Oceanographic data from the Environmental Impact Assessment of the Davis Sewage Outfall

Untreated, macerated wastewater effluent has been discharged to the sea at Davis Station since 2005, when the old wastewater treatment infrastructure was removed. This environmental assessment was instigated to guide the choice of the most suitable wastewater treatment facility at Davis. The assessment will support decisions that enable Australia to meet the standards set for the discharge of wastewaters in Antarctica in national legislation (Waste Management Regulations of the Antarctic Treaty Environmental Protection Act - ATEP) and to meet international commitments (the Madrid Protocol) and to meet Australia's aspirations to be a leader in Antarctic environmental protection.
The overall objective was to provide environmental information in support of an operational infrastructure project to upgrade wastewater treatment at Davis. This information is required to ensure that the upgrade satisfies national legislation (ATEP/Waste Management Regulations), international commitments (the Madrid Protocol) and maintain the AAD's status as an international leader in environmental management. The specific objectives were to:
1. Wastewater properties: Determine the properties of discharged wastewater (contaminant levels, toxicity, microbiological hazards) as the basis for recommendations on the required level of treatment and provide further consideration of what might constitute adequate dilution and dispersal for discharge to the nearshore marine environment
2. Dispersal and dilution characteristics of marine environment: Assess the dispersing characteristics of the immediate nearshore marine environment in the vicinity of Davis Station to determine whether conditions at the existing site of effluent discharge are adequate to meet the ATEP requirement of initial dilution and rapid dispersal.
3. Environmental impacts: Describe the nature and extent of impacts to the marine environment associated with present wastewater discharge practices at Davis and determine whether wastewater discharge practices have adversely affected the local environment.
4. Evaluate treatment options: Evaluate the different levels of treatment required to mitigate and/or prevent various environmental impacts and reduce environmental risks.

自2005年旧污水处理基础设施拆除以来，戴维斯站（Davis Station）一直将未经处理的浸渍废水（macerated wastewater）排放入海。本次环境评估旨在为戴维斯站遴选最合适的污水处理设施提供决策指引。本评估将助力澳大利亚满足《南极条约环境保护法案之废弃物管理条例》（ATEP）中规定的南极区域废水排放国家标准，同时履行《马德里议定书》（Madrid Protocol）项下的国际承诺，契合澳大利亚争做南极环境保护领军者的愿景。

本次评估的总体目标为提供环境相关信息，支撑戴维斯站污水处理升级的运营基础设施项目，确保升级后的设施符合国家法律法规（ATEP/废弃物管理条例）、国际承诺（《马德里议定书》），并维持澳大利亚南极局（Australian Antarctic Division，AAD）在南极环境管理领域的国际领军地位。本次评估的具体目标如下：
1. 废水特性研究：明确排放废水的各项属性（污染物浓度、毒性、微生物危害），以此为基础提出所需处理等级的建议，并进一步探讨近岸海洋环境排放所需的适宜稀释与扩散方案。
2. 海洋环境扩散与稀释特性评估：评估戴维斯站周边近岸海域的水流扩散特性，判断现有排污口的环境条件是否满足ATEP规定的初始稀释与快速扩散要求。
3. 环境影响分析：阐明戴维斯站现有废水排放实践对海洋环境的影响性质与波及范围，确定当前排放行为是否对当地海洋环境造成了不利影响。
4. 处理方案评估：针对各类环境影响，评估所需采取的不同等级处理方案，以减缓乃至消除负面影响并降低环境风险。