10.4122/1.1000001240 Antunes, P. A. Barbosa, A. E. Highway runoff characteristics in coastal areas \342\200\223 A case study in Aveiro, Portugal DTU Library, Technical University of Denmark (DTU) 2005 Coastal areas highway runoff monitoring salinity pollutants Higher School of Technology of the Higher Institute for Technology of Viseu, Environment Department Portuguese National Laboratory for Civil Engineering, Hydraulics and Environment Department en Conference full text 10.4122/1.1000001239 application/pdf 1 In the framework of a study for the Portuguese Road Institute, the authors carried out a monitoring study of the IP5 highway, located at the coast line. The TSS and the turbidity values measured in 40 runoff samples were relatively low, resulting from the low potential of the drainage area and surroundings to contribute with solids. Heavy metals results (Fe, Zn, Cu, Pb, Cd and Ni) were in accordance with other studies. It was confirmed the continuous decrease in Pb concentrations in stormwater. Analysis revealed high levels of salinity (161 mg/l) and chlorides (51.3 mg/l) that are usually reported only for roads with de-icing salts application. Searches in the literature revealed only one reference to marine aerosols as contributing to chloride presence in stormwater, and no notice of increased pavement deterioration in coastal highways. Salinity present in coastal areas may provoke structural alterations in the pavement that may be associated to a larger release of its constituents. The fact that black particles were observed both in the runoff samples and at the IP5 drainage system may be indicators of such phenomena. The authors plan to carry on further field and laboratory investigations, with the objective of better understanding these phenomena.