Update on the Ambient Air Quality Monitoring: October 2019

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.