Environmental Engineering Reference
In-Depth Information
dioxide, mercury, arsenic, and boron, if present in the reservoir). Activities such as
site clearing and grading, power plant and pipeline system construction, and trans-
mission line construction would have more intense exhaust-related emissions over a
period of 2 to 10 years. Impacts would depend on the amount, duration, location, and
characteristics of the emissions and the meteorological conditions (e.g., wind speed
and direction, precipitation, relative humidity). Emissions during this phase would
not have a measurable impact on climate change. State and local regulators may
require permits and air monitoring programs.
Cultural Resources
Potential impacts on cultural resources during the construction phase could occur due
to land disturbance related to the construction of the power plant and transmission
lines. Impacts include destruction of cultural resources in areas undergoing surface
disturbance and unauthorized removal of artifacts or vandalism as a result of human
access to previously inaccessible areas (resulting in lost opportunities to expand sci-
entific study and education and interpretive uses of these resources). In addition, for
cultural resources that have an associated landscape component that contributes to
their significance (e.g., sacred landscapes, historic trails), visual impacts could result
from large areas of exposed surface, increases in dust, and the presence of large-scale
equipment, machinery, and vehicles. Although the potential for encountering buried
sites is relatively low, the possibility that buried sites would be disturbed during con-
struction does exist. Unless the buried site is detected early in the surface-disturbing
activities, the impact to the site can be considerable. Disturbance that uncovers cul-
tural resources of significant importance that would otherwise have remained bur-
ied and unavailable could be viewed as a beneficial impact, provided the discovery
results in study, curation, or recording of the resource. Vibration, resulting from
increased traffic and drilling/development activities may also have effects on rock
art and other associated sites (e.g., sites with standing architecture).
Ecological Resources
Most impacts on ecological resources (vegetation, wildlife, aquatic biota, special
status species, and their habitats) would be low to moderate and localized during
the construction phase (although impacts due to noise could be high). Activities
such as site clearing and grading, road construction, power plant construction, ancil-
lary facility construction, and vehicle traffic have the potential to affect ecological
resources by disturbing habitat, increasing erosion and runoff, and creating noise
at the project site. Impacts on vegetation include loss of native species and species
diversity, increased risk of invasive species, increased risk of topsoil erosion and
seed bank depletion, increased risk of fire, and alteration of water and seed disper-
sal. Construction activities have the potential to destroy or injure wildlife (espe-
cially species with limited mobility); disrupt the breeding, migration, and foraging
behavior of wildlife; reduce habitat quality and species diversity; disturb habitat
(e.g., causing loss of cover or food source); and reduce the reproductive success of
some species (e.g., amphibians). Accidental spills could be toxic to fish and wildlife.
The noise from construction and vehicle traffic has a high potential to disturb wild-
life and affect breeding, foraging, and migrating behavior. Wild horses, burros, and
