Pilot study for artificial recharge of the South-Eastern Mesaoria Aquifer (Cyprus), using tertiary treated wastewater

In many arid or semi-arid countries, like Cyprus, groundwater is the main source for domestic and irrigation use. The degradation of groundwater resource can be quantitative and qualitative, if the abstraction exceeds the natural recharge rate. For this reason treated water at these areas is a valuable water resource and should be taken into account in designing a rational water policy. Furthermore, the interest in artificial recharge of groundwater using pretreated waste water continues to increase, especially in the semi-arid countries. In this paper, the possibility of artificial recharge in the South-Eastern Mesaoria (Kokkinochoria) aquifer, close to Liopetri village, is examined. This study area is characterised by low precipitation (330 mm) and it is covered by deposits of Nicosia formation, Pliocene aged, which consists of marls and fined to coarse grained calcitic sandstone. The aquifer is developed between the sandstones horizons and sands. The average thickness of the aquifer is up to 80 m and the maximum 120 m. Overpumping during the last decades, through a large number of boreholes, has caused a decline of groundwater level and the occurrence of negative piezometry up to 30 m below mean sea level. As a result, sea intrusion phenomena are recorded for distance up to 1-2 km inland. Therefore, the use of tertiary treated wastewater, which is produced at Agia Nappa-Paralimni treatment plant, is proposed for the application of artificial recharge through boreholes. Adequate pretreatment of the reclaimed water is also considered prior to the recharge, taking into account the final use of the aquifer’s water.