Effects of Atmospheric Salt Deposition on Highway Runoff Characteristics – A Pilot Case Study

Monitoring studies of road runoff, from two different sites (highways A25 and IP6), located on coastal areas of Portugal [6–8] detected high levels of salinity and Carbon Oxygen Demand (COD). Table 1 compares results for these two sites, displaying interesting similarities between the parameters connected to salinity and COD. On the other hand, pollutants typical for highway runoff characterization, such as total suspended solids (TSS) and the heavy metals zinc (Zn), copper (Cu) and lead (Pb) clearly indicate different levels of traffic pollution. [5, 7] proposed that such evidences should be related to the vicinity of the Atlantic Ocean, since the non-coastal Portuguese roads did not show this same pattern.