Abstract
Canadian municipalities have noted that 59% of their water systems and 68% of their sewer systems required repair. To rehabilitate, replace or construct a water or sewer pipeline, several methods can be used: open-cut or one of several trenchless technologies (TTs). The selection of the method positively affects the surrounding environment. Therefore, the impact on environment (IoE) becomes a vital concern in selecting the appropriate construction or rehabilitation method for water or sewer pipelines. The research presented in this paper aims at developing an IoE model that compares the open-cut and TT methods. The IoE factors and their related data are collected, analysed and categorised based on literature review and expert opinion. Two models are designed in order to assess the IoE of the open-cut and TT methods. Results of the open-cut technique show that the impact on social factor has the maximum relative weight of 0.36; however, the impact on project characteristics has 0.33 and on environment has 0.30. The impact of TTs on project characteristics has the highest weight of 0.38, in which social factor is the lowest (0.28). The IoE value, using the open-cut method, is 0.4739; however, its value using the TT method is 0.3346. The developed IoE model shows robust results in quantifying the impact on environment of underground utility work. This research is relevant to both industry practitioners and researchers. It develops models to determine the IoE for the open-cut and TT methods. They are also beneficial to the municipal experts.