Environmental Assessment
Volume C-3.5
Slurry Pipeline
Natural Risks
Ambatovy Project
42
January 2006
3.5
NATURAL RISKS
3.5.1
Introduction
This section presents the Environmental Assessment for the risks of natural
hazards to the public and environment due to the pipeline, as per the Ambatovy
Project (the project) Terms of Reference.
3.5.2
Study Area
The slurry pipeline Local Study Area (LSA) is shown in the plan presented in
Volume A, Figure 7.2-2. The pipeline is about 195 km long and will transport up
to 7.1 million dry metric tones per annum of nickel laterite from the mine to the
plant. Natural hazards such as earthquakes can originate from a wide regional
area that was studied as appropriate to determine the potential impacts on the
pipeline.
3.5.3
Baseline Summary
The Environmental Assessment is based on a separate study on natural risks for
the pipeline (Pipeline Systems Incorporated [PSI] 2005, which is provided in
Volume I, Appendix 6.1). A 195 km slurry pipeline was designed with 550 mm
outside diameter steel pipe and one pump station with two trains of six slurry
pumps. In this reference study, the baseline for the pipeline setting is described
in terms of route, climate and seismicity. Potential natural hazards, potential
consequences of failure due to natural hazards, industry experience and risks
were assessed.
3.5.4
Issue Scoping
Three primary natural hazards were identified in the risk assessment (PSI, 2005)
that could result in pipeline breakage and release of slurry. These were land
slides along the pipeline route, water erosion from rainfall and flooding, plus
seismic hazards. All the issues identified from stakeholder consultation were
also included in these hazard scenarios (Volume A, Section 6).
Land Slides
Pipeline damage can occur if a land slide or land slip should occur along the
pipeline route. In a land slide, material above the pipeline right-of-way would
slide down on top of the pipeline right-of-way and potentially damage the
pipeline platform and the pipeline route. A land slip would involve movement of
