Study of environmental pressure of industrial effluent on rivers with a composed pressure index

The deterioration of superficial water quality is a relevant issue as regards water management. Until today, most European rivers do not achieve qualitative standards defined by the Water Framework Directive (WFD). Given the goals of the WFD and taking into account current guidance for water quality management, this study has been carried out to evaluate pressures of anthropic activities - like industrial effluents, wastewater treatment plants, waste-to-energy plant, waste handling facilities, contaminates sites- on superficial waters.

In this study, we propose a simplified multidisciplinary methodology to perform a semi-quantitative analysis of water pressures on river segment starting from easily accessible data, thus attempting to overcome the endemic scarcity of monitoring data. In particular, the methodology proposes a procedure for: (1) identifying river segment exposed to pollution spills by the application of an expeditive raster-based numerical model; (2) determining a pressure index value for each identified river segment in relation to allocated spills. The developed pressure index offers the possibility of quantifying the significant pressures of several pollutant hotspots that impact simultaneously on a single river segment. The methodology has been tested over two rivers differently exposed to industrial and anthropogenic pressure and for which punctual environmental pollution hotspot were available at catchment scale.

The results allow to identify river segments most exposed to pollutant spills and, based on pressure index values, to do a comparative analysis between rivers segments with similar characteristics or to draw up a ranking magnitude of the river pressures. In this prospective, the developed methodology can represent a solid tool for decision-making processes and predictive studies in areas with no, or poor, monitoring data.