Arias, Andrea; Arufe, Sainza; Recarey, Montse; Fierro, Julio; Martínez, Cristina; Fernández, Isaac

Diffuse pollution is caused by anthropogenic activities that have no specific point of discharge, such as agriculture, transport, forestry… Pollutants deposited on to impervious surfaces (e.g. roads or pavements) are washed out by runoff water, such as metals, polycyclic aromatic hydrocarbons (PHAs), alkanes, pesticides… Moreover, traditional pavement is impermeable hindering the water filtration and absorption, which can affect the natural water cycle. The harmful effects of the urban runoff can increase the toxicity of aquatic or terrestrial ecosystems, so the need of treatment systems is crucial. The LIFE DrainRain project arises with the main objective of reducing that environmental impact in water bodies. A sustainable drainage system (SUDS) based on a photocatalytic porous pavement combined with an in-situ modular water treatment was evaluated from an environmental and economic perspective. Two pilot plants built in different geographical areas were analysed through Life cycle assessment (LCA) and life cycle costing (LCC). LCA methodology was applied from cradle-to-grave considering all stages. The two pilot plants were compared with a conventional pavement without treatment. Software Simapro 9.0 was used to calculate the most representative environmental categories, in this case they are climate change (CC) and eutrophication potential (EP). Although, environmental impacts in CC may increase due to the energy consumption for water treatment, the impacts in EP can decrease about 60%. In terms of environmental cost, the impacts can be reduced about 51%-80% depending on the localisation. Therefore, the inclusion of this innovative pavement followed by a wastewater treatment can reduce the environmental impacts in terms of EP and environmental costs. Thus, this alternative can be a good option for improving the water quality or recovering water for reuse. This research was supported by the LIFE program of EU (LIFE15/ENV/ES/000394).