concept EIA-rapport - Staatsolie

SRK Consulting: Project No: 439414 Staatsolie Pipeline EIA – Draft EIA Report Page 86
6.9.2 Conceptual Decommissioning Plan
The objective of the Conceptual Decommissioning Plan is to provide recommendations for the
decommissioning of the pipeline and rehabilitation of the area at the end of the operational lifespan
of the project, to achieve sustainable land use conditions and avoid or minimise costs and long term
liabilities to Staatsolie.
The method of decommissioning is likely to vary between above-ground and underground pipeline
sections. As such, it is expected that:
• Above-ground sections of the pipelines will be removed upon decommissioning. This is expected
to involve the depressurising and purging of the pipeline, physical removal of the pipe and all
associated structures and rehabilitation of the pipeline corridor. Maintenance of the corridor is
discontinued; and
• Underground sections of the pipelines will be abandoned in situ, as international best practice
recognises that removing pipelines from the ground is unlikely to be a commercially or
environmentally viable option (APIA, 2009). This is expected to involve the physical
disconnection, purging, cleaning and sealing (capping) of the pipelines. The pipe would then be
left to corrode and biodegrade in situ 39 .
The plan recommends measures to implement during the following three phases of the pipelines
project:
• Operations Phase: These measures relate to the minimisation of closure costs (e.g. through
ongoing containment of pollutants) and the successful planning of decommissioning.
• Decommissioning Phase: These measures are applicable during the decommissioning of the
pipelines project or individual pipelines to minimise residual impacts on the environment.
• Post closure: These measures include potential monitoring requirements, where appropriate,
following the decommissioning of the pipelines project or individual pipelines to monitor any
residual impacts on the environment post closure, based on information available at the time of
compiling the plan.
These measures are presented in Table 6-17.
39 Any ground subsidence due to the long term structural deterioration of a pipeline abandoned in place is considered unlikely
to be a critical issue by the Canadian Association of Petroleum Producers, as a structural failure due to corrosion may take
many decades and significant lengths of pipeline would not collapse at the same time. Ground subsidence would be negligible
for pipelines up to 232.9mm in diameters. Filling with an inert material may be appropriate at critical locations (e.g.
infrastructure crossings). This will need to be determined in consultation with the relevant authorities at the time of
decommissioning and take into account the long term plans for the pipeline (APIA, 2009).
REUT/DALC 439414_StaatsoliePipelineEIA_Draft EIA Report_Final June 2012