Managing Cumulative Impact in a ‘Greenfield’ Industrial Estate
The City of Cessnock, located in the lower Hunter Valley of NSW, is establishing a new ‘greenfield’ industrial estate, the Hunter Economic Zone (HEZ), to eventually accommodate about a hundred medium-to-large-size industrial establishments on 700 hectares of woodland. Even with best environmental practice cumulative impacts of pollution from the industries may be significant. The paper describes a study of likely air quality impacts and management tools.
The environmental margins are defined as the differences between existing air quality and ambient standards for various pollutants. They will be successively eroded as industries enter the estate. Inadequate attention to managing the margins could compromise full estate development, although dealing with such cumulative impacts prospectively is a relatively untried planning process.
There are several years’ meteorological data from the site supplemented by interpolative modelling. Existing air quality for key pollutants is available from a government monitoring site in the lower Hunter Valley. Using anticipated Australian industry profiles and emission factors, scenarios of likely emissions have been modelled to predict impacts on air quality and the erosion of margins. The appropriateness of the various available air quality models and recent emission inventories in building the scenarios is discussed.
NOx, PM10 and VOCs emerge from the study as pollutants to be managed carefully. The definition of responsibilities and development of tools for management of cumulative impacts in an industrial estate are discussed.