Air quality disclaimer. These graphs have been generated from raw data collected by Hawke's Bay Regional Council’s automatic telemetry system and may not have been processed through the Council’s quality control process. The data presented here is intended for general information purposes only. Quality assured data is available on request by emailing us.
Monthly results are also available.
The Hawke's Bay Regional Council's air quality monitoring network includes three stations with automatic PM10 monitors, which continuously record PM10.
Data from Napier and Hastings is used to monitor the State of the Environment (SOE), and to report on compliance with the new National Environmental Standard (NES) for air quality. (The third station is a temporary traffic monitoring site at Meeanee.)
The National Environmental Standards for Air Quality require that, by the year 2013, PM10 levels do not exceed an average of 50 μg/m3 each day on any more than one day per year.
As well as monitoring for compliance with the NES, these sites provide data for Council’s State of Environment (SoE) Reporting. The objective at these sites is to monitor background urban PM10 levels, rather than focus on a particular single source. Both sites reflect typical residential areas, have average traffic levels, and are not dominated by any particular industrial source.
Results show higher PM10 levels during the winter months. This is mostly due to home heating fires and the action of inversion layers in the evening that prevent smoke from dispersing.
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Screening monitoring is now being undertaken in Greenmeadows, Napier using Council's MicroVol monitoring equipment. The purpose of screening monitoring is to target new monitoring locations in Hawke’s Bay where no monitoring data exists, to assess whether PM10 is likely to be a problem or not.
The results of this survey should also enable verification of Council’s airshed modelling results for PM10 in the Taradale/Greenmeadows area of Napier airshed.
Sampling occurs every 3 days, and sample filters are processed the following month in the laboratory. The survey will be carried out over a one year period, with results posted on a monthly basis in the State of the Environment monitoring report for air quality.
The monitoring site is located at Reignier School, Greenmeadows, Napier
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PM10 Monitoring (Microvol) installation at Greenmeadows |
Airshed modelling of potential extent of NES exceedances in Napier airshed
In June 2005 an Air Emission Inventory was completed for the Hawke’s Bay region. This report evaluates sources of PM10 and other contaminants in the air, and was carried out for Hawke's Bay Regional Council by Dr Emily Wilton of Environet Ltd.
Hawke’s Bay Air Emission Inventory (Environet, 2005), PDF File, 1.5Mb
The report provides details of emissions in: Napier, Hastings, Flaxmere and Havelock North; the three areas of Wairoa, Waipawa and Waipukurau jointly; and the rest of the region. It assesses PM10 sources such as domestic heating, motor vehicles, industrial and commercial activities, outdoor burning, orchard heaters, shipping and aviation.
The report’s main finding was that domestic heating (mostly from woodburners) is the largest source of PM10 in Napier and Hastings in winter, which is when concentrations of PM10 exceed the Ministry for the Environment’s National Environmental Standard for air quality.
Relative contribution of different sources to average daily winter PM10 emissions in Hastings
Relative contribution of different sources to average daily winter PM10 emissions in Napier
An airshed modelling study in Hawke’s Bay was carried out by NIWA for the Regional Council. An airshed is an area where air quality is likely, or known, to exceed national air quality standards.
Airshed Modelling of PM10 levels in the Hawke’s Bay Region (Gimson, 2006), PDF File, 714Kb
The model simulates the National Environment Standard breaches for a typical year in Napier and Hastings.
Hastings has higher PM10 levels than Napier. Havelock North and Flaxmere may exceed the NES but the area of exceedance is small.
Modelling showed that Wairoa is compliant with the NES, but with PM10 concentrations reaching two-thirds of the NES level. The other urban areas (for example Waipukurau, Waipawa and Otane) appear to have low PM10 concentrations.
To attain the NES, the model estimates that emissions from domestic heating should decrease for PM10 by 79% in Hastings and 55% in Napier.
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As well as Council’s routine PM10 monitoring equipment (called BAM instruments), a GENT sampler has been located at Marewa Park, to enable us to identify which sources contribute to PM10 in Napier.
The contribution of different sources to PM10 concentrations has already been examined in Hastings and Auckland as part of a national study using this kind of instrument. PM2.5 (particles less than 2.5 microns in diameter) was also examined.
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Sources of PM10 in Hastings and Auckland (NIWA, 2007), PDF File, 3.1Mb
Contribution of sources to annual PM10 concentrations at Hastings
In Hastings, five sources were found to contribute to the PM10 concentrations. These were identified as domestic home heating, marine aerosol, motor vehicles, sulphate and soil. For this report, domestic heating sources also include outdoor burning of domestic waste. The main contributor to PM10 concentrations in Hastings was domestic heating, which was responsible for most of the annual concentrations.
Domestic heating was identified as the dominant source of PM10 during winter in Hastings by emission inventory, source identification, and airshed dispersion modelling.
The total background or “natural” contribution for Hastings during winter is estimated to be 13-15% of total PM10. The background component of the PM10 needs to be accounted for when developing strategies for reducing PM10 concentrations in order to achieve the NES by 2013.
PM10 monitoring for traffic impacts is being carried out by Hawke's Bay Regional Council in partnership with Transit at Meeanee Rd-Expressway intersection. The aim is to make a comparison of PM10 levels before and after construction of the overpass.
A BAM instrument was installed in 2005 together with PM10 source monitoring equipment (GENT sampler).
Monitoring in Spring 2008 following the construction of the Meeanee overbridge will help quantify the impact of the less congested road layout on PM10 levels near the intersection.
Please contact us if you require further information.
Information on air quality available in publications from the Ministry for the Environment.