Age-dating Diesel Fuel Spills: Using the European Empirical Time-based Model in the U.S.A.

Abstract

In 1993, a paper was published by Christensen and Larsen that oered a method for determining the age of diesel oil spills in soil (Christensen and Larsen, 1993 Ground Water Mount. R. Fall, 142±149). It presented an empirical timebased model of the degradation of diesel fuel in soils using chemical data gathered at petroleum release sites in Denmark and the Netherlands. Now, evaluation of the validity of the application of this work to subsurface petroleum releases in other countries remains.In the U.S.A., investigations assessing date(s) of release of diesel fuel in soils, e.g. age dating of subsurface petroleum contamination, have considerable interest. Litigation-driven scienti®c investigations with accompanying expert testimony in a court of law are underway. The number of instances where application of the Christensen and Larsen empirical time-based model to petroleum-contaminated properties is growing in the U.S.A. This paper presents two case studies which evaluate the applicability of the Christensen and Larsen empirical timebased model to petroleum-contaminated properties in general. It illustrates the approach using gas chromatographic data from two recently-completed projects evaluating the applicability of the Christensen and Larsen model to a No. 2 fuel oil/diesel fuel surface spill in the U.S.A. Results showed that the application of the model to petroleumcontaminated soils was scienti®cally valid, provided its applicability was evaluated using hypothesis testing for speci®c changes in the characteristics of the petroleum hydrocarbon distribution in a number of soil samples collected over time at one site. The paper oers observations on the application of the Christensen and Larsen model to petroleum found in the light non-aqueous phase liquid (LNAPL) phase and groundwater.# 2001 AEHS

Effect of pH modification on bilge waste biodegradation by a native microbial community

“…Preferential degradation of n-alkanes with respect to isoprenoid compounds was indicated by decrease in the n-C17/Pr and n-C18/Ph ratios (Table 2). These values have been used as good indicators of hydrocarbon biodegradation in ambient processes in water, groundwater and soil environments (Atlas, 1981;Pitchard and Costa, 1991;Wade, 2001). In initial and sterile control experiments, the calculated index values were similar to those found in pure fuels (Wade, 2001).…”

Allocating Cleanup Costs at Hazardous Waste Sites

“…For example, lead (19) or cesium (20) isotope data can sometimes provide information about the age of chemical release. Evaluating isoprenoids helps investigators to estimate the age of diesel releases (21)(22)(23). Information on documented releases, chemical handling, and storage and disposal practices must also be carefully evaluated.…”