Remediation of Petroleum Refinery Waste Pond Contents: A Case Study

Abstract

The objectives of this field study were to (1) remediate the contents of a pond containing petroleum refinery waste products, and (2) characterize the performance of the remediation effort in terms of changes in chemical concentration, toxicity of the waste material, and mobility of the remediated waste constituents. The study was conducted in a field land treatment unit (LTU) in two phases over 140 weeks. Site remediation and closure decisions should be based on criteria that indicate that protection of human health and the environment has been achieved. Thus, criteria used to determine performance should include measures of chemical loss as well as measures of mobility (leaching) and toxicity. In this field study, changes in both general (oil and grease, total petroleum hydrocarbons) and specific (benzene, toluene, ethylbenzene and xylene compounds and polycyclic aromatic hydrocarbons) were determined. Several measures of chemical mobility and LTU soil toxicity also were used. The data indicated that the land treatment of this waste material reduced the concentrations of general and specific hydrocarbons, reduced the toxicity of the material being treated, and contained the waste constituents, that is, little to no vertical migration of the chemicals measured occurred. At the end of both field phases of the study, considerable amounts of general hydrocarbons remained in the LTU soil, as indicated by total petroleum hydrocarbons, oil and grease, and total polycyclic aromatic hydrocarbon compound measurements. However, there were little chemical mobility and relative toxicity of the soil at the end of these phases.