Risk assessment of contaminated land with petroleum compounds

Abstract

Remediation and management of contaminated land by what we call historic pollution, i.e. legacies from the past, involves the risk assessment stage. The risk assessment for the presented case was the study of the area's history, the determination of the pollution level on the site, sampling, measurement and quantification of the significance of the pollution (environmental impact). The assessment of soil contamination exposed to crude oil and petroleum products is conducted by comparison between measured concentrations of total petroleum hydrocarbons (TPH) and intervention values (IV). Because TPH concentrations from C10 to C40 do take into considerations specific physic-chemical and toxical properties of the individual compounds our study considers not only TPH assessment, but also PAH and BTEX components. Investigation of historical dumps of petroleum residues, a less sensitive land, was achieved by monitoring TPH and groundwater HAP for ground and groundwater through judicious monitoring drills. Methodology of this study is adopted according to authors experience, following three stages: collection of data, comparison of TPH, PAH and BTEX concentrations versus IV, and establishing of interactions among the petroleum contaminants. The analyzes performed showed that the values determined for the TPH level, for the analyzed soil samples, taken up to the 5 m depth, exceeded the alert threshold (1000 mg / kg dry mater) and even the intervention threshold (2000 mg / kg d.m.) for less sensitive land. BTEX indices record values below the quantification limits. The total HAP content (naphthalene, phenanthrene, anthracene, fluoranthene, pyrene, benzo (a) pyrene, indene (1, 2, 3, cd) pyrene) is well below the alert threshold (25 mg / kg d.m.).