Summary
schedule. The option chosen does not use the lower elevation areas of
the valleys, avoiding the areas of highest population density.
The tailings facility will be constructed and operated in three phases to
permit progressive reclamation and progressive resettlement of affected
people. The processing of the ore results in about 1.3 tonnes of residue
(tailings) per tonne of ore – about 220 million tonnes in total over the
27 year life of the project. The tailings would be neutralized to a pH of 8
at the process plant and then pumped as a slurry into the tailings pond.
Due to the neutralization process most of the metals will be precipitated
as solids and immobilized in the tailings facility. The tailings area will
offer an opportunity for the solids to settle and consolidate.
Water, which will include rainwater, will be pumped from the tailings
facility back to the process plant where some will be reused; the balance
will be disposed of to the ocean via an outfall pipeline. In order to
minimize the discharge of water directly to the downstream environment,
the tailings facility is designed to be capable of temporarily storing
rainwater from a 1 in 50 year storm, above the maximum normal
operating level.
Dams containing the tailings would be built according to rigorous safety
standards that take into account extreme rainfall events and seismic
activity. Following mitigation, the residual risks during all project periods
are predicted to be low and within international standards. The main risk
concerns heavy rains causing maximum flows over pond spillways.
However, the extent of predicted flooding is relatively similar with or
without the tailings facility in place.
Key Impacts and Mitigation
Main issues identified through consultation and through the professional
experience of the Malagasy and international EA team included:
•
concerns over re-settlement and the resettlement process, including
land tenure, conflict resolution and adequacy of funding;
•
concern that the movement of tombs be compensated and
conducted in a culturally appropriate manner;
•
concern that water quality and quantity will be affected around the
tailings area, with impacts to crops, livestock and people;
•
concern over what will be pumped into the ocean from the tailings
area; and
•
danger to people if water comes over the top of the dam in a cyclone
or if the dam breaks.
January 2006
Ambatovy Project — 38
