Evaluation of the Environmental and Economic Impacts on the Life Cycle of Different Solutions for Toilet Flush Systems

The use of plumbing fixtures to promote water saving in the built environment is a common practice in water conservation programs. However, the environmental implications of fixtures replacement should be taken into consideration. This paper analyzes three different scenarios for the provision of water in toilets installed in a university campus. In scenarios 1 and 2, single flush and dual flush devices were installed in the toilets, respectively. In scenario 3, in addition to the installation of dual flush devices, a greywater reuse system from the lavatories was analyzed. The objective is to evaluate, through the Life Cycle Assessment, the environmental aspects related to these scenarios. The economic analysis of the three scenarios was also carried out. Measurements were taken on all plumbing fixtures installed in a building of a university campus in Southern Brazil. The research was conducted using smart meters in two periods: with single flush and dual flush devices installed in toilets. Considering the environmental impacts analyzed, scenario 3 presented lower water and energy consumption in the life cycle. Scenario 2, however, presented lower global warming potential. The net present value results were R$ 23,575.71, R$ 19,091.41, and R$ 22,500.55 for scenarios 1, 2 and 3, respectively.