Development of a chemical source apportionment decision support framework for catchment management

Area of Science:

• Environmental Chemistry
• Water Resource Management
• Geographic Information Systems

Background:

• EU legislation, like the Water Framework Directive, mandates stricter surface water quality standards for chemical contaminants.
• Identifying and quantifying pollution sources is crucial for implementing effective water quality management and the polluter pays principle.
• Diffuse and point sources contribute contaminants to surface waters, necessitating tools for source assessment.

Purpose of the Study:

• To develop and test a modeling framework for source apportionment of chemical contaminants in surface waters.
• To provide a decision support tool for assessing the relative contributions of various pollution sources.
• To facilitate the estimation of impacts from proposed water quality improvement measures.

Main Methods:

• Development of the Source Apportionment Geographical Information System (SAGIS) modeling framework.
• Utilization of readily available national datasets for model input.
• Estimation of contributions from multiple sector sources for nutrients, metals, and organic chemicals.

Main Results:

• The SAGIS model successfully estimates contributions of nitrogen, phosphorus, copper, zinc, cadmium, lead, mercury, nickel, a phthalate, and polynuclear aromatic hydrocarbons.
• The model quantifies pollution from multiple sector sources on a national scale.
• This represents a novel capability for a wide range of chemicals at the national level.

Conclusions:

• The SAGIS model provides a valuable tool for national-scale source apportionment of diverse chemical contaminants.
• It offers a common platform to support stakeholders in effective catchment management.
• The tool aids in addressing water quality standard breaches and applying the polluter pays principle.