Evaluation of Metals Leaching in Permeable Asphalt Pavement and Conventional Asphalt Pavement

A permeable asphalt pavement (PP) and a conventional asphalt pavement (PD) have been tested regarding the potential leaching of the metals Cd, Cr, Fe, Pb, Mn, Ni and Zn during 11 rain events immediately after their construction. Water samples were picked up for the rain water and in four sampling points of both pavements during every rain, two located at the surface of the pavements (PPE and PDE), and other two after infiltration in the pavements (PPI and PDI). The results show that there was introduction and transport of Cr, Fe, Pb, Mn, Ni and Zn during surface runoff on pavements. After water infiltration in the pavements, there was significant removal of Cr in the PD pavement, Pb and Zn concentrations did not decrease in depth and concentrations of Fe and Ni increased after infiltration. However, the concentrations of all metals in the leaching water are very low comparing with the minimum standard legal values set up for irrigation and discharge on water courses.