我國土壤及地下水風險評估制度之探討

Study of Soil and Groundwater Risk Assessment System in Taiwan

沈穎(Ying Shen) ； 楊慧庭(Hui-Ting Yang) ； 林威州(Wei-Zhou Lin) ； 魏顯祥(Xian-Xiang Wei)

《土壤及地下水污染整治》 1卷1期 (2014/07) Pp. 41-49

https://doi.org/10.6499/JSGR.2014.0101.003

摘要

我國土壤及地下水污染整治法（以下簡稱土污法）為環保法令中少數將風險評估與風險管理概念納入相關規範之法令，土污法對於污染場址管理之決策依據除採用剛性之法規標準外，搭配土污法風險評估方法之實施，現階段我國已完成健康風險評估方法之制訂，並著手於環境影響評估（生態風險評估）方法之建置。土污法對於場址風險管理係透過給予可採用風險評估結果進行決策之彈性，其方式除涉及風險評估作業、風險管理措施擬定外，對於政策面或主管機關之決策亦為重要一環，例如如何決定整治作業保護之目標、使用何種情境及參數，相關之風險評估與風險管理概念亦會影響我國土壤及地下水管制標準之訂定。此外，風險溝通部分亦為政策執行之重要關鍵，本文除探討風險評估與風險管理之搭配外，對於如何納入風險溝通機制、使用時機，亦探討現今與民眾風險溝通所面臨之問題，包括風險溝通需與民眾說明、或討論到何種深度，以及決策過程中使民眾參與之程度等問題，皆是未來我國落實以風險為基準之場址管理政策時必須要討論及制定之重要事項。

關鍵字

土壤及地下水污染 ； 風險評估 ； 風險管理 ； 風險溝通

並列摘要

Taiwan's Soil and Groundwater Pollution Remediation Act (SGPRA) includes health risk assessment mechanisms for the management of contaminated sites. Under this Act, contaminated sites that do not meet the related remediation standards due to hydrogeological conditions, contaminant characteristics, or the limitations of remediation technology should be the focus of risk assessments in order to develop site-specific remediation goals. In addition, for sites at which the soil or groundwater background concentration is already higher than the control standards, SGPRA requires the responsible parties to perform health risk assessments and environmental impact assessments in order to evaluate what actions should be taken. To ensure consistency when conducting risk assessments, the Taiwan EPA published ＂Health Risk Assessment Protocol and Report Drafting Guidelines for Soil and Groundwater Contamination Site＂ in 2006. Since then, the Taiwan EPA has continuously refined its risk assessment system, including integrated risk assessment, risk communication, and risk management. In 2013, the ＂Environmental Impact and Health Risk Assessment Regulations for Soil and Groundwater Remediation Site＂ were published in order to provide a set of general guidelines. This states that public opinion must be taken into consideration when making remediation decisions based on the results of risk assessments. The Taiwan EPA thus included mechanisms such as public participation and risk communication in its comprehensive risk analysis system. Article 24 of SGPRA states that, with the approval of the Taiwan EPA, site-specific remediation standards can be developed based on the results of environmental impact and health risk assessments. In this way, suitable remediation targets can be established, based on general exposure scenarios, related parameters, acceptable risks, neighboring areas, and site characteristics. Article 10 of the risk assessment regulations states that any approved remediation targets must consider both current and future use of the contamination site. And the total non-cancer hazard quotient has to be less than 1, and the acceptable risk has to be between 10^(-4) and 10^(-6). Under certain circumstances, if the risk cannot be reduced to this level, then a complete description of the related risk the reasons why it cannot be reduced should be provided in the related report. Site-specific remediation standards must also undergo a review process and receive approval from the central government, experts, and scholars before implementation. In many countries human health and ecological risk assessments can be carried out separately or in conjunction when it comes to establishing the related control standards. However, Taiwan does not have any prior experiences with such a system, and it is thus necessary to consider the land use situation, groundwater categories, exposure scenarios, and risk assessment parameters to assess whether risk assessment measures should be included in any control standards. Risk communication is the most important parts of a risk analysis system, since risk assessment and management can only be carried out in practice if such communication occurs. Current risk assessment regulations in Taiwan clearly state that public participation and risk communication must be conducted before carrying out any risk assessment, after the submission of a risk assessment report, while the risk assessment report is being reviewed, and after the acceptance of a health risk assessment report. In addition, risk communication must be carried out in an open and public manner in order for the public to better understand the whole decision-making process. Taiwan currently lacks experience in risk communication, and this can present problems with regard to decision-making by government authorities. Further education on risk assessment and risk communication skills is thus needed to improve soil and groundwater management in Taiwan, in order to obtain the goal of sustainable land use.

並列關鍵字

soil and groundwater contamination ； risk assessment ； risk management ； risk communication