Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Petrophysical characteristics of the contaminated shallow aquifer in the basement of the factory PAL INTERNATIONAL, Inc., in Prague-Kbely
Abstract
The multi-layered shallow aquifer identified by drilling into the basement of the factory in Prague-Kbely corresponds to upper loess, middle marlstone regolith, and lowennost siltstone units (based on petrography and particle-size analysis). These units and frequent changes in the hydraulic boundaries level within the marlstone regolith control the recharge and vertical leakage of water and contaminants, such as chlorinated hydrocarbon solvents and heavy metals (Cu, Cd, Cr, Ni, Pb, Zn). Selected cores were examined for /i/ particle-size distribution and inferred hydraulic conductivity, /ii/ adsorption capability for exchangeable cations, /iii/ heavy metal leaching as well as (iv) for concentrations of chlorinated ethylenes, mainly TCE, cis-DCE and TeCE (DNAPL). Bedrock paleorelief and lower permeability media explain the varying patterns of the preferred flow paths and pools of DNAPL contaminants. The Lower Turonian age of the pre-Quaternary sequence is supported by micropaleontological investigation of blue-grey siltstone enriched in organic carbon.
