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GEMS/AMIS Air Quality Monitoring Programme Annual Report 2004

1 Summary

2 Introduction

3 Air Pollutants Monitored

4 Ambient Air Quality Guidelines and Standards

5 Monitoring Sites

6 Methods

7 Results and Discussion

7 Results and Discussion

7.1 Site performance and quality assurance

The continuous monitors performed well during 2004. All sites having data capture rates well over 90%.

Monitoring at Kowhai Intermediate, Kingsland commenced in April 2004. Statistics below are taken from 8 April 2004, the date from which all instruments at Kowhai Intermediate, Kingsland were monitoring successfully.

Valid NO₂ data from the Greers Road, Burnside site was below 90% due to:

• communication difficulties with the instrument (between 31 March and 9 April 2004)
• an air conditioning failure. Monitoring was shut down during the period 13-21 September 2004 while a new air conditioning unit was installed
• Kelly Street, Mt Eden was decommissioned 26 October 2004 following almost seven months of parallel monitoring with Kowhai Intermediate, Kingsland between 8 April and 26 October 2004.

Overall site performance is shown in Table 3 below. This is based on 10-minute averages for continuously monitored data. Percent data capture is the percent of total instrument availability and includes down time for calibration and routine maintenance. Percent valid data is defined as the percent valid data following quality assurance (eg, invalidation of data resulting from calibrations, routine maintenance, spurious data, and excessively negative data).

Table 3: Percentage valid and capture data, January-December 2004

View Percentage valid and capture data, January-December 2004 (large table)

7.2 Carbon monoxide (CO) 2004

CO was monitored at Greers Road, Burnside. One hour and 8-hour averages have been calculated from 10-minute averages recorded by the instruments.

The maximum results and their dates are described in the following table.

Results are given in Figures 4 to 7.

Concentrations of CO at Greers Road, Burnside were below the ambient air quality 1-hour guideline (30 mg/m³) and 8-hour national environmental standard (10 mg/m³) during 2004.

7.3 Nitrogen oxides (NO₂ and NO) 2004

Oxides of nitrogen were monitored at Kelly Street, Mt Eden; Gavin Street, Penrose; Kowhai Intermediate, Kingsland; and Greers Road, Burnside. One hour and 24-hour averages have been calculated from 10-minute averages recorded by the instruments.

The maximums for NO₂ and their dates for each site are described in the following table.

Nitrogen dioxide results are presented in Figures 8 to 13 (Kelly Street), 14 to 17 (Kowhai), 18 to 23 (Gavin Street), and 24 to 29 (Burnside).

There were no exceedences of the NO₂ ambient air quality 1-hour standard (200 µg/m³) or the 24-hour guideline (100 µg/m³) during 2004 at any site in Auckland or Christchurch.

7.4 Sulphur dioxide (SO2) 2004

Sulphur dioxide was monitored at Gavin Street, Penrose and Greers Road, Burnside. One hour and 24-hour averages have been calculated from 10-minute averages recorded by the instruments. ACI monitoring was discontinued in January 2004.

The maximums for SO₂ and their dates for each site are described in the following table.

Results for Gavin Street, Penrose are shown in Figures 30 and 31and Greers Road, Burnside are shown in Figures 32 and 33. There were no exceedences of the SO₂ ambient air quality 1-hour standard (350 µg/m³) or the 24-hour guideline (125 µg/m³) during 2004 at any site.

7.5 Volatile organic compounds (VOC) January-December 2004

Monitoring of VOCs were conducted at four sites: Kelly Street, Mt Eden; Gavin Street, Penrose; Greers Road, Burnside; and Coles Place, Christchurch. VOC monitoring utilises passive sampling badges exposed over a three-month period. A set of results for each 2004 quarter are shown in Tables 4 to 7. See monitoring method in section 4.

The benzene 2000 annual average guideline is 10 µg/m³. The 2010 guideline is 3.6 µg/m³. The 2004 six-month and 12-month averages are described in the table below.

Note:

1. VOC monitoring at Kelly Street Mt Eden was decommissioned 26 October 2004. Results for October to December 2004 were not reported due to short sample period.
2. VOC monitoring at Kowhai began 16 July 2004.

Table 4: VOC results (January-March 2004)

Table 5: VOC results (April-June 2004)

Table 6: VOC Results (July-September 2004)

Note: VOC monitoring commenced at Kowhai on 16 July 2004.

Table 7: VOC results (October-December 2004)

Note: Mt Eden site decommissioned 26 October 2004 therefore no results have been reported for this quarter.

7.6 PM₁₀ 2004

PM₁₀ is recorded at Greers Road, Burnside, using a Thermo FH62-C14 Beta Gauge. PM₁₀ results measured by Auckland Regional Council at Gavin Street, Penrose and Kelly Street, Mt Eden sites, also using Thermo FH62-C14 Beta Gauges, are also included in this report. Twenty-four-hour averages have been calculated from 10-minute averages recorded by the instruments. All PM₁₀ data is reported at 0°C and 101.3 kPa.

The maximums for PM₁₀ and their dates for each site are described in the following table.

There were no exceedences of the ambient air quality standard (50 µg/m³) at Kelly Street, Mt Eden, Gavin Street, Penrose or Kowhai Intermediate, Kingsland during the 12-month period.

At Greers Road, Burnside, there were 25 exceedences of the 24-hour standard. Each exceedence and the date is listed in Table 8 below. Charts describing 24-hour averaged data for 2004 for each site are shown in Figures 34 to 35 (Kelly Street), 36 (Kowhai), 37 to 38 (Gavin Street), and 39 and 40 (Burnside). As there were exceedences at the Christchurch site, more data analysis was carried out as shown in Figures 41 to 47. All exceedences occurred over the winter period, a time when wood and other solid fuel burning is widely used to heat homes. As reported by Environment Canterbury, cold winter conditions strongly influence air pollution in the region. May 2004 was described as cloudy, rainy and windy compared with previous years. These conditions are less likely to cause air pollution and resulted in only two exceedences near the end of the month. June and July 2004 experienced more settled weather conditions and much higher particulate concentrations. A total of 22 exceedences occurred during this two-month period. Only one exceedence was recorded in August 2004.

Table 8: Greers Road, Burnside PM₁₀ exceedences of the daily NES 2004

Note : National environmental standard for PM₁₀ = 50 µg/m³.

7.7 Total suspended particulates (TSP) 2004

TSP is measured as a seven-day average from Kelly Street, Mt Eden, Gavin Street, Penrose, Kowhai Intermediate, Kingsland and Coles Place, St Albans. Maximum results are shown in the table below.

Notes: TSP monitoring began at Kowhai Intermediate School on 5 April 2004. TSP monitoring at Kelly Street, Mt Eden finished on 27 October 2004.

There were no exceedences of the Ministry of Health guideline of 60 µg/m³ at any site. The data from each site is described in Figures 1 and 2 below.

Figure 1: TSP seven-day average (Auckland sites)

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Figure 2: TSP seven-day average (Christchurch site)

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7.8 Lead (Pb) June-August 2004

Regrettably, TSP filters used for lead analysis were misplaced in storage following TSP measurements and have been unavailable for lead analysis. Subsequent to their removal, and before the filters were logged into the laboratory, there was a staff change and the filters were misplaced. A corrective action request was raised as a consequence and the subsequent investigation identified the following actions to prevent the recurrence of such an event in future:

• procedures for filter storage will be documented in Watercare's quality assurance system
• filters intended for further analysis will be stored as per the above filter storage procedure until analysis is required
• better training will be provided to staff during the hand over period of projects.

Figure 3: MFE Burnside CO 1-hour fixed average January-December 2004

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Figure 4: MFE Burnside CO 1-hour fixed average 1 January 2003-31 December 2004

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Figure 5: MFE Burnside CO 8-hour rolling average January-December 2004

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Figure 6: MFE Burnside CO 8-hour rolling average 1 January 2003-31 December 2004

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Figure 7: MFE Kelly Street NO₂ 1-hour fixed average January-December 2004

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Figure 8: MFE Kelly Street NO₂ 1-hour fixed average 1 January 1997-31 December 2004

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Figure 9: MFE Kelly Streest NO₂ 24-hour fixed average January-December 2004

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Figure 10: MFE Kelly Street NO₂ 24-hour fixed average 1 January 1997-31 December 2004

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Figure 11: MFE Kelly Street NO₂ and NO 1-hour fixed average January-December 2004

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Figure 12: MFE Kelly Street NO₂ and NO₂4-hour fixed average January-December 2004

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Figure 13: MFE Kowhai NO₂ 1-hour fixed average January-December 2004

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Figure 14: MFE Kowhai NO₂ 24-hour fixed average January-December 2004

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Figure 15: MFE Kowhai NO₂ and NO 1-hour fixed average January-December 2004

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Figure 16: MFE Kowhai NO₂ and NO₂4-hour fixed average January-December 2004

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Figure 17: MFE Gavin Street NO₂ 1-hour fixed average January-December 2004

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Figure 18: MFE Gavin Street NO₂ 1-hour fixed average 1 January 1997-31 December 2004

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Figure 19: MFE Gavin Street NO₂ 24-hour fixed average January-December 2004

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Figure 20: MFE Gavin Street NO₂ 24-hour fixed average 1 January 1997-31 December 2004

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Figure 21: MFE Gavin Street NO₂ and NO 1-hour fixed average January-December 2004

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Figure 22: MFE Gavin Street NO₂ and NO₂4-hour fixed average January-December 2004

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Figure 23: MFE Burnside NO₂ 1-hour fixed average January-December 2004

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Figure 24: MFE Burnside NO₂ 1-hour fixed average 1 January 2003-31 December 2004

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Figure 25: MFE Burnside NO₂ 24-hour fixed average January-December 2004

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Figure 26: MFE Burnside NO₂ 24-hour fixed average 1 January 2003-31 December 2004

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Figure 27: MFE Burnside NO₂ and NO 1-hour fixed average January-December 2004

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Figure 28: MFE Burnside NO₂ and NO₂4-hour fixed average January-December 2004

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Figure 29: MFE Gavin Street SO₂ 1-hour fixed average January-December 2004

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Figure 30: MFE Gavin Street SO₂ 24-hour fixed average January-December 2004

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Figure 31: MFE Burnside SO₂ 1-hour fixed average January-December 2004

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Figure 32: MFE Burnside SO₂ 24-hour fixed average January-December 2004

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Figure 33: MFE Kelly Street PM₁₀ 24-hour fixed average 1 January-26 October 2004

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Figure 34: MFE Kelly Street PM₁₀ 24-hour fixed average 1 January 2002-26 October 2004

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Figure 35: MFE Kowhai PM₁₀ 24-hour fixed average January-December 2004

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Figure 36: MFE Gavin Street PM₁₀ 24-hour fixed average January-December 2004

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Figure 37: MFE Gavin Street PM₁₀ 24-hour fixed average 1 January 2003-31 December 2004

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Figure 38: MFE Burnside PM₁₀ 24-hour fixed average January-December 2004

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Figure 39: MFE Burnside PM₁₀ 24-hour fixed average 1 January 2003-31 December 2004

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7.9 Analysis of PM₁₀ exceedences at Greers Road, Burnside

The following figures provide further analysis of PM₁₀ exceedences at Greers Road, Burnside. Figure 40 shows a comparison of relative PM₁₀ concentrations from different sites in Christchurch over the winter period May to August 2004. The Beta Gauge PM₁₀ data from Greers Road, Burnside compares well with taped element oscillating microbalance (TEOM) PM₁₀ data from Coles Place, St. Albans and shows that PM₁₀ concentrations are consistent across the city suggesting the incidents are not directly related to very localised sources of PM₁₀ but are perhaps more related to prevailing meteorological conditions such as temperature inversions.

Figure 41 provides an example of the diurnal trends in air pollution over a 48-hour period during the winter months. Figures 42 to 44 present the meteorological conditions that influence the diurnal trend. It is apparent when comparing wind speed (Figure 42) and PM₁₀ concentrations (Figure 41) that low wind speeds coincide with PM₁₀ peaks and conversely higher wind speeds coincide with low PM₁₀ concentrations. Reduced air mixing, caused by low wind speeds, results in poor dispersion of pollution while an unstable atmosphere caused by high wind speeds is conducive to pollution dispersion.

Low temperatures, often coinciding with still atmospheric conditions, can cause temperature inversions. This can contribute to higher PM₁₀ concentrations being measured as pollution is trapped at ground level. A comparison of temperatures measured at 1.5 and 10 m (Figure 43) does not indicate the presence or absence of a temperature inversion as the inversion height may be greater than 10 m, however, a diurnal trend is apparent. As the temperature drops during the evening, Christchurch residents light their heating appliances causing particle emissions to increase and PM₁₀ levels to peak just before midnight. As the fires die down and the atmosphere becomes more unstable toward morning, concentrations of PM₁₀ drop off.

A pollution rose for the same 48-hour period (Figure 44) describing the relationship between wind direction and PM₁₀ concentrations shows no obvious pattern.

Figure 40: Christchurch PM₁₀ comparison, beta gauge versus TEOM, 24-hour fixed average 1 May-30 August 2004

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Figure 41: MFE Burnside PM₁₀, typical winter diurnal trend, 24-hour fixed average 9-10 July 2004

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Figure 42: MFE Burnside wind speed,typical winter diurnal trend, 24-hour fixed average 9-10 July 2004

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Figure 43: MFE Burnside ambient temperature,typical winter diurnal trend, 24-hour fixed average 9-10 July 2004

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Figure 44: MFE Burnside pollution rose, 24-hour average 9-10 July 2004

Figure 45: MFE Burnside pollution rose 24-hour average June 2004

Figure 46: MFE Burnside pollution rose 24-hour average July 2004