Author: Emily Wilton (Environet)
Air quality monitoring for concentrations of PM10 (particles in the air less than 10 microns in diameter) has been carried out in Tokoroa since 1999. Results indicate concentrations exceed the Environment Waikato air quality target and ambient air quality guidelines for PM10 of 50 µg m-3 each year. In addition, the concentrations are in breach of the National Environment Standard (NES) for PM10 of 50 µg m-3. The latter allows for one breach of 50 µg m-3 per year. The maximum measured 24-hour average PM10 concentration in Tokoroa of 75 µg m-3 was recorded during 2001.
This study provides an estimate of sources of emissions of PM10 as well as carbon monoxide, sulphur oxides, nitrogen oxides, volatile organic compounds and carbon dioxide. The main focus of the study is on emissions of PM10 as existing concentrations are in breach of the NES. Ambient air concentrations of carbon monoxide, sulphur dioxide and nitrogen dioxide are unlikely to breach air quality guidelines or NES in Tokoroa. Sources of PM10 included in the inventory are domestic heating, motor vehicles, industrial and commercial activities and outdoor burning.
A survey of domestic home heating was carried out to determine heating methods and fuel use in Tokoroa. Woodburners were found to be the dominant home heating method in Tokoroa, being used to heat the main living area in around 53 per cent of homes. Gas use was also common with around 40 per cent of households using that method. Around 25 per cent of households used electricity heating. Many households used more than one method to heat the main living area of their home.
The main source of PM10 and PM2.5 emissions in Tokoroa was domestic home heating, which accounted for around 85 per cent and 88 per cent of total emissions respectively. For PM10, the remaining 15 per cent was distributed between motor vehicles (6 per cent), outdoor burning (8 per cent) and industrial emissions (1 per cent). Domestic heating also accounted for 66 per cent of the CO and 79 per cent of the VOCs. Motor vehicles were the main source of NOx and SOx.
Tokoroa Emission Inventory 2004
(401 kb, 57 seconds to download, 56k modem)
|2.1 Selection of sources||7|
|2.2 Selection of contaminants||7|
|2.3 Selection of areas||8|
|2.4 Temporal distribution||10|
|3.2 Home heating methods||12|
|3.3 Emissions from domestic heating||13|
|4.1.1 Vehicle kilometres travelled (VKT)||17|
|4.1.2 Emission factors||17|
|4.2 Motor vehicle emissions||18|
|5.||Industrial and commercial||21|
|5.2 Industrial and commercial emissions||23|
|6.2 Emissions from outdoor burning||23|
|7.||Other sources of emissions||24|
|Appendix One: Home heating questionnaire||29|