3.1 Introduction

Ambient air quality is the general quality of the air that surrounds us, outside buildings or structures, and is the result of climate and topography as well as the combined effects on the air of human activities (industrial, commercial and domestic) and natural sources.

Northland's air quality is dominated by the region's exposure to the prevailing south-westerly winds, which, particularly during the winter and spring, quickly disperse air pollutants. This, along with the relatively dispersed population, low vehicle density and sparse heavy industry, means that Northland enjoys a high standard of natural air quality.

However, monitoring has identified that at times pollutants approach or even exceed national air quality guidelines. These exceedances are restricted to specific locations and often occur under specific meteorological conditions.

Air quality policy

Regional Policy Statement

The Regional Policy Statement (RPS) for Northland (NRC 2002) contains objectives relating to air quality. These objectives seek to sustainably manage air quality in the Northland region.

The RPS objectives are:

· The sustainable management of the air resource by avoiding, remedying, or mitigating adverse effects on the environment from the discharge of contaminants to air.

· The reduction of the region's discharges of ozone-depleting substances and the net emissions of greenhouse gases in line with National Policy Statements.

The following is the anticipated environmental results after the implementation of the air quality policies in the RPS (NRC 2002):

· The widespread adoption of the best practicable option for all discharges to avoid, remedy or mitigate the adverse environmental affects that may result from the discharge.

· A significant reduction in the number of incidents involving pesticide use, backyard burning and other similar contaminant discharges.

· Greenhouse gas emission levels in line with government directives.

Regional Air Quality Plan

Since the introduction of the Resource Management Act 1991, the Northland Regional Council (NRC) has a responsibility to manage the quality of air in the region. In order to protect the quality of air the Regional Council has developed the Regional Air Quality Plan (RAQP) for Northland (NRC 2003), which has been operative since March 2003. The plan provides guidance to those using the region's air resource in addition to specifying rules on what discharges into the air are authorised. NRC also undertakes the following to manage the region's air quality:

· State of the environment monitoring.

· Resource consent compliance monitoring.

· Investigation and response to environmental incidents related to air quality.

National Environmental Standards

The Ministry for the Environment (MFE) introduced National Environmental Standards for air quality (MFE 2004) in 2004. The regulations set ambient standards for five pollutants: carbon monoxide, sulphur dioxide, nitrogen dioxide, ozone and PM10. The National Environmental Standards (NES) also prohibit certain activities and set emission standards and efficiency criteria for wood burners used for household heating.

Under the NES Regional Councils must monitor these five air pollutants and publicly notify any exceedances. The implementation of NES also requires Regional Councils to designate areas (airsheds) where air quality has been adversely affected.

Using research carried out by the National Institute of Water and Atmospheric Research (NIWA), the Regional Council identified five areas in Northland which are suspected of reaching or exceeding the NES. The five airsheds in Northland include Whangarei City, Marsden Point, Kaitaia, Kerikeri and Dargaville. Maps of the airsheds are available on the Regional Council website at the following link:

http://www.nrc.govt.nz/Environment/Air-quality/Rules/National-Environmental-Standards/.

More information on the National Environmental Standards can be obtained on the MFE website, using the following link:

http://www.mfe.govt.nz/laws/standards/air-quality-standards.html