Study of the 25-Year-Old Nipisi Oil Spill:  Persistence of Oil Residues and Comparisons between Surface and Subsurface Sediments

Abstract

During the years 1970-1972 the Nipisi, Rainbow, and Old Peace River pipeline spills occurred in the Lesser Slave Lake area of northern Alberta. The Nipisi spill was by far the largest of the three spills and is also one of the largest land spills in Canadian history. The most recent field survey was conducted in 1995 in order to determine which cleanup methods were most successful and to provide up-todate information about any changes in residual oil and vegetative recovery 25 years after the spills. The comprehensive chemical analysis data of the Nipisi samples indicate that (a) the Nipisi samples can be categorized into three groups plus the background group, according to the contamination level and degradation degree of the samples; (b) degradation of residual oil of surface samples (0-4 cm) had clearly occurred, and the weathered percentages of this group of samples were estimated to be in the range of 15-43%; (c) subsurface samples (10-40 cm) exhibited great quantities of oil even 25 years after the spills, indicating that the natural recovery rates were slow for this group of samples; (d) the extent of contamination and degree of degradation correlated strongly with sample depth; (e) oil trends were similar across the site, even though different treatments had been used after the spill at the site.

Biodegradation of dispersed oil in natural seawaters from Western Greenland and a Norwegian fjord

“…2d). Biotransformation was examined in the dispersions after normalization against the persistent biomarker 17α(H),21β(H)-hopane (30ab hopane), commonly used in biodegradation studies Wang et al 1998). No depletion of 30ab hopane was measured during the experiment (Online Resource 8).…”

Organic Cosolvent Effect on the Estimation of the Solubility of Oil Residues in Soil

“…The composition of each crude oil is unique and the oil in the environment is under very variable conditions, therefore a strong historical component exists in its current composition. This makes the testing in field samples to be of fundamental interest [1][2][3] since it is impossible to reproduce similar conditions in the laboratory. The oil residuals are hydrophobic but their solubility can be increased by means of the use of an organic cosolvent, as the alcohols.…”

Bioremediation Potentials of <i>Heterobasidion annosum</i> 13.12B and <i>Resinicium bicolor</i> in Diesel Oil Contaminated Soil Microcosms

“…Semple et al, (2003) stated that, in addition to biodegradation and volatilisation, hydrocarbons could be lost through sequestration. No effort was made in this work to evaluate the portion removed via abiotic routes, for instance by the use of internal biomarkers (Bragg et al, 1994;Wang et al, 1998) which would have been useful for the validation of bioremediation effectiveness (Bundy et al, 2004). The increases in weights of hydrocarbons extracted from the two fungal treatments on day 22 in the 7 % diesel treatment, at the same time as quantities from the control treatment continued to decrease are also difficult to explain.…”