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6 Methods

6.1 Quality assurance

All monitoring services are undertaken by Watercare Services Ltd in accordance with the Ministry for Environment’s Good Practice Guide for Air Quality Monitoring and Data Management and wherever applicable the appropriate Australian / New Zealand and US EPA monitoring methods.

Watercare Laboratory Services is accredited by IANZ (International Accreditation New Zealand) for the following methods:

  • AS 3580.7.1 – 1992 ‘Method 7.1: Determination of carbon monoxide – direct-reading instrumental method’.

  • AS 3580.5.1 – 1993 ‘Method 5.1: Determination of oxides of nitrogen – chemiluminescence method’.

  • AS 3580.4.1 – 1990 ‘Method 4.1: Determination of sulfur dioxide – direct reading instrumental method’.

  • AS/NZS 3580.9.3 – 2003 ‘Method 9.3: Determination of Ambient Particulates (Gravimetric Method) – TSP High Volume Sampling’

  • AS/NZS 3580.9.6 – 2003 ‘Method 9.6: Determination of Ambient Particulates (Gravimetric Method) – PM10 High Volume Sampling’

  • US EPA Equivalent Method EQPM-1102-150 ‘Thermo Anderson Series FH62-C14 Continuous PM10 Monitor Automated Equivalent Method’.

As part of the GEMS / AMIS programme, Watercare Laboratory Services provides the following monitoring services:

  • Instrument operation, calibration and maintenance. This includes the use of automatic daily calibration systems for all continuous ambient gas monitors ensuring that the requirements of the relevant Australian Standards for weekly calibration of continuous analysers are met.

  • Site maintenance as well as, when necessary, commissioning new sites and decommissioning old sites.

  • Data logging, polling, checking, re-scaling, validation, ratification and reporting. This encompasses the entire data quality assurance process ensuring that the final dataset reported is fit for the purpose of the GEMS / AMIS programme.

6.2 Analytical methods

6.2.1 Carbon monoxide

Measurements are made in accordance with AS 3580.7.1. – 1992 ‘Determination of Carbon Monoxide – Direct Reading Instrumental Method’. The performance of the instrument is checked using an automatic calibration system ensuring compliance with the method which requires instrumentation to be calibrated on a weekly basis.

The instruments themselves are infrared absorption gas analysers which continuously measure carbon monoxide. This allows data to be analysed and reported over a variety of average periods, including 10-minute, 24-hour and one year.

6.2.2 Nitrogen oxides

Measurements are made in accordance with AS 3580.5.1. – 1993 ‘Determination of Oxides of Nitrogen – Chemiluminescence Method’. The performance of the instrument is checked using an automatic calibration system ensuring compliance with the method which requires instrumentation to be calibrated on a weekly basis.

The instruments themselves are chemiluminescence gas analysers which continuously measure nitrogen oxides. This allows data to be analysed and reported over a variety of average periods, including 10-minute, 24-hour and one year.

6.2.3 Sulfur dioxide

Measurements are made in accordance with AS 3580.4.1. – 1990 ‘Determination of Sulfur Dioxide – Direct Reading Instrumental Method’. The performance of the instrument is checked using an automatic calibration system ensuring compliance with the method which requires instrumentation to be calibrated on a weekly basis.

The instruments themselves are UV fluorescence gas analysers which continuously measure sulfur dioxide. This allows data to be analysed and reported over a variety of average periods, including 10-minute, 24-hour and one year.

6.2.4 Volatile organic compounds

VOCs are measured each quarter (January–March, April–June, July–September and October–December) in accordance with the manufacturer’s instructions (3M Technical Data Bulletin 1028).

VOC samples are taken using passive (3M) sampling badges, which are exposed for a three-month period. The VOCs diffuse on to the badges, which are coated with activated carbon. Following exposure the samples are forwarded to AsureQuality who extract the VOCs using carbon disulphide and analyse them using GC-MS. AsureQuality are accredited for VOCs by GC-MS using NIOSH Method 1500.

Note: Investigations have determined that samples of 1,3-butadiene are unstable when held above -4.41ºC (BP) with significant reverse desorption occurring. Due to the potential for error over a three-month exposure period, 1,3-butadiene has not been analysed and reported. Alternative methods of measuring 1,3-butadiene are OSHA Method 56 and NIOSH Method 1024 both of these involve the use of solid sorbent coconut charcoal tubes.

6.2.5 Particulate matter (PM10)

Measurements are made in accordance with the US EPA Equivalent Method for measuring PM10 EQPM-1102-150 ‘Thermo Andersen Series FH62-C14 Continuous PM10 Ambient Particulate Monitor’. This method was designated as an Equivalent Method by the US EPA in accordance with 40 CFR Part 53 on 11December 2002.

The Thermo Andersen FH62-C14 is fitted with a size-selective PM10 head and measures the mass as it accumulates during sampling. As a result the instrument is able to record and output real-time measurements of PM10 data which allows measurements to be reported over a variety of average periods, including 10-minute, 24-hour and one year. The inlet temperature of all units operated by the Ministry for the Environment is 40°C.

6.2.6 Total suspended particulate matter (TSP)

Measurements of TSP are made in accordance with Watercare’s Air Quality Group Test Method T101 and the TSP analysis is performed in accordance with Watercare Laboratory Services Method GE08 (for TSP filters). It is a gravimetric method of measuring particulates and is modelled upon the High Volume sampler method. These techniques have been used to provide TSP data at existing GEMS / AMIS sites since 1964.

The equipment used to measure TSP is quite basic and involves ambient air being pulled through a glass fibre filter by a pump with a gas meter being used to measure the air volume drawn through the filter. The filter is weighed before and after sampling. The TSP concentration is determined from the weight of particulates collected and the air volume sampled.

6.2.7 Lead

Lead is sampled during the winter months, June–August, using same samples acquired to measure TSP. Analysis of lead is performed by Watercare Laboratory Services according to APHA Method 3030 and US EPA Method 200.8. This involves analysing each individual TSP filter exposed during the winter period using mixed acid digestion. This sample is then analysed for lead using ICP-MS. The concentration of lead is then determined from the amount of lead detected and the total volume of air sampled during that sample period. Concentrations are averaged for the three-month monitoring period.