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Air quality is important to the health and wellbeing of all Victorians. Most air pollution comes from industry, motor vehicles and domestic wood burning.
Many industrial activities require works approvals and licences from EPA.
EPA periodically reviews environmental policy and regulation.
Guidance for business and industry, including licensing and works approval guidance.
Information about the fees and charges levied by EPA.
EPA works with the community, businesses and other organisations to protect the environment.
The process to submit complaints about the conduct of an EPA authorised officer.
This bulletin is updated hourly with information calculated on data readings averaged over 8 hours for carbon monoxide and 1 hour for PM10, ozone, nitrogen dioxide, sulfur dioxide and visibility reduction. Detailed information on the calculation of the index is available below.
Data for a given hour are available at 30 minutes after the following hour. For example, data for 9 am-10 am is available at 10.30 am. See below for more information about station summaries, 'not available' and 'offline' reports.
EPA measures a range of pollutants at each of its monitoring stations. Each pollutant has a different impact on human beings or the environment. Two policies, the State Environment Protection Policy (Ambient Air Quality) and State Environment Protection Policy (Air Quality Management) set objectives for these pollutants.
The National Environment Protection (Ambient Air Quality) Measure sets nationally agreed air quality standards for a range of pollutants. There is one exception: visibility – where the current SEPP objectives will continue to apply.
Data in EPA air quality bulletins are expressed in terms of an air quality index. EPA has also adopted five-colour coded air quality categories. Data is assigned to a category based on the index value as listed in the table below.
A grey background indicates that the monitoring station is not instrumented for the pollutant or data is temporarily unavailable.
The station summary is determined after a check to see whether or not enough data have been measured to form a useful summary of air quality. This check involves ensuring at least one pollutant of major concern has been measured. In Victoria:
Currently EPA 24-hour summary air quality bulletins are issued twice daily (approximately 9.45 am and 3.45 pm) from Monday to Friday and daily (3.45 pm) on weekends.
Hourly data (via interactive map, data table) is available 24 hours a day, seven days a week on this website.
An index for any given pollutant is its concentration expressed as a percentage of the relevant standard, or:
It is therefore easy to interpret the pollutant index; that is, assess whether the pollutant is at a level which may cause harm.
An index value of 100 means the pollutant is currently at a concentration equal to an environmental standard level. These standards are designed to protect human health and the visual quality of the air environment, and are taken from either:
Expressing air quality as an index makes it easier to compare at a glance pollutant levels and air quality at different monitoring stations. The raw data (actual measurements/concentrations) are also available on our website - select 'data readings' as an option - for more detail.
* How calculated
A: For daily and weekly reports: Uses the maximum of the preceeding 24 one-hour averages. For hourly updates: Uses the selected hourly average (defaults to the latest available reading).
B: For daily and weekly reports: Uses the maximum of the preceding 16 rolling 8-hour averages. For hourly updates: Uses the 8 hours up to the selected hour (defaults to the latest 8-hour average).
C: For daily and weekly reports: Uses an average of the preceeding 24 hours of PM10 readings, divided by the 24-hour Air NEPM standard of 50 µg/m3. For hourly updates: Uses the selected hourly average PM10 (defaults to the latest available reading), divided by a derived 1-hour standard of 80 µg/m3.
The data obtained from EPA's monitoring stations are averaged over various averaging times depending on pollutant, as listed in the 'Pollutants, standard levels and calculation averaging times' table. These averages are calculated every hour by EPA.
The calculation is done separately for each station. There are two stages in the calculation. First, each pollutant measurement is converted into a pollutant index, and second, all the pollutant index values are combined together to form a station index.
In order to get an overall appreciation of air quality at a particular EPA monitoring station, the index for each pollutant is calculated. The maximum of these figures is taken to be the index for that monitoring station.
See also 'Determination of an overall station summary'.
Assume the values listed in the table below have been measured at an EPA monitoring station, and that EPA is preparing the 9 am bulletin on 2/2/98.
Smoke from bushfires can lead to significant deterioration in air quality, with high concentrations of fine particles and reduced visibility being the main concerns. View the bushfires and air quality page.
Page last updated on 5 Feb 2013
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State Government of Victoria