The extraction of oil and gas is typically undertaken in isolated areas that are sparsely populated or entirely unpopulated, or from platforms out at sea where impacts relate primarily to the environment and marine ecosystems. However, in countries such as Nigeria and Colombia the extraction of oil takes place in more populated areas and has severe negative effects on public health and safety, the environment and access to clean water.
Oil and gas is usually transported long distances over land via pipelines. The positioning of pipelines is frequently controversial due to their considerable environmental impact, and their effects on indigenous populations and animals. Pipelines often require careful maintenance to minimise the risk of leaks to avert severe environmental damage. By piercing holes in pipelines, it is possible to steal the oil inside. Such sabotage is common and frequently causes spills.