (scale 1) to hazardous (10) based on National Ambient Air Quality Standards (NAAQS). Currently, there are three Western Cape Government-owned ambient air quality monitoring stations located in the GRDM, viz. in Mossel Bay, George and Oudtshoorn. The George monitoring station reports live data to the South African Air Quality Information Systems (SAAQIS). The current status in terms of the AQI is one (1 = very good) in George, while for the entire country it is currently 3, which is also considered to be good.
According to satellite images below, obtained from (Copyright (c) 2020 Cameron Beccario 2020), there was a 48% reduction in ground level SO2 pollution on 22 April 2020, when compared with 28 April 2019. The same phenomenon occurred with PM10, which indicates a reduction of almost five times. This correlates well with international studies reported by the international media in respect of PM2,5 concentrations being four times lower than normally experienced in major polluted cities across the world.
SO2 Concentrations of 4.01µg/m3 on 8 April 2019
SO2 Concentrations of 1.93µg/m3 on 22 April 2020
PM10 concentrations of 39µg/m3 measured during 28 April 2019
PM10 concentrations of 8µg/m3 measured during 27 April 2020
Although there is a reduction in air pollution, the effect of air pollution is experienced over years. It is indeed so that the current improvement in air quality is too little over a short period of time to make a significant effect. However, people could again see clear skies over places where it was not possible for the last couple of years. The most valuable benefit therefore would be the awareness that flow from the visible improvement and the subsequent effect on people’s perceptions. The perceptions of affected communities is paramount for effective air quality management.
Above: Mr Angus Andries assists representatives from Johnsons Bricks, Vantell Bricks, Kurland Bricks, South Cape Galvanizing and Rheebok Bricks.
Every year the District Air Quality unit of Garden Route District Municipality (GRDM) assists Industrial companies in the Garden route region with the annual submission of their National Atmospheric Emissions Inventory System (NAEIS). GRDM held four workshops with Industries since January 2020.
“Industry sectors are clustered together in order for the District to assist them with the reporting of their 2019 emissions on the system,” said Dr Johann Schoeman, Manager: Air Quality Management.
He further added, “This is a legislative, and therefore, compulsory reporting in terms of the NAEIS Regulations. Each Listed Industry in the South Africa must report its emissions before 31 March on an annual basis.”
GRDM is the only district in the Western Cape that assists its industries in the form of workshops. This trend has continued over the past four (4) years at the GRDM sub-office in Mossel Bay. At the sessions, online questionnaires are completed and a 100% submission rate is always achieved.
WHAT IS THE NAEIS SYSTEM USED FOR?
The NAEIS system is an online reporting platform of emissions such as Carbon dioxide, Carbon monoxide, Sulphur dioxide, Volatile Organic Compounds, Hydrogen sulphide, Oxides of Nitrogen, Particulate Matter, to name a few. It is important for industrial companies and the District to know what emission trends are in order to plan properly.
GRDM’s Air Quality Management Unit will not only continue to manage air quality in the district, but also assist industry with air quality-related matters. Clean air can ultimately only be achieved through a collaborative approach, which is why the District’s Air Quality vision, “To have air quality worthy of the name: Garden Route” is achieved and upheld.
The Garden Route District Municipality’s (GRDM) Air Quality Management Unit is pleased to announce that the futuristic robotic looking portable ambient air quality monitoring station has returned after repairs at Scentriod in Canada.
The Scentinal SL50 is used by the GRDM’s Air Quality Management Unit for high accuracy screening purposes as well as obtaining baseline information on ambient air quality in a specific air space in the vicinity of proposed new developments. The robot measures all meteorological parameters, Nitrogen Dioxide, Sulphur Dioxide, Carbon Monoxide, Hydrogen Sulphide, Total reduced sulphates and Amines, Methane, Volatile Organic Compounds and Particulate Matter with sizes of 1, 2.5 and 10 micron. The equipment plays a pivotal role in managing air shed and determining the potential accumulative effects in a specific air shed.
The station was recently deployed to the Mossel Bay Harbour in order to obtain baseline information on the ambient air quality in the surrounding area.
The 3rd Generation Air Quality Management Plan (AQMP) was recently adopted during a council meeting. The AQMP identified potential air quality “hotspots” within the seven (7) municipalities in the region, by means of a dispersion modelling which make use of emission factors and mathematically simulate on how air pollutants disperse in the ambient atmosphere. The aim of this study was to identify areas of concerns that exist outside the knowledge of the GRDM’s Air Quality Management Unit.
The possible areas of concern are:
Bitou: Particulate Matter (PM10)
Knysna: Nitrogen Dioxide
George: Particulate Matter (PM10)
Mossel Bay: Nitrogen Dioxide and odours
Oudtshoorn: Particulate Matter (PM10), Sulphur Dioxide and Nitrogen Dioxide
Following the identification of the potential areas of concern and pursuing objective 1.5 of the GRDM’s 3rd Generation AQMP, which task the Air Quality Unit to “Initiate and coordinate short-term air quality monitoring projects (where applicable) to verify the dispersion modelling results in potential problem areas”, monitoring will commence in the Knysna, to verify the effect of vehicle emissions in the Main Road of the tourist town.
99-percentile NO2 concentrations along Main Road in Knysna. Burgundy coloured regions show areas where the air quality standard of 200 µg/m3 may potentially be exceeded.
Subsequent to the Knysna monitoring run, the Scentinal Station will be move to the other areas of concern, namely Bitou and Oudtshoorn. There are continuous emissions monitoring stations in the George-, Mossel Bay- and Oudtshoorn municipal areas, and the focus will therefore be in regions where there is no permanent monitoring site.
