Air quality monitoring network review

New South Wales led the national process reviewing the design of Australian air quality monitoring networks.

Legislative context for the review

The design of Australian air quality monitoring networks, and the measurement and reporting of air quality is guided by the National Environment Protection (Ambient Air Quality) Measure (AAQ NEPM), made under the National Environment Protection Council Act 1994 (Cth) (NEPC Act).

The AAQ NEPM was first reviewed in 2011. In 2015, an Expert Working Group (EWG) made of representatives from participating Australian jurisdictions was tasked with progressing technical recommendations from the AAQ NEPM review, grouped by projects. Commencing 2015, EWG Project 2 assessed the feasibility of executing Recommendations 10 and 11 of the AAQ NEPM review.

  • Recommendation 10: Redesign monitoring networks to represent population exposure on a pollutant-by-pollutant basis without compromising data collection for long-term trend analysis. A procedure to determine the location and number of sites similar to the European Union (EU) and/or United States Environmental Protection Agency (US EPA) is recommended.
  • Recommendation 11: Remove the population threshold and formula to enable monitoring on potential population risk rather than on population size.

Who was involved in the review?

The national review of Australian air quality monitoring networks (EWG Project 2) was led by the NSW Office of Environment and Heritage (OEH), overseen by an interagency project group comprising representatives from Victorian, South Australian and Queensland environment agencies.

The terms of reference for the review were developed in consultation with an external Stakeholder Advisory Panel with representatives from the following disciplines: air quality research; environmental health research; community engagement; air quality monitoring practitioners from other jurisdictions, and the NSW Office of the Chief Scientist & Engineer.

An independent consultancy was engaged to conduct the review.

What were the outputs from the review?

The independent review occurred in two streams:

The Expert Working Group consolidated these independent reviews into an updated guidance: Review of Air Quality Monitoring Network Design.

Review outcomes

Findings and recommendations from the National Environment Protection Measure Expert Working Group Project 2.

  1. The guidance on NEPM monitoring network design is comprehensive and often more comprehensible than other comparable international guidance material.
  2. NEPM guidance on monitoring is flexible, allowing jurisdictions to monitor air quality anywhere. It does not restrict monitoring to regions only with populations over 25,000.
  3. Most jurisdictions are meeting their NEPM monitoring requirements. However, population growth in some regions means that jurisdictions should re-assess monitoring requirements based on the latest available census data.
  4. There is inconsistency in the designation of monitoring station types between jurisdictional monitoring plans and in annual reports.
  5. Monitoring for CO, NO2, SO2 or Pb is probably adequate for all jurisdictions.
  6. Additional ozone monitoring in some inland and coastal regions may be required to support screening of this pollutant.
  7. PM10 and PM2.5 monitoring should be expanded (noting that the recent changes to the Air NEPM Particle standards will require expanded PM2.5 monitoring by 2018).
  8. The benefits of using the ABS Significant Urban Area population data rather than the Urban Centres and Localities data for network design should be investigated.
  9. A review of international guidance on network design found no evidence to suggest that current NEPM monitoring network classifications do not meet international best practice.
  10. Population thresholds represent current international practice in determining minimum monitoring requirements and do not inhibit risk-based monitoring.
  1. Jurisdictional monitoring plans should be updated annually with changes documented clearly and transparently.
  2. Jurisdictional monitoring plans should be reviewed and re-submitted every 5 years to ensure currency of population coverage and pollutant screening assumptions.
  3. The population threshold of 25,000 to guide monitoring network design and NEPM assessments should be retained.
  4. The ABS Significant Urban Area product should be the basis of population assessments for monitoring design
  5. Jurisdictions should re-assess their screening determinations at the earliest time practical.
  6. Jurisdictions should re-assess ozone monitoring requirements based on the updated 2007 screening procedures, focusing on large inland and coastal centres.
  7. Screening procedures for PM2.5 should be developed and screening procedures for PM10 should be updated to reflect changes in the NEPM, focussing on maximum PM10 levels excluding exceptional events.
  8. An expert group should review trends in monitoring network design and advise jurisdictions on changes to monitoring design requirements. The group may also act as a review panel for monitoring plans.
  9. Clause 14 of the NEPM should be amended to:
    14 Performance monitoring stations
    (1) The number of performance monitoring stations needs to be based on determining potential population risk.
    (2) Additional performance stations may be needed where it's required to determine population exposure in high risk areas.
    (3) Subject to subclauses (1) and (2) the number of performance monitoring stations for a region with a population of 25,000 people or more must be at least the next whole number above the number calculated in accordance with the formula:
    1.5P+0.5, where P is the population of the region (in millions).