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Assessment Methodology

Environmental Assessments – An Introduction
An environmental assessment consists of a set of investigative technical procedures conducted in a specific area to identify, evaluate and mitigate the biophysical, social and other relevant impacts of a given event or project on the environment, with a view to ensuring that such considerations be integrated into policy and decision-making in the region.
The process comprises four main phases:
Phase 1: Reconnaissance
Phase 2: Sampling
Phase 3: Laboratory analysis
Phase 4: Reporting
The first stage of an environmental assessment is a desk study phase including a survey of the region by satellite imagery, a review of the findings of previous reports and the collation of local anecdotal information. This is followed by a period of field observation and a preliminary evaluation of potential environmental impacts.
UNEP experts and local recruits will survey the Ogoniland sites for obvious signs of oil impacts. This data will be collated onto Site Assessment Forms. Experts will also use the process to familiarize themselves with the region’s geographical and ecological features, as well as the local infrastructure.
Once all the sites have been assessed and screened, sites requiring immediate or further investigation will be prioritized.
Based on the data collected in the reconnaissance field surveys, experts will install monitoring equipment and collect soil and water samples from selected sites in the field.
Highly technical equipment as well as basic hand-held devices will be used to collect the samples. Training will be provided to local people to assist in the sampling exercise, to enhance local capacity and to promote skills transfer.
The field observations and readings from the monitoring equipment will give a preliminary indication of the amount of oil present in specific areas. However, the samples will need to be chemically analysed in laboratories for scientific verification.
Laboratory analysis
This third phase is conducted by an independent internationally-accredited laboratory, to ensure unbiased scientific analysis.
Samples recovered by the UNEP teams will be individually labeled with a unique reference number that includes the exact geographic coordinates of the location from where each was taken. This number will stay with the samples throughout the laboratory analysis phase, allowing for cross-referencing.
UNEP experts will ship the samples to the laboratory on a regular basis. Sample integrity will be maintained by using containers provided by the laboratory and standard refrigeration processes throughout their transportation.
Each sample will be analysed for a range of contaminants, such as hydrocarbons, phenols and heavy metals.
The analysis of air samples will focus on pollutants associated with gas flaring, as well as those related to oil spills.
The results of the environmental assessment will be collated and published in a comprehensive report.
The report will present the findings of the different technical teams and offer recommendations for remediation. A series of 3D maps and satellite imagery will form a visual picture of the scope and depth of the oil contamination in a given area.
Once the report has been released, it will be made available to the public in print and online.
This important document will serve as a key vehicle for stakeholder discussions on how to proceed with remediation and activities for sustainable development.
UNEP experts from across the globe will form specialist teams to carry out the site reconnaissance and sampling for the environmental assessment.

Specialist teams will focus on the following technical sectors:

Contaminated land: Experts will collect samples of soil, as well as ground and surface water at varying depths and strategic locations in the landscape. Once the samples have been chemically analysed to determine the presence, extent and nature of the oil pollution, the contaminated land team will make recommendations on how to rehabilitate the land to a condition that is environmentally acceptable, according to international standards.


Fisheries: Samples of soil, river sediment, and ground and surface water will be collected at varying depths from strategic areas across the region. These samples, as well as fish stocks will be assessed for damage resulting from exposure to oil. The fisheries experts will then make recommendations for future action needed.


Public health: A system of air monitoring will be established using specialized equipment installed at strategic locations in the field.

This equipment will measure the level of gases and organic compounds in the air, in order to determine ambient air quality.
The team experts will use the results from the monitoring equipment to predict any possible effects of oilfield fires on public health.

Biodiversity: Agriculture, indigenous plant and animal species, and local ecosystems will be studied to determine potential adverse changes in productivity or wildlife due to oilfield infrastructure and activities.

Recommendations will be made by the biodiversity team experts to minimize impacts on local ecosystems, and encourage native species to thrive.