Gazetted Airsheds as shown in the Canterbury Air Regional Plan.Clause 14 States:The ambient air quality standard for a contaminant at any place -(a) that is in a region or part of a region specified by the Minister by Noitce in the Gazette; and(b) that is in the open air; and(c) where people are likely to be exposed to the contaminant.Airsheds extend from ground level up, with no specified upper limit, including coastal marine areas. NIWA has provided guidance on the definition of Airsheds, but the defintion is up the councils. The airsheds within the Canterbury Region were derived based on Urban Planning Zones - particularly the Residential and Commercial zones from the various District Plans.
