Industry news

Environment: The Tilenga project design features to help mitigate impacts

Day 27 #90daysofoil

TotalEnergies, the operator of Tilenga oil and gas project shall employ an embedded mitigation, a system that incorporates physical design features and management measures to protect the environment during production.

The embedded mitigation is based on International Industry Practice (GIIP) which is intended to avoid, or control potentially significant environmental impacts.

“As part of the on-going project design process, measures to avoid or minimize impacts have been identified and incorporated within the pre-project and Front End Engineering and Design phases,” reads the Environment Social Impact Assessment (ESIA) for the Tilenga project.  

Although the project area covers 110,000 hectares, environmental foot print is expected to be felt only in 1.1% (1,112 hectares) of the total area. The Tilenga project area covers Murchison Falls National Park (MFNP), Albert Delta Wetland System, and Ramsar site along the Victoria River Nile. This is also an important bird area, known to support rare and endangered bird species.

MFNP is the largest and second most visited national park in Uganda. It is adjacent to: Karuma Wildlife Reserve, Bugungu Forest Reserves. The two form the Murchison Fall Protection Area. 

Yet there is justification to exploit other endowments found beneath surface endowment of this sensitive biodiversity area. In 2006, a commercial volume of oil and gas currently at 6.5billion barrels of oil was discovered in the Albertine Graben, western Uganda. 1.4billion is recoverable. In addition there are 160billion cubic meters of gas resources. 

The discovery would be a game changer – government understood that commercializing the products would help reduce import bills on petroleum products, create jobs for Ugandans, expand revenue base for the national treasury and create lasting value chain for the entire economy. 

Importantly, government plans to exploit finite resources while protecting the infinite surface resources. That is why experts did detailed Environmental and Social Impact Assessment (ESIA) for Tilenga project. The produced ESIA report meets Environment Impact Assessment Regulations 1998 and requirements by the International Finance Corporation Performance Standards 2012.

The ESIA is expected to guide operations in a manner that damage to the environment will be avoided where necessary, or mitigated and restored to create a win-win situation.   

The ESIAs shows that the oil production activities will impact on the terrestrial biodiversity, aquatic life, landscape, wildlife habitat and ecosystems integrity, noise and air pollution, generation of hazardous wastes, impacts on ground water quantity and contamination of ground water by waste water releases, contamination of surface water bodies and impacts on community health, safety and security.     

Tilenga ESIA public hearing

In 2020, National Environment Management Authority (NEMA) held public hearings for the Tilenga project, where concerns raised by the public were considered. “This study establishes that the majority of CSOs recommendations were adopted and incorporated in the approved ESIAs, Certificates of Approval CoA) and pieces of environmental legislations,” reads a Coalition of Civil Society on Oil and Gas report prepared after the public hearings. 

The safeguards

A network of pipelines will collect the oil produced from each well pad and transported to the CPF located within the Industrial Area planned at Ngwedo sub-county, Buliisa District. The processed crude will then be transported via an export pipeline through Tilenga feeder pipelines. 

“Pipelines will be trenched and buried to allow safe passage of wildlife. To avoid harm to humans and wildlife, the pipelines will be coated which also protects it from corrosion. Bridges for humans and animals will be considered,” reads the report

Pipe laying and Backfill will be done immediately to minimize exposure of open trenches to wildlife and humans.  

Meanwhile, produced water will be mixed with de-oxygenated water from Lake Albert prior to reinjection back into the oil reservoir. There will be no discharge of produced water into the environment. The sludge produced will be treated before disposal. 

During production phase surface water will be managed and discharged to the environment through a sustainable drainage system approach. It will deliver most benefits for water quality, quantity and amenity biodiversity as it replicates natural drainage before development. This system takes into account seasonal variations in localized hydrology, wildlife sensitivity.

The CPF will include a flare stack which is a key safety feature that will only be used to depressurize the plant for emergency, process upsets and maintenance. There will be no routine flaring at CPF and any flaring shall not exceed 48 hours per event according to the ESIA report. 

“The design of the project has been developed with the impact mitigation hierarchy where the preference is avoidance of negative impacts where practicable, followed by minimization and as last resort, compensation,” TotalEnergies stated in its ESIA report.

The NEMA Act 2019 mandates the polluter to meet the environmental restoration costs. 

The company has also avoided any construction of well pads in the Ramsar sites. There will also be no flaring unless under emergency situation, no gas venting and keeping greenhouse emission as low as possible.     

Biodiversity experts have established that different wildlife species have specific habits. For example, lions prefer hideouts of bushy areas while the Kobs have specific mating grounds. The elephants on the other hand follow same route during migration by using natural instincts while Buffalos’ are often all over the place and this presents danger to oil and gas workers.

“As a result, where feasible, the chosen options avoided the more sensitive areas,” adds the ESIA report.

Tilenga project phases

ESIA considered the site preparation and enabling works, which shall last for five years. This phase includes site preparations, Bugungu airstrip upgrade works, civil works for Well Pads and the water abstraction systems, road modification/constructions and construction of Victoria Nile Ferry Crossing, and Masindi Vehicle Check Point. After this phase the drilling rigs will be demobilized and drilling activities ceased. 

Construction and pre-commissioning is associated with the construction of main facilities at the industrial Area including the Central Processing Plant (CPF), well pads drilling, production and injection network which includes: pipelines and flowline network and water abstraction system. 411 wells will be drilled from 34 well pads. This phase will last 7 years.

Commissioning and operations looks are starting up the operations of the facilities expected to commence 36 months after effective date of construction contract award. This duration will last 25 years.

Decommissioning involves removal of the infrastructure and restoration of the land at the end of the project’s life.

The Full TILENGA ESIA report is available on the link below.

To top