Author: Emily Wilton (Environet)
The burning of wood and coal for domestic home heating is the cause of air quality issues in many New Zealand towns. In the Waikato, air quality monitoring has already shown high concentrations of PM10 in Te Kuiti. An earlier emission inventory for that area confirmed domestic fires were the main source of the PM10 problem (Noonan, 1997).
The purpose of this emission inventory is to quantify the emissions to air from domestic space heating in the study areas of Taupo, Huntly, Matamata and Putaruru. These data can then be used to assist in prioritising future air quality monitoring and identifying contaminants that may be of concern. Emission inventories can also be an effective air quality management tool when used in conjunction with other data to determine the effectiveness of different management strategies in reducing emissions.
A survey of home heating methods and fuels was conducted in Taupo, Huntly, Matamata and Putaruru during winter of 2000. The burning of wood was the main method of home heating in Taupo, Matamata and Putaruru with around 50-60 per cent of households using that fuel. In Huntly, the burning of wood, coal and gas were all common methods of home heating.
During the winter, 36 tonnes of wood and less than 0.5 tonne of coal is burnt in Taupo per day. This compares with 12, 26 and 14 tonnes of wood burnt in Huntly, Matamata and Putaruru, respectively. The greatest quantity of coal burnt per day is in Huntly - 26 tonnes. Other towns in the study area burn less than two tonnes of coal per day. Gas use ranges from one to five tonnes per day.
The greatest quantity of PM10 emissions from domestic heating within the four towns occurs in Huntly where 860kg of PM10 are discharged to air per day. This compares with 409kg in Taupo, 361kg in Matamata and 175kg in Putaruru. The majority of the PM10 emissions from domestic heating in Huntly are from the burning of coal on open fires and enclosed burners. The burning of wood on open fires and older wood burners contributes the majority of the PM10 domestic heating emissions in Taupo, Matamata and Putaruru.
Taupo has the lowest PM10 emission rate relative to the size of the study area, emitting 409 g/ha per day compared with 1719, 657 and 438 g/ha in Huntly, Matamata and Putaruru, respectively. Carbon monoxide emission rates (g/ha) are highest in Matamata because of the predominance of wood use in that location. In Huntly, SOx emission rates are considerably higher than the other study areas reflecting the prevalence of coal burning in that location.
Emissions data from the four study areas were compared to results of the 1997 emission inventory for Hamilton, Te Kuiti and Tokoroa. The two studies show emission rates (g/ha) for PM10 were highest in Huntly, Te Kuiti and Tokoroa. All areas, except Taupo and Putaruru, were found to have higher PM10 emission rates than Christchurch, a city widely acknowledged as having a significant PM10 problem. A monitoring schedule, based on emissions data alone, would therefore suggest giving priority to the monitoring of PM10 in Huntly, Te Kuiti and Tokoroa. Monitoring of CO should also be considered in these towns, as should the monitoring of SO2 in Huntly.
Taupo, Huntly, Putaruru and Matamata Domestic Heating Emission Inventory
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|List of Tables||I|
|List of Figures||Ii|
|2 Inventory design||2|
|2.1 Selection of sources||3|
|2.2 Selection of contaminants||3|
|2.3 Selection of study areas||3|
|2.4 Temporal distribution||9|
|2.5 Domestic heating survey||9|
|2.6 Home heating methods||10|
|3 Domestic heating emissions||11|
|3.1 Method used to calculate emissions||11|
|3.2 Total domestic heating emissions||12|
|3.3 Domestic heating emissions in Taupo||16|
|3.4 Domestic heating emissions in Huntly||18|
|3.5 Domestic heating emissions in Matamata||20|
|3.6 Domestic heating emissions in Putaruru||22|
|3.7 Domestic heating emissions by time of day||24|
|4 Comparison to other urban centres||24|