In 2004, the Ministry for the Environment published national environmental standards in relation to air quality.
These standards set limits for five common air pollutants.
|Pollutant||Averaging time period||Maximum allowable concentration||Number of allowable exceedances|
|Carbon monoxide||8 hours||10 mg/m³||1|
|Nitrogen dioxide||1 hour||200 μg/m³||9|
|Ozone||1 hour||150 μg/m³||0|
|Sulphur dioxide||1 hour||350 μg/m³||9|
|1 hour||570 μg/m³||0|
|PM10||1 day||50 μg/m³||1|
The national environmental standards also:
- Ban activities that discharge significant amounts of dioxins and other toxics into the air
- Require all new wood burners installed in urban areas to meet a design standard
- Require landfills with over one million tonnes of refuse to collect greenhouse gas emissions
For further information on these standards, see the Ministry for the Environment website, under 'air quality standards'.
The national environmental air quality standards for PM10 were amended in April 2011. The main changes are:
- Extending the target date for councils to comply to 2016 for polluted airsheds and 2020 for heavily polluted airsheds to meet the ambient PM10 standard. Blenheim is considered a ‘polluted’ airshed and so will need to comply with the standards by 2016.
- Allowances will be made for ‘exceptional’ events such as dust storms, volcanic eruptions etc. Such events will be required to be notified to the Ministry for the Environment for exclusion when assessing compliance with the standard.
- From September 2012, new industries which contribute significantly to the PM10 load in polluted airsheds will be required to have offsets to mitigate against their overall contribution to the PM10 load within the airshed. This requirement replaces the current restrictions on industrial consents.
- A ban on new open fires in homes in polluted airsheds from September 2012.
In 2005, regional councils were required to outline urban areas which either were, or were likely, to exceed the national environmental standards (NES) for PM10.