Kontinuerlig föroreningsspridning från vägbroar till ytvattenrecipienter med tillämpning på Segeåns avrinningsområde / Continous pollutant emissions from road bridges to receiving waters with application to the Segeån catchment area
Heavily trafficked roads routinely generate a wide spectrum of pollutants, many of these are listed as priority substances according to the EU Water Framework Directive (WFD). Watercourses that intersect with major roads are exposed to both airborne and waterborne traffic generated pollutants, possibly deteriorating the receiving waters. Four bridges within the Segeån catchment area (in the southwest of Scania, Sweden) were identified, using a prioritization methodology, as interesting objects for environmental investigation. The bridges were environmentally analyzed assuming pollutant levels in road runoff according to benchmarks from the UK Highways Agency. They were not found to have any chronic impact on the water qualities of the recipients. However, it could be concluded that temporary pollutant peaks, e.g. caused by heavy storm events, at some locations could lead to exceedance of the EU MAC-EQS (Maximum Allowable Concentration – Environmental Quality Standard) as a result of as little as the waterborne pollutant contribution from one bridge solely. In order to ensure that concentration of priority substances in receiving waters fall below the EU WFD EQS’s, installation of barriers towards airborne pollution along road bridges and improved bridge deck runoff management is suggested.