Environmental Engineering Reference
In-Depth Information
Specific environmental impacts related to geothermal energy exploration, drilling,
construction, operation, and maintenance activities are discussed in the following
sections.
G
eothermal
e
nerGy
e
xPloration
anD
D
rillinG
i
mPacts
Activities during the resource exploration and drilling phase are temporary and
are conducted at a smaller scale than those during the construction, operations,
and maintenance phases. The impacts described for each resource would occur
from typical exploration and drilling activities, such as localized ground clear-
ing, vehicular traffic, seismic testing, positioning of equipment, and drilling. Most
impacts during the resource exploration and drilling phase would be associated
with the development (improving or constructing) of access roads and exploratory
and flow testing wells. Many of these impacts would be reduced by implementing
good industry practices and restoring disturbed areas once drilling activities have
been completed.
Air Quality
Emissions generated during the exploration and drilling phase include exhaust from
vehicular traffic and drilling rigs, fugitive dust from traffic on paved and unpaved
roads, and the release of geothermal fluid vapors (especially hydrogen sulfide, carbon
dioxide, mercury, arsenic, and boron, if present in the reservoir). Initial exploration
activities such as surveying and sampling would have minimal air quality impacts.
Activities such as site clearing and grading, road construction, well pad develop-
ment, sump pit construction, and the drilling of production and injection wells would
have more intense exhaust-related emissions over a period of 1 to 5 years. Impacts
would depend upon the amount, duration, location, and characteristics of the emis-
sions and the meteorological conditions (e.g., wind speed and direction, precipita-
tion, 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
Cultural resources could be impacted if additional roads or routes are developed
across or within the historic landscape of a cultural resource. Additional roads
could lead to increased surface and subsurface disturbances that could increase
illegal collection and vandalism. The magnitude and extent of impacts would
depend on the current state of the resource and their eligibility for the National
Register of Historic Places. Drilling activities could result in long-term impacts
on archeological artifacts and historic buildings or structures, if present. Surveys
conducted during this phase to evaluate the presence and/or significance of cul-
tural resources in the area would assist developers in locating sensitive resources
and siting project facilities in such a way as to avoid or minimize impacts on these
resources.
