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2
D[SC~?IPTBO~ OF OPERATIONS
PHYSICAL EFFECTS OF
AI CT'C INDUSTRIAL ACTIVI~
Activities required for the production of petroleum products in the Arctic
include exploration, field development and production, and transportation.
Their potential for causing harm to the arctic environment has been
reviewed by Engelhardt (Engelhardt, 1985a,b; COGLA, 1985a) and more
recently to the offshore in general by the International Maritime
Organization's Group of Experts on the Scientific Aspects of Marine
Pollution (GESAMP, 19921. The physical effects of industrial activity in
polar environments can be outlined as follows:
Seismic exploradon requires He generation of sound waves, generated
by mechanical devices and discharges from air guns. High-energy sound
waves are propagated in unconsolidated sediments and consolidated rocks,
as well as in seawater and biological material, and can cause local or
regional disturbance of fish, marine mammals, and other wildlife.
Variables that influence the severity of such damage include nearshore
topography and ice cover.
.
Vessel traffic, including icebreakers, can generate both noise and
changes in ice breakup patterns, giving rise to concerns about disturbance
of wildlife migration routes, especially He bowhead whale' s.
· Exploration and production drilling generates noise, discharges of
drilling wastes (cuttings, mud, drilling fluids) and production wastes
(produced waters), and He risk of petroleum discharges Trough blowouts,
31
7
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32 OCS DECISIONS: ALASKA
all of which can cause mild to severe damage (mild to severe are expert
judgments of the GESAMP committee and were not quantified).
Oil spills draw attention in the Arctic as Hey do elsewhere. Spills in
polar waters are not as well understood as are those in temperate waters,
partly because Were is less basic knowledge of the polar environment and
partly because Here is less specific knowledge about the effects of of! on
polar organisms and ecosystems.
All phases of petroleum exploration and production can cause positive or
negative changes in the arctic environment and in He lives of its people.
Transportation of oil and oil products also results from petroleum
development, and Here is a potential for oil discharge in transportation
accidents. The evaluation of effects is complex from industrial, environ-
mental, and societal perspectives. This report concentrates on environmen-
tal information and its adequacy for evaluating potential impacts, including
those generally perceived by many as beneficial, such as jobs and improved
economy, health services, and schools, as well as Hose generally perceived
as negative, such as social disruption, environmental damage, and He loss
or erosion of traditional cultures.
Environmental Concerns
The possibility Hat of! spills can result from OCS oil and gas develop-
ment and transport and He potential for damage to resources such as
fisheries and to endangered species have caused great public concern.
Over possible sources of harm associated wig OCS development include
the discharge of drilling muds and produced water at well sites. Seismic
surveys and the construction and operation of platforms and pipelines can
disturb wildlife and interfere wig commercial, recreational, and subsistence
fishing. Possibly adverse direct social and economic impacts are associated
with He construction of onshore support facilities (NRC, 1978; MMS,
1987b). In Alaska, He possibility of damage to marine mammals Blat are
important culturally and for subsistence, especially bowhead whales, is of
particular concern, as is the possibility of other chronic environmental
effects (Engelhardt, 1985b; GESAMP, 1992~. The effects of of} spills and
drilling-mud discharges were discussed in earlier NRC reports (NRC, 1975,
1983a, 1985~. Table 2-! summarizes some of He negative potential effects
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DESCRIPTION OF OPERA TION5 33
TABLE 2-1 Negative Biophysical Concerns Associated with Industrial
Activities on the Coastal and Marine Environments in the Arctic
Activity Category
Seismic exploration
Issues
· Seismic energy releases
.
· Vessel , noise
· Equipment noise (on ice)
Exploration and production · Liquid effluents
drilling · Solid wastes
· Gaseous emissions
· Operational noise
· Vessel and vehicle (on iced traffic
· Aircraft traffic
· Blow-outs
Hydrocarbon production and · Produced water
transport · Gaseous emissions
· Operational noise
· Vessel and/or vehicle traffic
· Aircraft traffic
· Ruptured storage units
Vessel noise
Tanker spills
Pipeline dredging
Pipeline rupture
Marine construction
.
Artificial islands
Coastal bases
· Channel excavation
High explosives
· Causeways
Icebreaking · Vessel noise
· Traffic channels
Abandonment of production
facilities
Vessel and aircraft traffic
· High explosives
· Residual materials
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34 OCSDECISlONS: ALASKA
of OCS exploration and development activities on the coastal and marine
environments, but it is not exhaustive. Potential effects include pressure
effects of some types of seismic surveys, disturbance of the seabed as a
result of rig emplacement and platform installation, and noise at all post-
lease phases of activity. Oil spills also are possible during Me exploration
stage, and there are potential effects from post-production activities such as
the removal of platforms.
Even though OCS oil discharges are estimated at only ~ % of of! spills
into the worms oceans from all sources (NRC, 1985; GESAMP, 1992),
they are a major source of public concern. From 1970 to 1991, there were
1,839 spills of more than ~ barrel each from OCS leases in the Gulf of
Mexico 82 were more than 50 barrels for a total estimated at 191,913
barrels. In the Pacific duing the same period, there were 34 spills-one of
which was more than 50 barrels for a total of 328 barrels. Total spillage
for both regions from 1970 to 1991 thus was 192,288 barrels (MMS,
1992b). (Natural seepage in the Pacific OCS for the period is estimated
to have been more Man 28,000 barrels. Seeps release small amounts of oil
gradually, rather than large amounts all at once. Consequently, weathering
and reduction of toxicity are rapid, as are degradation processes. Spies
(1983) found more animals near California seeps than in nonseep areas and
suggested that the base of these food webs is made up of fast-growing
populations of hydrocarbon-degrading microorganisms.) From 1964 to
1990, Mere were 24 of! spills of more than 1,000 barrels each from OCS
leases for an estimated total of 447,678 barrels. The potential effects of
offshore production-site abandonment pose unresolved concerns; Mere is
lithe practical experience wad pos~production sites. Offshore produchon-
site decommissioning is an area of study and experimentation. In Me Gulf
of Mexico and offshore California, platforms have been removed and
recycled, as well as converted to reefs (MMS, 1987c, 1989, 1991a;
GESAMP, 1992).
Exploration, development, production (Neff et al., 1987), and pos~pro-
duction acquires can affect marine communities. Potential effects associ-
ated wig each stage are distinct and require different suites of studies to
predict their extent and duration. Exploration and production ac~vides can
result in Me discharge of several classes of contaminants, including petro-
leum hydrocarbons (from drilling fluids, produced waters, and spillage) and
trace metals (from drilling fluids and produced waters). The relative impor-
unce given to each contaminant class depends on previous exploration and
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DESCRIPTION OF OPERA TION5 35
production activities and on operational practices in a given area (Boehm,
1987).
011 SPIIIS
This assessment of the adequacy of information for leasing OCS areas
under consideration for of! and gas exploration and development focuses on
the marine environment of the Arctic. In general, the marine Arctic is
characterized by three types of areas: those that are ice-free in summer;
transition zones that contain deformed first-year and multiyear pack ice that
show seasonal shifts in actual distribution and that are marked uniquely by
He presence of leads and polynyas and a well developed under ice ecology;
and the areas of permanent polar ice pack, which is predominantly
multiyear and shows little biological activity. In a general way, the boun-
dary between transition zone and permanent pack ice roughly corresponds
to the edge of the Chukchi and Beautort shelves.
Ice, especially where it is associated with areas of open water, forms a
special habitat type that hosts a large number of species and ecological
processes. The deformed pack ice at the ice front is an important envi-
ronment for benthic and pelagic organisms (Dunbar, 1981~. Epontic
communities (assemblages living on the undersurfaces of the ice) are
important to the productivity of arctic oceans. The open water of leads,
polynyas, and pack ice is Be seasonal habitat of many seabirds and marine
mammals whose annual migrations tend to follow the lead patterns that form
at breakup. The generally high productivity of these areas provides food
for the birds, marine mammals, and fish.
An important environmental concern in the Arctic is the impact of of}
spills. Ice greatly influences the fate of oil spilled in the Arctic, and Be
general behavior of oil in ice appears to be reasonably well understood,
although the behavioral details are still debated and will undoubtedly vary
with the properties of the oil and Be details of Be ice conditions (Mackay,
19854. Under-ice spills are retained in the irregular undersurface, but free
of} can concentrate in breading holes and in open leads and wind can herd
oil against Be ice edge. Low temperatures and restricted access to Be
atmosphere retard vocalization and prolong Be toxicity of spilled oil. It is
possible to hypothesize an increased vulnerability on Be part of seabirds,
marine mammals, and Be ice-edge ecosystem in general. Biological
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36 OCSDECISlONS: ALASKA
timing-the time when an of! spill occurs in relation to the life histories or
behaviors of populations or organisms-is a major factor in predictions of
impact in these instances.
Other environmental conditions need to be considered. The arctic habitat
is divided into several parts. Clearly defined localities-such as shallow-wa-
ter estuaries-form often exclusive and obligatory breeding or staging areas
for many species. Walruses and spotted seals use traditional hauling-out
areas. For many northern birds, the availability of appropriate onshore
breeding areas is limited. Shallow coastal lagoons are used extensively by
bird, mammal, and fish populations at specific times of the year, so an oil
spill in one of these areas can have an impact on an entire species if it
occurs at a time when a sigruficant proportion of the population is present.
Some of dlese areas are centers of subsistence harvesting by Alaska Natives
~iupiat Eskimo) and others, and any impact can be significant both to He
resource species and to the harvester. Experience win over spills-in-
cluding Be Exxon Chavez tells us Mat He spills often create significant,
longer-term socioeconomic disruption with consequences in turn for He
credibility of industry and government.
One area of the arctic environment that can show little or no post-spill
biological impact is He intertidal community. Although intertidal areas are
productive and highly diversified near temperate oceans, Hey are of less
year-round significance in He Arctic because of He biologically limping
effects of seasonal ice and low temperature. If an of} spill were to occur
during a foraging or staging season for large numbers of shorebirds,
however, Here would be a risk of harm to Pose animals.
routine Operations and
Habitat Disturbance
There is direct disturbance of He seafloor during platform construction.
This is limited to a very small area. A change in benefit habitat also can
occur from He discharge of drill cuttings. Most damage, however, is
caused when oil-based drilling muds are used (Davies et al., 1989; NRC,
1985), although they are not used in Alaskan waters. This kind of change
is greater wig production Han wig exploration drilling, simply because the
amount of material discharged in a single location is much greater during
production. Some contamination has been found in sediment and bendlic
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DESCRIPTION OF OPERATIONS 37
organisms several kilometers distant from the source site (GESAMP, 1992~.
From a larger geographic perspective, the habitat changes are localized and
recovery by recolonization appears to be possible.
Waste Dlscharees
Exploration involves the drilling of wells to determine He nature of
potential gas and of! reservoirs in the aftermath of regional geological
research and geophysical analysis. Exploration generally lasts only weeks
to a few months, and usually involves just one well. It is important to note
that it can take up to 10 years from permit application to exploration.
Therefore, impacts are not concentrated in time. Exploration-well
discharges are composed mostly of drilling fluids and drill cuttings. Very
localized effects, such as the smothering of bottom dwellers, can be seen in
the immediate vicinity of a platform.
Development drilling follows the drilling of successful wildcat or
exploratory wells and can continue into the production phase of operations
when the commercial reservoir is being produced. These operations can
involve a large number of wells, and they are typically conducted from a
fixed platform. There is, however, a trend in offshore development areas
to use many deviated wells from a single platform with subsea production
equipment to develop a field, although these have not been used at ice-
covered sites. Discharges include drilling fluids, drill cuttings, and well
treatment fluids. Very localized effects can be seen here as well.
Production activities begin as each well is completed during the
development phase. The production phase involves active recovery of of!
or gas from producing formations. Development and production activities
can occur simultaneously until all wells are completed or reworked.
Production water waste streams are the most significant discharges during
production operations. The current state of knowledge regarding envi-
ronmental effects and discharge controls was presented in Be proceedings
of a recent conference on We topic (Ray and Engelhardt, 1992~. The bulk
volumes of Apical discharges from offshore oil and gas activities are shown
in Table 2-2.
The largest volume of material discharged from production activities is
formation water derived from He petroleum reservoir. Drilling fluids and
cuttings, ballast water, and storage displacement water are also discharged
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38 OCS DECISIONS: ALASKA
TABLE 2-2 Typical Quantities of Wastes Discharged During Offshore Oil
and Gas Exploration and Production Activities
Approximate amounts (tons)
Exploration well
Drilling mud
Periodically
Bulk at end
Cuttings (dry mass)
Base oil on cuttings
Productior' site
Drilling mud
Cuttings
Production water
15 - 30
1 50 - 400
200- 1,000
30- 120
45,000
50,000
1 ,500/day-varies greatly with
reservoir
a Actual loss to environment may be higher (Chenard et al., 19899.
b Estimate based on 50 wells drilled Dom a single offshore production
play, drilled over 4 to 20 years (Neffet al., 1987~.
c Single playboy (Menzie, 19829.
Source: GESAMP, 1992.
but are largely reinfected. Minor discharges can include produced sand,
deck drainage, well completion and workover fluids, cement residues, blow-
out preventer fluid, sanitary and domestic wastes, gas- and oil-processing
wastes, cooling water, desalination brine, and test water from fire-contrl}
systems.
environmental effects
The biophysical effects of waste discharges from ocean platforms have
been reviewed by GESAMP (1992~:
· Data from the North Sea and Me Gulf of Mexico show that changes
can occur in benefit communities close to production sites. The changes
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DESCRIPTION OF OPERATIONS 39
are attributed mainly to the discharge of drilling wastes, including cuttings
(NRC, 1985).
Changes in Me ben~ic communities around production sites can be
demarcated into zones of effect, and the extent of these zones depends on
We amount and type of industrial activity and on the physical oceanographic
setting. From a regional perspective, the total area of the seabed affected
is very small or negligible.
· Produced water discharges can affect benthos, but are unlikely to be
significant except in relatively shallow water areas, perhaps less than 20 to
30 m.
· The effects of drilling discharges from single-well exploration and
mulUple-well development and production activities are similar qualitatively,
but differ greatly in magnitude, spatial extent, and predicted recovery rams.
Current evidence indicates Cat Me recovery of affected sites begins
soon after drilling ceases.
· It is highly unlikely Cat Me discharge of chemical wastes from
offshore exploration and production causes any hazard to human heals.
TABLE 2-3 Major Permitted Discharges and Potential Impact-Causing Agents
Associated with Offshore Oil and Gas Exploration and Production in the United
States
Drill cuttings
Drilling fluids
Cooling water deck drainage, ballast
water
Domestic sewage
Sacrificial anodes, corrosion,
antifouling paints
Production water
Hydrocarbons
1,100 tons/exploration well, less for
development well
900 tons/exploration well, 25% less for
development well
May be treated in an oiVwater separator
Primary activated sludge treatment
May release small amounts of several
metals (Al, Cu. Hg, In, Sn, Zn)
Treated in oil/water separator to
reduce total
To meal1 of 48 ppm, daily maximum
72 ppm
Source: Neff et al., 1987.
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40 OCS DECISIONS: ALASKA
· Although the discharge of production water from platforms can taint
fish on the basis of absolute concentration, dilution of the plume within
I ,000 m of the discharge site renders the risk minor.
Although the GESAMP (1992) review suggested that the effects of waste
discharges are limited, this conclusion was based predominantly on data
from temperate environments. The GESAMP (1992) evaluation did make
a recommendation relevant to this evaluation of MMS Alaskan OCS studies:
It said that the information is drawn almost exclusively from experience in
North Sea and North American offshore operations, and that additional
information should be obtained from a larger variety of environments and
from latitudes in more vulnerable localities, such as shallow or enclosed
waters and the Arctic.
12eoulato~ Controls
Regulatory controls Hat govern the discharges from offshore of} and gas
Aiding vary among jurisdictions and change over time as new information
becomes available on the effects of discharges. In the United States,
offshore discharges are regulated through a permitting system administered
by Be U.S. Environmental Protection Agency. Major permitted discharges
and agents that can cause damage are summarized in Table 2-3 (Neff et al.,
1987).
Representative terms from entire chapter:
production activities
