SANITARY SEWAGE TREATMENT IN ANTARCTICA: IMPACTS OF NATIONAL AND INTERNATIONAL POLICY AND DIFFICULT SITE CONDITIONS

The National Science Foundation (NSF) retained Consoer Townsend Envirodyne Engineers, Inc. (CTE) to evaluate alternatives for, and design, a domestic wastewater treatment facility for the McMurdo Research Station (McMurdo) located in Antarctica. Currently, raw sewage generated from McMurdo, average summer flow of approximately 0.1 mgd, is only treated with maceration prior to direct discharge into the Antarctic Ocean, where this treatment meets the international regulation for Antarctica. The NSF proposed that design of a new wastewater treatment facility should be based on the 1972 Clean Water Act (40CFR113) to provide greater protection of the pristine Antarctic environment. Therefore, the effluent quality for this plant was designed to meet a monthly average of 30 milligrams per liter (mg/l) of five-day Biochemical Oxygen Demand (BOD5) and 30 mg/l of Total Suspended Solids (TSS) with disinfection. Key factors influencing decisions made regarding treatment approaches included the harsh environmental conditions, remoteness of the facility, and single, yearly visits of a supply/disposal vessel. Based on both quantitative, economic factors and qualitative operational and logistical factors, the selected treatment processes included preliminary treatment with maceration, extended aeration with clarification for secondary treatment, UV irradiation for disinfection, aerobic digestion for produced biosolids, belt press for dewatering, and dewatered cake transport to the United States for disposal.