Comparative Assessment of Approaches to Predicting the Fate and Transport of Dissolved Phase Hydrocarbons in Chalk Aquifers
Chalk aquifers, unlike granular porous media, are characterised by heterogeneity across scales of interest, including fracturing and dual porosity. Chemical transport and fate in such aquifers is complex, and thus contamination events represent a potential threat to water supplies from such aquifers, such as in England.
The aim of this project was to assess and improve risk-assessment methodologies that rely on simulation of fate and transport of dissolved phase hydrocarbons. A core part of the project was development of new models and assessment of existing modelling approaches. ECOL collaborated with the University of Edinburgh in developing and validating detailed models of biodegradation of petroleum hydrocarbons, particularly benzene, toluene, ethylbenzene and xylene (BTEX) and methyl tertiary butyl ether (MTBE). The results of this effort provided a basis for evaluating the performance of simpler models that are used routinely in risk-assessment studies, particularly those that rely on natural attenuation as a remediation strategy.