Atlas of Contaminated Sites

Notable case, Bori, Rivers State, Nigeria

Ogoniland (Niger Delta)

A territory of about 1,000 km² in the Niger Delta, the site of oil production since the late 1950s, contaminated by decades of spills and well fires. UNEP's 2011 assessment is the reference study of oil pollution in an inhabited area.

Microbial bioremediation

Status
Remediation under way
Area
100,000 ha on land1
Activity
since 1958
Media
soil, groundwater, surface water, sediment, air, living organisms
Kind of site
oil
  1. Area. About 1,000 km²: the extent of Ogoniland as a whole according to UNEP (2011), not the contaminated area. UNEP investigated 69 sites in detail.

Contaminants

Organic compounds

Status

Remediation under way

The HYPREP-led clean-up is under way: field work began in January 2019 (Wikipedia). HYPREP's website, read in 2026, lists 65 sites for remediation, 34 shoreline clean-up contractors in five Gokana communities and 2.5 million mangrove seedlings. In 2011 UNEP estimated 25–30 years for restoration.

Story

Shell found oil in Ogoniland in 1956 and production began in 1958. Pipelines, wells and flow stations were built among villages, farmland and mangrove creeks. From 1990 the Movement for the Survival of the Ogoni People (MOSOP) protested against the environmental damage; its spokesman Ken Saro-Wiwa was executed in 1995. Spills went on afterwards, from infrastructure that was never decommissioned and from artisanal refining: for the two Bodo spills of 2008 Shell agreed in 2015 to pay 80 million dollars.

At the request of the Nigerian government, UNEP studied the area for 14 months: more than 200 locations examined, 122 km of pipeline rights of way, 69 sites investigated in detail, more than 4,000 samples, 142 monitoring wells. The 2011 report found hydrocarbons in soil at depths of at least 5 m in 49 cases and in groundwater above Nigerian standards at 41 sites. At Nisisioken Ogale an 8 cm layer of refined product floated on the groundwater feeding the wells, and the water people drank contained benzene at over 900 times the WHO guideline. In the creeks the mangroves were stripped of leaves, their roots coated in a bitumen-like substance.

UNEP recommended a restoration fund with an initial one billion dollars. HYPREP was set up in 2012; the programme was relaunched in 2017 and work started in 2019.

Timeline

  1. 1956Shell discovers a commercially viable oil field in Ogoniland.
  2. 1958Oil production begins.
  3. 1990MOSOP presents the Ogoni Bill of Rights.
  4. 1995Ken Saro-Wiwa and other MOSOP leaders are executed.
  5. 2008Two oil spills at Bodo.
  6. 2011UNEP publishes its Environmental Assessment of Ogoniland.
  7. 2012HYPREP is established.
  8. 2019January: engineers arrive and clean-up work begins.

Health

UNEP (2011) concluded that people are exposed to hydrocarbons in outdoor air and drinking water. Benzene was detected in all air samples (0.155–48.2 µg/m³); about 10% of the values exceeded the concentration that WHO and USEPA associate with a 1 in 10,000 cancer risk. Accumulation of hydrocarbons in fish was not found to be a serious health issue.

Remediation

  1. 2019soil remediationRemediation of the sites listed by UNEP, divided by HYPREP into complex sites (soil and groundwater) and medium-risk sites (mainly soil). The techniques are not described on the page read.
  2. 2023shoreline clean-up and mangrove replantingShoreline clean-up at B-Dere, K-Dere, Kpor, Goi and Bomu and replanting of red, black and white mangroves; 90 local workers trained in September 2023, 2.5 million seedlings according to HYPREP.

Plants and fungi at this site

Microbial bioremediationField scale

Remediation by enhanced natural attenuation (RENA): contaminated topsoil is worked in place to encourage soil micro-organisms to break down the hydrocarbons. It was the method Shell (SPDC) applied at Ogoniland sites and the only one UNEP saw in use.

Outcome Judged ineffective by UNEP (2011): it was applied to the surface layer only, while contamination often went deeper than 5 m and reached the groundwater. At 10 of the 15 sites SPDC recorded as remediated, pollution still exceeded closure values; at eight it had reached the groundwater.

From the literature

Species that acted on one of this site's contaminants in at least one study. The list is automatic and takes no account of this site's soil, concentrations or climate.

Plants

Fungi

The rest are on the contaminant pages.

Sources

  1. Environmental Assessment of Ogoniland (full report, copy hosted by HYPREP), UNEP, 2011
  2. Remediation, HYPREP, Federal Ministry of Environment, Nigeria
  3. Ogoniland, Wikipedia, 2026
  4. Environmental issues in the Niger Delta, Wikipedia, 2026

Draft compiled from public sources, not yet reviewed.