有害廢棄物清運風險分析

Abstract

有害廢棄物由於具有危害性，因而有必要重視其清運風險，一般規劃時假設有害廢棄物是送至最近的處理廠，然而本研究發現實際情形並非如此，與過去優選模式或清運規劃原則明顯不同，因而影響清理系統整體規劃與相關決策，故有必要發展一套方法評估有害廢棄物的清運效率與風險，以期改善有害廢棄物清理管理與規劃的決策品質。 本研究首先分析清運處理現況，為了解在地與跨區處理情形，建立在地處理率指標及跨區處理率指標，並考量處理廠許可情形，建立許可在地處理率指標、在地許可容量率指標及許可跨區處理率指標。接著建立最短距離清運方案作為分析比較之基準，且據以發展方法評估清運效率與風險，效率依據風險管理的需求主要評估與最短距離清運方案間的差異及跨區清運量，因此建立最短距離差異指標及跨區清運量指標。風險部分則主要考量清運距離與人口密度、潛在危害度及跨區清運等因子，依據上述因子發展出依運距與人口密度評估有害廢棄物清運風險指標、潛在危害度清運風險指標及跨區清運風險等指標，以期有系統的評估有害廢棄物清運效率與風險。 以所建立指標評估台灣有害事業廢棄物清運情形，共分為七區評估，結果發現跨區清運情形甚多，尤其部分區域因處理廠少，跨區清運比例高，如第1及7區分別有7及8類廢棄物全部跨區處理。且有不少並非送至最近的處理廠，如第1、6及7區有54-65%是送到較遠的地區處理，亦因而提高所經過地區的風險。與最短距離清運方案比較可發現溶出毒性類及生物醫療類實際清運總距離與理想方案差異較大，高達8萬3千至9萬公里，主要原因為此二類處理廠分佈雖較其他類別平均，但實際清運以跨區較高，亦提高其清運風險，依所得風險指標值亦可看出不少區域及類別的風險仍有不小的改善空間。依據所得結果，有必要檢討清運處理系統，以減少跨區清運，降低清運風險，所建立的指標可有效率的評估有害廢棄物清運效率與風險，並作為相關規劃與決策的重要依據。

Since hazardous wastes (HWs) are harmful, the risk of HW collection is thus an essential issue to evaluate. In general, researches and planning models assume that most HWs are delivered to the closest treatment plant. However, in Taiwan, it is not true and quite different from this assumption. This reality can subsequently alter the decisions made for the HW collection system and related tasks and also significantly increase the HW transportation risk. This study was thus initiated to develop indicators to assess the HW transportation risk and collection efficiency for improving the quality of related management and planning decisions. This study first analyzed current HW collection situation, especially for off-region collections, based on two proposed indicators of In-region Treatment Ratio and Off-region Treatment Ratio. According to the total maximal allowable amount of all treatment plants in each region, three indicators were proposed: In-region Treatment Permit Ratio, In-region Permit Ration and Off-region Treatment Permit Ratio. An optimization model was established to analyze an ideal collection plan for which the waste of each source is sent to the closest treatment plant. This ideal plan, although not real, serves as a baseline for comparison. According to the difference to this ideal plan, two additional indicators of Distance Difference to the Ideal Plan and Off-region Collection Quantity were proposed for evaluating the efficiency of the collection system. This study also evaluate the risk of the HW collection based on collection distance, population density, waste potential hazard, and the number of regions crossed during collection, and three indicators of HW Transportation Risk, Potential Hazard-based Risk, and Off-region Collection Risk were proposed. The proposed indicators are expected to systematically assess the efficiency and risk of the HW collection system in Taiwan. The proposed indicators were applied to our national HW collection. The entire nation was divided into seven regions. The results show that the total HW quantity for off-region treatment is quite high, especially for the regions without enough treatment plants. For example, regions 1 and 7 have 7 and 8 types, respectively, of wastes being sent to the treatment plants in other regions. A significant portion of wastes were delivered to the treatment plant far away from the sources. Regions 1, 6, and 7 have 54-65% HWs being sent to such plants and subsequently caused high transportation risk. While compared to the ideal plan, the total collection distance for Dissolvable Toxic and Biological Medical wastes are both much longer than the ideal one, about 83,000 to 90,000 km, even though the treatment plants for both waste types are evenly distributed. The results of risk indicators show that most regions and waste types need to improve their HW collections. The national collection and treatment system should be carefully re-evaluated to significantly reduce the off-region treatment and associated risks. The developed indicators can be used to effectively assess HW collection efficiency and risk and also support related management and planning decisions.