Evaluating interdiction of oil pipelines at river crossings using environmental impact assessments

The deliberate damaging of oil pipelines (interdiction) is a key problem in the global petroleum industry and tends to have a strong spatial identity. It also has local, national and international implications for energy security and susceptible environmental receptors. This paper specifically focuses on Nigeria, a country often affected by complex environmental problems associated with oil and gas activities. Partly because Environmental Impact Assessment (EIA) in Nigeria was only promulgated in 1992, there has been no specific study of pipeline interdiction and how it could be better addressed in future EIAs, especially at river crossings where oil pollution is usually significant. Therefore through a careful collation of data from different sources, this paper for the first time aims to: (1) evaluate how pipeline interdiction has been addressed in sampled EIAs; (2) assess interdiction trend per unit of pipeline length over a 16-year period; (3) identify points on pipeline river crossings that are especially sensitive to oil spills. A linearly-weighted equation was used to estimate interdiction per 1000 pipeline kilometres per year. River network and pipeline shapefiles were geoprocessed in ArcGIS 9.2 to identify river crossing locations and the spatiotemporal trend of interdiction was plotted. Key findings include: (a) high interdiction rates per 1000 pipeline kilometres ranging from 1.4 to 735 per year; (b) at least 115 pipeline river crossing locations exist in Nigeria and constitute potential oil-spill hazards; (c) these hitherto unavailable pipeline river crossing data unsurprisingly show the majority of such locations are within southern Nigeria. These results should guide future oilfield developments, including oil production and transportation facility projects, through efficient scoping and mitigation strategies. We argue that there is a need for systematic requirements to effectively address the anticipation/mitigation of future pipeline impacts in EIAs to better support oil spill contingency planning and reduce environmental problems.