GEOCHEMICAL AND HYDROGEOLOGICAL INVESTIGATION IN A LANDFILL SITE OF NORTHERN GREECE

摘要

The landfill is located 3 Km north of the city of Kavala, Northern Greece, accommodates 40,000-45,000 tons/year of wastes and extends over 50,000 m~2 (5 ha) at 330m above sea level. In 2009, the local authorities opted for the construction of a new, larger, regional landfill, in the vicinity of the old one, that will accommodate 70,000-75,000 tons/year of wastes or even more. The new, modern landfill will be a well-engineered facility, located, designed, operated, and monitored to ensure compliance with Government regulations. Storage of any waste material in a landfill poses several potential problems. One problem is the possible contamination of soil, groundwater and surface water that may occur as leachate produced by water or liquid wastes moving into, through and out of the landfill migrating into adjacent areas. The Kavala authorities, fully aware of the environmental risks and in the interest of protecting the public health and the environment, have undertaken a systematic geochemical and geophysical study, before developing additional criteria for further evaluation of the new site concerning engineering and financial feasibility. Since landfills may present long-term threats to groundwater, the total absence of groundwater horizons is essential. To prevent the wastes from escaping, rocks as tight (waterproof) as possible are also needed. The geophysical study performed on the whole area demonstrated the total absence of groundwater horizons. It is also noticed the absence of surface water bodies. In order to have reference chemical analyses of the area and determine sources of possible non anthropogenic contaminants, a total of thirty samples (7 soil and 23 rock samples) in and around the landfill were collected and a complete geochemical study was performed. Compared to the Earth's crust elements concentration, the majority of the rock samples showed higher concentrations for Cd, Bi, As and Sb, while soil samples show an enrichment factor in Cr, Ni and As when compared to the guidelines given for soil sediments in the New Dutch List for soil sediments. The high concentrations of some elements are attributed to the ore occurrences found spread in a mineralization area north of the city of Kavala.