Numerical flow and transport models for simulating current and predicted nitrate contamination in groundwater in the Bonifica di Arborea area (W. Sardinia, Italy)

In Italy the protection of groundwater against the deterioration of both quality and quantity is one of the top priorities of water policy and this is reflected in the substantial regulatory developments. The assessment of groundwater vulnerability to contamination is required to be conducted in accordance with environmental regulations, the most significant at the national level being Legislative Decrees 152/2006 and 30/2009, which concern a variety of environmental issues. One common form of pollution of both surface and groundwater that has been afflicting industrialised countries for decades, is nitrate contamination. This is also a major issue in Sardinia where, by means of the Water Protection Plan (PTA) it has been possible to delineate potential Nitrate Vulnerable Zones (ZVN) at the regional scale. Pursuant to the Regional Government resolution No. 1/12 of 18/01/2005, the Bonifica di Arborea, where intensive agriculture and dairy farming form the mainstays of the local economy, has been designated as a ZVN. Numerical flow and transport models have been employed to simulate groundwater conditions for assessing current nitrate contamination of the shallow aquifer. Using the calibrated and validated numerical model, it was also possible to simulate future scenarios, essential for drawing up plans for effective interventions.