Environmental Assessment
Volume E-3.3
Tailings Facility
Soils
Ambatovy Project
31
January 2006
The key question for soils is:
Key Question ST-1
What Effect Will the Tailings Facility Have on
Soils?
A linkage diagram for potential impact pathways is provided in Volume H,
Appendix 9. Table 3.3-1 presents the impact of mine activities with soil
resources, focusing on key issues.
Table 3.3-1 Project Interaction Matrix
Project Activities or Facilities
Soil
(a)
Issue
Comments
pre-construction phase
geotechnical drilling
N
increased short-term soil
erosion risk on slopes >10%
short-term issue
construction and operation phase
vegetation clearing
H
wind and water erosion; soil
compaction from equipment
water erosion risk will be high
until exposed areas revegetated
topsoil removal
M to H
wind and water erosion risk
increases, loss of soil quality
(nutrient loss, soil compaction)
impact depends on length of
time soil exposed
tailings dike construction
M to H
wind and water erosion; soil
compaction from equipment
impact depends on length of
time soil exposed
tailings basin construction
N
no major issues
some topsoil may be salvaged
prior to tailings basin
construction
reclamation and closure phase
removal of equipment
P
removal of contamination
source
positive effect
site remediation
P
remediation of any
contamination
positive effect
reclamation
P
reclamation of disturbed areas
positive effect
(a)
Interaction Ratings: N - Negligible; L - Low; M - Moderate; H - High; and P - Positive.
Many of these issues are inter-related. For example soil removal and disturbance
is related to loss of soil nutrients. Only those activities rated moderate or high
were analyzed in detail in the assessment.
Impact Pathways
Key Question ST-1 analyzes the effects associated with construction, operations
and reclamation of the tailings facility 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 tailings area
include site clearing and surface disturbance to permit tailings dike and basin
construction and operation. Area preparation for facility construction will
involve removing soil cover. Some topsoil may be salvaged for future
