THE IMPACT OF CONTAMINATION FROM A MUNICIPAL SOLID-WASTE LANDFILL (ZAGREB, CROATIA) ON UNDERLYING SOIL

The present study was conducted on the main landfill of the city of Za greb which contains about 5 million tons of waste disposed of directly onto highly permeable alluvial sediments. The investigations were aim ed at assessing the impact of contamination from the landfill on under lying soil and comprised the determination of a broad spectrum of inor ganic and organic constituents in the samples (Size fractions <2 mm) o f.solid waste, soil and aquifer sediments. Both the total content of v arious contaminants as well as their part which is readily leachable w ith water were determined in the examined samples. Compound classes id entified in the landfill can be classified into the two main categorie s: (I) markers of biological waste and of its microbial transformation (ammonia, dissolved organic carbon, short-chain aliphatic acids, phen ols, derivatives of abietic acid) and (2) markers of anthropogenic was te (toxic metals, hydrocarbons, chlorinated hydrocarbons, surfactant-d erived compounds, phthalates, pharmaceutical chemicals). The complex a ssemblages of contaminants were shown to change dramatically during th e;transport from the solid waste through unsaturated zone of the soil to aquifer sediments. It was shown that, in addition to the vertical i nfiltration of leachate from the solid waste, the hydrological regime of groundwater has also a strong impact on the contaminant distributio n in soils below the landfill. (C) 1998 IAWQ. Published by Elsevier Sc ience Ltd.