UNEP Environmental Assessment of Ogoniland

Executive Summary


Covering around 1,000 km2 in Rivers State, southern Nigeria. Ogoniland has been the site of oil industry operations since the late 1950s. Ogoniland has a tragic history of pollution from oil spills and oil well fires, although no systematic scientific information has been available about the ensuring contamination.

With this independent study, conducted at the request of the Federal Government of Nigeria, the United Nations Environment Programme (UNEP) reveals the nature and extent of oil contamination in Ogoniland.

The Environmental Assessment of Ogoniland covers contaminated land, groundwater, surface water, sediment, vegetation, air pollution, public health, industry practices and institutional issues.

This report represents the best available understanding of what has happened implications for affected populations – and provides clear operational guidance as to how legacy can be addressed.

Assessment process

Involving desk review, fieldwork and laboratory analysis, the two year study of the environmental and public health impacts of oil contamination in Ogoniland is one of the most complex on-the ground assessments ever undertaken by UNEP.

UNEP recruited a team of international experts in disciplines such as contaminated land, water, forestry and public health, who worked under the guidance of senior UNEP managers. This team worked side-by-side with local experts, academics and support teams comprised of logistics, community liaison and security staff.

The UNEP project team surveyed 132 kms of pipeline rights of way and visited all oil spill sites, oil wells and other oil related facilities in Ogoniland, including decommissioned and abandoned facilities, that were known and accessible to UNEP during the fieldwork period, based on information provided by the Government regulations, Shell Petroleum Development Company (Nigeria) Ltd (SPDC) and community members in and around Ogoniland.

During aerial reconnaissance missions, UNEP experts observed oil pollution which was not readily visible from the ground, including artissanal refining sites. Information provided by Ogoniland residents about oil contamination in their communities supplemented official oil spill data supplied by the Nigerian Government and SPDC.

Following its initial investigations, UNEP identified 69 sites for derailed soil and groundwater investigations. In addition, samples of community drinking water sediments from creeds surface water, rainwater, fish and air were collected throughout Ogoniland and in several neighbouring areas. Altogether more than 4,000 samples were analyzed including water drawn from 142 groundwater monitor4ing we4lls drilled specifically for the study and soil extracted from 780 boreholes. The UNEP project team also examined more than 5,000 medial records and stated 264 formal community meetings in Ogoniland attended by over 23,000 people.

The samples were collected following internationally accepted sample management procedures and dispatched for analysis to accredited (ISO 17025) laboratories in Europe. The analyses examined in the study included certain groups of hydrocarbons that are known to have adverse impacts and which are therefore dealt with selectively in oil spill assessment and clean up work. The most importance of these are BTEX (benzene, toluene ethyllbenzene and xylened and PAHs (polycyclic aromatic hydrocarbons) Volatile organic compounds (VOCs) were the main target of UNEP’s air quality investigations.

Extensive remote sensing analyses complemented the fieldwork. Review of legislation institutions, oil industry practices and invaluable remediation technologies were also undertaken by international experts to complete the study.

A selection of the study’s key findings and recommendations are summarized below. Given the vast amount of data generated during the assessment, the following content should not be considered in isolation

Summary of findings

UNEP’s field observations and scientific investigations found that oil contamination in Ogoniland is widespread and severely impacting many component of the environmental. Even though the oil industry is no longer active in Ogoniland, oil spills continue to occur with alarming regularity. The Ogoni people live with this pollution every day.

An Ogoniland has high rainfall, any delay in clearing up an oil spill leads to oil being washed away, traversing farmland and almost always ending up into the creeks. When oil reaches the root zone, crops and other plans begin to experience stress and can die, and this is a routine observation in Ogoniland. At one site, Ejama-Ebubu, in Eleme local government area (LGA), the study found heavy contamination present 40 years after an oil spill occurred, despite repeated clean-up attempts.

The assessment found that overlapping authorities and responsibilities between ministries and a lack of resources within key agencies has serious implication for environmental management on the ground, including enforcement.

Remote sensing revealed the rapid proliferation in the past two years of artisanal refining, whereby crude oil is distilled in makeshift facilities. The study found that this illegal activity is endangering lives and causing pockets of environmental devastation in Ogoniland and neighbouring areas.

Contaminated soil and groundwater

* The report concludes that pollution of oil by petroleum hydrocarbon in Ogoniland is extensively in land areas, sediments and swampland. Most of the contamination is from crude oil although contamination by refined product was found at three locations.

* The assessment found there is no continuous day layer across Ogoniland exposing the groundwater in Ogoniland (and beyond) to hydrocarbons spilled on the surface. In 49 cases, UNEP observed hydrocarbons in soil in depths of at least 5in. This finding has major implications for the type of remediation required.

* At two-thirds of the contaminated land sites close to oil industry facilities which were assessed in detail, the soil contamination exceeds Nigerian national standards, as set out in the Environmental Guidelines and Standards for the Petroleum Industries in Nigeria (EGASPIN).

* At 41 sites, the hydrocarbon pollution has reached the groundwater at levels in excess of the Nigerian standards as per the EGASPIN legislation.

* The most serious case of groundwater contamination is at Nissioken Ogale in Eleme LGA, close to a Nigerian National Petroleum Company product pipeline where an 8 cm layer of refined oil was observed floating on the groundwater which serves the community wells.


* Oil pollution in many intended creeks has left mangroves denuded of leaves and stems, leaving roots coated in a bitumen-like substance  sometimes 1 cm or more thick. Mangroves are spanning areas for fish and nurseries for juvenile fish and the extensive pollution of these areas is impacting the fish life-cycle.

* Any crops in areas directly impacted by oil spills will be damaged and root crops, such as cassava, will become unusable. When farming recommences, plants generally show signs of stress and yields are reportedly lower than in non-impacted areas.

* When an oil spill occurs on land, fires often break out, killing vegetation and creating a crust over the land, making remediation or revegetation difficult.

* Channels that have been widened and the resulting dredged material are clearly evident in satellite imagoes, decades after the dredging operation. Without, proper rehabilitation, former mangrove areas which have been converted to bare ground are being colonized by invasive species such as nipa palm (which appears to be more resistant  to heavy hydrocarbon pollution than native vegetation).

* In Bodo West, in Bonny LGA, an increase in artisanal refining between 2007 and 2011 has been accompanied by a 10% loss of healthy mangrove cover or 307,381 on2. If left unchecked, this may lead to irreversible loss of mangrove habitat in this area.


* The UNEP investigation found that the surface water throughout the creeks contains hydrocarbons. Floating layers of oil vary from thick black oil to this sheers. The highest reading of dissolved hydrocarbon in the water column, of 7,420 pg/l, was detected at Ataba-Otokroma, bordering the Gokana and Andoni LGAs.

* Fish tend to leave pullulated areas in search of cleaner water, and fishermen must therefore also move to less contaminated areas in search of fish. When encountered in known polluted areas, fishermen reported that they were going to fishing grounds further upstream or downstream.

* Despite community concerns about the quality of fish, the results show that the accumulation of hydrocarbon in fish is not a serious health issue in Ogoniland but that the fisheries sector is suffering due to the destruction of fish habitat in the mangroves and highly persistent contamination of any of the creeks, making them unsuitable for fishing.

* Where a number of entrepreneurs had set up fish farms in or close tot he creeks, their businesses have been ruined by an ever- present layer of floating oil.

* The wetlands around, Ogoniland area highly degraded and facing disintegration. The study concludes that while it is technically feasible to restore effective ecosystem functioning of the wetlands, this will only be possible if technical and political initiatives are undertaken.

Public health

* The Ogoni community is exposed to production hydrocarbons in outdoor air and drinking water, sometimes at elevated concentrations. They are also exposed through dermal contacts from contaminated soil, sediments and surface water.

* Since average life expectancy in Nigeria is less than 50 years, it is a fair assumption that most members of the current Ogoniland community have lived with chronic oil pollution throughout their lives.

* Of most immediate concern, community members at Nisisioken Ogale are drinking water from wells that is contaminated with benzene, a known carcinogen, at levels over 900 times above the World Health Organisation (WHO) guideline. The report states that this contamination warrants emergency action ahead of all other remediation efforts.

* Hydrocarbon contamination was found in water taken from 28 wells at 10 communities adjacent to contaminated sites. At seven wells the samples are at least 1,000 times higher than the Nigerian drinking water standard of 3 ug/l. Local communities are aware of the pollution and its dangers but state that they continue to use the water for drinking, bathing, washing and cooking as they have no alternative.

* Benzene was detected in all air samples at concentrations ranging from 0.155 to 48.2 up/m5. Approximately 10 per cent of detected benzene concentration in Ogoniland were higher than he concentrations WHO and the United States Environmental Protection Agency (USEPA) report as corresponding to a 1 in 10,000 cancer risk. Many of the benzene concentrations detected in Ogoniland were similar to those measured elsewhere in the world, given the prevalence of fuel use and other sources of benzene. However, the findings shows that  some benzene concentrations in Ogoniland were higher than those being measured in more economically developed regions where benzene concentration are declining because of efforts to reduce benzene exposure.

Institutional issues

* First issued in 1992, the EGASPIN form the operational basis for environmental regulation of the oil industry in Nigeria. However, this key legislation is internally inconsistent with regard to one of the most important criteria for oil spill and contaminated site management – specifically the criteria which triggered remediation or indicate its closure (called the intervention and target values respectively).

* The study found that the Department of Petroleum Resources (DPR) and the National Oil Spill Detection and Response Agency (NOSDRA) have differing interpretations of EGASPIN. This is enabling the oil industry to close down the remediation process well before contamination has been eliminated and soil quality has been reasoned to achieve functionality for human  animal and plant life.

* The Nigerian Government agencies concerned lack qualified technical experts and resources. In the five years since NOSDRA was established, so few resources have been allocated that the agency has to proactive capacity for oil-spill detection. In planning their inspection visits to some oil spill sites, the regulatory authority is wholly reliant on the oil industry for logical support.

* The oilfield in Ogoniland is interwoven with the Ogoni community. The fact that communities have set up houses and farms along rights of way is one indicator of the loss of control the part of the pipeline operator and the government legislator.

* The UNEP project team observed hundreds of industrial packing bags containing 1,000, 1,500 m3 of waste, believed to be cuttings from oil drilling operations, dumped at a former sand mine in Oken Oyaa in Eleme LGA. The open disposal of such waste in an unlined pit demonstrates that the chain of custody in the region between the water generator, transporter and disposal facility is not being followed.

Oil Industry practices

The study concludes that the control, maintenance and decommissioning of oilfield infrastructure in Ogoniland are inadequate. Industry best practices and SPDC’s own procedures have not been applied, creating public safety issues.

* Remediation by enhanced natural attenuation (RENA) – so far the only remediation method observed by UNEP in Ogoniland – has not proven to be effective. Currently, SPDC applies this technique on the land surface layer only based on the assumption that given the nature of the oil, temperature and an underlying layer of clay, hydrocarbons will not move deeper. However, this basic premise is not sustainable as observations made by UNEP show that contamination can often generates deeper than 5m and has reached the groundwater in many locations.

* Ten out of the 15 investigated sites which SPDC records show as having completed remediation, still have pollution exceeding the SPDC (and government) remediation closure values. The study found that the contamination at eight of these sites has migrated to the groundwater.

* In January 2010, a new Remediation Management System was adopted by all Shell Explorations and Production Companies in Nigeria. The study found that while the new changes are an improvement, they still do not meet the local regulatory requirement or international best practices.

Summary of recommendations

The study concludes that the environmental resto4ration of Ogoniland is possible but may take 25 to 30 years. The report contains numerous recommendations that, once implemented will have an immediate and positive impact on Ogoniland. Further recommendations have longer time lines that will bring lasting improvements for Ogoniland and Nigeria as a whole.

The hydraulic connecting between contaminated land and creeks has important implication for the sequence of remediation to be carried out. Until the land-based contamination has been dealt with, it will be futile to begin to clean up of the creeks.

Due to the wide extent of contamination in Ogoniland and nearby areas, and the varying degrees of degradation, there will not be one single clean-up technique appropriate for the entire area. A combination of approaches will therefore need to be considered, ranging from active intervention for cleaning the top soil and replanting mangrove to passive monitoring of natural regeneration. Practical action at the regulatory operational and monitoring levels is also proposed.

It is recommended that the restoration of mangroves be viewed as a large-scale pilot project in which multiple approaches to clean-up and restoration, once prove, can be replicated elsewhere as needed in the Niger Delta.


Emergency measures

The report identifies eight emergency measures which, from a duty of care point of view, warrant immediate action.

1. Ensure that all drinking water wells where hydrocarbons were detected are marked and that people are informed of the danger.

2. Provide adequate sources of drinking water to those households whose drinking water supply is impacted.

3. People in Nissioken Ogale who have been consuming water with benzene over 900 times the WHO guideline are recorded on a medical registry and their health status assessed and followed up.

4. Initiate a survey of all drinking water wells around those wells where hydrocarbons were observed and arrange measures (1-3) as appropriate based on the results.

5. Post signs around all the state identified as having contamination exceeding intervention values warning the communi9ty not to walk through or engage in any other activities at these sites.

6. Post signs in areas where hydrocarbons were observed on surface water warning people not to fish, swim or berth in these areas.

7. Inform all families whose main water samples tested possible for hydrocarbons and advise them not to consume the water and

8. Mount a public awareness campaign to warn the individuals who are undertaking artisanal refining that such activities are damaging their health.


* To begin prioritising specific locations to be cleaned up, restored or rehabilitated, the report suggests the following framework:

– Priority 1, All instances where the Ogoni community is known to be at risk.

– Priority 2. Instances where contamination could potentially affect te community (e.g where groundwater, fishing grounds or agricultural land are impacted)

– Priority 3. Instances where a community’s livelihood support base is impacted, and

– Priority 4. Instances where there is no immediate risk to people but where there is non-compliance with the law.

Operational recommendations

* Immediate steps must be taken to prevent existing contaminated sites from being secondary sources of ongoing contamination while further risk assessment and investigation are undertaken for detailed planning of the clean-up of Ogoniland during a recommended Transition Phase.

* All sources of ongoing contamination, including the artisanal refining which is currently ongoing in the creeks, must be brought to a swift end before the clean-up of the creeks, sediments and mangroves can begin.

* A campaign in Ogoniland to end illegal oil-related activities should be jointly conducted by the government, oil companies and local authorities. It should include an awareness component highlighting the disproportionate environmental footprint of artisanal refining (borne by all sections of the community) and spell out training, employment and livelihood incentives that will encourage people away from participating in this illegal activity.

Technical recommendations for environmental restoration

* Surface water. Clean-up activities of the mangroves and soil should not be initiated before all possible measures are taken to stop ongoing pollution from reaching the creeks.

Restoration of swamplands. The most extensive area in terms of treatment of contamination will be the topsoil from the swamplands. The two main options are manual cleaning of contaminated topsoil and low-pressure water jetting. A portable facility which can be fixed on a barge, move through the bigger creeks and act as a base for decontamination crews, should be considered.

A proposed Integrated Contaminated Soil Management Centre will be a modern industrial enterprise in Ogoniland employing hundreds of people. On-site mini treatment centres’ for bioremediation and excavation water will also act as staging areas feeding the main soil treatment ensure.

* Treatment of contaminated sediments. Decisions on intervention for sediment treatment are more complicated than simply basing them on an intervention value. Issues of erosion, vegetation damage and impact on local aquatic ecosystems as well as potential for natural recovery all need to be part of the decision-making process. In some cases, contaminated sediments will have to be dredged as part of the clean-up or they will act as reservoirs of pollution after the ongoing pollution has been eliminated.

Decontamination of groundwater. The issue of hydrocarbon contamination needs to be addressed in a comprehensive manner, but clean-up actions must be site-specific. In making decisions about the clean-up of groundwater, addition factors such as proximity to the community  absorption characteristics of the soil and all possible pathway must be considered and this will require additional data to be gathered as part of the detailed clean-up planning process.

* Mangrove restoration. Local nurseries should be established so that healthy, indigenous plants will be available to vegetate heavily impacted mangrove stands. Rehabilitation will focus on red mangroves along the waterfront and on white mangroves inland – which have been most severely impacted – and also on containing the spread of invasive species.

Recommendation for public health

* Everyone who has consumed water from contaminated sources should be requested to undertake a comprehensive medical examination by physicians knowledgeable about the possible adverse health effects of the hydrocarbons detected.

* A focused medical study should be initiated to track the health of the Ogoni community over their lifetimes to ensure any possible health impacts are identified early enough and acted upon.

Summary of UNEPS Recommendations for Monitoring

Monitoring                                               Monitoring approach                                                        Frequency

Prevention Surveillance                  Aerial scouting                                                                     Weekly

                                                                    Surveillance from boats                                                      Weekly

                                                             Surveillance of facilities & incidents sites                       Weekly

Groundwater                                    House visits in impacted communities                          One-off

                                                             Wells around impacted sites & facilities                          Monthly

Water Bodies                                              Surface water                                                                    Monthly

                                                                           Sediments                                                                          Quarterly

                                                                            Fish                                                                                       Quarterly

                                                             Benthic organism                                                                        Quarterly

Vegetation                                    Transects in creeks & oil field sites                                     Once a year

                                                            Mangrove Fauna                                                                            Once a year

                                                            Analyses of satellite imagery                                                Once a year

Air quality                                   Particulate measurement, hydrocarbons                            Monthly

Public health                              Cohort registry of highly exposed communities                 Yearly

                                                           Public health registry of entire Ogoniland community     Yearly                                  


Recommendations on monitoring

* During and following clean-up operations in Ogoniland, a monitoring programme should be put in place in consultation with the national institutions mandated to deal with specific environmental issues. All monitoring activities should be communicated to the community and all results should be publicly available.

* Comprehensive air quality monitoring across Ogoniland should be initiated to detect ongoing pollution, to help establish guidelines for processing public health and to track improvements at sites where clean-up activities are under way.

* A public health registry should be established for the entire Ogoniland population in order to determine health trends and take proactive action individually or collectively where impacts related to long term exposure to hydrocarbon pollution are evident.

Recommendations for changes to regulatory framework

* Transfer oversight of the EGANPIN legislation from DPR to the Federal Ministry of Environment, with the concurrent transfer of staff or by recruiting and training new staff.

* Comprehensively review existing Nigerian legislation on contaminated site clean-up considering recent international development in regulation and incorporating community consideration to determine remediation closure levels so that decisions on new legislation are seen as both transparent and inclusive.

Recommendations for Government

* The report recommended that the Government of Nigeria establishes an Ogoniland Environmental Restoration Authority to oversee implementation of this study’s recommendations. With a fixed initial lifespan of 10 years, the Authority will have a separate budget which will accrue from an Ogoniland environmental Restoration Fund and its staff will largely be seconded from relevant national and state institutions.

* The overall cost of the clean-up should not be an obstacle to its implementation. Therefore, an Environmental Restoration Fund for Ogoniland should be set up with an initial capital injection of USD 1 billion contributed by the oil industry and the Government. To be managed by the Authority, the Fund should be used only for activities concerning the environmental restoration of Ogoniland, including capacity building, skills transfer and conflict resolution.

* A Centre of Excellence for Environmental Restoration should be established in Ogoniland to promote learning in other areas impacted by oil contamination, in the Niger Delta and elsewhere in the world. Offering a range of activities and services, the Centre could run training courses in environmental monitoring and restoration and ultimately become a model for environmental restoration attracting international attention.

* Build the capacity of government agencies to enable them to fulfil their mandates through such actions as increasing human resources and equipment, and improving the technical skills of staff.

* A public awareness campaign should be mounted to improve the community’s understanding of the environmental and health impacts arising from hydrocarbon contamination in Ogoniland. This should include a formal education component in the academic curricula in the Niger Delta.

Recommendations for oil industry operators

* SPDC procedures for oil spill clean-up and remediation need to be fully reviewed and overhauled so as to achieve the desired level of environmental restoration. In addition to procedures and clean-up methods, contracting and supervision also need to be improved.

* SPDC should conduct a comprehensive review of its assents in Ogoniland and develop an `Asset Integrity Management Plan for Ogoniland and a decommissioning plan. These plans should be communicated to the Ogoni people.

* It is recommended that SPDC works with the Nigerian regulators to clarify the paradox of remedial intervention and target values being the same. The parties should also agree on a consultative approach to setting site-specific clean-up values.

* In the event that a decision is made to restart oil exploration and production activities in Ogoniland, the region should be treated as a green-field site of high environmental and social sensitivity. This would mean applying the latest technologies and environmental guidelines, such as re-evaluating pipeline routes to minimise environmental damage and allocating a percentage of all project costs for environmental and sustainable development initiatives in Ogoniland.

Recommendations for the Ogoniland community

* The Ogoni community should make full advantages of the employment, skills development and other opportunities that will be created by the clean-up operation which is aimed at improving their living CONDITIONS and livelihoods.

* Community members should avoid protracted negotiations over access by oil spill response teams as this means that responses to spills are delayed resulting in a far greater environmental impact.

* The community should take a proactive stand against individuals or groups who engage in illegal activities such as bunkering and artisanal refining.

The way forward

Restoring the livelihoods and well being of future Ogoni generations is within reach but timing is crucial. Given the dynamic nature of oil pollution and the extent of communication revealed in UNEP’s study failure to begin addressing urgent public health concerns and commencing a clean-up will only exacerbate and unnecessarily prolong the Ogoni people’s suffering.

A Transition Phase is recommended to maintain momentum and begin detailed planning in the intervening period between the release of UNEP’s environmental assessment and the commencement of a clean-up operation guided by an Ogoniland Environmental Restoration Authority.

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