Title : Sea water intake, McMurdo Type : Antarctic EAM NSF Org: OD / OPP Date : July 23, 1993 File : opp93108 NATIONAL SCIENCE FOUNDATION OFFICE OF POLAR PROGRAMS OFFICE OF THE ENVIRONMENT 202/357-7766 MEMORANDUM Date: July 23, 1993 From: Acting Environmental Officer Subject: Environmental Action Memorandum (Sea Water Intake Quay Improvements at McMurdo Station, Antarctica) To: Director, Office of Polar Programs Safety and Health Officer Manager, Polar Operations Section Facilities Engineering Projects Manager Head, Safety Environment & Health Implementation Team Environmental Engineer Environmentalist, ASA REFS: Safety, Environment and Health Program Policy Memorandum 90-2. Authorization, and Reporting Procedures for, Gathering and Use of Fill at McMurdo Station, Antarctica. Dated October 1, 1990. Environmental Action Memorandum (Blasting for, and Placement of, Fill Rock at McMurdo Station, Antarctica, During the 1990-91 Season), Dated October 2, 1990. Memorandum, Subject: Review of "Environmental Assessment for Collection (and Placement) of Earth Fill Material," Dated November 17, 1990. Environmental Action Memorandum (Collection of Earth Fill Materials at McMurdo Station During the 1992-1993 Season), Dated December 1, 1992. Dayton, P.K., G.A. Robilliard and R.T. Paine, 1970. Benthic Faunal Zonation as a Result of Anchor Ice at McMurdo Station, Antarctica, [pp. 244-258]. In Antarctic Ecology (M. Holdgate ed.), Academic Press, New York. This Environmental Action Memorandum describes the need for making improvements at the sea water intake quay. Specifically, the new building, Building 179, would be replaced as a larger structure to accommodate piping and electrical controls for the Crary Science and Engineering Center (CSEC) aquarium seawater intake line. The new Building 179 would be better insulated and contain electrical wiring which complies to Code. Building 178 will be removed to eliminate an unnecessary building and reduce maintenance requirements. 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) Terry Johnson, Environmentalist; Carol Andrews, Environmental Engineer; Ralph Stokes, Senior Construction Coordinator; and Jeff Montroy, Project Engineer, on July 12, 1993; background information as well as the questions and responses are shown below: Background An earth intake quay is the location where seawater is drawn out of McMurdo Sound for producing potable water and supplying water to research aquariums. Water is drawn through a vertical well pipe which is surrounded by fill material (the quay) to protect it. In approximately 1983, the quay was extended into the Sound and a new intake well pipe was installed in conjunction with the construction of a new seawater desalination plant. The old intake well is still in place and has been used occasionally as a backup to the new well. A small building (Building 178) was constructed in 1983 on the quay over the old intake well. The 7.29 square meter (78.5 square foot) building functioned as a heated enclosure which contained a space heater and electrical service for the connection of pipe heat trace cable. This temporary building is made of wood framing with plywood exterior siding. The walls are insulated with rock-wool bats. See Attachment 1 for a photograph of the building. The new intake well was constructed when the quay was extended in order to draw water from a point farther below the annual sea ice to preclude ice formation in the intake well. The new well consists of a 24"-diameter vertical concrete pipe rising from a 36"-diameter horizontal concrete pipe in an inverted "T" configuration. The horizontal pipe is located approximately 42 feet below the top of the quay, approximately 32 feet below the mean water level. A temporary plywood building (Building 179) was placed over the intake well where it emerges from the top of the quay. The function and construction of Building 179 is the same as Building 178 over the old intake well, with the exception of an oil-fired furnace used to heat Building 179, rather than use of an electric heater in Building 178. The Contractor proposes to continue making improvements to the intake quay. These improvements are expected to occur according to the following schedule: Activity Schedule Replace temporary Building 179 1992-93 Austral Summer Remove and retrograde Building 178 1993 Winter/1994 Summer Install stanchions 1993-94 Austral Summer Place fill material to repair erosion 1993-94 Austral Summer Install erosion control 1994-95 Austral Summer Environmental Assessment Queries and Responses GENERAL 1. What is the specific purpose of the proposed activity? The Contractor proposes the following improvements to the intake quay: A) Remove and retrograde Building 178 and cap the old intake line; B) Remove and retrograde Building 179 and replace it with a pre-fabricated metal building; C) Replace temporary wood cribbing under the seawater intake line between Building 179 and former intake well location with permanent steel stanchions (approximately 10 stanchions); D) Place fill material around quay to replace eroded fill; and E) Place concrete blocks or revetment mats around the quay. The general purposes of the proposed activities are to improve the functions at the quay. The purpose of replacing Building 179 is to provide a larger structure to accommodate piping and electrical controls for the Crary Science and Engineering Center (CSEC) aquarium seawater intake line. New Building 179 also would be better insulated and contain electrical wiring which complies with the National Electric Code. Building 178 is to be removed to eliminate an unnecessary building, thus reducing maintenance requirements. Placing rip rap and revetment mats or concrete blocks is proposed to reduce erosion of the quay. Design of the intake quay erosion control system is still in the preliminary stage. More detailed information regarding erosion control design will be submitted by the Contractor as it becomes available. What alternatives to the proposed activity have the Program and the Contractor considered? The Contractor has considered the proposed activities and the "no action" alternative to each activity. Various alternative methods of erosion control have also been considered, including use of concrete mats, concrete blocks, sheet piling, and rock-filled gabions. Have probable impacts of all alternatives been considered by the Program and the Contractor? Please explain how. Under the no action alternative, the existing buildings would remain in place. In this case, the CSEC aquarium seawater intake line could not be installed as designed. The aquarium intake line is required to support marine research. Also, the aesthetic improvement of removing the old, wood buildings would not be realized. The old buildings are constructed of unpainted plywood and have become weathered and unsightly. The amount of energy used by the intake buildings would remain the same rather reduced by installation of a building with increased energy efficiency. Also, flue gas emissions from the furnace in Building 179 and fuel storage on the quay would continue rather than being eliminated by the use of an electric unit heater in the new building. If concrete blocks or other erosion control methods are not installed around the quay, the fill used to construct the quay will erode more quickly. Thus, the quay would require more frequent repair and additional fill, which is not in compliance with the United States Antarctic Program (USAP) fill use minimization policy. However, placing concrete erosion control devices (mats or blocks) or sheet piling requires importing large quantities of non-native materials, as well as the use of sophisticated installation equipment and construction diver labor. ASA Engineering estimates that the cost of purchasing, transporting, and installing imported erosion control devices is roughly twenty times the annual cost of repairing the intake quay erosion. The impacts of the proposed activities include waste generation (construction debris from removed buildings), and, potentially, airborne dust generation during fill material generation and placement, stanchion installation, and building removal. The buildings to be removed are not painted. Therefore, generation of paint dust containing heavy metals will not occur. Although revetment mats would be placed partially below water, the mats are constructed of inert materials (concrete and metal) and not expected to impact sea water quality. Fill material would be collected from approved areas such as those identified in the (Environmental Action Memorandum) "Collection of Earthen Fill Material at McMurdo Station During the 1992-93 Season," December 1, 1992. Placement of additional earth fill material and erosion control mats or concrete blocks would temporarily increase the suspended solids content and turbidity of the seawater near the intake quay and would disturb a portion of the shallow marine zone (zero to six meters water depth). This area is subjected to annual scouring action by the sea ice (Dayton, et. al). Therefore, disturbance to the area caused by construction activities are not expected to be significant. Building 179 is currently heated by a furnace. Fuel for the furnace is stored near the building in a 1,040-liter (275-gallon) tank which is occasionally filled by using a fuel delivery truck. If fuel is spilled near the intake well, the fuel could potentially travel along the interface between the pipe and fill material to the water and impact aquatic fauna. Spilled fuel could also be drawn into the seawater intake line and contaminate station drinking water supplies. Significant improvements have been made by the Contractor to reduce spills due to "day-tank" over-filling such as improved fuel-level gauging systems. A number of spills have occurred in past years at McMurdo day tanks, thus, the occurrence of a spill at the intake quay day tank but not likely. Should the chosen alternative involve potential impacts, how would these impacts be mitigated by the Program or the Contractor? To mitigate potential impacts caused by a fuel spill on the quay, the Contractor will replace the oil-fired furnace with an electric heater and carefully remove the fuel storage tank. Waste generation would be minimized by reusing the furnace, currently in Building 179, in another location at McMurdo Station, if possible. The building materials are not in reusable condition. Dust generation on site would be minimized by wetting the fill material as necessary, and disassembling the buildings rather than crushing them on-site. Measures to mitigate the impacts of collecting and transporting earth fill material will be addressed in a separate EAM. Have measures to assess the indirect costs of the proposed activity been identified or considered by the Program or the Contractor? Please explain how. Yes. Removal of Building 178 and capping the old intake well would eliminate a back-up to the new intake well. However, the Contractor has found that drawing seawater from a temporary intake hole drilled into the annual sea ice when the new intake well is unavailable is as, or more effective, than using the old well. A backup inlet to the new intake well is rarely needed; it is expected that one will be required less than once every other year. Drilling a hole in the sea ice has the same impacts as drilling access holes for researchers. A "fish hut" is temporarily placed over the hole and electrically heated to keep water conveying equipment from freezing. The Contractor has also considered the proposed activities in relation to changes to the water treatment system, which are in the planning stage. The Contractor believes the proposed upgrades to the sea water intake quay would be compatible with changes to the water treatment system. If waste water treatment allows the station to move to 100% fresh water recycle, a sea water intake facility will still be required to supply water to aquariums. LAND USE AND PLANNING 2. Where would the proposed activity be located, specifically? The proposed activities would occur on the sea water intake quay. See attached map (Attachment 3). Have alternative locations been considered by the Program or the Contractor? If yes, which are they; if no, explain why. No. The location of the proposed activities is dictated by the location of the existing intake quay and associated structures. Moving the quay to a different location would cause more environmental problems than the proposed improvements to the existing quay and associated structures. 3. How would any aesthetic impacts to the are from the proposed activity be handled by the Program or the Contractor? Replacement of the existing wooden structures with one prefabricated metal building will improve the aesthetics of the intake quay. The revetment mats and stanchions would be neatly placed to provide an orderly appearance. See attached photos of existing Buildings 178 and 179, and Building 124, which is similar to replacement Building 179. 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. Yes. Impacts associated with collecting the fill material would occur from the proposed activity. Approximately 155 cubic meters (207 cubic yards) of fill will be required in the 1993-1994 austral summer season. Mitigation of such impacts have been addressed in environmental documentation relating to fill material collection. After Building 178 is removed, the old intake well will no longer be useful. A portion of the old well, which is embedded in the quay, will probably be temporarily abandoned. It cannot be removed without excavating the fill material around it which makes up the quay. The old well will be covered to prevent it from posing a safety hazard. 5. Would the proposed activity change the traditional use(s) of the proposed (or chosen) site? If yes, how; if no, why. No. The proposed activities would only serve to improve the existing activity at the site, which serves as part of the water supply system. 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 quay is a man-made structure. Therefore, the proposed activities would not disturb any areas which would otherwise be left in a natural state. IMPACT AND POLLUTION POTENTIAL AND ENVIRONMENTAL MANAGEMENT: 7. How has protection of the environment and human health from unnecessary pollution or impact 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])? The new metal building (179) could be reused for another purpose in the future, thus reducing one-time-use materials. In the past, concrete revetment mats have failed prematurely due to improper anchoring, but the Contractor has taken steps to improve the anchoring system and prolong the useful life of the mats. 8. Would the proposed activity change ambient air quality at the proposed (or chosen) site? If yes, how; if no, why. No. The activity does not entail use of major earth moving equipment which would generate dust, but heavy equipment will be required. The heavy equipment engine emissions will temporarily increase air pollution in the area. Replacement of Building 179 with an electrically heated building eliminates heating furnace flue gas emissions at this location. 9. Would the proposed activity change water quality or flow (drainage), at the proposed (or chosen) site? If yes, how; if no, why. Yes. Construction activities associated with placing erosion control mats would temporarily increase suspended sediments in the vicinity of the quay. Fill material would be placed on the top of the quay and not below the water line. No long-term water quality impacts would be expected. The buildings would not come into contact with water, nor change drainage patterns. Concrete revetment mats are constructed of inert materials (concrete and aluminum or stainless steel cables) which would not leach contaminants. Removing the temporary building which required fuel to run the furnace reduces the potential for release of fuel on the quay. 10. Would the proposed activity change waste generation or management at the proposed (or chosen) site? If yes, how; if no, why. The existing wood buildings would be retrograded as construction debris. Salvageable portions would be saved for reuse where possible. The buildings are unpainted; therefore, they are not contaminated with heavy-metals and can be disposed of as nonhazardous construction debris. The debris would be placed in the location identified by ASA Waste Management to be processed and retrograde. 11. Would the proposed activity change energy production or demand, personnel and life support, or transportation requirements at the site? If yes, how; if no, why. Yes. The activity would eliminate use of JP-8 on-site. Overall energy demand at the site would be decreased by eliminating one building and replacing the other with a more efficient, better insulated structure. New Building 179 would have R-20 rated insulation. The current structure's R-value is estimated by ASA Engineering to be less than R-11. The proposed activities would improve water supply capabilities, a vital part of the station life-support system. The activities would not increase station personnel or life-support requirements. 12. Is the proposed activity expected to adversely affect scientific studies or locations of research interest (near and distant, in the short-term and in the long-term)? If yes, how; if no, why. No. The proposed activity is to upgrade the seawater intake system required to supply sea water to the new CSEC aquarium. The activity would enhance scientific research at the station. 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. Only minor, temporary air emissions would be expected to result from the proposed activities. 14. Does the site of the proposed activity serve as habitat for any significant assemblages of Antarctic wildlife (for example, mosses or lichens, or antarctic birds or marine mammals)? No. The quay is a man-made structure which has been characterized by a high degree of human activity in the past. Seals and penguins can be seen occasionally in the vicinity of the quay. However, the quay and surrounding area it do not serve as wildlife habitat. The benthic zone nearest the quay has been disturbed by past activities and is subject to repeated disturbances by sea ice. Therefore, no long-term detrimental impacts would be expected. If tasked by NSF, the marine biologists of T-320, who are familiar with the biota in the area surrounding the intake quay, could survey the area likely to be affected by the proposed activities to assess potential impacts. ASA Construction divers may also be able to provide information regarding the current state of local underwater communities. (Reference the EAM, "McMurdo Station Sewer Outfall Quay Reinforcement Project," question 14, for further discussion of the habitat in the near-shore vicinity of McMurdo Station). HUMAN VALUES: 15. Would the proposed activity encroach upon any historical property of the site? If yes, how; if no, why. No. The quay is not on the list of historic Ross Island sites. 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). If the quay is decommissioned, the below-grade portion of the stanchions may be difficult to remove, unless the quay itself is removed. The buildings on the quay could be completely removed. OCCUPATIONAL SAFETY AND HEALTH CONCERNS 17. What occupational safety and health related issues may have to be addressed during this activity (for example, OSHA standards or consensus standards)? If none, explain why. According to response #8, earth moving equipment is not expected to generate significant airborne dust concentrations. Noise exposure may be present above 85 dBA. What steps could be taken to eliminate any problems, risks or hazards associated with those issues? Explain why? Wet method techniques (water spray) will be used to minimize dust emissions during heavy equipment use. Safety and Health will be contacted by the work area supervisor at the start of the job to conduct an initial sound level survey. 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? Employees will be informed of any identified health and safety issues in a safety meeting prior to the start of work. 19. Identify all potentially hazardous materials, chemicals, or equipment that are proposed for use? Heavy equipment will be used in earth moving operations. A rock drill will be used to dig holes for the pipe stanchions. 20. If any physical hazards would be present, how would they be controlled? Personnel will be required to stay clear of the work area when earth moving and/or drilling operations are underway. 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 marine environment near McMurdo Station. The proposed activity is expected to have beneficial effects with respect to enhancement of scientific research and replacement of old, unaesthetic buildings with a new more energy efficient and better wired building at the Station. With adherence to U.S. Antarctic Program policy on earth fill materials collection, the proposed activity will improve the environment within and near McMurdo Station. The Program and the Contractor are authorized to undertake the proposed actions. ATTACHMENTS: 1. Photograph and description of Building 178 2. Photograph and description of Building 179 3. Site Map