Oil and Natural Gas - Energy Policy Analysis: A Conceptual Framework - page 89

Figure 4.3 Combustion Turbine Power Plant

Exhaust

Turbine

Oil
Storage

Air
Intake

Compressor

Transformer

Combustion
Chambers

Generator

Natural
Gas Line

Source: Tennessee Valley Authority 2011.

maintenance of a plant (USDOI 1980). When smaller amounts of sulfur are produced, it may be
trucked away or incinerated.
Soil productivity and capability can be adversely impacted. Wherever the earth's surface is
disturbed, soil compaction and surface erosion can take place. Mechanized equipment has the
greatest effects on compaction and erosion. Thus, any activities requiring equipment are prone to
these impacts. Mass movement stability hazards such as potential landslides, avalanches, rockfalls,
earthflows, and expansive soil and rock can occur if they are not identified and corrective measures
taken. When soil is destroyed, the vegetation dependent upon it is also lost (MDFWP 1983, 14).
Vegetation is primarily impacted by construction of roads and facilities. Wildfires, which may
occur accidentally during any of the phases of oil and gas exploration and development, may
cause destruction of considerable vegetation. After vegetation destruction, erosion may follow
and destroy soils and water quality (MDFWP 1983, 14).
Water quality can be adversely affected by sedimentation resulting from erosion where roads
and trails cross streams. This is particularly common in the exploration (seismic) phase and
when high-grade roads, drill pads, processing facilities, and pipelines are constructed. Stream
channels may be scoured if sumps or retention pond walls rupture. Surface water contamination
may occur from leaks in mud and evaporation pits, oil spills (both crude and refined), produced
water ponds, and well blowouts (MDFWP 1983, 14). Produced water, which ranges from brack-
ish to highly saline, must be treated to meet water quality standards before being discharged into
surface waters. Produced waters are often injected into dry holes, depleted wells, or back into
the producing formations during secondary recovery. Groundwater contamination may occur
from surface leaching, introduction of well fluids into deep groundwater aquifers, or spills from
pipelines (USFS 1979). Geological hazards other than those associated with surface soil move-
ment (landslides, mudflows, and avalanches) include subsidence and earthquakes. There is little
evidence that oil and gas production can trigger earthquakes (MDFWP 1983, 15). Cultural values,
including archeological and historical sites, may be adversely impacted by any surface-disturbing
activity. A cultural resource inventory of the entire area that will be disturbed is required by the
National Historic Preservation Act of 1966 prior to any ground disturbance that might adversely
affect archeological sites on federal lands (MDFWP 1983, 15). Private lands are governed by
state historic preservation laws.