Environmental Assessment
Volume C-3.5
Slurry Pipeline
Natural Risks
Ambatovy Project
45
January 2006
•
The selected route will avoid geotechnically unstable areas and where
this is not possible, special designs will be applied to mitigate any
geotechnical risk.
•
In sensitive areas such as at river or road crossings, within inhabited
zones, etc., a deeper burial depth and/or thicker pipe will be considered
to mitigate the risk of damage. This design is particularly effective in
river crossings where the pipe can be buried below the “worst case”
scour event.
The proposed pipeline will be designed, constructed, operated and maintained in
accordance with American Society of Mechanical Engineers (ASME) B31.11 –
“Slurry Transportation Pipeline Systems”. This code has been applied to other
slurry pipelines around the world and provides proven guidelines which ensure
pipeline safety. Use of an experienced design team will result in a state-of-the-
art pipeline system.
Safety systems will be installed to minimize operational risks including those
from natural hazards. To ensure rapid operator response to an unexpected event,
the pipeline will be equipped with a state-of-the-art control system including a
leak detection system. Early detection of a pipeline leak ensures rapid response
and minimizes the risk of environmental impact.
Specific risk mitigation prevention measures planned to address the three
principal natural hazards follow.
Land Slides
The major risk of damage to a pipeline is land slip or failure of the pipeline
platform. The route optimization/selection will seek mature, stable geotechnical
structure to minimize the risk of slip. The following additional designs will be
implemented:
•
The pipeline will always be installed on the uphill side/shoulder of the
pipeline platform ensuring maximum distance from the natural surface.
•
Special attention will be paid to natural water drainage for the land
above the pipeline platform to ensure no blockage. Culverts and other
water diversion structures will be used to provide drainage and prevent
saturation of the earth containing the pipeline.
•
The pipeline will only be installed in natural, cut soil. It will not be
installed in fill material which could fail more easily than mature soils.
•
Erosion control measures including reseeding, water diversion, geo-
textiles, etc., will be used along the pipeline platform to prevent damage
after construction is completed.
