Groundwater recharge in an endoreic basin with reclaimed municipal wastewater

摘要

The aim of this paper was to evaluate the groundwater pollution in an endoreic basin in southern Italy. The aquifer circulation was carried out on two different levels: a shallow groundwater, with a water table of about 10 m, and a deep groundwater in a karst aquifer, with a water table of 140–190 m. Reclaimed municipal wastewater and superficial water collected in the catchment area were both drained in a swallow hole linked with the deep groundwater. The agricultural practice conducted in the endoreic basin produced an excess of nitrate in the soil. Nitrate was subsequently washed out and displaced in the groundwater. With regard to the EU Drinking Water Directive (98/83/EC), the research activity conducted during 2003 showed the absence of pollution in the deep groundwater used for drinking water supply. The shallow groundwater, instead, was strongly influenced by agricultural and pasture activities, with detectable levels of nitrates and bacteria. In order to reduce the load of pollution entering the swallow hole and then in the deep groundwater, the realisation of a constructed wetland plant was proposed to improve the quality of reclaimed wastewater, as well as to pursue the wastewater reuse in agriculture.