地下儲槽與管線滲漏潛勢評估系統

Abstract

近年來台灣地區環保意識高漲，民眾與環保人士對於污染問題也越來越重視。截至98年底為止，全台汽機車已超過2100萬輛，汽油的使用為不可或缺的民生工業；而根據環保署在91年至97年間所執行的加油站、大型儲槽地下水潛在污染源之調查，發現加油站站齡超過10年以上之800座加油站中有42座加油站之土壤或地下水遭受污染；10年以下加油站（82-86年設立）之400座加油站中有18座受到污染；87年以後設立之400座加油站中有16座受到污染。由此可知，加油站的污染問題非常值得去探討。然而，現今對於加油站油品類儲槽系統土壤及地下水污染調查、驗證作業及整治等工作已有一定的規範，但目前現有的資源並沒有一套完整的系統能夠分析其風險。因此，本研究透過文獻之整理，再經過專家訪談，將影響加油站滲漏原因分成五大目標：（一）地下儲槽系統、（二）環境影響、（三）營運情形、（四）監測、（五）管理，五大目標又包含其評估標的與標的細項；接著透過專家問卷之方式，訂定每個目標與細項之風險值，建立一套風險評估之標準；最後依據此標準建置滲漏潛勢評估系統，利用網頁的簡便操作方式，只需根據現場調查所得到之資料逐項輸入，就能立即了解加油站之滲漏潛勢。問卷分析結果，五大目標的權重如下：（一）地下儲槽系統30%、（二）環境影響15%、（三）營運情形15%、（四）監測25%、（五）管理15%。當加油站在所有標的細項都處於最佳的狀態時，可得到最低風險值為39.76分。最後套用系統，嘉義市5個加油站實際監測資料，分析結果顯示，風險得分介於57 - 64分之間，其中又以加油站之設置日期以及受過環保署受訓之員工比例對於總分的影響最大。

In Taiwan, the concern of the environmentalists and the public on environmental pollution grows significantly in recent years. The groundwater pollution due to leakage of underground storage tanks of gasoline stations is one of the major issues. As of 2009 there are over 21 million automobiles in Taiwan and the gasoline consumption is inevitably large. According to the investigation on gasoline stations and facilities with large above ground storage tanks conducted by the EPA during 2000 to 2008, there are 42 out of 800 gasoline stations operated more than 10 years and 18 out of 400 gasoline stations operated less than 10 years have caused soil and groundwater pollution. On the other hand, only 16 stations out of the 400 gasoline stations established after 1998 have caused soil and groundwater pollution. However, although the gasoline stations have installed various leak detection systems, there is no assessment system based on the risk of potential leakage of underground storage tanks to facilitate the management of gasoline stations. Therefore, by comprehensive review of literatures and interview with experts, this study classifies factors that cause an oil spill to five major categories: (1) underground storage tank facilities, (2) site conditions, (3) operation conditions, (4) monitoring measures, and (5) management effort. Second by designed questionnaires for experts, this research determines a risk value of each category and item, and establishes assessment criteria for the risk assessment. Based on these criteria, which establish the leakage potential assessment system, gasoline station or corporate managers can access and use the system via Internet to understand potential risk by entering data they attained. The results from analyzing the questionnaires are be categorized to a variety of ratios in the five major categories: (1) the management of underground storage tank system 30%, (2) environmental effects 15%, (3) operating conditions 15%, (4) monitoring 25%, (5) managements 15%. When all of the items of a gasoline station are under the best conditions, the lowest risk value is 39.76. For example, the applied system receives monitoring data at 5 gasoline stations in Chiayi City whose risk score is between 57 and 64. The most important factor that affects the risk score is the date of establishment of the gasoline station and the ratio of staffs who have attend the training courses and been certified by the EPA.