Towards Development of Risk-Based, Soil and Groundwater Screening Values (Threshold Values) for Petroleum Hydrocarbon (PHC) in Libya and Tunisia by Considering Climate and Regional “Geographical” Factors

Abstract

Petroleum Hydrocarbon Contamination (PHC) is a widespread environmental problem that can be found in many countries. Several contaminated land management approaches have been developed so far, all of which include some form of site investigation, risk assessment and remediation processes. Most of these approaches are often based on risk-based land management concepts. Most countries have a common framework for a risk assessment procedure for contaminated sites which endanger human health, involve ecological risk, and risks to water resources and construction materials. Usually, risk assessment of contaminated land is triggered by suspicious soil or groundwater contamination which is identified by Screening Values (SVs) approach. SVs specify generic quality standards for contaminated land. The application of SVs varies from adjusting long-term quality objectives, through making further investigations, to applying remedial actions. SVs derivation methods have scientific, geographical, socio-cultural, regulatory and political categories. They therefore differ from country to country. However, a “one-size-fits-all” approach is often adopted and a single SV might be applied to all areas within a country. In this paper, the authors demonstrated how differences in climatic and environmental conditions within a country may require the use of region-specific SVs. Here, Exposure SVs for PHC in Libya and Tunisia were used.