Environmental Assessment
Volume B-3.3
Mine
Soils
Ambatovy Project
33
January 2006
3.3.3.2 Key Question Evaluation
The key question for soils is:
Key Question ST-1
What Effect Will the Mine Have on Soils?
A linkage diagram for potential impact pathways is provided in Volume H,
Appendix 9.
Impact Pathways
Key Question ST-1 analyzes the effects associated with construction, operations
and reclamation of the mine on the loss or alteration of soil within the Local
Study Area (LSA).
Activities resulting in the direct loss or alteration of soil in the mine include site
clearing and surface disturbance to permit mine construction and operation. Area
preparation for facility construction will involve removing the soil cover.
Topsoil may not be salvaged for future reclamation operations on ferricrete soils.
While the mine will be progressively reclaimed, methods for reclamation of
vegetation on tropical soils are still in development.
Soil erosion is a process involving soil movement from one area to another by
wind and water. Soil erosion can result in alteration or loss of soil quality, a
process that can subsequently affect vegetation growth. The mine will result in
vegetation removal, thereby exposing the soil and increasing the probability for
erosion.
Soil compaction results in a reduction in porosity and an increase in soil bulk
density. It is caused by external pressure resulting from construction-related
equipment and vehicle traffic. The potential loss of soil structure from soil
compaction can affect vegetation growth, especially root development, aeration
and drainage. The mine will involve equipment traffic and activity on soils.
Spills and leaks during operation can result in the alteration of soil chemistry and
physical properties, which in turn can affect vegetation, surface water and
groundwater quality. There is a potential for spills and leaks associated with the
mine.
Ferricrete soils occur on the mine plateaus and create unique growing conditions
for azonal vegetation. Since the dense surface horizon of ferricrete soils cannot
be reproduced, the loss of unique soils will occur.
