Skip navigation
Tribal Energy and Environmental Information Clearinghouse
Tribal Energy and Environmental Information Clearinghouse: Environmental resources for tribal energy development
Energy Resources Assessments & Monitoring Laws & Regulations
Energy Resources Assessments & Monitoring Laws & Regulations |  Home  |  News  |  FAQ  |  Glossary
Document Library
Federal and Tribal Contacts

Geothermal Energy: Construction Impacts

Potential environmental impacts from construction activities are generally similar to but more extensive than those during the exploration and drilling phase, but of shorter duration than those during the operations and maintenance phase.

Activities that may cause environmental impacts during construction include site preparation (e.g., clearing and grading); facility construction (e.g., geothermal power plant, pipelines, transmission lines); and vehicular and pedestrian traffic. The construction of the geothermal power plant would disturb about 15 to 25 acres of land. Transmission line construction would disturb about one acre of land per mile of line. Impacts would be similar to but more extensive than those addressed for the exploration and drilling phase; however, many of these impacts would be reduced by implementing good industry practices and restoring disturbed areas once construction activities have been completed. Potential impacts from these activities are presented below, by the type of affected resource.

Acoustics (Noise)

The primary source of noise during the construction phase would be the construction of the geothermal power plant, which would occur over a period of 2 to 10 years. Near residential areas, noise levels could exceed the EPA guideline but would be intermittent and extend for only a limited time.

Air Quality

Emissions generated during the construction phase include exhaust from vehicular traffic and construction equipment, 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). Activities such as site clearing and grading, power plant and pipeline system construction, and transmission line construction would have more intense exhaust-related emissions over a period of 2 to 10 years. Impacts would depend upon the amount, duration, location, and characteristics of the emissions and the meteorological conditions (e.g., wind speed and direction, precipitation, and 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 to 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 scientific study and educational 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 or 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. While the potential for encountering buried sites is relatively low, the possibility that buried sites would be disturbed during construction 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 cultural resources of significant importance that would otherwise have remained buried and unavailable could be viewed as a beneficial impact, provided the discovery results in study, curation, or recordation 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 to 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, ancillary 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 to 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 dispersal.

Construction activities have the potential to destroy or injure wildlife (especially 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); 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 wildlife and affect breeding, foraging, and migrating behavior. Wild horses, burros, and grazing livestock could be adversely affected by the loss of forage and reduced forage palatability (due to dust settlement on vegetation) and restricted movement around the development area.

Environmental Justice

Environmental justice impacts occur only if significant impacts in other resource areas disproportionately affect minority or low-income populations. It is anticipated that the development of geothermal energy could benefit low-income, minority, and tribal populations by creating job opportunities and stimulating local economic growth via project revenues and increased tourism. However, noise, dust, visual impacts, and habitat destruction could have an adverse affect on traditional tribal life ways and religious and cultural sites. Development of wells and ancillary facilities could affect the natural character of previously undisturbed areas and transform the landscape into a more industrialized setting. Development activities could impact the use of cultural sites for traditional tribal activities (hunting and plant-gathering activities, and areas in which artifacts, rock art, or other significant cultural sites are located).

Hazardous Materials and Waste Management

Solid and industrial waste would be generated during construction activities. Much of the solid waste would be nonhazardous, consisting of containers and packaging materials, miscellaneous wastes from equipment assembly and presence of construction crews (food wrappers and scraps), and woody vegetation. Industrial wastes would include minor amounts of paints, coatings, and spent solvents. Most of these materials would likely be transported off-site for disposal. In forested areas, commercial-grade timber could be sold, while slash may be spread or burned near the well site.

Health and Safety

Potential human health and safety impacts during the construction phase would include exposures to geothermal fluids or steam during maintenance activities, system failures, or well blowouts, and hazardous materials such as petroleum, oils, lubricants, and herbicides; and the risk of serious injuries or accidents. Adverse impacts could also occur from the risk of electrical fires and wildfires caused by project activities; electric shock during transmission line and substation maintenance; and vehicular accidents due to increased traffic on local roads. The potential for such impacts can be minimized if appropriate safety procedures are implemented.

Land Use

Temporary and localized impacts to land use would result from construction activities. These activities could create a temporary disturbance in the immediate vicinity of a construction site (e.g., to recreational activities or livestock grazing). The magnitude and extent of impacts from constructing power plants and pipeline systems would depend on the current land use in the area; however, long-term impacts on land use would be minimized by reclaiming all roads and routes that are not needed once construction is completed. All other land uses on land under well pads, buildings, and structures would be precluded as long as they are in operation. Construction activities are unlikely to affect mining and energy development activities, military operations, livestock grazing, or aviation on surrounding lands. Activities affecting resources and values identified for protection areas would likely be prohibited.

Paleontological Resources

The potential for impacts on paleontological resources is high where grading and excavation intercept geologic units with important fossil resources. Ground clearing and vehicular traffic have the potential to impact the fossil resources at the surface. The disturbance caused by all these activities could increase illegal collection and vandalism. Disturbance that uncovers paleontological resources of significant importance that would otherwise have remained buried and unavailable could be viewed as a beneficial impact, provided the discovery results in study, collection, or recordation of the resource.


Construction phase activities would contribute to the local economy by providing employment opportunities, monies to local contractors, and recycled revenues through the local economy. The magnitude of these benefits would vary depending on the resource potential. Construction of a typical 50-megawatt (MW) power plant and related transmission lines would require an estimated 387 jobs and $22.5 million in income, but would vary depending on the community. Job availability would vary with different stages of construction. Expenditures for equipment, materials, fuel, lodging, food, and other needs would stimulate the local economy over the duration of construction.

Economic impacts may occur if other land use activities (e.g., recreation, grazing, or hunting) are altered by geothermal development. Constructing facilities will alter the landscape and could affect the nonmarket values of the immediate area. Many of these land uses may be compatible; however, it's possible that some land uses will be displaced by geothermal development.

Soils and Geologic Resources

Impacts to soils and geologic resources would be greater during the construction phase than for other phases of development because of the increased footprint, and would be particularly significant if biological or desert crusts are disturbed. Construction of additional roads, well pads, the geothermal power plant, and structures related to the power plant (e.g., the pipeline system and transmission lines) would occur during this phase. Construction of well pads, the geothermal power plant, the pipeline system, access roads, and other project facilities could cause topographic changes. These changes would be minor, but long term. Soil compaction due to construction activities would reduce aeration, permeability, and water-holding capacity of the soils and cause an increase in surface runoff, potentially causing increased sheet, rill, and gully erosion. The excavation and reapplication of surface soils could cause the mixing of shallow soil horizons, resulting in a blending of soil characteristics and types. This blending would modify the physical characteristics of the soils, including structure, texture, and rock content, that could lead to reduced permeability and increased runoff from these areas. Soil compaction and blending could also impact the viability of future vegetation. Any geologic resources within the areas of disturbance would not be accessible during the life of the development. It is unlikely that construction activities would activate geologic hazards. However, altering drainage patterns or building on steep slopes could accelerate erosion and create slope instability.


Geothermal development would result in the need to construct and/or improve access roads and would result in an increase in industrial traffic. Overweight and oversized loads could cause temporary disruptions and could require extensive modifications to roads or bridges (e.g., widening roads or fortifying bridges to accommodate the size or weight of truck loads). An overall increase in heavy truck traffic would accelerate the deterioration of pavement, requiring local government agencies to schedule pavement repair or replacement more frequently than under the existing traffic conditions. Increased traffic would also result in a potential for increased accidents within the project area. The locations at which accidents are most likely to occur are intersections used by project-related vehicles to turn onto or off of highways from access roads. Conflicts between industrial traffic and other traffic are likely to occur, especially on weekends, holidays, and seasons of high use by recreationists. Increased recreational use of the area could contribute to a gradual increase in traffic on the access roads.

Visual Resources

Impacts to visual resources would be considered adverse if the landscape were substantially degraded or modified. Construction activities would have only temporary and minor visual effects, resulting from the presence of workers, vehicles, and construction equipment (including lighting for safety); and from vegetation damage, dust generation, scarring of the terrain, and altering landforms or contours. Reclamation following construction to restore visual resources to pre-disturbance conditions would lessen these impacts.

Water Resources (Surface Water and Groundwater)

Impacts to water resources during the construction phase would be moderate because of ground-disturbing activities (related to road, well pad, and power plant construction) that could lead to an increase in soil erosion and surface runoff. Impacts to surface water would be moderate but temporary and could be reduced by implementing best management practices based on stormwater pollution prevention requirements and other industry guidelines.

During the construction phase, water would be required for dust control, making concrete, and consumptive use by the construction crew. Depending on availability, it may be trucked in from off-site or obtained from local groundwater wells or nearby municipal supplies.