Environmental Assessment
Volume C-4.3
Slurry Pipeline
Fish and Aquatic Resources
Ambatovy Project
134
January 2006
road crossing (culvert, bridge, water ford) and the success of erosion control and
reclamation plans.
Change in Water Quality
Clearing and grading of the pipeline and service road RoW, in-water construction
activities and operation of ancillary facilities (camps, hydrostatic testing) will
affect surface water quantity and quality in the streams and rivers crossed by the
slurry pipeline. Aquatic habitat will be directly affected at the pipeline excavation
site, and downstream by sediment that is entrained during construction or erosion
from surface runoff on watercourse approaches. These changes may affect the
presence, abundance and distribution of aquatic biota downstream of the site.
Increased turbidity and sedimentation (TSS) during construction are the primary
water quality changes which may affect aquatic ecosystems along the pipeline,
access or service roads. Use of applicable Best Management Practices during
construction will minimize potential effects and impacts will be low.
4.3.5.6 Impact Analysis
Residual Impacts
Residual impacts of aquatic habitat loss as a result of the slurry pipeline
construction operation and closure are summarized in Table 4.3-7. These impact
assessments are based on assumptions that the observations from the watercourse
sub-samples are representative of other watercourses along the route, and that
mitigation / implementation of the management plans are successful in
eliminating or reducing effects on the aquatic environment.
