Title : Snow-removal melt areas at McMurdo Type : Antarctic EAM NSF Org: OD / OPP Date : August 3, 1993 File : opp93112 OFFICE OF POLAR PROGRAMS ENVIRONMENT SECTION 202/357-7766 MEMORANDUM Date: August 3, 1993 From: Acting Environmental Officer Subject: Environmental Action Memorandum (Use of New Snow Melt Areas, McMurdo, Antarctica) To: Director, Office of Polar Programs Manager, Polar Operations Safety and Health Officer Facilities Engineering Projects Manager Head, Safety, Environment and Health Implementation Team Environmental Engineer Environmentalist, ASA This Environmental Action Memorandum describes the need for a proposed action to remove snow from certain areas around McMurdo Station and place it in designated locations to melt during the austral summer. The Acting Environmental Officer posed a set of questions relating to the proposed actions, and to the potentially affected environment. These questions were responded to by Antarctic Support Associates', (ASA) Carol Andrews, Environmental Engineer; Bill Haals, Operations Supervisor, McMurdo; Charlie Hanson, Supervisor, Equipment Operations; Larry Cook, Superintendent, McMurdo Operations on July 23, 1993; background information about the proposed action as well as the questions and responses are shown below: Background A number of different areas in and around McMurdo Station are used for storing snow which is cleared from around buildings, cargo lines, and other structures at McMurdo Station. Currently the Contractor clears snow from around town and places much of it in the "snow dump" located between the waste retrograde yard and the cargo area known as the "Ballpark." The Naval Support Force Antarctica (NSFA), who has been responsible for building and maintaining the ice pier used by vessels, typically pushes snow off the pier and portions of the wharf into the northern corner of Winter Quarters Bay. During the 1993 austral winter, McMurdo Station has received unusually high snowfall. As of 25 June 1993, the existing McMurdo Station snow melt area ("snow dump") was 12 meters in height. The ASA Winter-over Operations Supervisor estimates that five or six four-meter thick lifts would have to be added to the dump before August 1993 (WINFLY) as part of ongoing snow clearing operations. This does not include the large amount of snow that typically must be scraped from around buildings, walkways, and cargo lines during WINFLY. The Contractor's proposed long-term snow management approach is as follows: temporarily stockpile snow in various locations around the station. As ice conditions allow, place clean snow at a designated location on the sea ice. Use the sea ice site until snow removal activities begin scraping hard-packed snow down to the rock surface. This occurs early in the austral summer season, typically in mid-November, when the snow remaining on roads turns slick and must be removed for safety reasons. After that time the Contractor proposes to place the snow, which would have a much higher dirt content than snow cleared earlier in the season, along the "ham shack road" east of Observation Hill. This road was originally constructed to provide access to an alternate vessel offload site, and was used at one point to access the sea ice runway. Using two or more snow melt sites as proposed would allow use of the optimal site, the sea ice, while minimizing environmental impacts. Due to this year's weather conditions, including high snow fall and high winds, the sea ice is not currently strong enough to be driven on by heavy vehicles. Therefore, the Contractor proposes to take the following actions during the 1993 austral winter: 1) cease use of the current snow dump, 2) push snow from the road along the shore between the intake and outfall quays onto the beach between the quays (not onto the sea ice), 3) haul snow to a new snow dump location east of Observation Hill, and 4) leave snow in place whenever possible to minimize the quantity which must be moved. Due to the condition of the roads in the vicinity of the proposed snow dump site east of Observation Hill, dump trucks would be emptied from the turnoff leading to Buildings 87, 89, and 126. The large ravine there would allow for snow to be dumped and pushed further down by machinery. Clean-up of the area by the labor pool would occur as snow melts and exposes any debris. General 1. What is the specific purpose of the proposed activity? The purpose of the activity is to remove snow from certain areas in and around McMurdo Station and place it in designated locations to melt during the austral summer. Snow must be removed from around buildings to provide access for emergency vehicles. Snow must also be moved to expose cargo lines and prepare the pier to receive another layer of ice as part of pier maintenance activities. What alternatives to the proposed activity have the Program and the Contractor considered? Three basic alternatives have been considered: 1 )select one or more new snow storage/melting locations (the proposed activity), 2) cease snow removal activities, and 3) "no action" (continued snow removal and use of the existing snow dump). Have probable impacts of all alternatives been considered by the Program and the Contractor? Please explain how. If "no action" is taken, then snow would continue to be placed at the current snow melting area (commonly referred to as the snow dump). This would result in a number of impacts, including 1) unsafe conditions for personnel bringing snow up to and moving it on top of the existing snow dump, 2) a large amount of snow drifting in the hazardous waste retrograde yard, which is located on the lee side of the snow dump, 3) surface water ditch erosion as snow melt runoff travels through McMurdo Station to Winter Quarters Bay, including erosion as the water passes through the former Winter Quarters Bay dump area, and 4) transport of sediment and hydrocarbons from past fuel spills into Winter Quarters Bay as the runoff travels through contaminated areas. Because physical limitations make piling snow in the current snow dump to a total height of 30 meters virtually impossible, the Contractor does not believe that continued use of the existing snow dump is a viable option. Also, there are significant safety concerns relating to working heavy equipment on such a tall, steep-sided snow hill. Furthermore, the Contractor believes the environmental impacts of the proposed activity are less than continued use of the current snow dump. Ceasing snow removal activities altogether is not considered an acceptable alternative. The pier is a vital part of the transportation link which resupplies the station each year. Thus pier maintenance is considered a vital activity, including moving snow on the pier and wharf as necessary. Also, snow must be moved from roads and around buildings for safety and operations reasons. A number of potential sites to be used rather than the existing snow dump have been considered. These sites are shown on the attached map of McMurdo Station (Attachment 1). The advantages, disadvantages, and potential environmental impact of each of these proposed sites are summarized below. The criteria used to select proposed sites are described below under Question 2. Site A: Along the shore on either side of Hut Point Advantages: o close to the ice pier where much snow removal will occur; o snow melt runoff is near the ocean; Disadvantages: o the site is too close to Scott's Hut, which is protected historic property; o the site is too small to hold a large quantity of snow o in nearby open water, a colony of seals (approximately 50) has congregated at the point as of 6 July 1993; o the site is close to a regular ice crack location running southwest from Hut Point where seals haul out. Site B: Northern corner of Winter Quarters Bay Advantages: o very close to pier and wharf; o has been used for this purpose in recent years; o snow melt runoff is near the ocean. Disadvantages: o as of 6 July 1993,snow cannot be pushed at this site due to the dangerous conditions of the bay ice (a meter or more of snow covers a ten-centimeter layer of slush over only 75 centimeters of ice); o need to ensure the site does not interfere with research activities in Winter Quarters Bay (T-320, T- 325, S-326); o dumping (anything)into Winter Quarters Bay should be avoided until remediation options are evaluated. Site C: Former snow dump at top of slope east of Winter Quarters Bay Advantages: o very close to the areas in "downtown" McMurdo which require snow removal; Disadvantages: o snow melt runoff from this location would erode the fill material which has been placed over former Winter Quarters Bay dump and may leach out contaminants as it passes through the dump; o may interfere with proposed sediment mapping activities to evaluate potential remediation measures; o site may interfere with research activities in Winter Quarters Bay (T-320, T-325, S-326; o dumping (anything)into Winter Quarters Bay should be avoided until remediation options are evaluated. Site D: On the beach along the road between the outfall and intake quays Advantages: o close to areas in town requiring snow removal; o has been used for this purpose in recent years; o snow melt runoff is near the ocean. Disadvantages: o need to ensure the site does not interfere with research activities just off-shore of this site (T-320, T-325); o site is not large enough to accommodate a large quantity of snow; o may interfere with the transition area of the sea ice runway road if dust entrained in the snow increases melt rate of the ice. Site E: Sea ice (approximately 1.25 kilometer off shore) Advantages: o snow melt goes directly into ocean, rather than running overland which causes erosion and transports sediment and contaminants to the ocean; o the snow would not have to be "mined" (moved around) to encourage melting to free up room for more snow or other land uses; this would result in significant reductions in labor, equipment use, and fuel, which in turn decreases environmental impacts of snow removal; o does not occupy land for one or more year (depending on melt rate) which may be better used for other purposes; o available area to accommodate large quantities of snow is nearly unlimited. Disadvantages: o 1.25 kilometer or greater round-trip haul distance from snow removal areas; o bearing capacity of the sea ice at the proposed site must be assessed to determine what snow depth can be supported safely and without causing cracks which may affect the sea ice runway or the runway road; o any debris which is entrained in snow brought to the site would have to be picked from the snow surface or would be carried off with the ice and deposited at sea. Site F: Southeast of Observation Hill Advantages: o site could accommodate a large quantity of snow; o melt water would run into surface water drainage ditches which the Contractor believes do not cross areas which have been contaminated by past fuel spills or waste disposal practices; o these is no planned use for the site known to the Contractor; o debris entrained in the removed snow would be left behind after the snow melts (the site has been slated for debris pick-up regardless of whether or not it is used as a snow melt site); o relatively short (one-half kilometer) mile haul distance from downtown McMurdo. Disadvantages: o the road leading from the ham shack turnoff to the landing area near the cove is extremely dangerous to large vehicles such as dump trucks; in places, the road has caved in and hardly wide enough for a dump truck to negotiate,especially in low to no light conditions during winter and WINFLY; to remedy this situation, the Contractor would widen the road using snow during the austral winter, and repair it next summer with dirt. Site G: Southwest of Observation Hill Advantages: o low visual impacts from "downtown" McMurdo Station; o the site is already a snow field; o the site is more than 91 meters (300 feet) below the top of Observation Hill and therefore would not interfere with Historical Property. Disadvantages o the site may not be useable during most of the year - the access roads to the site are typically only open in mid- summer, and are not maintained during the austral winter; during inclement weather and low to no-light situations the road becomes a danger due to its narrow and steep path; this area is also a natural catch basin for blowing snow so that drifting would be high; o access roads to the site, both going up from "The Pass" and especially from the old aquarium side, have relatively steep inclines; as such, the roads are considered difficult to drive on, particularly in snowy conditions; o the surface for travel to the site would have to be re-built; the road is in need of repair and the top section of the road directly below Building 87 is solid rock and extremely rough; o wear and tear on the vehicles would be great because trucks would have to haul up a steep grade to get to the top of the hill no matter what route was taken; o the area below Building 87, known as the "brine glacier", was created years ago by man-made means (outflow from the old water treatment plant) and has yet to melt; therefore the melt rate of a snow dump at this site would likely be relatively slow. Should the chosen alternative involve potential impacts, how would these impacts be mitigated by the Program or the Contractor? The proposed activity would potentially have the following environmental impacts: 1) air emissions released by heavy equipment used to push or transport snow; it is estimated that snow removal equipment (dump trucks, front-end loaders, etc.) would operate 7.5 hours per day, six days per week, for approximately four months (depending on weather) to accomplish required snow removal; 2) release to the ocean of sediment and contaminants picked up by melt water from snow placed at land-based melt sites; and 3) release to the ocean of pollutants contained in snow, including litter and dust. To mitigate impacts of operating heavy equipment the vehicles would be maintained in proper operating condition and checked for oil or fuel leaks. Also, the Contractor would minimize the amount of snow which must be moved by limiting snow removal operations to those which are vital for safe station operation. To mitigate impacts of debris which may be contained in the snow the Contractor would pick up the debris after the snow melts. Monitoring of surface water runoff from the proposed snow melt site east of Observation Hill would be included in the environmental monitoring plan which the Contractor is presently drafting. Have measures to assess the indirect costs of the proposed activity been identified or considered by the Program or the Contractor? Please explain how. Snow removal is part of routine station maintenance activities. Therefore, indirect costs which are new for the Program are limited to costs associated with change in snow melt site locations. The Contractor believes that the longer transport time to the new sites would be offset by reductions in time spent tending the snow piles to maximize melt rates, particularly at sea ice site. Indirect costs of snow removal include labor and equipment time required to tend the snow piles, including debris picking and pushing snow into windrows to increase the surface area and melt rate. Also, roads, buildings, or other structures, which may be damaged by snow removal activities, may require repair. The Contractor includes staffing for tending snow piles into the annual budget. The Contractor would take care during snow removal operations to avoid damaging structures. Land Use and Planning 2. What is the specific location of the proposed activity? The activity will take place at various locations in and around McMurdo Station. The Contractor will remove snow around buildings and cargo lines. NSFA will remove snow from the pier and portions of the wharf as necessary to perform pier maintenance (until 1 October 1993, when the Contractor is scheduled to assume pier construction and maintenance activities). Snow would be piled temporarily in a number of locations. Snow located along the road between the water intake and sewer outfall quays, including the transition area, would be pushed just off the shoulder of the road onto the beach area (not onto the sea ice). Some snow would eventually be placed at a designated site on the sea ice (Site E). A snow melt site east of Observation Hill (Site F) would be used when ice conditions make use of the sea ice site impossible, and after snow removal operations begin picking up more dirt. Have alternative locations been considered by the Program or the Contractor? If yes, which are they; if no, explain why. Yes. As discussed above a number of locations have been considered. The site selection process considered a number of factors, including, 1) impacts on locations used for scientific research (this disqualified coastal areas of diveable depths between Hut Point and Cape Armitage), 2) impacts on ice quality in the vicinity of the sea ice runway and the runway road, in particular the ice-ground transition area, 3) the haul distance from locations where snow must be removed, 4) environmental impacts resulting from snow melt runoff, and 5) impacts of any debris which may be contained in the snow. 3. How would any aesthetic impacts to the area from the proposed activity be handled by the Program or the Contractor? To minimize aesthetic impacts the Contractor would pick up debris contained in the snow as it surfaces to the extent feasible, and attempt to place and spread the snow to create a natural appearance. 4. Would the proposed activity have any other indirect impacts on the environment? If yes, what are they; if no, explain why none are expected. Placing snow on sea ice impedes transmission of sunlight through the ice, which may affect biological growth in the underlying ice and water column. Research by Sullivan, et. al., in the vicinity of McMurdo Station [Reference: "The Influence of Light on Growth and Development of the Sea-Ice Microbial Community of McMurdo Sound" by C.W. Sullivan, et. al., and "Seas Ice Microbial Communities. IV. Growth and Primary Production in Bottom Ice Under Graded Snow Cover" by Grossi, et. al.] demonstrated the impacts on biological growth caused by various thicknesses of snow. The thickness of the snow layer overlying sea ice varies, depending on the year and the location of the ice. Placing additional snow on the sea ice in a limited area as proposed is not expected to have significant environmental impacts because the high snow fall this year will probably produce a naturally thick layer of snow over the ice. At snow depths greater than one meter, virtually no microbial growth occurs beneath the ice, so a greater snow depth would have no impact. Snow on the sea ice may form a fresh water pond which would eventually drain into the ocean. The sea ice in the vicinity may melt at a different rate than surrounding ice due to the thicker layer of snow and "black body" heating caused by dust which may be entrained in the snow. The Contractor does not foresee any negative environmental impacts due to fresh water ponding or differential ice melting rates. The depth of snow placed on the sea ice would be limited by the load-bearing strength of the ice. If this strength is exceeded the added weight could cause cracks to develop in the sea ice. Such cracks may interfere with the ice runway, roads on the sea ice, or research activities. The Contractor would take steps to prevent crack formation, and locate Site E to minimize the impacts of any cracks which do form as a result of the proposed activity. Hauling snow to Site F would require use of a seldomly used road east of Observation Hill. If an increase from traffic on the road damages it, repairs may have to be made during the austral summer season. 5. Would the proposed activity change the traditional use(s) of the proposed or chosen site? If yes, how; if no, why? Although snow naturally exists on the sea ice and the Program routinely creates roads on the ice, the sea ice has not been used for this purpose in recent years. Site F (east of Observation Hill) also has not been used for this purpose recently. 6. Are the physical and environmental characteristics of the neighboring environment suitable for the proposed activity? If yes, explain why; if no, explain why. Yes. The sea ice is an optimal location for the snow "dump" because the melt water enters the ocean directly, rather than flowing overland. Also, the site would not require tending during the austral summer to increase snow melt rates to make room for more snow the following year, because the snow would float north and melt with the sea ice. Site F is suitable for the proposed activity as it would allow retrieval of any debris and fill material entrained in the snow. The Contractor does not know of any activities which would be displaced by using Site F. Impact and Pollution Potential and Environmental Management 7. How has protection of the environment and human health from unnecessary pollution been considered for the proposed activity (includes such considerations as pollution abatement or mitigation, and waste management [e.g., of noise, dust, fuel loss, disposition of one-time-use materials, construction wastes])? Snow clearing and hauling operations would produce noise, including back-up alarms. ASA Safety has discussed hearing protection requirements with ASA Operations (see Occupational Safety and Health Concerns discussion below). Snow removal operations near dormitories would be scheduled during regular working hours to minimize disturbance. The Contractor believes that the proposed sites represent an environmental improvement over the current snow dump location, as they would not generate melt water which passes through areas contaminated by past fuel spills, for example, ditches around bulk fuel tank D-1. The activity is not expected to produce dust, and does not involve use of materials or construction. 8. Would the proposed activity change ambient air quality at the proposed or chosen site? If yes, how; if no, why? Yes. Temporary, minor, changes to air quality would be caused by the proposed activity. The proposed activity does not pose a new addition to air pollutant sources, as snow removal is an annual activity. The extent of the activity depends on the annual snowfall. The activity would mainly occur between July and October. Vehicle trips required to haul snow to the designated sites would discharge air pollutants which result from fuel combustion. The Contractor has estimated the potential quantity of fuel which would be used during the 1993 austral winter by trucks pushing and hauling snow to the melting areas. These estimates are shown below. In summary, between 14,610 liters and 29,030 liters of fuel would be required for the activity. High Estimate for hauling snow: 6,320 liters (1670 gallons) Assumptions: 38,230 cubic meters (50,000 cubic yards) of snow, moved an average of 1.7 kilometer (1 mile) (resulting in a 3.4 kilometer round-trip), by trucks which average 2.6 kilometers per liter (6 miles per gallon) and carry an average of 7.6 cubic meters (10 cubic yards) of snow per load Low Estimate for hauling snow: 1363 liters (360 gallons) Assumptions: 23,000 cubic meters (30,000 cubic yards) of snow, moved an average of 0.8 kilometer (0.5 mile) (resulting in a 1.6 kilometer round-trip), by trucks which average 3 kilometers per liter (7 miles per gallon) and carry an average of 9 cubic meters (12 cubic yards) of snow per load High Estimate for pushing snow: 22,710 liters (6000 gallons) Assumptions: 38,230 cubic meters (50,000 cubic yards) of snow moved Low Estimate for pushing snow: 13,250 liters (3,500 gallons) Assumptions: 23,000 cubic meters (30,000 cubic yards) of snow moved 9. Would the proposed activity change water quality or flow (drainage), at the proposed or chosen site? If yes, how; if no, why? Yes. At the sea ice site, a fresh water pond would be created which would eventually enter the ocean. This addition of fresh water simply represents a relocation of the point at which the fresh water enters the ocean, and would not be expected to cause a significant change in water quality. Placing snow at Site F would increase the quantity of melt water at that site. This water would follow existing drainage patterns which transport melt water from that watershed to McMurdo Sound (see Attachment 2 for approximate location of Site F drainage pattern). The Program and Contractor are in the process of developing a comprehensive environmental monitoring plan which may include collecting samples from snow melt sites. 10. Would the proposed activity change waste generation or management at the proposed or chosen site? If yes, how; if no, why? No. Some litter which is entrained in the snow may be collected, sorted, and turned over to waste management personnel. However, this would not constitute a change to normal operations or an increase in waste generation rates. 11. Would the proposed activity change energy production or demand, personnel and life support, or transportation requirements at the proposed or chosen site? If yes, how; if no, why? The proposed activity would not change energy production or demand, or personnel and life support requirements. Because the proposed locations of the new snow melting sites are more distant from town than the current snow dump, transportation requirements would increase slightly. Given the large quantity of snow to be moved this year, the transportation requirements for snow removal would be greater than average. See discussion under Question 8 above regarding the number of truck trips to the snow dump required. Increased traffic (trucks hauling snow) on the sea ice road may increase the maintenance of the road, particularly the transition area. 12. Is the proposed activity expected to adversely affect scientific studies or locations of research interest (near and distant, short-term and long-term)? If yes, how; if no, why? No. The sea ice location will be located beyond the near- shore research sites. 13. Would the proposed activity generate pollutants that might affect terrestrial, marine or freshwater ecosystems within the environs of the station or inland camp? If yes, how; if no, why? No. In fact, the location of the new melt sites would eventually decrease the amount of surface water flowing through contaminated areas of McMurdo Station. This in turn would decrease the quantity of contaminants (mainly hydrocarbons) transported into McMurdo Sound by runoff. Air quality emissions from vehicles moving snow would not constitute a change in the composition or quantity of air pollutants typically emitted at the station. Therefore, air pollutants generated by the activity would not be expected to affect ecosystems in and around the station. 14. Does the site of the proposed activity serve as habitat for any significant assemblages of Antarctic wildlife (for example, mosses, lichens, antarctic birds or marine animals)? Of the various areas affected by the activity the following potential wildlife habits have been noted: 1) Site A - the beach around Hut Point is currently occupied by seals and therefore will not be used. Site F - skuas have been known to nest on the southeast side of Observation Hill; proposed Site F, east of Observation Hill, is at the base of the hill, and is not believed to be located in an area frequently used by skuas for nesting. Most of the activity in that location would occur prior to the typical date when skuas arrive at McMurdo Station [reference: "South Polar Skuas at McMurdo Station, Ross Island, 1991-1992," G.D. Miller, et. al., Biology Department, University of New Mexico]. Skuas also occasionally rest on the sea ice. Human Values 15. Would the proposed activity encroach upon any historical property of the proposed or chosen site? If yes, how; if no, why? No. None of the activities would disturb historical property. Other Considerations 16. What other environmental considerations may be potentially affected by the proposed activity at the proposed or chosen site? For example, have impacts associated with decommissioning of the activity been considered (and how)? The proposed activity does not involve erection of any structures, either temporary or permanent. Snow piled on land would melt over a number of years, depending on the weather. Snow placed on sea ice would melt in place or move north with the sea ice when it breaks up. Occupational Safety and Health Concerns 17. What occupational safety- and health-related issues may have to be addressed during this activity (for example, Occupational Safety and Health Administration (OSHA) standards [29 CFR 1910], other consensus standards)? If none, explain why. Problems that may be encountered are as follows: Noise generated by the heavy equipment; Weather related visibility problems; Traffic from other vehicles on same road; and Use of qualified heavy equipment operators. What step would be taken to eliminate any problems, risks or hazards associated with those issues? Explain fully. Noise survey of heavy equipment operations following ASA Hearing Conservation Program guidelines. Heavy equipment operators ensuring cab windows are kept free from frost and ice until sufficient heat is generated to defrost cab. Transportation supervisor will instruct drivers of community vehicles to give a wide berth to snow removal crews during removal operations. All heavy equipment operators are required to be experienced and are qualified by a licensing procedure. 18. Are staff or participants aware of the potential safety and health issues or problems; and, are they prepared to deal with them effectively? If yes, explain how. If no, why not? Yes. All heavy equipment operators are experienced, all are trained in hearing conservation techniques and hearing protection provided, and all are required to attend regular shop safety meetings. 19. Identify all potentially hazardous materials, chemicals, or equipment that are proposed for use (for example, drilling fluids, and pressure vessels)? Diesel fuel and engine oil used in the heavy equipment are subject to spill, however, the possibility is remote. 20. If any physical hazards would be present, how would they be controlled (excluding cold temperature problems)? Explain fully. Ice and slick surfaces present a hazard for operators of heavy equipment when entering and exiting the equipment. Extra caution should be taken by the operators in this situation. The sea ice area to be used may or may not be suitable for use. The Navy is currently evaluating the site, and will advise accordingly. The road to Site F, east of Observation Hill, is in need of repair depending on area to be utilized. Finding The Acting Environmental Officer, after reviewing the information provided above, believes that the proposed activity will pose less than minor and less than transitory impacts to the environment near McMurdo Station. The Acting Environmental Officer has approved Site D, Site E, and Site F for snow dump sites when conditions warrant alternative sites. The Contractor should develop an alternative site/operational plan which briefly describes and sets the priorities for selecting the alternative sites. The Program and the Contractor are authorized to undertake the proposed actions. Jane Dionne Attachment 1: McMurdo Site Plan showing location alternatives Attachment 2: Site F site plan Table 1: Comparison of Alternative McMurdo Station Snow Melt Sites