Contractor's environmental performance assessment system (C-EPAS)

Abstract

Construction activities have considerable impacts on both the natural and the built environment in various ways. Existing research works suggest that construction activity has adverse environmental effects, such as the loss of soil and agricultural land, the loss of forests, and the consumption of non-renewable energy resources. Construction activity also contributes to the environmental pollution through releasing dust, toxic fumes and noise during the construction process. In line with the promotion of sustainable development, increasing research efforts have been devoted to investigating methods for mitigating the environmentally adverse effects caused during the process of implementing construction activities. One development is to assess the environmental performance of a construction product at different stages during its life cycle, thus proper action can be taken to mitigate the poor performance if identified. Various assessment systems have been developed for assessing the environmental performance of a construction project. However, it appears that little study has been conducted to find an appropriate way to assess a contractor's environmental performance. In fact, the contractor plays the key role in executing construction activities, and its environmental performance has a strong association with the overall environmental performance in the process of implementing a construction project. Thus the implementation of environmental management across a contractor's operational activities is considered an important contribution towards protecting the environment. To assist contractors understand the level of their environmental performance, a methodology to assess theirenvironmental performance is necessary. This study develops an effective method for assessing a contractor's environmental performance to calculate a contractor's environmental performance index (C-EPI). In order to calculate the C-EPI, a contractor's environmental performance assessment system (C-EPAS) is built up through formulating various parameters and performance assessment benchmarks to present a calculation model. Parameters adopted in the system include the environmental performance factors affecting the contractor's environmental performance and the environmental performance indictors used to evaluate the contractor's environmental performance. A detailed survey was conducted for collecting the data used for determining the weightings of the parameters applied in the assessment system C-EPAS. In applying the system C-EPAS, the value of assessment indicators needs to be allocated. For this, the benchmarks of the indicator values are formulated. In order to calculate the C-EPI, the relative weightings of environmental performance factors to individual performance indicator are determined with applying the Non-Structural Fuzzy Decision System (NSFDS) method. Based on the establishment of the environmental performance factors, indicators, benchmarks and weightings, a quantitative formula is used in calculating the value of C-EPI. The operation procedures in applying C-EPAS have been programmed, leading to the development of the C-EPAS computing system. The principles and functions of the C-EPAS are defined and the procedures for operating the system areflowcharted. The operation system of the C-EPAS has been developed to user-friendly software. The adequacy of the principles embodied in the C-EPAS computing system and the applicability of the system operation procedures of the system have been tested and proven through conducting a case study.