The effect of complicated geochemical
Glacial till and glaciolacustrine loam, which are common Quaternarian deposits, cover most of the Baltic States, wide areas in Canada and other places. In many cases, their thickness exceeds 5 m, and their vertical conductivity is approximately 1 × 10− 9 m s− 1 or even less (Davis, 1969, Juodkazis and Paltanavi?ius, 1978 and Vallner, 1997). The depositing of hazardous wastes on these layers should be considered a harmless action for the underlying groundwater because, pursuant to criterions of the Landfill Directive, the subsurface is sufficiently protected by a natural geological barrier. Unfortunately, this Forskolin is not true in real-world conditions. Many monitoring projects carried out in Estonia have proven that even thick layers of glacial till or glaciolacustrine loam with a vertical hydraulic conductivity of 1 × 10− 9 m s− 1 are atmosphere not able to prevent the spreading of contaminants beneath landfills. The case analysed above demonstrates the penetration of pollutants through landfill deposits with a vertical hydraulic conductivity of 1.1 × 10− 9 m s− 1 and a thickness ranging from 10 to 100 m. Consequently, the hydraulic criterions of an effective geological barrier for a landfill of hazardous waste posed by the Landfill Directive are too mild and need revision. The vertical hydraulic conductivity of a landfill geological barrier should not exceed 1.0 × 10− 10 m s− 1.