Title : Sanitary wastewater management, McMurdo Type : Antarctic EAM NSF Org: OD / OPP Date : December 29, 1989 File : opp93003 FINDING Proposed Action: Proposal for Improvement of Sanitary Wastewater Management at McMurdo Station, Antarctica. Sponsoring Agency: U.S. Antarctic Program (USAP) Office of Safety, Environment and Health Division of Polar Programs Directorate for Geosciences National Science Foundation Environmental Summary: The discharge of raw sewage and other wastewater (i.e., kitchen and bath wash water) into the ocean at McMurdo Stations is highly controversial. The newly proposed Antarctic Treaty Code of Conduct recommends maceration of station domestic wastewater and deposition where conditions exist for rapid dispersal in the ocean. USAP has, for a number of years, considered various alternatives for the effective treatment and management of domestic wastewater discharges from its coastal antarctic stations. Currently, wastewater effluent from McMurdo Station is discharged directly to McMurdo Sound. The goals of the proposed action are to establish primary treatment of the wastewater through maceration and dilution and to submerge the now elevated outfall. The action will include monitoring of current patterns, and periodic testing of the effluent. Environmental Determination: X "I find the proposed action to be of no significant environmental impact." /"I find the proposed action to be of no significant environmental impact provided that it is modified by the following mitigative measures:...." / "I find the proposed action to be of significant environmental impact." The Environmental Impact Assessment is attached to this document. The Assessment, together with this FINDING, has been distributed to those organizations indicated on the attached list. signed Date: Dec 29, 1989 Robert W. Corell Assistant Director for Geosciences Additional information on the Environmental assessment and the FINDING can be obtained by contacting Dr. Sidney Draggan, Environmental Officer, Office of Safety, Environment and Health, Division of Polar Programs, National Science Foundation, Washington, DC 20550; Telephone (202)357-7766. EXTERNAL DISTRIBUTION LIST Council on Environmental Quality U.S. Environmental Protection Agency Office of Federal Activities U.S. Department of State Parties to the Antarctic Treaty +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ENVIRONMENTAL IMPACT ASSESSMENT for IMPROVEMENT OF SANITARY WASTEWATER MANAGEMENT at McMurdo Station, Antarctica Prepared by the Division of Polar Programs National Science Foundation December 1, 1989 Approved: signed Date: December 7, 1989 Sidney Draggan, Ph.D. Environmental Officer Approved: signed Date: December 10, 1989 Peter E. Wilkniss Division Director +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ENVIRONMENTAL ASSESSMENT IMPROVEMENT OF SANITARY WASTEWATER MANAGEMENT MCMURDO STATION, ANTARCTICA CONTENTS INTRODUCTION BACKGROUND The Long-Range Development Plan Current Safety, Environment, and Health Developments CURRENT WASTEWATER SITUATION Characterizing McMurdo Station's Wastewater Current Patterns in McMurdo Sound Potential Effects of Fill Placement on the Benthos Potential Effects of the Wastewater Effluent on the Benthos OVERVIEW OF THE PROPOSED ACTION Proposed Action Alternatives Considered PURPOSE OF THE ENVIRONMENTAL IMPACT ASSESSMENT Description of the Project Environment Existing Site Conditions Site of the Proposed Action Proposed Site Alterations or Improvements Buildings or Other Structures Other Site Alterations or Improvements Description of McMurdo Station's Utility Systems ENVIRONMENTAL ANALYSIS Environmental Assessment Criteria Use of natural resources Pollution Environmental management associated with the action Human values Project modications considered ASSESSMENT QUERIES Summary of Responses Use of natural resources Pollution Environmental management associated with the action Human values Project modications considered COMMENTS AND RECOMMENDATIONS REFERENCES APPENDIX A FIGURES Figure 1. Current Patterns in McMurdo Sound near McMurdo Station. Redrawn from J. Barry (Personal communication). Figure 2. Schematic drawing of Benthic Survey Sampling Transects at location of proposed action. Figure 3. Map of McMurdo Station. Figure 4. Schematic Drawing of Plan for Proposed Action. Figure 5. Schematic Drawing of Plan for Proposed Action. TABLES Table 1. McMurdo Station wastewater analysis Table 2. McMurdo Station sewage and brine flow INTRODUCTION The United States Antarctic Program (USAP) is the nation's program for research and presence in Antarctica. It is funded and managed by the Federal Government. The National Science Foundation (NSF) has overall funding and management (lead agency) responsibility for USAP and U.S. activities in Antarctica. NSF conducts detailed planning of logistics, and transmittal of logistics requirements to the Naval Support Force Antarctica, to the U.S. Coast Guard (primarily provision of icebreaker services), and to a civilian contractor (currently ITT/Antarctic Services, Inc.). NSF guides these support units in facilities management, design, planning, engineering, construction, and maintenance. Background The site of McMurdo Station was chosen by the United States, during the International Geophysical Year, as the main logistics staging base for U.S. activities in Antarctica. The site has an important role as a base in the support of science on the Antarctic Continent. Periodic reviews of national policy and scientific research objectives have repeatedly confirmed that McMurdo Station's location makes it the primary choice for staging U.S. scientific activities in Antarctica for, at least, the next several decades. Early development of the site of McMurdo Station was characterized by an ad hoc construction program developed to satisfy rapidly changing operational and scientific requirements. During this early development the Antarctic Program was viewed by decision makers as expeditionary, and many of the structures were considered temporary in nature. In the mid-1960s, the U.S. Navy (as the Program's manager) recognized that U.S. presence in Antarctica was more permanent than had been thought, and additional construction was begun. This construction included reticulated water and sewage utility connections. Many of these old facilities are in use today. This period in McMurdo's development lasted through the early 1970s when responsibility for the Program was transferred to the National Science Foundation. Unfortunately, over many years the budget for facilities construction has been austere, limiting the orderly replacement of all old expeditionary structures and facilities. Additionally, increased emphasis on scientific research, and an increasing level of scientific research being accomplished at McMurdo Station placed burdens on an already over-loaded facilities infrastructure. Many temporary structures and facilities were added to satisfy needs. The Long-Range Development Plan. To address the facilities infrastructure shortfall, and in recognition of increasing awareness about wise antarctic development and environmental management, NSF commissioned a Long Range Development Plan (LRDP) in the late 1970s. Today, NSF continues to be engaged in an extensive program to upgrade McMurdo Station's physical plant. The LRDP addresses safety, environmental, quality of life, scientific and logistic support, and other issues instrumental in delineating a program of planned station development. The following criteria governed formulation of the LRDP: o Reduction of the station's physical size to minimize utility runs and circulation requirements; o Consolidation of like functions; o Grouping of operational functions requiring continual interface; o Adoption of a construction program that affords early completion of priority facilities; o Development of a physical layout that minimizes energy and manpower requirements (includes closing of seasonal-use facilities); o Development of a physical plant layout suitable for efficient operation by either military or civilian personnel; and o Development of a construction program that will not adversely affect station or aircraft operations. Throughout the construction plan proposed in the LRDP, a parallel demolition program was outlined to eliminate outmoded, inefficient or unsafe facilities. Though the LRDP is over 10 years old, it serves, as yet, as the basis for development and new construction at McMurdo Station. In 1980, the USAP prepared a Final Programmatic Environmental Impact Statement (EIS) that reviewed the continuation of the Program, including the introduction of improved waste treatment technologies from time to time (Division of Polar Programs 1980). Since the proposed action is within the program analysis of the EIS, this Environmental Impact Assessment (EIA) will be considered part of the tiering process associated with that EIS. Currently, this programmatic EIS is being supplemented by the Division of Polar Programs. Current Safety, Environment, and Health Developments. In the President's Fiscal Year (FY) 1990 budget request to the U.S. Congress, the National Science Foundation proposed a major, multi- year Safety, Environment, and Health Initiative. One of the environmental goals of the initiative is to bring present operations into agreement with current regulations, prevailing attitudes, and current technology. This Initiative would provide the human and financial resources needed to effect environmental- related improvements, including waste disposal and management, and environmental monitoring. In FY 1990, NSF expects to receive about $10.0M to plan and implement environment-related tasks. Current Wastewater Situation The discharge of raw sewage and other wastewater (i.e., kitchen and bath wash water) into the ocean at the McMurdo and Palmer Stations is highly controversial. The existing Code of Conduct for Antarctic Expeditions and Station Activities adopted by the Antarctic Treaty parties recommends, at a minimum, that all sewage from coastal stations be macerated before dispersal (Scott Polar Research Institute 1987). The newly proposed Code of Conduct for Antarctic Expeditions and Station Activities recommends maceration of coastal station domestic wastewater and deposition where conditions exist for rapid dispersal in the ocean (Scientific Committee on Antarctic Research 1989). USAP has, for a number of years, considered various alternatives for the effective treatment and management of domestic wastewater discharges from McMurdo Station into McMurdo Sound, Antarctica. Currently, wastewater effluent from the station (i.e., human faeces and urine, bath water, and kitchen wash water) is discharged directly to McMurdo Sound. Immediately adjacent to this raw sewage outfall is an outfall for brine from McMurdo's desalination plant. Characterizing McMurdo Station's Wastewater. Two wastewater samples were analyzed to characterize the station's wastewater effluent at the end of the 1988-1989 austral research season. General indicators of pollution used in these tests indicated, as expected, an effluent best characterized as a strong, raw domestic sewage. No unusual levels of heavy metals or substances deemed toxic or hazardous were found in the effluent (Table I). TABLE I McMurdo Station Wastewater Analyses Sampling Date Parameter Measured 05-JAN-89 09-FEB-89 Arsenic <0.02 ppm <0.02 ppm Boron (soluble) 0.4 ppm 0.3 ppm Cadmium <0.02 ppm <0.02 ppm Copper 0.45 ppm 0.50 ppm Cyanide <0.01 ppm <0.01 ppm Iron 3.3 ppm 0.8 ppm Lead 0.05 ppm <0.05 ppm Manganese <0.05 ppm <0.05 ppm Mercury <0.05 ppm <0.05 ppm Nickel <0.05 ppm <0.05 ppm Selenium <0.02 ppm <0.02 ppm Silver <0.05 ppm <0.05 ppm Zinc 0.5 ppm 0.35 ppm Ammonia-N 13.4 ppm 16.6 ppm Nitrate-N 0.45 ppm 0.11 ppm Nitrate-N 0.017 ppm 0.018 ppm Total Kjeldahl-N 71.2 ppm 131.0 ppm Total Phosphorus 250.0 ppm 13.0 ppm Total Suspended Solids 182 539 Volatile Suspended Solids 132 500 Total Dissolved Solids 1248 2045 Biochemical Oxygen 545 1680,1590 Demand ORGANICS Chloroform 0.0011 <0.0004 Bromoform <0.0002 <0.0002 Bromodichloro-methane <0.0001 <0.0001 Chlorodibromo-methane <0.0001 <0.0001 Glycol <0.6 <0.6 VOLATILE ORGANICS Benzene <0.004 <0.004 Carbon tetrachloride <0.0001 <0.0001 1,2 dichloroethane <0.0150 <0.0150 1,1 dichloroethylene <0.002 <0.002 1,1,1 trichloroethane <0.0001 <0.0001 para dichlorobenzene <0.020 <0.020 vinyl chloride <0.005 <0.005 methyl isobutyl ketone <0.2 <0.2 methyl ethyl ketone <1.3 <1.3 USAP actively enforces policies that prohibit the addition of toxic or hazardous substances into the wastewater effluent streams of its antarctic coastal stations. In its interpretation of the results of this limited, yet rigorous, sampling effort the testing laboratory noted that given the characteristics of the domestic sewage effluent NSF needed "... to evaluate the acceptability of the strength of this waste in the context of the isolation of the base, the volume of waste being released and the potential for dilution and dispersion" (C.J. Nokes, personal communication). Information on sewage and brine flow were obtained from a single set of measurements conducted by the Manager of the Eklund Biological Laboratory at McMurdo. Results of this limited study appear in Table II. TABLE II Parameter Sewage Brine Combined Measured Discharge Discharge Discharge Temperature (oC) 25.5 36.0 30.3 Salinity (ppt) - 46 21 Refractive Index - 1.3415 - Flow Rate (L/sec) 1.9 1.6 3.5 Consideration, with respect to ocean currents and biotic communities in the vicinity of the existing wastewater outfall, has been given to the selection of an appropriate site for a proposed submerged outfall. This was to assure that effluent is not taken up by the seawater intake for drinking water production (from desalination); and, to minimize potential impacts to the scientific research value of near shore marine environments at McMurdo Station that might be caused by sewage effluent as well as sedimentation from fill materials used to support a submerged outfall. Current Patterns in McMurdo Sound. While most studies of seawater circulation patterns in McMurdo Sound have been made in the vicinity of McMurdo Station, the activity of currents near the site of the proposed action are, as yet, incompletely understood (Raytheon Service Company 1983; Barry and Dayton 1988). Recent data and opinion (J. P. Barry, personal communication) on nearshore current patterns indicate a predominant northward flow. It is known that current direction changes with the tidal cycle but that net movement is northward. Currents in the area of the proposed submerged wastewater outfall are believed weak; however, measurements have been made in that area (Figure 1). During 1990, USAP plans to install current meters in the area of the proposed submerged outfall to clarify the nature of current patterns. This information will be assessed and included in the supplement to the programmatic EIS. Potential Effects of Fill Placement on the Benthos. On November 20, 1989, a survey of the benthos at the site of the proposed submerged wastewater outfall was conducted by divers. Three 100- foot transect lines were deployed at the base of the proposed wastewater outfall jetty. The lines were marked at 25-foot intervals. North and south transect lines were placed at opposing 45o angles to the central (westerly) transect line that followed the path of the proposed submerged outfall (Figure 2). At 25-foot intervals along each of these transect lines, divers made visual sightings and measurements within a 4.0 foot2 area. At thirteen sampling sites, they noted: o abundance and variety of benthic organisms; o depth of siltation (in inches); and o pneumofathometer depth soundings. Numbers of motile benthos (starfish, urchins, worms, and fish) were greater at nearshore sampling sites; numbers of sessile benthos (anemones) were greater at offshore sampling sites. These observations were consistent with observations made previously at the site of McMurdo Station's seawater intake. Siltation ranged from an average depth of about 0.75 inches at the 25- and 50-foot marks of each transect line to about 2.25 inches at the 100-foot marks. Silt in the area of the proposed action was noted to be coarser than that noted previously at the site of McMurdo's seawater intake. This difference may indicate that silt at the site of the proposed action derives from the effluent issuing from the existing elevated outfall rather than from surface runoff. Tangentially, during four years of work at the site of McMurdo's seawater intake, large quantities of fill and rock were used to prepare a jetty resulting in moderate dispersal of silt. Silt deposition offshore decreased with increasing depth. This moderate siltation over a four year period appears to have had little or no effect on marine life at the site of seawater intake jetty (D. Rubino, personal communication). The survey team noted that the benthic communities at the site of the proposed action and at the seawater intake jetty were comparable; and, that numbers of organisms increase proportionally with depth. The influx of freshwater from either snowmelt or from the existing elevated outfall may account for this relationship. Barry and Dayton (1988a, 1988b) have noted dramatic differences in the productivity of McMurdo Sound's benthos. These authors note that advective processes clearly influence benthic faunal patterns; but, that existing information on their productivity fails to explain these patterns. Siltation from the placement of fill is expected to have minimal effect on benthic communities in the vicinity of the proposed action as their presence actually derives from siltation resulting either from freshwater runoff or the existing wastewater outfall. Siltation would have an effect on the sponge community near the site of proposed action; however, this community has already been adversely affected by previous siltation (P. Dayton; R. McLean, R. Reed, and S. Railsback, personal communications). Variables Determining the Potential Effects of the Wastewater Effluent on the Benthos. Additional measurements are needed to supplement the information on effluent characteristics reported in Table II since flow rates for sewage and brine noted there were approximately equal: a brine flow rate significantly higher than that for sewage would be expected. The discrepancy may be due to the fact that the single sample was obtained while the Old Water Plant was in use (supplementing the freshwater output of the New Water Plant); or, because the sample was obtained at a time when water usage exceeded water production. Also, more information is needed on the temperature of effluent that would issue from the proposed submerged outfall. Its temperature will depend on heat loss as it passes through the proposed outfall pipe. This heat loss will depend on pipe type and size, and effluent flow rate and velocity. Distribution of suspended solids from the proposed submerged wastewater outfall will depend on the characteristics of the resultant plume. Nearshore benthic communities will be afforded greater protection if the plume exits the outfall pipe at low velocity, allowing suspended solids to deposit in a confined area. A neutrally-buoyant or slowly rising plume is most desirable. A plume's dispersion and buoyancy characteristics are controlled by the density of the effluent (which depends on effluent temperature and salinity) and by its exit velocity. A plume's temperature may be adjusted by controlling addition of brine and by selecting the pipe diameter to control heat exchange over the length of the pipe (different pipe diameters and outlet sizes result in different rates of effluent cooling). Salinity of a plume may be adjusted by controlling addition of brine. Effluent exit velocity may be controlled by choice of effluent pipe diameter. Smith and Nelson (1985, 1986) and Wilson et al. (1986) have noted that warming and dilution of antarctic surface waters tend to increase primary productivity and promote productivity in higher trophic levels. Such warming and dilution would accrue from the domestic wastewater effluent as would increased input of nutrients associated with the effluent (i.e., for example, carbon, nitrogen, and phosphorus). El-Sayed and Mandelli (1965) and Holm-Hansen (1985) have shown that nutrient levels in antarctic waters are usually high and they believe that these may not be critical to primary production. These studies suggest that only very high levels of warming, seawater dilution and nutrient input could be expected to alter (negatively or positively) the character or benthic communities near the McMurdo Station submerged wastewater outfall. OVERVIEW OF THE PROPOSED ACTION Proposed Action Initiation of Maceration and Dilution of McMurdo's Domestic Sewage Effluent and Installation of a Submerged Wastewater Outfall. As noted above, USAP has considered over several years how best to improve treatment of the domestic wastewater effluent generated at McMurdo Station. The first goal of such improvement is to establish primary treatment of the wastewater through maceration and dilution (with the hot brine residual from the station's seawater desalination facility) prior to discharge to McMurdo Sound. This improvement would go beyond recommendations in the Antarctic Treaty's Codes of Conduct noted above. The action will include subsequent monitoring of nearshore current patterns, and periodic analysis of the primary treated effluent to determine if additional treatment is necessary. Figures 3 and 4 show the location of the proposed action. Alternatives Considered Alternatives considered during planning for the proposed action included: o Do nothing; o Adopt only dilution of the wastewater prior to elevated outfall discharge; o Adopt only maceration of the wastewater prior to elevated outfall discharge (as recommended in the Codes of Conduct); o Adopt dilution and maceration of the wastewater prior to elevated outfall discharge; o Adopt nearshore, submerged raw effluent discharge with dispersion; o Adopt secondary treatment of the wastewater prior to submerged discharge, with consideration of necessary infrastructure and required levels of performance; o Adopt tertiary treatment of the wastewater prior to submerged discharge, with consideration of necessary infrastructure and required levels of performance; and o Adopt a closed system for the recycling and recovery of all substances in McMurdo Station's domestic wastewater. PURPOSE OF THE ENVIRONMENTAL IMPACT ASSESSMENT NSF's Division of Polar Programs has conducted this environmental assessment to provide the cognizant officials of all USAP components, and interested parties, with an understanding of environmental issues pertinent to the proposed action. The assessment was conducted pursuant to Executive Order 12114, and Antarctic Treaty Consultative Meeting Recommendation XIV-2 (Human impact on the antarctic environment: Environmental impact assessment.). The assessment addresses the environmental implications of initiating primary treatment of McMurdo Station's wastewater by the processes of maceration and dilution; and, discharging this primary treated effluent via a submerged outfall into McMurdo Sound, Antarctica. This assessment examines whether this action will significantly affect the quality of the environment at that location. This document and its findings will be transmitted to Antarctic Treaty Parties through appropriate channels. Description of the Project Environment Existing Site Conditions. McMurdo Station (77o51'S 166o40'E) is located on Ross Island, Antarctica. The island is of volcanic origin and is roughly triangular in shape, approximately 45.0 miles on a side. Land not covered by ice and snow amounts to only a small percentage of the island's total area. Approximately 2.0 square miles of land are exposed in the vicinity of McMurdo Station, of which less than 0.5 square miles constitutes the station complex. McMurdo Station is located on the southern slope of a circular basin which is bordered by three prominent hills and McMurdo Sound which is 8,047 square miles in area. The entire station area consists of volcanic rocks that are predominately basaltic. Scoriaceous and cindery masses are found on the ground's surface. McMurdo Station has 8 basic land use categories: o Science Support Facilities; o Living Facilities; o Logistic Support Facilities; o Recreation Facilities; o Air and Ship Operations Facilities; o Utilities' Plants; o Utilities' Systems; and o Circulation Systems. Site of the Proposed Action. Figure 4 shows the area at McMurdo Station where the proposed action will take place. The current elevated (about 4 feet above the seawater surface) and separate sewage and brine outfalls are located at the southern side of Winter Quarters Bay. An existing quay, to be extended as part of the proposed action was constructed earlier from local fill material (see Figure 5). Proposed Site Alterations or Improvements. This assessment details USAP's proposal to initiate primary treatment (through maceration and dilution of McMurdo Station's domestic wastewater effluent) and to combine and submerge the now elevated outfalls. The end of the new outfall pipe would be about 50 feet offshore (Figure 4) To protect the proposed 16-inch diameter, polyethylene outfall pipe from damage by sea ice, it would be placed within a 48-inch diameter corrugated steel culvert. The submerged outfall pipe/culvert combination would be supported by a 15 to 20 foot, seaward extension of the outfall quay that would then slope down further seaward to a depth of about 50 feet (Figure 5). The supporting and extending material would be fill obtained from an existing construction site. It is estimated that about 3,000 cubic yards of this fill material will be required for extension of the quay and for support of the submerged outfall pipe/culvert combination. A sample of this fill material was sieved, dried and subjected to a grain size distribution analysis. The analysis revealed that about 25 percent of the fill material is within a size category of 2.0 mm diameter or less. With sufficient current activity, fill of this size could spread to areas surrounding the work area during placement of the fill. Buildings or Other Structures. A building to house a sewage macerator and dilution facilities already exists at the site of the proposed action. Other Site Alterations or Improvements. Re-routing of the domestic wastewater outfall to maximize the separation between the outfall and the seawater intake for potable water production has been considered. The facilities utilidor serving the area of the proposed action will be enlarged. Description of McMurdo Station's Utility Systems. In the early days of the Program, some structures at McMurdo Station were connected by a complex utility system with overhead lines for electrical distribution and aboveground lines for water distribution and sewage collection. Buildings were added to the distribution system as the Program matured. Separate support structures were built for the overhead power, telephone, and fire alarm lines as well as for the aboveground fire suppression water, seawater, potable water, wastewater, and fuel distribution lines. These utilities are currently being relocated into a single support structure carrying all utilities in a single, consolidated right- of-way. Water lines at McMurdo Station are a combination of fiberglass, polyvinyl chloride, cooper, and galvanized piping. Insulation for these lines are a mix of different materials. These lines are being replaced, in conjunction with the consolidated right-of-way concept (within a pre-insulated utilidor pipe). Most of the larger buildings at McMurdo are now connected to portable water lines and to sewer lines. Most of the domestic sewage is collected and piped by a gravity system to the elevated outfall located on the southern side of Winter Quarters Bay. This main outfall has existed at several locations, but in the same general area, for as long as McMurdo Station has had a sewage collection system. One temporary outfall operates; but, it will be incorporated into the main outfall. ENVIRONMENTAL ANALYSIS The proposed action involves the initiation of primary treatment of McMurdo Station's wastewater by the processes of maceration and dilution; and, the discharge of this primary treated effluent via a submerged wastewater outfall into McMurdo Sound, Antarctica. It does not signify the potential for an increase in research or logistic activity within the Program (as materials to accomplish the action are currently on-site). The action is expected to upgrade wastewater characteristics and should allow for more efficient waste management. Environmental Assessment Criteria To assist in the identification of potentially sensitive or critical environmental effects, the Division of Polar Programs used a set of 21 environmental impact criteria as a guide for this analysis. These criteria, in five categories, are shown below: I. USE OF NATURAL RESOURCES 1. Will the proposed action change traditional use of the site? 2. Will the proposed action use land or ocean areas for purposes unsuitable to their physical or environmental characteristics? 3. Will the proposed action have any associated indirect impacts on the environment? II. POLLUTION 4. Has protection of the environment and human health from unnecessary pollution been considered for this proposed action (includes such considerations as pollution abatement or mitigation, and waste management)? 5. Has environmental protection been considered in any construction or logistics operations associated with implementation of proposed action (i.e., disposition of one-time use materials, construction wastes)? 6. Will the proposed action change ambient air quality at the site? 7. Will the proposed action change ambient water quality at the site? 8. Will the proposed action change waste generation or management at the site? 9. Will the proposed action change energy production or demand, personnel and life support, or transportation requirements at the site? 10. Will the proposed action adversely affect scientific studies or locations of research interest (near and distant, short- term and longterm)? 11. Will the proposed action affect terrestrial marine or freshwater ecosystems within the environs of McMurdo Station? III. ENVIRONMENTAL MANAGEMENT ASSOCIATED WITH THE ACTION 12. Overall, will the proposed action include measures and facilities for the management of biological laboratory wastes? 13. Overall, will the proposed action include direct or indirect measures and facilities for the management of laboratory or industrial chemicals or substances that may be deemed hazardous or toxic? 14. Overall, will the proposed action include measures and facilities for the management of radioisotopes and radioisotope wastes? 15. Overall, will the proposed action include measures and facilities for assuring occupational health and safety? IV HUMAN VALUES 16. Will the proposed action encroach upon any historical property of the site? 17. What other aspects of the site and what environmental values associated with the site, that might be affected by the proposed action, have been considered? V. PROJECT MODIFICATIONS CONSIDERED (includes alternatives and mitigative measures considered). 18. Have alternatives to the proposed action been identified; and, have the probable effects of such alternatives been considered? 19. Have measures have been identified and considered to mitigate adverse impacts of the proposed action? 20. Have any modifications of the proposed action been taken or considered to minimize environmental impacts? 21. Have measures to assess the indirect costs of the proposed action been identified or considered? Environmental Impact Assessment Queries to Responsible Officials and Experts Officials responsible for the proposed action, cognizant NSF staff members, and experts knowledgeable about the proposed action, antarctic marine environments and environmental impacts were interviewed about the proposed action. Relevant representatives of the NSF's Committee on Environmental Statements and Office of the General Counsel were also canvassed concerning this assessment (see Appendix A for individuals queried). Summary of Responses In the following paragraphs, the responses of these officials and experts on the environmental impact criteria and relevant environmental issues are summarized: USE OF NATURAL RESOURCES. Criterion 1. Received, overall, a NO response. From the early days of McMurdo Station development, the station's wastewater effluent has been disposed of at, or near, the site of the proposed action. Criterion 2. Received, overall, a NO response. Given the relatively large size, high productivity and normally high nutrient levels of McMurdo Sound, it possesses a capacity to assimilate (Woodwell 1987) the organic carbon (and other nutrient elements) associated with the stations wastewater effluent. Criterion 3. Received, overall, a YES response. Initiation of primary treatment of domestic wastewater at McMurdo Station will make the effluent more assimilable. Outfall submersion will enhance dispersion--again improving effluent assimilation through the natural environmental process of degradation. It will also preclude use of additional treatment that would be both cost-and energy-inefficient or that would introduce environmentally- troublesome substances (e.g., trihalomethanes) into the natural environment. POLLUTION Criterion 4. Received, overall, a YES response. The proposed action represents an effort at pollution abatement within the contexts of the antarctic environment and antarctic operations. It will enhance wastewater management at McMurdo Station. Criterion 5. Received, overall, a YES response. Most of the materials to be used for the proposed action are already on-site or of local origin. This precludes environmental impacts associated with materials transportation. Excess materials from construction will be either re-stocked or retrograded, as necessary. Criterion 6. Received, overall, a NO response. Criterion 7. Received, overall, a YES response. The proposed action will improve the assimilability of McMurdo Station's wastewater effluent through natural environmental processes. Wastewater management at the station will improve as the effluent will be monitored in a more comprehensive fashion. Criterion 8. Received, overall, a YES response. Overall, wastewater management and monitoring will be enhanced. Criterion 9. Received, overall, a YES response. Use of maceration equipment may incur a slight increase in energy usage. The effluent's diluent (brine) is a by product of water desalination that would have to be pumped into McMurdo Sound irrespective of the proposed action (i.e., there will be no additional energy usage for dilution). There will be an increase in effort for environmental monitoring associated with the proposed action. Criterion 10. Received, overall, a YES response. The submersion of the outfall, coupled with appropriate plume characteristics will confine solids associated with the effluent. Additional impacts to the sponge community near McMurdo Station, already affected by siltation from prior activities and snowmelt runoff, are expected to be negligible. Criterion 11. Received, overall, a YES response. Siltation associated with fill placement and outfall operation is expected to enhance development of the soft-bottom (benthic) communities in a localized area in which they normally do not exist. The sponge community will experience a negligible negative impact from siltation. Primary productivity in an area already rich in nutrients is not expected to change. ENVIRONMENTAL MANAGEMENT ASSOCIATED WITH THE ACTION Criterion 12. Received, overall, a YES response. No laboratory waste, other than those permitted for wastewater disposal by USAP policies, will enter the domestic sewage system. Criterion 13. Received, overall, a YES response. USAP has, and enforces, policies precluding disposal of such wastes substances in the domestic sewage system. There are acid collection or neutralization facilities, and waste oil capture systems available, and in use. Toxic or hazardous substances are collected and retrograded. Criterion 14. Received, overall, a YES response. All radioisotope wastes is collected and retrograded. Criterion 15. Received, overall, a YES response. HUMAN VALUES Criterion 16. Received, overall, a NO response. Criterion 17. Received, overall, a YES response. The proposed action is near a site that experienced poor environmental protection and management in the past. The proposed action includes efforts to ameliorate environmental damage at and near that site. PROJECTED MODIFICATIONS CONSIDERED. Projected Modifications Considered Criterion 18. Received, overall, a YES response. Criterion 19. Received, overall, a YES response. USAP plans to conduct further monitoring of current patterns at the site, as well as more comprehensive analysis of the effluent. Should these efforts evidence problems, USAP is prepared to consider higher levels of wastewater treatment. Criterion 20. Received, overall, a YES response. Originally, only primary treatment (maceration and dilution) was considered. Adoption of outfall submersion, following expert advice, was viewed as more environmentally compatible and more sensitive to the scientific value of McMurdo's nearshore marine environments. Criterion 21. Received, overall, a YES response. COMMENTS AND RECOMMENDATIONS Following the period of enquiry, responses of the responsible officials and experts were analyzed and summarized. Again, this environmental impact assessment addressed the environmental implications of initiation of primary treatment of McMurdo Station's wastewater by the processes of maceration and dilution; and, the discharge of this primary treated effluent into McMurdo Sound, Antarctica via a submerged wastewater outfall. The results of any monitoring and modelling efforts not available, or incomplete, during the period of this environmental impact assessment will be considered during the supplementing of the Programmatic Environmental Impact Statement (PELS) for the U.S. Antarctic Program. Work to supplement this PEIS is now going on. Overall, the discussion and responses provided by the panelists suggest that the proposed action will not significantly affect the quality of the environment at McMurdo Station, Antarctica. Given the findings of this environmental impact assessment, it is recommended that a finding of no significant impact be attached to the proposed action. REFERENCES Barry, J. P. and P. K. Dayton. 1988a. Current patterns in McMurdo Sound, Antarctica and their relationship to local benthic communities. Polar Biology 8:367-376. Barry, J.P. and P. K. Dayton. 1988b. Hydrographic patterns in McMurdo Sound, Antarctica and their relationship to local benthic communities. Polar Biology 8:377-391. Division of Polar Programs. 1980. U.S. Antarctic Program, Final Environmental Impact Statement (reprinted October 1984). National Science Foundation Report No. NSF 84-81. National Science Foundation, Washington, DC. Holm-Hansen, O. 1985. Nutrient cycles in Antarctic marine communities (pp. 6-10). In W. R. Siegfried, P. R. Condy, and R. M. Laws (eds.), Antarctic Nutrient Cycles and Food Webs. Fourth Scientific Committee on Antarctic Research Symposium on Antarctic Biology. Wilderness, South Africa (September 1983). El-Sayed, S. Z. and E. F. Mandelli. 1965. Primary Production and standing crop of phytoplankton in the Weddell Sea and Drake Passage. Antarctic Research Series 5:87-106 Raytheon Service Company. 1983. Report on the McMurdo Station Water Quality Study. Middletown, RI. Scientific Committee on Antarctic Research (SCAR). 1989. Waste Disposal in the Antarctic: Report of the SCAR Panel of Experts on Waste Disposal. Scott Polar Research Institute. Cambridge, England. 53pp. Scott Polar Research Institute. 1987. Handbook of the Antarctic Treaty System (Fifth Edition). Scott Polar Research Institute. Cambridge, England. Smith, W. O. and , D. M. Nelson. 1985, Phytoplankton bloom produced by a receding ice edge in the Ross Sea: Spatial coherence with the density field. Science 227:163-166. Smith, W. O. and, D. M. Nelson. 1986. Importance of ice edge phytoplankton production in the Southern Ocean. BioScience 36:251- 257. Wilson, D. L., W. O. Smith, Jr., and D. M. Nelson. 1986. Phytoplankton bloom dynamics of the waters of the western Ross Sea ice edge. I. Primary productivity and species-specific production. Deep-Sea Research 33:1357-1387. APPENDIX A Chairman Dr. Sidney Draggan Office of Safety, Environment and Health Responsible Officials Mr. Gary Staffo Office of Safety, Environment and Health Mr. Erick Chiang Operations Section Mr. David Bresnahan Operations Section Mr. Robert Haehnle Operations Section Mr. George Fitzsimmons Operations Section Mr. Thomas Forhan Operations Section Dr. Ted E. DeLaca Science Section Dr. Bernhard Lettau Science Section Dr. Polly A. Penhale Science Section Dr. Roger Hanson Science Section Mr. Charles E. Myers Information and Coordination Section Other NSF Staff Dr. Julian P. Shedlovsky NSF Committee on Environmental Statements Mr. Lawrence Rudolph Office of the General Counsel External Experts Dr. James P. Barry Scripps Institution of Oceanography Dr. Paul Dayton Scripps Institution of Oceanography Mr. Harry Fyke ITT Antarctic Services, Inc. Dr. Judith A. Hansen Scripps Institution of Oceanography Dr. Steven Kottmeier ITT Antarctic Services, Inc. Dr. Donal T. Manahan University of Southern California Dr. Richard McLean Oak Ridge National Laboratory Mr. Richard Morrill ITT Antarctic Services, Inc. Mr. C. J. Nokes Chemistry Division, New Zealand Department of Scientific and Industrial Research Dr. John Oliver Moss Landing Marine Laboratory Dr. John Pearse University of California - Santa Cruz Dr. Steven Railsback Oak Ridge National Laboratory Dr. Robert Reed Oak Ridge National Laboratory Mr. Sherwood Reed Cold Regions Research and Engineering Laboratory Dr. Richard Rivkin University of Maryland Mr. R. D. Roop Labat-Anderson, Inc. Mr. Douglas Rubino ITT Antarctic Services, Inc. Dr. Cornelius W. Sullivan University of Southern California