Monitoring approach
Air quality is measured continuously in real-time using standard monitoring methods at core monitoring sites with these data displayed on GWRC’s live data viewer (graphs.gw.govt.nz) or LAWA (lawa.org.nz/explore-data/wellington-region/air-quality). Measurements from core sites are used for checking compliance with national health standards and guidelines and for tracking long term trends. Day-to-day levels of air pollution are strongly influenced by the weather, so variables such as wind speed and direction are measured at core monitoring sites to help interpret air quality measurements.
Monitoring methods
| Monitoring Instrument | Sites (2019) | Method | Units | |
|---|---|---|---|---|
| PM10 | ||||
| Thermo Andersen series FH62 C14 beta attenuation monitor | Lower Hutt, Upper Hutt, Wainuiomata | Automated method equivalent to the United States Code of Federal Regulations (CFR)1 | μg/m3 | |
| Thermo Scientific 5014i beta attenuation monitor | Masterton West Masterton East Wellington Central | EQPM-1102-150 Method 9.11: Determination of suspended particulate matter – PM10 beta attenuation monitors in accordance with AS/NZS 3580.9.11:2008 | μg/m3 | |
| PM2.5 | ||||
| Thermo Andersen series FH62 C14 beta attenuation monitor + Very Sharp Cut Cyclone particle size separator. | Wainuiomata | Does not have USEPA equivalency | μg/m3 | |
| Thermo Andersen 5014i + Very Sharp Cut Cyclone particle size separator. | Masterton West Masterton East Wellington Central | EQPM-0609-183 Method 9.12: Determination of suspended particulate matter – PM2.5 beta attenuation monitors in accordance with AS/NZS 3580.9.12:2013 | μg/m3 | |
| CO | ||||
| API 300 series analysers | Masterton West Wellington Central Upper Hutt | Gas Filter Correlation Infrared in accordance with AS 3580.7.1:2011 Method 7.1: Determination of carbon monoxide – Direct-reading instrumental method | Parts per million (ppm) converted to mg/m3 by multiplying by 1.25 (0°C) | |
| NO2 | ||||
| API 200 series analysers | Masterton West Wellington Central Upper Hutt | Chemiluminescence in accordance with AS 3580.5.1:2011 Method 5.1: Determination of oxides of nitrogen – Direct-reading instrumental method | Parts per billion (ppb) converted to μg/m3 by multiplying by 2.05 (0°C) | |
| Passive diffusion tube | Various | NZ Transport Agency (2017) Ambient air quality (nitrogen dioxide) monitoring network. Operating Manual 2017/18 | μg/m3 | |
1 Title 40 – Protection of the Environment, Volume 2, Part 50, Appendix J: Reference Method for the Determination of Particulate Matter as PM10 in the Atmosphere.
