有害廢棄物清運及新處理廠址之系統性評估指標

Abstract

由於有害廢棄物產量每年持續增加，且其清運會影響鄰近環境與民眾，因此有必要建立指標評估清運系統對周圍環境與居民的影響，而新設一個處理廠亦會影響整體有害廢棄物清運系統。故本研究將建立一套指標用以評估有害廢棄物清運系統以及供評估新設廠址對清運系統的影響，以作為相關規劃決策及選址的依據。 首先由於路網及門牌點資料量大，故先進行前處理以節省後續分析時間。然後建立一套指標，包括均衡性、在地異地處理比例、總體性分析、物質潛在危害度、運輸風險、與最短路徑方案之差異等指標，均衡性指標主要依據影響均量、影響均人口及道路風險訂定。其他指標雖之前曾以二點間最短距離及人口密度估算，但會與真實情況差異頗大，本研究因而改為依據真實路網及門牌資訊計算，以所建立的指標綜合評估台灣本島有害廢棄物清運系統。新設廠址分析先假設以最短距離及引力法重分配各處理廠所處理的產源，然後再以所建立的指標評估新廠址新設後對清運系統的影響，以改善選址的品質。 應用各指標於全省清運系統中，均衡性指標可評估對沿線影響是否平衡；在地異地處理指標供了解分佈狀況；總體性指標以及運輸風險指標供分析清運所帶來風險；物質潛在危害度指標評估危害程度；依不同重分配方法比較新廠址對整體系統之影響程度，可改對廠址選擇之決策品質。

Since the quantity of domestic hazardous waste (HW) keeps increasing and the HW collection may significantly affect the adjacent environment and residents, it is thus necessary to establish indicators to assess the impacts of a hazardous waste collection system (HWCS). A new treatment plant can alter a HWCS and subsequently the potential risk posed by the entire HWCS is also changed. Therefore, this study applies the proposed indicators to assess a HWCS and to facilitate the analysis for siting a new treatment facility. The indicators are expected to improve relevant planning and siting decisions. First, it is time consuming to process the large amount of road network and address location data, so they are pre-processed for saving the computational time in following analyses. Then, a set of indicators are established, including distribution equity, in-zone and off-zone treatment ratios, potential hazard based on substance characteristics, transportation risk, and the difference to the shortest distance distribution. The distribution equity indicator is mainly based on average population exposure or transportation risk. Other indicators were previously determined by the shortest distance between two points and population density, but they all have considerable differences to the real situation. Instead, the study applies real road network and address location data for computing the indicators. The indicators are used to assess the HWCS in Taiwan and to assess several new facility sites, according to simulated collection redistributions, for evaluating their applicability for improving HWCS assessment and siting decision. After applying the indicators to the Taiwan HWCS, the distribution equity indicator has been demonstrated to be able to assess whether the impacts along collection routes are balanced or not. The in-zone and off-zone treatment ratios give a clear picture of HW treatment distribution. The overall and transportation risk indicators provide the risks posed by the HWCS. The potential hazard indicators assess harmful levels. For simulating the treatment distribution after a new treatment site joining the HWCS, the shortest-distance and gravity methods, respectively, are used to reallocate the original treatment distribution. All indicators were recomputed for each new HWCS. The differences among all indicator results for each new HWCS and the original one can significantly facilitate siting analyses and the quality of a siting decision is expected to be greatly enhanced.