Environmental Engineering Reference
In-Depth Information
trenches. Mining operations would disturb the ground surface, and runoff would
erode fine-grained soils, increasing the sediment load farther down in streams and
rivers. Mining on steep slopes or on unstable terrain without appropriate engineering
measures increases the landslide potential in the mining areas. Possible geological
hazards (earthquakes, landslides, avalanches, forest fires, geomagnetic storms, ice
jams, mudflows, rock falls, flash floods, volcanic eruptions, geyser deposits, ground
settlement, sand dune migration, thermals springs, etc.) can be activated by excava-
tion and blasting for raw material, increasing slopes during site grading and con-
struction of access roads, altering natural drainage patterns, and toe-cutting bases of
slopes. Altering drainage patterns accelerates erosion and creates slope instability.
p
AleontologiCAl
r
esourCes
Potential impacts on paleontological resources during construction include (1) com-
plete destruction of the resource if present in areas undergoing surface disturbance
or excavation; (2) degradation or destruction of near-surface fossil resources on- and
offsite resulting from changing the topography, changing the hydrological patterns,
and soil movement (removal, erosion, sedimentation); and (3) unauthorized removal
of fossil resources or vandalism to the locality as a result of human access to previ-
ous inaccessible areas. The accumulation of sediment mentioned above could serve
to protect some localities by increasing the amount of protective cover.
t
rAnsportAtion
Short-term increases in the use of local roadways would occur during the construc-
tion period. Heavy equipment would need to be continuously moved as construc-
tion progresses along the linear project. Shipments of materials are not expected
to significantly affect primary or secondary road networks but would depend on
the ever-changing location of the construction site area relative to material source.
Overweight and oversized loads could cause temporary disruptions and could require
some modification to roads or bridges (such as fortifying bridges to accommodate
the size or weight). The weight of shipments is also a parameter in the design of
access roads for grade determinants and turning clearance requirements.
V
isuAl
r
esourCes
Potential sources of visual impacts during construction include visual constraints
in the landscape due to access roads and staging areas, conspicuous and frequent
small-vehicle traffic for worker access, and frequent large-equipment (trucks,
graders, excavators, cranes, and, possibly helicopters) traffic for project and access
road construction. Project component installation would produce visible activity
and dust in dry soils. Project construction may be progressive, persisting over a
significant period of time. Ground disturbance (e.g., trenching and grading) would
result in visual impacts that produce contrasts of color, form, texture, and line. Soil
scars and exposed slope faces could result from excavation, leveling, and equip-
ment movement.
