The fossil fuel company Shell must be held accountable for significant and systematic pollution caused by oil extraction in the Niger delta, lawyers will argue in the supreme court. Nigerians from the Ogale and Bille communities say they have suffered decades of pollution, including the contamination of their water wells with potentially cancer-causing chemicals, as well as the devastation of mangrove vegetation, all of which was documented by the UN in a groundbreaking report in 2011. The United Nations environment programme (UNEP) said in its report it could take 30 years to clean up the pollution caused by oil extraction and recommended an initial fund of $1bn (£800m) for the first five years to be paid by the oil companies that operate in Ogoniland – including the largest company, Shell. The law firm Leigh Day, which represents the communities, has taken the appeal process to the UK supreme court to argue that Shell, one of the world’s 10 largest corporations by revenue, with assets of more than $400bn, must answer for the environmental failures of its subsidiary Shell Petroleum Development Company of Nigeria (SPDC) because the company is registered in London. The high court ruled in January 2017 that Shell was not responsible for the harm because it was merely a holding company that did not exercise any control over SPDC. A report this month by Friends of the Earth, Amnesty International and other NGOs said the people of Ogoniland were still waiting for a thorough clean-up of the oil spills. The report said only a fraction – 11% – of the total area contaminated was being cleaned up, and even in the area targeted the work had not been completed. The report said: “In order to address its devastating legacy of pollution in Nigeria, Shell should also pay for clean-up of the rest of the Niger delta and compensate communities affected by its activities. “The tragic and unresolved situation in Ogoniland demonstrates the urgency for governments – including those of the UK and the Netherlands where Shell is headquartered – to issue strong legislation mandating companies to respect human rights and environmental standards across their global operations.” King Okpabi, the ruler of the Ogale community, said: “The Ogale community is praying for success in the supreme court. We have always been adamant that the only hope for the people of Ogale to get justice for decades of pollution visited upon us by the acts of Royal Dutch Shell is through the courts of the United Kingdom.” Due to the coronavirus pandemic, members of the community are not able to be present to observe the case. Lawyers will tell the supreme court the communities have brought the claims in respect of severe and ongoing harm against RDS and its Nigerian subsidiary SPDC – a company that “was and continues to be the single most dominant of the independent oil companies who have exploited the oil resources of Nigeria”. Richard Hermer QC, representing the communities, told the court on Tuesday: “These are multiple spills over a number of years causing devastating damage to land and water wells … Systematic failures either to stop devastating oil spills or remedy their profound impact.” Hermer said the damage to mangrove fields covered 13,000 hectares, more than twice the area of Manhattan. According to Shell’s own records, the community has been affected by at least 40 oil spills from its pipelines and equipment since 1989, including 23 spills in the past four years. Shell said: “We share the same goal as all Shell-operated ventures globally, of operating safely without harm to people and protecting the local environment. Both Bille and Ogale are areas heavily impacted by crude oil theft, pipeline sabotage and illegal refining, which remain the main sources of pollution across the Niger Delta. “Litigation in courts unfamiliar with the realities on the ground – and Nigerian law – does not address the issue of criminal interference in the operations of Nigerian companies. Nigeria has a well-developed justice system that is capable of dealing with these claims. We maintain the court of appeal in London rightly decided this case should not proceed in the English courts.” Shell disputed the findings of the UNEP report. The company said: “This report fails to recognise that the majority of UNEP recommendations need multi-stakeholder efforts coordinated by the federal government of Nigeria and that SPDC has acted on all recommendations specifically directed to it in the UNEP report – and completed most of them.”