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INITIAL ENVIRONMENTAL EVALUATION FOR THE PROPOSED REPLACEMENT,

OPERATION, AND DECOMMISSIONING OF ICE WHARVES AT

MCMURDO STATION, ANTARCTICA

May 1992

National Science Foundation

Division of Polar Programs

Washington, D.C.
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CONTENTS

1. INTRODUCTION............................................................ 1

2. PURPOSE AND NEED FOR ACTION ...........................................1

3. ALTERNATIVES, INCLUDING THE PROPOSED ACTION ...........................3

3.1 DESCRIPTION OF THE PROPOSED ACTION ..............................3

3.1.1 History of the Use of Ice Wharves at McMurdo Station ...... 3

3.1.2 Construction .............................................. 6

3.1.3 Use and Maintenance of the Ice Wharf ....................11

3.1.4 Disposal .................................................. 12

3.2 ALTERNATIVES TO THE PROPOSED ACTION ............................13

3.2.1 Use of a Steel Barge or Barges ..........................13

3.2.2 Construction of a Permanent Pier ........................14

3.2.3 Ice Dock Alternative.....................................14

3.2.4 No-Action Alternative ...................................14

4. AFFECTED ENVIRONMENT .................................................15

5. ENVIRONMENTAL CONSEQUENCES AND MITIGATION ............................16

5.1 PROPOSED ACTION ................................................16

5.2 ALTERNATIVES TO THE PROPOSED ACTION ............................17

5.2.1 Use of a Steel Barge or Barges ..........................17

6. FINDINGS .............................................................19

7. LITERATURE CITED .....................................................21

8. LIST OF PREPARERS.....................................................23
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ACRONYMS AND ABBREVIATIONS

ASA Antarctic Support Associates, Inc.

cfm cubic feet per meter

cm centimeter or centimeters

ft foot or feet

GPM gallons per minute

IEE Initial Environmental Evaluation

in. inch or inches

kg kilogram

L liter or liters

lbs pounds

m meter or meters

min minute

NSF National Science Foundation

NSFA Naval Support Force Antarctica

PCBS Polychlorinated biphenyls

SEISSupplemental Environmental Impact Statement

USAP U.S. Antarctic Program
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INITIAL ENVIRONMENTAL EVALUATION FOR THE PROPOSED REPLACEMENT,

OPERATION, AND DECOMMISSIONING OF ICE WHARVES AT

MCMURDO STATION, ANTARCTICA

1. INTRODUCTION

The National Science Foundation (NSF) is responsible for the U.S. 

Antarctic Program (USAP) that supports a substantial scientific research 

program in Antarctica, often in cooperation with other countries. The USAP 

maintains three year-round stations in Antarctica—McMurdo Station on Ross 

Island (Fig. 1), the Amundsen-Scott South Pole Station, and Palmer Station on 

the Antarctic Peninsula. McMurdo Station is the major base for providing 

logistics support to numerous scientific field camps on the continent each 

austral summer. Logistic and operational support are provided by the 

Department of Defense [the Naval Support Force Antarctica (NSFA), U.S. Army, 

and U.S. Air Force], the U.S. Department of Transportation [U.S. Coast Guard],

and a civilian contractor [currently Antarctic Support Associates, Inc. 

(ASA)].

An important component of USAP logistic support for the continent, and 

for maintenance of safe conditions for personnel is the annual resupply by 

ship of supplies and fuel that arrive at McMurdo in late January and February.

Since 1976, cargo and fuel have been offloaded using an ice wharf1 located in 

Winter Quarters Bay. In 1991, NSF published a Supplemental Environmental 

Impact Statement (SEIS) on the U.S. Antarctic Program (NSF 1991) that contains

a brief description of the ice wharf and its use at McMurdo Station. This 

Initial Environmental Evaluation (IEE) is tiered to the SEIS and has been 

prepared to address specifically the potential environmental impacts of the 

construction, use, and periodic replacement of the ice wharf.

2. PURPOSE OF AND NEED FOR ACTION

Docking, loading, and offloading ships at McMurdo Station, Antarctica, 

require a large stable platform capable of supporting heavy equipment and 

cargo and providing a safe working environment. Since 1973, ice wharfs have 

 

 

1Voelker et al. (1991) note that the term ice wharf and ice pier are synonymous in the context of the McMurdo facility. The term 

ice wharf is used here for consistency.
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been constructed to serve this function. An ice wharf has a finite life and 

must be replaced periodically (Voelker et al., 1991, NSF 1991). In February 

1991 the ice wharf at Winter Quarters Bay developed several cracks extending 

below the water 
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Figure 1. McMurdo Sound and vicinity.
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line that rendered the wharf inoperable for the 1992–1993 season. Replacement

of a new ice wharf is therefore needed to accommodate ships that visit McMurdo

Station during one period each year to offload cargo and fuel and load wastes 

and other materials that are to be returned to the United States or New 

Zealand for disposal or reuse. The resupply ship and the fuel ship are 

accommodated normally between the end of January and the first two weeks of 

February each year. Ice wharves may continue to be replaced in the future. 

In order to resupply McMurdo Station during the 1992–93 season, construction 

of a new ice wharf, or planning for another alternative, must be initiated 

during the austral winter.

The purpose of this IEE is to evaluate potential environmental impacts 

that would result from the construction, operation, and eventual disposal of 

ice wharves. The specific actions are (1) construction of an ice wharf during

the winter season, (2) use of the ice wharf, and (3) eventual disposal of the 

ice wharf when its useful life is over.

3. ALTERNATIVES, INCLUDING THE PROPOSED ACTION

The proposed action is to periodically construct a new ice wharf using 

methods that have been developed since the early 1970s. In addition to 

construction of new wharves, this IEE also evaluates the use of ice wharves 

for offloading cargo and fuel and for other ship visits that occur in late 

January and February of each season and their eventual disposal at the end of 

their useful lives.

Alternatives to the proposed action that are evaluated in this IEE are 

(1) to replace the ice wharf with one or more steel barges, (2) replace the 

ice wharf with an ice dock, (3) construct a permanent pier, and (4) the noaction alternative of not replacing the ice wharf, and offloading cargo and 

fuel from an anchored vessel directly onto the sea ice at some distance from 

the Station.

3.1 DESCRIPTION OF THE PROPOSED ACTION

3.1.1 History of the Use of Ice Wharves at McMurdo Station
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The ice wharf has been located in Winter Quarters Bay along the Hut 

Point peninsula (Fig. 2). The ice wharf is used to dock vessels for unloading

cargo and petroleum products and
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Figure 2. McMurdo Station facilities.
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for loading wastes and other materials to be retrograded2 to the continental 

United State (or other nations when permitted). Different designs of this 

wharf have been tried over the years. A history of the development of docking

facilities is summarized here and in Table 1.

Table 1. History of docking facilities at McMurdo Station, Antarctica

Year

Pre 

1964

Cargo was unloaded from ships on the annual sea ice about 10 km 

from McMurdo Station and moved to shore by sled.

1964 Shorefast ice at Hut Point served as a wharf.

1972 A steel and wood dock was constructed but destroyed by storm.

1972 A 7.6  15.2 m non-floating ice dock was built for the 1973 

season.

1973 A large floating ice wharf (140.2 m seaward face and 193.5 m 

landward face) was built. It was 6.1 to 8.8 m thick and extended 

51.8 m from shore.

1976 A second ice wharf (about 250 m on the seaward face and about 365 

m on the landward face) was completed. It was 6.4–7.6 m thick and 

extended about 90 m from shore.

1980 A third ice wharf was completed. It's dimensions are not 

documented, but it was 4.6 m thick.

1983 A fourth ice wharf was built similar in dimensions to the 1976 

wharf. Thickness of the wharf at the beginning of the summer 

season was 4.6 m. Ice was added to the wharf in 1984, 1987, 1988, 

and 1989. Ice thickness probably exceeded 9 m by 1989.

1990 A fifth ice wharf was built similar in design to the 1976 wharf 

but only 3.0 to 3.7 m thick. About 1.5 m of ice was added in 

1991.

 

 

2The term retrograde is used by USAP to indicate the process of returning any items (e.g., wastes materials, and scientific 

samples) to the United States or other countries for disposal, recycling, or reuse.
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1992 A new ice wharf is proposed that would have a seaward face of 

about 198 m and shoreward face of 256 m. It would extend about 99 

m from shore and be 6.1–6.7 m thick.
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During the International Geophysical Year and for several years 

thereafter cargo was offloaded onto the annual sea ice about 10 km from 

McMurdo and hauled by sled train to Ross Island. In 1963–64, Winters Quarters

Bay was opened by ice breaker and the shore ice was used as a natural wharf, 

eliminating many hazards associated with transporting cargo across the sea 

ice. This natural wharf deteriorated and was replaced by a steel and wood 

dock structure between 1968 and 1972. This dock was destroyed in March 1972 

by small icebergs driven into Winter Quarters Bay during a storm. The first 

ice dock, 7.6  15.2 m, was built in the winter of 1972 and was used in 

conjunction with two short piers for the January–February 1973 shipping 

season. In 1973 a large floating ice wharf was built that lasted through the 

1975 season. A second large ice wharf, built in 1976, lasted until 1979 and 

was replaced during the winter of 1980 (NSFA 1981). The third wharf was built

in 1983, was repaired annually, and lasted until 1990. In February 1990, this

pier was towed 25 km to sea for disposal (NSFA 1990). The last ice wharf 

built in 1990 (Fig. 3) broke into three large pieces in February 1992, was 

cabled together, and, then was resurfaced for the 1991–1992 season. It was 

removed from Winter Quarters Bay in March 1992.

3.1.2 Construction

Table 2 indicates the type and quantities of materials used during this 

construction process. Table 3 lists the construction equipment to be used. 

Lessons learned from the construction and operations of previous wharves 

indicate that the procedures detailed in the Engineering Manual for McMurdo 

Station (Hoffman 1979) should be followed in constructing a new ice wharf. 

The basic guidelines are as follows:

(1)Design the wharf to be a fully floating structure to reduce stress due to 

partial grounding.

(2)Restrain the wharf from drifting out of position by use of bollards and 

cable lash-up.

(3)Oversize the wharf to allow for retreat of the seaward ice face due to the 

loss of ice in the annual trimming and straightening of the ship docking

face.
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(4)Reinforce the wharf with steel cables so if it does crack it will hold 

together until it refreezes. Set the cables back from the face by about

30.5 m so they do not interfere with trimming.

(5)Begin construction soon after 61 cm of sea ice has formed so the ice is 

thick enough to support equipment and there is enough time to achieve 

the required thickness of the wharf (6.7–7.9 m) before it is used in 

January.
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Figure 3. Schematic (not to scale) of 1990 ice wharf in Winter Quarters 
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Bay, McMurdo Station, Antarctica.
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Table 2. Types and quantities of materials used during construction of the 

ice wharf.

Type Use Amount (estimate)

Seawater To make ice 170,340,000 liters

1" steel cable Reinforce wharf 6400 m (2134 m/layer)

2" steel pipe To enable steel cable to 

be looped

107 m

1.5–2.0" steel pipe Flooding gauges 91 m

1.9 cm or smaller gravel

and fines

Provide a non-slip 

working surface on wharf

4,500–5,000 yd3 (3760–

4180 m3)

JP-8 gas Fuel for the construction 

equipment, lighting 

pumps, and heated 

building

18,900 liters

Mogas Gasoline for automotive 

and similar engines

9,500 liters

(6)Emphasize extra safety precautions when building the wharf such as 

incorporating a "buddy" system for all workers because of the slippery 

surfaces and difficult working conditions.

The following procedures may be modified slightly since each 

reconstruction must be specifically adopted to the existing conditions.

Construction would begin after the sea ice reaches 61 cm in thickness. 

Snow would be bermed to a depth of about 30 to 60 cm along the perimeter of 

the wharf (Fig. 4) in order to contain water that is pumped onto the ice. Two

5680 L/min (1500 GPM) pumps would be used to flood the wharf surface with 

about 10 cm of water. Steel pipe, 3.8 to 5.1 cm (1.5 to 2 in.) in diameter 

would be used as flooding gauges. The 10.2 cm of water is expected to freeze 

in about 24 hours which would allow another 10.2 cm layer to be added. When 

the ice thickness of the wharf reaches 1.5 m (Fig. 5), steel cable would be 

woven around a series of 5.1 cm (2 in.) steel pipes that are set into drilled 
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holes. An area of about 61  15.2 m would be reinforced and would require 

about 2130 m of cable. Flooding would continue to build the ice up for 

another 1.5 m and a second layer of cable would be added. A third layer would

be added when the ice is 4.6 m thick. The finished thickness of the wharf is 

planned to be 6.1 to 6.7 m. Lighting for the
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Figure 4
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Figure 5
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Table 3. Equipment to be used in construction of the ice wharf.

Type Function

2 1500 GPM pumps Pump water to flood the wharf for ice formation.

2 graders and a 

D4 and D6 dozer

Make snow berm and spread surfacing materials.

2 forklifts Make poles and pipe.

Grid roller Compaction of surface materials and eliminate air 

bubbles in freezing ice.

Trencher Help create a straight smooth surface on the seaward 

facing ice.

Tracked drill 

(auger)

Drill holes for bollard setting.

Tracked drill Drill holes for gauges and cable loop pipe.

Compressor 600 

cfm

Provide compressed air for air driven equipment.

construction period would be fixed on 9.1 m wooden utility poles. Shorter 

sections of these poles would be used for bollards. These would be placed 

into the ice by drilling and blasting holes, placing the poles and freezing 

them in place with a mixture of fresh water and mineral fines.

Before the wharf is used for offloading a ship, a 15 to 20 cm layer of 2 

cm and smaller gravel (friable pumice) taken from a borrow area would be 

applied to the surface. The seaward face of the ice wharf would also be 

trimmed and straightened by trenching and/or blasting the ice. About 20 

people would be involved in the construction which would probably begin in May

and finish in October. 

3.1.3 Use and Maintenance of the Ice Wharf

The wharf is used primarily for docking a tanker that unloads fuel in 

late January and a cargo ship that unloads supplies and loads materials for 

retrograde and transport back to the United States or New Zealand. The ice 
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breaker that arrives in early January and research vessels that may visit 

McMurdo also use the ice wharf.

At the end of the austral summer season, the surface material would be 

removed and stored for reuse the following season. At least on one occasion, 

a storm wet the surface material and froze it in place. Ice was than added on

top of that material and new surface material was added. Use of the wharf may 

result in spills of fuel, antifreeze, oil, or hydraulic fluids. The surface 

material generally absorbs such spills. Any noticeable spills would be 

cleaned up and drummed for retrograde. Before removal the NSFA would collect 

twenty (20) 10.0-gram samples of the surfacing materials from random locations

on the wharf. The samples would be stored frozen in pre-cleaned, 8-ounce, 

clean wide-mouth glass bottles for analysis of possible contamination. An 

action plan for the sampling of earth-fill materials will be provided by NSF 

to NSFA.

Annually the seaward face of the ice pier becomes eroded by wave action 

and discharge of water from ships that dock at the wharf. In the past, 

discharge of coolant water from docked ships has greatly eroded the wharf 

face. A wharf face curtain and a metal deflector shield would be incorporated

into the design to minimize erosion of the ice. These precautions would be 

taken to extend the useful life of the ice wharf.

The eroded face of the wharf would be trimmed by explosives and 

trenching. Holes 10.2-cm wide would be drilled in a single line, to a depth 

of 3.7 m on 0.9 to 1.2 m centers. Each hole would be loaded with a uniform 

charge of 3.7 m of 4,064 gr/cm (1600 gr/in.) detonation cord (7,010 m/sec 

velocity). The line would be about 5 m back from the seaward face. After 

blasting, the ice breaker would clear the fractured ice face and remove it 

from the bay. The 30.5 m of ice in front of the reinforced area of the ice 

wharf (Fig. 3) would provide the surface for trimming over the life of the 

wharf (approximately 4 years or more).

The wharf could be subjected to much stress due to wave action, 

grounding, and ice breakout by the icebreaker. The cable in the 61 m by 152 m

area (Fig. 4) would be designed to prevent the wharf from coming apart if 

cracks develop. Part of the maintenance schedule would be to allow the cracks

to refreeze (heal) and then to form additional ice on top to strengthen the 

wharf. It is assumed that ice would be added each year. 

3.1.4 Disposal
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When the ice wharf deteriorates (e.g., becomes too small or fractured), 

it would be towed to sea and released to melt with the annual sea ice. Prior 

to disposal all surfacing material has been, and would continue to be scraped 

off; and all structures that can be detached would be removed. Removal of the 

ice wharf is essential because it would prevent another wharf from being built

due to space limitations and would be an obstacle to ships entering the bay.
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3.2 ALTERNATIVES TO THE PROPOSED ACTION

3.2.1 Use of a Steel Barge or Barges

An alternative to reconstructing the ice wharf is to replace it with a 

relatively permanent structure that would be towed to McMurdo and located at 

the site of the previous ice wharfs in Winter Quarters Bay. This structure 

would consist of one or more steel barges that could be fabricated for or 

purchased by the USAP and towed to Antarctica. The following discussion of 

the steel barge alternative is based primarily on a draft study commissioned 

by NSF to develop a conceptual design and cost estimate for a steel barge to 

replace the ice wharf at McMurdo Station (Voelker et al. 1991).

Under this alternative, USAP would either contract to have a new 

seagoing barge or barges constructed at a foreign or U.S. shipyard or would 

purchase a conventional seagoing barge or barges currently available on the 

world market due to the slumping worldwide economy. The conceptual design is 

for a single steel barge that would be 122 m long and 30.5 m wide. The barge 

would have a draft of 4.6–6.1 m and a freeboard of 3 m, for a maximum depth of

approximately 7.6 m. The barge would be designed for a useful life of 30 

years with low maintenance. The design waterline, while at Winter Quarters 

Bay, was selected as 4.6 m; this would result in a 3-m freeboard that would 

provide easy access between the barge and shore. From the deck edge, the 

vertical sides would extend 2.1 m down to permit easy use of fenders between 

the barge, vessels moored alongside, and the shore. At 0.9 m above the 

waterline the vertical hull would change to a sloped lower hull to ensure that

ice features do not impinge on the vertical plates. A specially strengthened 

metal "ice belt" of 13.9 kg-plating (30.6 lb) would extend a vertical distance

of 3 m between the 5.5-m and 2.4-m waterlines. The standard plating used 

would be 9.3 kg (20.4 lbs), except for the ice belt. The barge would have a 

low friction hull coating (Inertia 160 or equivalent). The deck would be 

diamond patterned steel and would be covered with about 10 cm of fill material

from a McMurdo borrow area. For winter freeze-in, the barge would be ballasted

with diesel fuel or some type of antifreeze and anti-corrosion fluid. Once 

acquired, the barge could be towed to Antarctica by the U.S. Coast Guard 

icebreaker that makes an annual round trip to Antarctica or by a specially 

chartered seagoing tug. The barge would be moored to the shore at Winter 

Quarters Bay.
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The conceptual design for building a single barge as described above 

would provide a smaller work area (122  30.5 m) than the 152  61 m area 

initially envisioned. The single barge design was based on standard 

engineering design criteria for length, breadth, and depth for an ocean-going 

barge. The Voelker et al. (1991) study suggests that a larger work area might

be achieved by using two or four barges. Should this option be pursued, 

uncertainties about ice build up between the barges and possible twisting 

moments from cargo stored on one of the barges or being transferred from one 

barge to another would need to be evaluated. The single-barge wharf could be 

equipped with a conveyer system for moving the cargo from ship to shore rather

than using tractors and trailers, thus compensating for the reduced work area.

This option using steel barges could be a possible long-term solution. 

It would take 2–4 years to implement, but would require low maintenance over a

30- to 35-year expected lifetime.

3.2.2 Construction of a Permanent Pier

After the natural shorefront ice was destroyed through use and wave 

action in 1968, an attempt was made to replace it with a steel and wood panel 

structure. This structure was completed in 1972 but was promptly destroyed by

a storm that drove ice against the dock. It took several years to remove the 

debris and some steel I beams may still be frozen in the ice near the shore. 

The failure of this dock emphasizes the need for the wharf structure to be 

able to withstand heavy pounding of surf and small icebergs. Currently no 

permanent pier structure has been designed for McMurdo Station, and history 

and recurring extreme sea state conditions suggests this alternative is not 

feasible and is not considered further.

3.2.3 Ice Dock Alternative

Building an ice dock at Winter Quarters Bay differs from constructing an 

ice wharf in three major ways. First, an ice dock is much smaller than an ice

wharf. The previous ice dock was 7.6  15.2 m and was a simple platform onto 

which containers were lifted for removal. Because it is not large enough for 

large trucks to turn around on, the handling time and unloading time is 

greatly increased. Second, the work would have to take place near the edge of

the dock, thus creating a safety hazard. Third, the dock cannot be used for 

mooring a ship, and thus all lines would need to be tied to shore as well as 
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sea anchors deployed. Safety of the vessel would be a concern in the event of

a severe storm. This alternative is, therefore, not considered viable and is 

not considered further.

3.2.4 The No-Action Alternative

This alternative would require ships to dock at the sea ice edge some 

distance from McMurdo. The sea-ice alternative would require all cargo 

containers to be small enough to be moved by sled and light enough to be 

supported by the sea ice. The time to offload and load the ship which 

currently takes 12–14 days using the ice wharf would be greatly extended. 

Over 9 million metric tons of material comes into and out of McMurdo each year

by ship. Also, this is the time when the ice is becoming thin and safety on 

that ice is an overriding USAP concern. The extended time needed to offload 

the ships, the constraints on container size, and safety concerns indicate 

that this alternative is not viable, and no further discussion of it is

provided here.

4. AFFECTED ENVIRONMENT

McMurdo Station (7751S, 16640E) is the major support station for the 

USAP. The station is located on Ross Island and consists of more than 

100 structures, extensive storage yards, an ice wharf, an annual sea-ice 

runway, a skiway, a helicopter landing area, and other ancillary structures 

and features (e.g., communications antennas and roads).

McMurdo Station is located on a southward-projecting peninsula of Ross 

Island at the edge of the Ross Ice Shelf (Fig. 1). Its weather is affected by

cold air drainage flowing off the continent and ice shelf and strong cyclones 

that develop over the Ross and Amundsen seas. Mean monthly temperatures at 

McMurdo range from -3C (26 F) in December and January to -28C (-18F) in 

August. Extreme maximum and minimum temperatures of 7C (42F) and -51C (-

59F), respectively, were recorded during a 13-year period at McMurdo. The 

mean annual temperature is approximately -18C (0F). The average 

precipitation is 17.4 cm of water equivalent annually. Ice fog is common 

throughout the year and sometimes reduces visibility to zero.
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Man's activities at McMurdo have greatly influenced the benthic 

populations of Winter Quarters Bay. Inorganic material such as discarded 

equipment and general trash litter the bottom of Winter Quarters Bay and can 

be found up to 6 km north to the Cinder Cones (Dayton and Robilliard 1971). 

Levels of purgeable hydrocarbons in Winter Quarters Bay sediments are as high 

as 4500 ppm (Lenihan et al. 1990) and are pyrolytic in origin (i.e., products 

of incomplete burning or generated by such high temperatures as those 

encountered in engines). Polychlorinated biphenyls (PCBs) with a composition 

identical to that of Arochlor 1260 are present in the sediment on the order of

1 ppm, a level that would be considered high in coastal or estuarine 

environments. This pollution is primarily confined to the bay (approximately 

0.1 km2 in area) because of limited circulation and an underwater sill that 

partially encloses the bay and restricts water movement and flushing 

(Risebrough et al. 1990). Fill material along the shore of the wharf area has

eroded into the bay for about 8 to 9 m (Voelker et al. 1991, Appendix B).

McMurdo Sound is a deep body of water with depths reaching 500 m just 10 

km west of McMurdo (Barry and Dayton 1988). Ross Island and adjacent McMurdo 

Sound provide important breeding sites for such marine mammals and bird 

species as Weddell seals, Adelie penguins, and Emperor penguins. Weddell 

seals and migratory skuas are the most conspicuous wildlife in the immediate 

vicinity of McMurdo Station. Killer whales and leopard seals are present in 

the area and prey on seals and penguins in the vicinity when open channels 

form in the ice.

Because more than 97% of Antarctica's 14-million-km2 land mass is 

covered by ice, exposed rock and other substrate available to support 

terrestrial ecosystems is limited.

5. ENVIRONMENTAL CONSEQUENCES AND MITIGATION

5.1 PROPOSED ACTION

Environmental impacts from the construction, operation, and disposal of 

the ice wharf are minimal. These consist of fuel use and associated 

emissions, construction material use, disposal at sea, collection and use of 

surfacing material, use of explosives, and safety issues. The use of about 

18,900 liters of JP8 and 9,500 liters of Mogas (gasoline) to run the 
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construction equipment and provide for the electricity for the pumps is less 

than 0.01 percent of the fuel burned at McMurdo each year. The total 

emissions from use of fuel at McMurdo have been evaluated in the SEIS for the 

U.S. Antarctica Program and found to have been both less than minor or 

transitory impacts (NSF 1991). Construction material consists primarily of 

steel and water. There are also some wooden utility poles that would be 

imbedded in the wharf. Transportation of these materials to McMurdo would 

result in no impacts of concern, because they represent a very small 

percentage of the cargo on the resupply ship (cargo may exceed 6.5 million 

metric tons). Disposal of these items at sea as the wharf melts should result

in little adverse impact. The steel would eventually dissolve through 

oxidation unless it is released to deep waters that are anaerobic. Iron 

released through oxidation provides a limiting nutrient for phytoplankton 

production. The utility poles would be likely to float for several years, 

providing substrate for attachment of sessile organism until they are 

destroyed by biological processes. Collection and use of the fill materials 

is an ongoing action at McMurdo Station, occurs only at designated borrow 

areas, and results in acceptable impacts (NSF 1991). Efforts to collect all 

contaminated fill on the ice wharves for retrograde should prevent impacts due

to the spread of any hazardous substances. 

Safety in Antarctica is a primary concern and is given highest priority 

by USAP. The ice wharf would be used only by people with ice safety training 

and by qualified equipment operators. If existing guidelines are followed, 

the wharf greatly increases the safety of offloading and loading compared to 

the no-action alternative of using the sea ice or an ice dock that is too 

small for safe equipment operation. Use of explosives to trim the ice face 

usually results in only a few detonations of a line of charges per year. 

These operations would be performed only by qualified personal with the proper

training. No safety problems from these operations have been noted in the 

past or are expected in the future.

5.2 ALTERNATIVES TO THE PROPOSED ACTION

5.2.1 Use of Steel Barge or Barges

5.2.1.1 Potential environmental impacts
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Experience in the Arctic has shown that steel barges can be used 

successfully for long periods (Voelker et al. 1991). A life time of 30 years 

or more is a reasonable expectation. These barges generally have no special 

ice-strengthened features, and operators report that "nothing dramatic ever 

happens as a result of the freezing-in process." Barges that have been used 

in the Arctic environment include single-skinned river fuel barges, lightshelled seismic vessels, and double-skinned, heavily constructed icebreaking 

barges. In the Arctic, the main concern is not from the freezing-in process, 

but rather from the danger of the barge being swept away with the ice during 

ice breakup. Careful selection of the location for freezing-in the barges is 

needed to ensure that they are securely moored.

Under this alternative, the barge would be towed to Antarctica from its 

construction site or point of acquisition. On at least one past occasion, a 

fuel barge was towed to Antarctica by an icebreaker that was making its annual

roundtrip to support the USAP. There was a significant reduction in cruising 

speed (from 12 knots to 2–4 knots) and transit time for the icebreaker. 

Careful planning would be required to avoid effects on icebreaker-supported 

activities such as refueling of Marble Point and support of science. 

Possibilities for avoiding such impacts would be to obtain a longer period of 

support from the U.S. Coast Guard, possibly arrange to have two icebreakers 

available, or have the barge or barges towed by a commercially chartered 

seagoing tug. Environmental impacts from towing the barge would be primarily 

include an increased amount of fuel used by the icebreaker. 

Although the barge or barges would be designed for low maintenance, 

replenishment of the deck coating or non-skid surface would be required on an 

annual basis, and repair of minor structural damage associated with normal 

usage of the barge would be needed periodically. No requirement of periodic 

dry docking is anticipated, and should significant structural damage to the 

barge occur, it could probably be towed to a drydock in New Zealand for 

repair. Periodically, the deck surface material would be replaced. (It is 

possible another type of deck surface would be used.) Because the deck 

coating would be procured in the United States and then transported to 

Antarctica, the current practice of acquiring earth materials in the McMurdo 

area for spreading on the working surface of the ice wharf would no longer be 

required, and the already minimal impacts associated with collection of these 

materials would be reduced. Environmental impacts from maintenance activities

are likely to be both less than minor and transitory.
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Heated storage would be required for the fenders used between the barge 

and vessels tieing up to the wharf. Such storage could result in impacts of 

building a new storage facility, but existing storage may be available.

It is possible that some dredging would be needed in the area where the 

barge or barges would be anchored. This could create adverse impact because 

contaminated bottom sediments (NSF 1991) would be disturbed and perhaps 

remobilized. Unique benthic communities (NSF 1991) could be disturbed or 

destroyed by dredging. However, this area is already highly disturbed and the

sediments contaminated with hydrocarbons. To the extent possible, dredging 

would be avoided. The barge may require seabed anchors to keep it in place, 

which could also result in disturbance of bottom sediments and communities. 

This potential impact should be minimal because of the localized disturbance.

5.2.1.2 Recommendations

The following recommendations contained in Voelker et al. (1991) should 

be implemented if a final design for using a steel barge or barges to replace 

the ice wharf is pursued:

1.Acquire additional monthly data on ice thickness in the immediate vicinity 

of and adjacent to the ice wharf site at Winter Quarters Bay and obtain a 

series of ice cores in this area to estimate ice strength. This 

information would be used to evaluate if the deterioration of the ice 

piers is related in part to the wastewater discharge that occurs within 

about 150 m of the site. More information on the bottom contours and 

substrate conditions is also needed. If it appears that dredging is 

needed to allow a barge to be used, a detailed mitigation plan should be 

developed to ensure that any adverse impacts from the dredging operation 

and the resulting spoils are minimized.

2.Explore the acquisition and use of existing equipment from Arctic 

operations. The suitability of such equipment would need to be evaluated 

carefully. If an existing barge or barges could be obtained, considerable 

time and expense could be saved and additional capabilities (e.g., having 

cranes, work areas, or berthing capabilities) might be possible.

3.Examine the possibility of mooring the barge farther from the shore to 

eliminate the need for shore-side fenders.
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4.Determine if improved methods of deploying oil spill retention booms could 

be incorporated into the design of the barge.

5.Evaluate the possibility of carrying cargo on the barge when it is towed to 

McMurdo. Such transport could free up space on the annual resupply vessel 

for other materials, equipment, and supplies. If schedules could be 

coordinated, delivery of materials needed for the construction of the new 

South Pole Station could be expedited.

6.Determine the need to develop some type of cable or chain to draw across the

bay to protect the barge from icebergs.

6. FINDINGS

The proposed construction of ice wharves at McMurdo Station would result 

in both less than minor or transition impacts. Construction of the 

replacement ice wharf would require steel cables, steel pipe, and wooden poles

that are incorporated into the ice structure. Use of the wharf would require 

annual collection of earth materials that would be applied to the surface of 

the wharf immediately before it is used each season. Although such materials 

are scraped from the wharf surface at the end of each year and stockpiled for 

future use, a considerable quantity of these materials become embedded in the 

ice structure and are not recoverable. The surface of the ice wharf may 

become contaminated with minor spills of petroleum products from the operation

of heavy equipment and the transfer of fuel from the tanker. Although such 

spills would be cleaned up to the extent feasible, some residual contamination

could be retained in the ice wharf structure. The useful life of the ice 

wharf is uncertain. Although attempts are being made to improve the design so

that the wharf would have an extended life, history to date indicates that an 

average of four years is to be expected because the underlying ice 

deteriorates and cracks form to the point that the structure begins to break 

up. At the end of its useful life, therefore, the wharf would be towed to sea

and released. After the wharf is set adrift, the steel cable, imbedded earth 

materials, and any contamination would gradually be released to the ocean. 

The environmental impacts of this disposal are considered to be negligible 
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because they occur very gradually and the resulting contamination levels, if 

any, would be very small.

Reasons for ice wharf failure or longevity are not well understood. The 

fewer wharves that are built the less materials must be used and eventually 

disposed of. It is therefore suggested that the following recommendations be 

considered for implementation. Some of these recommendations are aimed at 

using the wharves as a laboratory to increase our understanding of ice stress 

and failure in order to increase the life of future wharves, if they are 

built. These recommendations are:

1.Perform theoretical analysis or wave flexure in a floating ice wharf, 

measurement of the ice properties in the wharf, determination of local 

bathymetry, and monitoring of water motion and ice reflection during the 

open-water season should be done.

2.Use the proposed McMurdo snow and ice laboratory or suitable institution for

the study of ice wharves.

3. Evaluate the effects of the McMurdo heated wastewater discharge on ice 

wharves.

 

A substantial effort should also be made to avoid the cracking of the 

ice wharf during sea ice breakout by the icebreakers. Historically this seems

to be the single greatest reason for wharf failure. Combinations of trenching

and blasting just prior to ice breakout should continue to be explored as 

preventive measures. 

Obtaining twenty (20) 10.0 gram samples of the surface material and

evaluation of those samples for possible contamination is necessary to detect 

and to limit the potential spread of any contaminants. Evaluation of these 

samples must be done prior to reuse of the surface materials.

The use of a steel barge or barges to replace the ice wharf has many 

potential advantages. Based on experience with barges in the Arctic, a barge 

or barges may have a 30-year or longer life. If a barge or barges were to be 

used for the wharf, construction activities currently required each winter 

season for the ice wharf would no longer be needed, resulting in fewer 

(approximately 6) workers needed in the winter-over crew. There is a 

possibility that mooring the barges to the shore at Winter Quarters Bay would 

require dredging. Dredging could result in adverse environmental impacts by 
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release of contaminated materials (e.g., PCBs and residual petroleum products)

from the substrate and disturbance or destruction of unique bottom 

communities. The barge or barges would require low maintenance, consisting 

primarily of periodic resurfacing of the deck, tanks, and sides. Each year 

the barges tanks would need to be ballasted to limit potential damage from 

freezing and ice. If diesel fuel could be used to ballast these tanks, the 

barge would represent an additional fuel storage facility. A risk analysis of

the potential of a fuel leak from the ballast tanks would be required before 

this option was pursued. Other possibilities for ballast are available. Use 

of a single barge would limit the size of the work area and would probably 

require the development of a conveyer or boom system to move cargo to and from

the shore. Use of two or four barges would require additional studies of the 

effects of ice buildup between the barges and their ability to resist damage 

from unequal distribution of weight during cargo transfer. Use of steel 

barges is not a viable option for the 1992–93 season, but it should be given 

serious consideration for implementation in the future. USAP will conduct 

additional environmental review should this alternative be pursued.

Other alternatives that were considered were a permanent pier, an ice 

dock, and the no action alternative of using sea ice as a docking facility. 

These alternatives were dismissed because they did not seem to be practical 

and/or there were major safety concerns.

7. LITERATURE CITED

Barry, J. B., and P. K. Dayton. 1988. "Current patterns in McMurdo 

Sound, Antarctica, and their implications for productivity of 

local benthic communities." Polar Biology 8:367–376.

Dayton, P. K. and G. A. Robilliard. 1971. "Implications of pollution to the 

McMurdo Sound benthos." Antarctic Journal of the United States 8:53–56.

Hoffman, C. R. 1979. Engineering Manual for McMurdo Station. Civil 

Engineering Laboratory, Port Hueneme, California.

Lenihan, H. S., J. S. Oliver, J. M. Oakden, and M. D. Stephenson. 1990. 

"Intense and localized benthic marine pollution around McMurdo Station, 

Antarctica." Marine Pollution Bulletin 21(9):422–430.
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National Science Foundation (NSF). 1991. Final Supplemental Environmental 

Impact Statement for the U.S. Antarctic Program. Division of Polar 

Programs, Washington, D.C.

Naval Support Force Antarctica (NSFA). 1981. Report of Operation Deep Freeze

81, 1980–81. U.S. Navy, COMNAVSUPPFORANTARCTICA, Port Hueneme, 

California.

Naval Support Force Antarctica (NSFA). 1984. Report of Operation Deep Freeze

84, 1983–84. U.S. Navy, COMNAVSUPPFORANTARCTICA, Port Hueneme, 

California.

Naval Support Force Antarctica (NSFA). 1990. Report of Operation Deep Freeze

1989–90. U.S. Navy, COMNAVSUPPFORANTARCTICA, Port Hueneme, California.

Risebrough, R. W., B. W. DeLappe, and C. Younghans-Haug. 1990. "PCB and PCT 

contamination in Winter Quarters Bay, Antarctica." Marine Pollution 

Bulletin 21(11):523-529.

Voelker, R. P., P. V. Minnick, L. A. Schultz, and J. W. St. John. 1991. 

Conceptual Design and Cost of a Steel Barge to Replace the Ice Pier at 

McMurdo, Antarctica. Draft Report submitted to the Division of Polar 

Programs, National Science Foundation, Washington, D.C.
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8. LIST OF PREPARERS

NATIONAL SCIENCE FOUNDATION, DIVISION OF POLAR PROGRAMS 

Dr. Sidney Draggan, Environmental Officer

OAK RIDGE NATIONAL LABORATORY

R. B. McLean, Ph.D., Marine Biology, Florida State University; B.A., Biology, 

Florida State University; 18 years' experience in environmental 

assessment.

R. M. Reed, Ph.D., Botany/Plant Ecology, Washington State University; A.B., 

Botany, Duke University; 18 years' experience in environmental 

assessment.