Use of advanced chemical fingerprinting in PAH source identification and allocation at a coal tar processing site

Advanced chemical fingerprinting analyses were used to determine source allocation at a former coal tar processing facility which had been converted to a petroleum recycling site. Soil samples from the site had high petroleum hydrocarbon concentrations and elevated levels of polynuclear aromatic hydrocarbons (PAH). Comparisons of PAH distributions were used to differentiate the coal tar hydrocarbons from the petroleum hydrocarbons in soil samples. A more specific technique was needed to accurately allocate the contribution of the two sources to the observed PAH contamination in the soil. Petroleum biomarkers (steranes and triterpanes) which are present in crude oils and many refined petroleum products but are absent in coal tar were used to quantitatively allocate the source of the PAH contamination based on the relative ratio of the PAH to the biomarkers in soil samples. Using the resulting coal tar/petroleum source ratio the contribution of petroleum to the overall PAH contamination at the site was calculated. A multivariate statistical technique (principal component analysis or PCA) was used to provide an independent validation of the source allocation. The results of the source allocation provided a foundation for the site clean-up and remediation costs