Geostatistical estimation of risk for soil and water in the vicinity of olive mill wastewater disposal sites

AbstractOlive mill wastewater (OMW) is often disposed of in poorly engineered evaporation ponds or various environmental receptors in most Mediterranean countries causing contamination of soils and water bodies. The aim of this work is to estimate the risk for soils and waters as a result of OMW disposal in an area of 15 km2 at Rethymnon, island of Crete, Greece. Soil, surface, and groundwater samples were collected over a period of five years and geostatistics using the kriging approach was considered for the assessment of risk. Risk maps for several pollutants, namely phenols, Ni, Cr, and available P, in soil and water were produced. The results of the study indicate the presence of hot spots in the area under investigation, mainly in the vicinity of OMW disposal sites. Finally, the fate of contaminants in affected media is discussed and a framework for monitoring of soils and water bodies in areas affected by OMW disposal is proposed.