Sources of nitrate contamination in the mean sea level aquifer of Malta

Abstract

A study on the sources that lead to the nitrate contamination of the mean sea level aquifer of Malta. Although the sources of nitrate origin are known, the relative extent of pollution caused by each of these contaminants is not known. This pollution was quantified by correlating the contaminating sources with Lhn nitrate concentration of groundwater on the basis of a watershed model. This investigation involved the collection processing and analysis of various data (groundwater nitrate concentration, land use, sewage networks, importation of fertilizers etc.) that is held at the Works, Agriculture and Trade Departments. The concentration of nitrates in groundwater has been steadily increasing for many years. This investigation has shown that about 45% of nitrate fertilizers (including manure) are not used up by the crops but are leached into groundwater. It also has been shown that the primary source of pollution is the use of artificial fertilizers.