hazard identification
Because the solvent fraction of dilbit typically comprises volatile aromatics like naptha and benzene, reasonably rapid carrier vapourisation can be expected to follow an above-ground spill ostensibly enabling timely intervention by leaving only a viscous residue that is slow to migrate. Effective protocols to minimize exposure to petrochemical vapours are well-established. and oil spilled from the pipeline would be remediation were followed by the unlikely to reach the aquifer unless incomplete introduction of another carrier (e.g. a series of torrential downpours
The Keystone XL extension is designed to be buried under four feet of soil. which will hinder post-spill vapourisation of the carrier fraction. Diluent and bitumen will migrate at diff erent rates, depending on the temperature and composition of the surrounding soils. but separation will take place more slowly as the aromatics diffuse through sediment rather than through air The introduction of benzene and other volatile organic compounds (collective BTEX) to the subterranean environment compounds the threat posed by a pipeline leak Particularly if followed by rain, a pipeline breach would result in BTEX dissolution and equilibration of benzene in water. followed by percolation of the admixture into the aquifer. Benzene can cause many health problems and is carcinogenic with EPA Maximum Contaminant Level (MCL) set at 5 ug/l. for potable water. Although it is not well studied. single benzene exposure events have been linked to acute Additionally. the exposure of livestock mainly cattle. to benzene ha carcinogenesis. been shown to cause many health issues. such as neurotoxicity, fetal damage and fatal poisoning