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OCR for page 155
11
Ma for Effects and Their Accumulation
The Committee on Cumulative Environmental Effects
of Oil and Gas Activities on Alaska's North Slope was
charged with reviewing information about oil and gas activi-
ties on Alaska's North Slope with the objective of assessing
their known and probable cumulative effects of those activi-
ties on the physical, biotic, and human environments of the
North Slope and the adjacent marine environment. The com-
mittee also was directed to assess future cumulative effects,
based on its judgment of likely changes in technology and
the environment. The committee attempted to be thorough in
its analyses to reduce the likelihood that important effects-
and how they might accumulate would be undetected. The
results of the committee's investigations are detailed in
Chapters 6 through 9.
The importance of effects is perceived differently by
different individuals or groups. The committee is not aware
of a satisfactory way of attributing some absolute degree of
importance to effects, and so it attempted to describe the
basis on which it assessed importance of the effects. For ex-
ample, it considered ecological consequences, importance
given by North Slope residents, irreversibility, degree of
controversy, and economic consequences for North Slope
residents.
As described in Chapter 10, there was considerable dif-
ficulty with assembling information for some analyses, both
because of gaps in data and because of the inaccessibility of
some information. Nevertheless, the committee did identify
important effects of industrial activities on the North Slope
and how they accumulate. Details that support its judgments
are provided earlier in the report.
The committee based its projections of future accumula-
tion of effects on a 50-year scenario that assumes political
stability and world prices for petroleum products that support
the continued expansion of oil and gas activities westward
across the Arctic Coastal Plain and southward into the foot-
hills of the Brooks Range (Chapter 5~. Some effects are not
155
yet manifest; they will accumulate as consequences of past
and current activity. They would occur even if North Slope oil
and gas exploration and production ended today. Other effects
will accumulate as a result of new activities. Mostly, they will
involve increases of current effects, but new effects are likely
to be created as well both by the expansion and by the ulti-
mate retraction of industrial activity.
Assessments of future effects are problematic because
of the connection between world politics and the oil market.
It is possible to guess, but no one knows for certain how the
events of the next decade will affect oil prices or availability.
Moreover, future industrial activities will be carried out in a
physical climate that will change in ways that are difficult to
predict. Nevertheless, if oil activity expands and a gas pipe-
line is built, the continuing accumulation of effects is virtu-
ally certain.
Many laws and regulations affect oil and gas explora-
tion, development, production, and transportation, and many
federal, state, and local government offices are involved (see
Appendix I). Regulatory oversight can be critical in reduc-
ing the accumulation of undesirable effects. The committee's
predictions of future effects and their accumulation assume
that regulatory oversight will continue at least to the extent
of the recent past.
All of the effects identified by the committee accumu-
lated as the result of the actual spread of industrial activity
on the North Slope or as responses to the news that such
activity was likely to occur.
Since the 1960s, industrial activity on the North Slope
has grown from a single operational oil field at Prudhoe Bay
to an industrial complex that stretches from the Alpine field
near the mouth of the Colville River on the west to the
Badami oil field, about 39 km (23 mi) from the borders of
the Arctic National Wildlife Refuge in the east. In 2001, oil
development on the North Slope consisted of 19 producing
fields connected to the rest of Alaska by a highway and a
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156
pipeline that cross the state. The network consists of 115
gravel drill sites, 20 pads with processing facilities, l 15 pads
with other support facilities, 91 exploration sites, 13 offshore
exploration islands, 4 offshore production islands, 16 air-
strips, 4 exploration airstrips, 1,395 culverts, 960 km (596
mi) of roads and permanent trails, 450 mi (725 km) of pipe-
line corridors, and 219 mi (353 km) of transmission lines.
Gravel roads and pads cover more than 3,500 ha (8,800
acres), not including the Trans-Alaska Pipeline and the
Dalton Highway, and gravel mines have affected nearly
2,600 ha (6,400 acres). Ubiquitous permafrost requires that
this infrastructure not thaw its own foundations, imposing
an architecture with environmental consequences of it own.
Massive gravel fills under roads and other work surfaces are
required to raise them 1.8 m (6 ft) above the tundra. Heated
buildings and pipeline networks must be elevated on pilings,
and the closely spaced oil wells are extensively refrigerated.
This network has grown incrementally as new fields have
been explored and brought into production (Chapter 4~. For
a variety of reasons, nearly all roads, pads, pipelines, and
other infrastructure whether in current use or not are still
in place and are likely to remain into the future. Their effects
are manifest not only at the physical footprint itself but also
at distances that vary according to the environmental com-
ponent affected. Effects on hydrology, vegetation, and ani-
mal populations occur at distances up to several kilometers,
and cumulative effects on wildland values especially vi-
sual ones extend much farther, as can the effects on marine
mammals of sound generated by some offshore activities.
All effects attributable to the structures and the activities
associated with them accumulate, and many will persist as
long as the structures remain, even if industrial activity
ceases.
SOCIAL CHANGES IN NORTH SLOPE
COMMUNITIES
Without the discovery and development of North Slope
petroleum, the North Slope Borough, the Alaska Native
Claims Settlement Act, and hence the Arctic Slope Regional
Corporation, either would not exist or would bear little resem-
blance to their current form. Petroleum development has re-
sulted in major, significant, and probably irrervisible changes
to the way of life on the North Slope (Chapter 9~. The primary
vehicle of change is revenue that has flowed into communities
from property taxes levied by the North Slope Borough on the
petroleum industry's infrastructure. Many North Slope resi-
dents view many of these changes positively. However, social
and cultural changes of this magnitude inevitably have been
accompanied by social and individual pathology. Those ef-
fects accumulate because they arise from several causes, and
they interact. As adaptation occurs, the communities and the
people who make them up interact in new and different ways
with the causes of social change.
CUMULATIVE EFFECTS OF ALASKA NORTH SLOPE OIL AND GAS
Interference With Subsistence Activities
Offshore exploration and development and the an-
nouncement of offshore sales have resulted in perceived
risks to Inupiaq culture that are widespread, intense, and
themselves constitute a cumulative effect (Chapter 9~. The
people of the North Slope have a centuries-old nutritional
and cultural relationship with the bowhead whale and cari-
bou. Most view offshore industrial activity both the ob-
served effects and the threat of a major oil spill as threat-
ening the bowhead population and, thereby, their cultural
survival. Noise from exploratory drilling and marine seis-
mic exploration has caused fall-migrating bowheads to
avoid noise above 117-135 dB. The distances over which
the migratory pathways of the whales have changed are not
yet known, but the deflections forced subsistence hunters
to travel greater distances than formerly to encounter
whales. The results are increased risk of exposure to the
dangers of the open sea and the increased likelihood that
whale tissues will deteriorate before carcasses are landed
and butchered. Recently the Alaska Eskimo Whaling Com-
mission has reached agreements that restrict seismic-vessel
operations during the fall hunting period, but they are rene-
gotiated annually.
The threat of a major oil spill also is viewed with trepi-
dation by the coastal Inupiat, even though no such spill has
yet occurred. These threats are accumulate because they in-
teract with other factors such as climate change and because
they are repeated with every new lease sale.
On-land subsistence activities have been affected by
the reduction in the harvest area in and around the oil fields.
The reductions are greatest in the Prudhoe Bay field, which
has been closed to hunting, and in the Kuparuk field, where
the high density of roads, drill pads, and pipelines inhibits
travel by snow machine. The reduction in area used for
subsistence is most significant for Nuiqsut, the village clos-
est to the oil-field complex. Even where access is possible,
hunters are often reluctant to enter oil fields for personal,
aesthetic, or safety reasons. There is thus a net reduction in
the available area, and this reduction continues as the oil
fields spread.
Although there has not yet been industrial activity in the
Arctic National Wildlife Refuge, proposals to explore and
develop oil resources there have resulted in perceived risks
to the Gwich'in culture that are widespread, intense, and
themselves are accumulating effects (Chapter 9~. The
Gwich'in have a centuries-old nutritional and cultural rela-
tionship in Alaska and the Yukon Territory with the Porcu-
pine Caribou Herd. Most view petroleum development in
the 1002 Area of the Arctic National Wildlife Refuge as a
threat to the herd and, thereby, to their cultural survival. The
threats accumulate because there have been repeated at-
tempts to develop the area and there is continuing pressure
to do so.
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MA JOR EFFECTS AND THEIR A CCUMULA TION
Aesthetic, Cultural, and Spiritual Consequences
Many activities associated with petroleum development
have changed the North Slope landscape in ways that have
had aesthetic, cultural, and spiritual consequences that accu-
mulate. The consequences have increased along with the area
of tundra affected by development, and they will persist for
as long as the landscape remains altered.
Roads, pads, pipelines, seismic-vehicle tracks, and
transmission lines; air, ground, and vessel traffic; drilling
activities; landfills, housing, processing facilities, and other
industrial infrastructure have reduced opportunities for
solitude and have compromised wildland and scenic values
over large areas (Chapter 9~. The structures and activities
also violate the spirit of the land, a value that is reported by
some Alaska Natives to be central to their culture. Given
that most of the affected areas are not likely to be rehabili-
tated or restored to their original condition, those effects
will persist long after industrial activity has ceased on the
North Slope.
DAMAGE TO TUNDRA FROM OFF-ROAD TRAVEL
The tundra on the North Slope has been altered by ex-
tensive off-road travel, some of which may not be directly
related to oil and gas activity. Networks of seismic-explora-
tion trails, ice roads, pads, and all-terrain vehicle trails cover
large areas. The currently favored three-dimensional seis-
mic surveys require a high spatial density of trails, and the
potential damage is substantial because larger camps and
more vehicles are used than were used previously for two-
dimensional exploration. Although the technology for ac-
quisition of seismic data continues to improve, damage has
not been totally eliminated, and some areas have been ex-
plored repeatedly sometimes revisits to gather more com-
plete data using new and better technologies; sometimes to
gather data already gathered by a competitor who did not
share the proprietary information.
Some seismic-exploration effects accumulate because
areas are revisited before the tundra recovers from previous
surveys. Seismic exploration can damage vegetation and
cause erosion, especially along stream banks. In addition,
because seismic trails are readily visible, especially from the
air, they affront the residents and degrade the visual experi-
ence of the landscape. Data do not exist to determine the
period that the damage will persist, but some effects are
known to have lasted for several decades (Chapter 7~.
Seismic exploration is expanding westward into the
National Petroleum Reserve-Alaska and southward into the
foothills of the Brooks Range. Current technology and gov-
ernment regulations will not prevent damage to the tundra.
Moreover, exploration will be conducted in regions where
the topography is more complex and where permafrost con-
ditions are more variable and less well known than on the
Arctic Coastal Plain, where most exploration has been done
(Chapter 5~. The nature and condition of permafrost in the
157
Brooks Range foothills is poorly characterized, and the hilly
topography increases the likelihood that vehicles will dam-
age vegetation, especially on knolls and riverbanks, causing
increased erosion, exposing bare soil, and promoting devel-
opment of thermokarst. This exploration will probably be
carried out in a warming climate, with milder winter tem-
peratures. It is hard to predict the consequences of vehicular
traffic in winter on tundra under those conditions.
ROADS
Roads have had effects as far-reaching and complex as
any physical component of the North Slope oil fields. In addi-
tion to covering tundra with gravel, indirect effects on vegeta-
tion are caused by dust, roadside flooding, thermokarst, and
roadside snow accumulation. The effects accumulate and in-
teract with effects of parallel pipelines and with off-road ve-
hicle trails. The measurable direct effects covered approxi-
mately 4,300 ha (10,500 acres) in the developed fields, not
including indirect effects of the Dalton Highway. Roads also
alter animal habitat and behavior and can increase access of
hunters, tourists, and others to much of the region; enhance
communication among communities; and increase contacts
between North Slope communities and those outside the area.
EFFECTS ON ANIMAL POPULATIONS
Animals have been affected by industrial activities on
the North Slope (Chapter 8~. Bowhead whales have been
displaced in their fall migration by the noise of seismic ex-
ploration. The full extent of that displacement is not yet
known. Some donning polar bears have been disturbed. The
readily available supply of food in the oil fields has resulted
in the persistence of higher-than-normal densities of preda-
tors, such as brown bears, arctic foxes, ravens, and glaucous
gulls. Those animals are important predators on nests, nest-
lings, and fledglings of many bird species, and the reproduc-
tive success rate of some bird species in the developed parts
of oil fields has been reduced to the extent that it is insuffi-
cient to balance mortality. Serious efforts have been made,
in the form of educating workers, fencing dumps, and using
animal-proof waste receptacles, to reduce the amount of
supplemental food available to predators. Those efforts have
been only partly successful; some predators have become
expert at accessing garbage and it is difficult to persuade
people to stop feeding them.
Reproductive rates of some bird species are, at least in
some years, insufficient to balance mortality. That is, they are
"sink populations" whose densities have been maintained only
by steady immigration from "source" areas where reproduc-
tive rates exceed mortality. As industrial activities continue to
expand, increasing numbers of sink areas are likely to be cre-
ated and more and more source areas are likely to be degraded.
Ecology theory and empirical data indicate that populations
can decline suddenly if source areas are significantly degraded.
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158
How industrial activity interacts with source-sink popu-
lation dynamics is difficult to assess because local population
studies alone, no matter how detailed, cannot detect all ef-
fects. To anticipate and predict sudden population decline
from disrupted source-sink population dynamics, analyses
must focus on those species most likely to be affected, and
studies must gather specific kinds of data. The number of vul-
nerable species cannot be determined because demographic
information does not distinguish source and sink habitats, but
several species of birds could be adversely affected.
As a result of conflicts with industrial activity during calv-
ing and an interaction of disturbance with the stress of sum-
mer insect harassment, reproductive success of Central Arctic
Herd female caribou in contact with oil development from
1988 through 2001 was lower than for undisturbed females,
contributing to an overall reduction in herd productivity. The
decrease in herd size between 1992 and 1995 may reflect the
additive effects of surface development and relatively high
insect activity, in contrast to an increase in the herd's size
from 1995 to 2000, when insect activity was generally low.
Although the accumulated effects of industrial development
to date have not resulted in large or long-term declines in the
overall size of the Central Arctic Herd, the spread of industrial
activity into other areas that caribou use during calving and in
summer, especially to the east where the coastal plain is nar-
rower than elsewhere, would likely result in reductions in re-
productive success, unless the degree to which it disturbs cari-
bou could be reduced. Without specific information on the
exact nature of future activity and its precise distribution, it is
not possible to predict to what degree distribution and produc-
tivity of caribou herds would be affected.
OlL SPILLS
Major oil spills have not occurred on the North Slope or
in adjacent oceans as a result of operations there. There have
been three major spills from the North Slope segment of the
Trans-Alaska Pipeline. Many small terrestrial spills have oc-
curred in the oil fields but they have not been frequent or
large enough for their effects to have accumulated. They
have contaminated gravel, which has been difficult to clean
up and has made the gravel unavailable for rehabilitation.
The threat of a large oil spill especially offshore is a
major concern among North Slope residents. This continu-
ing concern is an accumulating effect. The effects of a large
oil spill at sea, especially in broken ice, would likely be sub-
stantial and accumulate because of the fluid environment and
the inadequacy of current methods to remove more than a
small fraction of spilled oil.
ABANDONED INFRASTRUCTURE AND
UNRESTORED LANDSCAPES
The oil industry and regulatory agencies have made dra-
matic progress in slowing the accumulation of effects of
CUMULATIVE EFFECTS OF ALASKA NORTH SLOPE OIL AND GAS
gravel fill by reducing the size of the footprint required for
many types of facilities and by substituting ice for gravel in
some roads and pads. They also have directed some atten-
tion to rehabilitating or restoring already-disturbed sites.
Despite this, only about 1 % of the habitat affected by gravel
fill on the North Slope has been restored. Other than for well-
plugging and abandonment procedures, state, federal, and
local agencies have largely deferred decisions about the na-
ture and extent of restoration. The lack of clear performance
criteria, standards, and monitoring methods at the state and
federal level to govern the extent and timing of restoration
has hampered progress in restoring disturbed sites. If resto-
ration would make potential future use of a site more expen-
sive or perhaps impossible, restoration is likely to be de-
ferred. In addition, because so much gravel has been
contaminated by petroleum spills, its reuse and the restora-
tion of pads and roads could be constrained because of the
added difficulty of restoring contaminated sites. There also
is potential liability that constitutes a barrier to reuse of con-
taminated gravel.
Surface structures pose problems, but there also are por-
tions of the Trans-Alaska Pipeline that are buried. The pipe-
line connecting Alpine to Prudhoe Bay runs under the
Colville River. The vulnerability of those buried pipes to
shifting river channels and their removal after production
ceases could pose serious problems.
By the time restoration becomes more practical be-
cause better methods are available and because the opera-
tional value of the sites has diminished, the revenue flow
from oil and gas also will have declined. The large, well
capitalized multinational oil companies are likely to have
sold off substantial parts of their operations to smaller com-
panies with more limited resources. Because the obligation
to restore abandoned sites is unclear, and because the costs
to restore abandoned sites are likely to be very high, the
committee judges it unlikely that most disturbed habitat on
the North Slope will ever be restored. Natural recovery in
the Arctic is very slow, because of the cold; so the effects
of abandoned structures and unrestored landscapes could
persist for centuries and accumulate with effects of new
structures.
RESPONSE OF NORTH SLOPE CULTURES TO
DECLINING REVENUES
The standard of living of North Slope communities de-
pends largely on a steady flow of money related to oil and
gas activities. This way of life will be impossible to main-
tain unless significant revenues continue to come into those
communities from outside; the prospects of other sources
of revenue appear to be modest. Painful adjustments can
and probably will be postponed for as long as oil and gas
are being extracted, but eventual adjustment is unavoid-
able. The nature and extent of these adjustments will be
determined by the adaptations North Slope societies have
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MA JOR EFFECTS AND THEIR A CCUMULA TION
made to the cash economy made possible by oil and gas
and other activities.
TRADE-OFFS ARE INEVITABLE
Continued expansion will exacerbate existing effects
and create new ones. Whether the benefits derived from oil
159
and gas activities justify acceptance of the foreseeable and
undesirable cumulative effects is an issue for society as a
whole to debate and judge. However, if informed decisions
are to be made, the nature and extent of possible effects must
be fully acknowledged and incorporated into regulatory strat-
egies and decision-making processes. We hope this report
will assist this process.
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cow
160
Cumulative Environmental Effects of Oil and Gas Activities on Alaska 's North Slope
Oil- and Gas-Related Activities and Bowhead Whales
The activities most likely to affect bowhead whales are marine seismic exploration,
exploratory drilling, ship and aircraft traffic, discharges into the water, dredging and island!
construction, and production drilling. To date there have been documented effects of industrial
noise. As was true of early censuses, the current understanding of the effects of noise on
bowheads was achieved only after long efforts of Alaska Native hunters to correct early,
imperfect studies (Chapter I). There have been no major offshore oil spills on the North Slope.
Marine seismic exploration produces the loudest inclustrial noise in the bowhead whale
habitat. Some seismic surveys are conducted in winter and spring on the sea ice, but most are
done in the summer-autumn open-water period. Thus, bowheads and seismic boats are in the
same areas during the westward fall migration. In the nearshore Alaskan Beaufort Sea, nearly all
the fall-migrating bowhead whales avoided an area within 20 km (12 mi) of an operating vessel,
and deflection ofthe whales began at up to 35 km (21 mi) from the vessel (Richardson 1997,
1998, 1999; NMFS 2002~. Noise levels received by these whales at 20 km (12 mi) were ~ 17-135
dB (NMFS 2002).
Disturbance to fall migrating bowhead whales also has been shown in relation to offshore
drilling in the Alaskan Beaufort Sea. At He 1992 Kuv~um site the approaching fall-migrating
whales began to deflect to the north at a distance of 32 km (19 mi) east of the drilling platform
and bowhead calling rates peaked at about the same distance (Brewer et al. 1 993). At the ~ 993
Kuv~um #3 site the whales were nearly excluded from an area within 20 km (12 mi) of the
drilling platform (Davies ~ 997, Hall et al. 1 994).
During the 1986 open-water drilling operations at the Hammerhead site, no whales were
detected closer than 9.5 km (6 mi) from the driliship, few were seen closer than ~ 5 km (9 ml),
and one whale was observed for 6.8 hours as it swam in an arc of about 25 km (! 5 mi) around
the dr~Ish~p (LGL and Greeneridge ~ 987). The zone of avoidance therefore seemed to extend
15-25 km (9-15 mi) from the driliship. Acoustic studies done at the same time provided received
levels of driliship noise that can be related to the zone of avoidance. At ~ 5 km (9 mi) from the
1986 Corona, site received sound was generally 105-125 dB (LGL and Greeneridge 1987); at
km (6 mi) Mom Hammerhead, received sound was generally 105-130 dB.
Estimating Future Accumulation of Effects
Industrial Noise
If oil- and gas-related activities continue in the Alaskan waters of the Beautort Sea, the
major noise will be generated with marine seismic exploration. Other significant noise will
continue to be produced by exploratory and production drilling, island construction, and vessel
transit. The probable consequences are diversion of animals from their normal migratory path,
possibly into areas of increased ice cover, and less use of the fall migration corndor as feeding
habitat.
If two or more types of disturbance occur at the same time or in the same general area,
the effects could be greater than those observer! from single sources. The greatest diversion
would occur if two or more seismic vessels operated simultaneously with one just offshore of the
other.
Representative terms from entire chapter:
industrial activity
