Energy and Cost Benefit Evaluation of a Urine Diversion System—A Case Study at Highway Service Areas in Japan

In this study, the reduction on the environmental load by the replacement of conventional toilets with low environmental load toilets such as water recycling urine-diverting toilet newly developed at highway service areas in Japan was quantified and a cost-benefit analysis concerning introducing low environmental load toilets were performed. Moriya service area which is one of the large–scale service areas and Minori service area which is the middle–scale one were selected for the case study. As for the results, the pollution load, especially, total nitrogen and phosphorous were expected to be reduced by 94% and 79 % from existed system, respectively, in the Minori service area. Concerning the burden of energy and cost, the payback periods by introducing the urine diversion system were 0.3 and 0.8 years for energy, and 2.8 and 12.6 years for cost at Moriya and Minori service area, respectively.