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Appendix H: Summary of Recommendations

 

Number

Recommendation

1

Screening methods

Screening methods cannot be used to determine compliance with the NES for air quality or to establish whether an airshed meets the ambient air quality guidelines. They may, however, be used to provide indicative data for other monitoring purposes.

A screening method’s level of accuracy and precision must be suitable for the purpose of monitoring (eg, occupational health and safety equipment is not suitable for ambient air quality monitoring).

2

Hydrogen sulphide

The recommended method for hydrogen sulphide is fluorescence monitoring, in accordance with AS3580.4.1–2008, Methods of sampling and analysis of ambient air – Determination of sulphur dioxide – Direct reading instrumental method.

3

Lead content of PM10

The recommended method for lead content of PM10 is high-volume gravimetric sampling in accordance with United States Code of Federal Regulations, Title 40 – Protection of Environment, Volume 2, Part 50, Appendix J and Appendix G.

4

Benzene and 1,3-butadiene

The recommended methods for benzene and 1,3-butadiene are:

USEPA method TO-1Method for the determination of VOCs in ambient air using Tenax®adsorption and gas chromatography / mass spectrometry (GC/MS)

USEPA method TO-14ADetermination of VOCs in air using specially prepared canisters with subsequent analysis by gas chromatography

USEPA method TO-15Determination of VOCs in air collected in specially prepared canisters and analysed by gas chromatography / mass spectrometry (GC/MS)

USEPA method TO-17Determination of VOCs in air using active sampling onto sorbent tubes

BS EN 14662-1:2005Ambient air qualityStandard method for measurement of benzene concentrations – Pumped sampling followed by thermal desorption and gas chromatography

BS EN 14662-2:2005Ambient air qualityStandard method for measurement of benzene concentrationsPumped sampling followed by solvent desorption and gas chromatography

BS EN 14662-3:2005Ambient air qualityStandard method for measurement of benzene concentrationsAutomated pumped sampling with in situ gas chromatography

BS EN 14662-4:2005Ambient air qualityStandard method for measurement of benzene concentrationsDiffusive sampling followed by thermal desorption and gas chromatography

BS EN 14662-5:2005Ambient air quality – Standard method for measurement of benzene concentrations – Diffusive sampling followed by solvent desorption and gas chromatography.

5

Formaldehyde and acetaldehyde

The recommended method for formaldehyde and acetaldehyde is USEPA method TO-11ADetermination of formaldehyde in ambient air using adsorbent cartridge followed by high performance liquid chromatography (HPLP).

6

Benzo(a)pyrene

The recommended methods for BaP are:

USEPA method TO-13ADetermination of polycyclic aromatic hydrocarbons (PAHs) in ambient air using gas chromatography / mass spectrometry (GC/MS)

BS EN 15549:2008Air qualityStandard method for the measurement of the concentration of benzo(a)pyrene in ambient air.

7

Mercury, chromium and arsenic

The recommended method for mercury, chromium and arsenic is:

PM10 sampling in accordance with 40CFR Part 50, Appendix J, followed by analysis using atomic absorption spectroscopy or an equivalent method.

For mercury:
Method IO-5 (Sampling and analysis for vapour and particle phase mercury in ambient air utilising cold vapour atomic fluorescence spectrophotometry)

BS EN 15852 – Ambient air quality – Standard method for the determination of total gaseous mercury.

8

Meteorological monitoring

The minimum monitoring required is as follows:

  • mast, 6 m minimum, 10 m preferable

  • wind speed (resolution 0.1 m/s accuracy ± 0.2 m/s, start-up 0.2 m/s)

  • wind direction (resolution 1º, accuracy ± 2º, referenced to true north)

  • air temperature (resolution 0.1ºC, accuracy 0.2ºC)

  • automated logging system, reliable power, with battery back-up.

The use of the Cartesian coordinate system is recommended, whereby data is converted to its x and y components. This data can then be accumulated in a vector form. This solves averaging and unweighted direction problems. Results may subsequently be converted to polar coordinates, if required.

Desirable measurements are:

  • humidity (or dew point) (resolution 1% relative humidity (rh), accuracy ± 5% rh)

  • solar radiation (for stability estimates) (resolution 1 W/m2, accuracy 10 W/m2)

  • rainfall (resolution 1 mm)

  • temperature profile (T at two heights – 1.5 m and 10 m, needs 0.1ºC accuracy) using identical sensors at both heights.

Specific siting requirements:

Must be free of influence of trees, buildings, structures – should be at least two times the height away from the obstacle, and for wind sensors it should be at least 10 times the height away from obstacles (refer to Part I, sections 5.9.2 and 6.2 of the Guide to Meteorological Instruments and Methods of Observation (World Meteorological Organization, 1996; Oke TR, 2006).

Required time resolution:

  • data should be collected at the same minimum time resolution as air quality data

  • resolution should be at least hourly.

Period of monitoring:

For atmospheric modelling and trend analysis, a minimum of one year’s data is recommended.

9

Independent accreditation

Accreditation of agencies/firms undertaking air quality monitoring by an independent and approved accreditation organisation is strongly recommended.

10

Operation of a beta attenuation monitor

  • Enclosure temperatures should be maintained at 25°C ± 3°C to avoid moisture collecting on filter paper.

  • Regular maintenance in accordance with the operation manual is critical. Irregular and/or inadequate maintenance can result in up to 20 per cent variation.

  • The sample heater should be switched off for at least one hour before calibration.

  • The condition of the radioactive source should be checked twice a year (R2 count). It may be necessary to adjust after two to three years due to decay in the radioactive source.

  • Inlet temperature should be set to 40°C.

  • Equipment should be maintained in accordance with operation manual (refer also to AS/NZS 3580.9.11:2008).

  • Data correction to gravimetric equivalent is not generally recommended.

  • Where possible, humidity should be logged along with appropriate meteorological data.

11

Operation of a Operation of a tapered element oscillating microbalance (TEOM)

It is recommended that TEOMs be fitted with a filter dynamics measurement system (FDMS) when monitoring for national standards.

Alternatively, TEOMs can be used without the FDMS by using a correction factor that is determined by co-locating the TEOM with a gravimetric monitor for at least one year.

12

The importance of filter conditioning

Manual methods for particulate monitoring are all based on weighing material collected on a filter. It is therefore important to recognise that the pre- and post-conditioning of the filter and the filter weighing techniques are just as important as the selection and use of the sampling equipment.

Most filters will absorb moisture from the atmosphere, so filter weight will vary in accordance with the surrounding humidity. Particulate matter collected on the filters will also behave in the same way. It is therefore essential that the filters be carefully conditioned and weighed under conditions of constant temperature and humidity, both before and after sampling.

Detailed procedures for filter handling, conditioning and weighing are given in the relevant standard method specifications. For example, the USEPA recommends that filters be conditioned for at least 24 hours at a humidity between 20 to 45%, ± 5%, and a temperature of 15 to 30°C, ± 3°C (40 CFR Part 50, Appendix J).

13

Representativeness of monitoring

The use of existing air quality monitoring data, emissions inventories and atmospheric dispersion modelling is recommended when determining ‘worst’ locations.

Regional exposure should also be taken into consideration when determining the ‘worst’ location.

Ambient air monitoring should take into account temporal variations in contaminant concentrations.

14

Instrument enclosure temperatures

The temperature inside instrument enclosures should remain constant (ideally around 25ºC or at any other temperature stated in the instrument’s user manual).

Installation of an air-conditioning unit with heat and cool cycles inside instrument enclosures is recommended to prevent variations in temperature.

15

Site selection

Regional, neighbourhood and compliance sites should follow the Australian / New Zealand standard (AS/NZS 3580.1.1.2007).

Peak sites can deviate from the standards when necessary.

Whenever site locations do not meet the standard requirement, this should be clearly detailed in the site metadata.

A minimum co-location period of one year is recommended when relocating monitoring sites.

16

Monitoring records

Agencies operating monitoring instruments need to keep detailed records of visits and maintenance, preferably in electronic form.

17

Calibration

Calibrations should be carried out in accordance with the manufacturer’s specifications and the requirements of the standard method.

Span and zero checks are recommended on a daily basis.

Multi-point calibrations should be performed not less than six months apart.

18

Equipment maintenance

The routine maintenance and service requirement outlined and recommended by the instrument manufacturer should be followed.

19

Calibration and maintenance documentation

As a vital part of data quality assurance it is recommended that detailed procedure manuals and schedules for instrument maintenance and calibration be established.

20

Training

Air quality monitoring technical staff should be provided with basic training on core air quality monitoring competencies.

Another effective method of training and systems improvement is to participate in reciprocal auditing activities between monitoring agencies.

21

Data acquisition, storage and data checks

The use of an external datalogger is recommended for all instruments to eliminate one source of variation using analogue connections.

All data should be stored in a central database that is regularly backed up.

It is recommended that daily data checks be done for each telemetered site (or whenever data is downloaded from untelemetered sites), and events noted that may affect results.

22

Data adjustment

Data quality assurance should be subsequent to multi-point calibrations for gases and done at least monthly given that the NES for air quality require public reporting of a breach within 30 days of its occurrence.

Applying the response curve to raw data can correct gradual changes to baselines but is not recommended when there is a sudden baseline change.

A minimum co-location period of one year is recommended before correcting data. A copy of raw data should be archived, and all corrected data should be marked to inform data users.

23

Negative data

Negative and positive spikes should be reviewed during the data analysis process to evaluate whether they are real or spurious. Unless there is good evidence to remove a value, it should be left in and a comment made in the metadata.

Where negative values are within the expected error of the instrument, they should be retained within the data set to avoid creating a positive bias in the final result.

Where large negative spikes are observed in the data record from some particulate monitors, check to see whether a large positive spike is also present. If both a large positive and a large negative spike are present, then remove both spikes as invalid data and check the inlet temperature sensors for faults.

24

Per cent valid data and data capture rate

Sites used for compliance monitoring should achieve at least:

  • 75% valid data for averaging

  • 95% data capture.

Per cent valid data for averaging = number of valid data points obtained
                                               total number of data points in the averaging period

Data capture rate = number of valid data points obtained
                           total number of data points for the period – calibration/maintenance data points

25 Site metadata
Documented site metadata should be used when interpreting air quality monitoring results.
Metadata should be recorded either in hard copy or in a database.

Parameter

Explanation

Monitoring site metadata

 

Indicators/contaminants monitored

List all the contaminants that have been or are being monitored at the site

Site code

Site code specified by monitoring agency

Site title

Common name of site; eg, Taihape

Location

Street address of site

Region

For example, Southland region

Co-ordinates

New Zealand Mapping Series/Grid reference preferable (latitude and longitude optional)

Equipment owner’s name/s

Name of party/ies who own the equipment at the site

Land owner’s details

Name/s and contact information of land owner/s

Equipment housing

For example, shed, lab, air conditioning

Housing environment

For example, air conditioning at 25oC

Monitoring objectives

For example, to determine population exposure in high-density areas where air quality is suspected to be poor

Site topography

For example, there are hills 1 km to the southwest; to the north are high-rise commercial buildings

Location and description of major emission sources

This should include information on the nature, location and distance to predominant sources (eg, roads, factories, domestic fires)

Site category

See section 6.2

Scale of representation

See section 6.2

Site height above sea level

 

Electrician and air conditioner service person contact details

 

Photographs of the site

 

Meteorological site metadata

 

Meteorological variables measured

For example, wind speed, wind direction, temperature at height at which they are measured

Meteorological data operator

Person who operates the met station

Location of meteorological site

For example, on site up mast 6 m high, at the neighbouring airport

Meteorological data information

Where met data can be obtained (eg, met service, regional council)

Regional and local meteorological characteristics

A brief description of met conditions likely to affect air quality at the site (eg, inversions, prevailing wind direction)

Contaminant metadata

 

Contaminant

For example, PM10, NO2

Data owner

Name of organisation that actually owns the data recorded by equipment

Instrument/s

Name and any other details of the instrument/s (make, brand, serial number and model). If using more than one instrument, include both in this section

Period of operation

Dates when equipment was operated (eg, 12.3.2001 to 8.5.2003 or 11.3.2008 ongoing)

Method

Details of the standard method followed to operate the equipment (eg, USEPA or AS/NZS standard). Also, include details of any deviation from the standard method (eg, conditioning and weighing of filters).

Data logging

For example, remote via modem, or not used

Data storage

Describe how the data is stored by the data owner

Sampling period

How often the concentration is sampled and measured

Sampling probe height

Height of probe above ground

Calibration frequency

Summarised details of equipment calibration

Per cent valid data

Amount of data that has passed quality assurance checks (see Recommendation 24), recorded on a yearly basis (eg, 2005 – 95%; 2006 – 98%; 2007 – 96%)

26 Monitoring units
The recommended units for recording and archiving the monitoring results of gases are parts per million (ppm) or parts per billion (ppb), with conversion to mg/m3 or µg/m3 at 0ºC for reporting purposes.
PM10 results should be recorded and archived as µg/m3 at 0ºC.
27 Time format
Times and dates should always be reported in New Zealand Standard Time.
Labelling of the midnight hour should be 24.00 instead of 00.00.
28

Reporting data formats
It is recommended that data from all monitoring sites be reported in the following format:


Contaminant

Data format

Nominal precision

Carbon monoxide

X.X mg/m3

tenth of a mg/m3

Nitrogen dioxide

X.X µg/m3

tenth of a µg/m3

Ozone

X.X µg/m3

tenth of a µg/m3

Particulate matter (PM10)

XX µg/m3

a whole µg/m3

Sulphur dioxide

X.X µg/m3

tenth of a µg/m3

Lead

X.X µg/m3

tenth of a µg/m3

 

29 Significant digits and rounding-off protocols
The recommended data format in section 9.2 specifies the significant digits for the reporting of a contaminant.
When the value following the significant digit is equal to or greater than five, the digit should be rounded up; otherwise, the digit is retained.
For all monitoring sites, an exceedence occurs when the reported concentration is above the standard, after rounding to the significant digit.