Summary
Project Description
Mined ore will be mixed with water from the Mangoro River and
supplemented with collected storm runoff water, to prepare a slurry of
40% ore and 60% water. The slurry is then pumped through a 55 cm
diameter buried pipeline to the process plant on the coast. A number of
pipeline route alternatives have been compared during project planning,
with respect to engineering, economic, social and environmental costs
and benefits. The assessed route runs adjacent to an old forest railway
line from the mine site to near Andasibe. It then turns east to Fanovana
avoiding the Mantadia National Park, before heading north to near
Fitanisirana. Here it turns east to the north of Lanonana, up to
Androsalabo and generally parallels the RN2 to the Toamasina plant
site. The assessed pipeline route was chosen, in consultation with
government representatives and NGOs, to avoid crossing national parks
and primary forest in the Ankeniheny–Zahamena forest corridor. In the
Torotorofotsy Ramsar site it is routed along an old railway line at the
north edge of the wetland.
The pipeline will be buried along its approximately 195 km length, with
the exception of some steep sided river channels, which would have
aerial crossings. Pipeline burial depths beneath streams will be at a
depth that will prevent pipeline scouring within the stream. The disturbed
surface near crossings and elsewhere will be reclaimed to minimize
erosion. A control system will be built into the pipeline to monitor the
movement of the slurry and to halt the flow of slurry if required.
Aerial survey of pipeline route
Hydrostatic testing of the pipeline will be conducted before it is
commissioned to ensure there are no leaks. That testing will require
water withdrawal from rivers and/or streams. Withdrawal locations will
be selected with the aim of minimizing changes in affected water bodies.
Water will typically be disposed of to designated vegetated areas. Any
water disposed directly to water bodies will be controlled to minimize flow
impacts and ensure there are no water quality related issues.
Long-term safe and reliable operation of the slurry pipeline began in the
design phase and will continue through operations. Application of
proven design practices and development of project-specific safety
systems ensures this reliability can be achieved. Commercially
operating slurry pipelines have provided reliable service in high
earthquake zones (Chile and Peru), extremely wet environments (Brazil),
and in remote regions (China and Australia). The proposed slurry
pipeline route does not present unique conditions for which successful
pipeline designs have not been achieved. In all aspects, the pipeline is
within commercially proven limits. The residual risks during all project
periods are in the low category and within international standards to
minimize risk to downstream public and environmental resources.
Pipeline construction would utilize local labour where possible. However
this would not be high, because of a rapid construction schedule and
January 2006
Ambatovy Project — 21
