Non Point Source Pollution Assessment - A Geospatial Appoach

Urban catchments are exposed to a wide range of pollutants from various sources, which are commonly described as diffused or non-point source (NPS) pollution. This paper describes a geo-spatial methodology applied to a Contaminant Load Model that improves and enhances the current spreadsheet approach developed by the Auckland Regional Council. The geospatial approach leads the Contaminant Load Modelling (CLM) process towards advanced and optimised decision making for determining and responding to the complex NPS pollution issues.

NPS pollution is a significant contributor to water quality degradation and poses a great challenge for control and abatement.

An integrated approach for Catchment Management needs to incorporate Contaminant Load Modeling (CLM) in order to demonstrate a sufficient understanding of impacts of urbanisation and other activities on the environment and in this particular case on stormwater runoffs.

However, NPS pollution assessment techniques require more clarity within the industry and there are a number of challenges such as:

• The need for a consistent approach to analysis, tools and the data to be used in assessments;
• The need for clarity in interpretation, presentation and understanding of the outputs;
• The need for better communication of the technical information to various users and stakeholders.

The geospatial approach enables the collection, analysis and modeling of relevant data with an advantage of combining existing and acquired geospatial data onto a single IT platform, thus enhancing strategic decision making for integrated catchment management.