Constructed Wetlands for the Treatment of Runoff from the Newbury Bypass

The A34 Newbury bypass crosses sensitive watercourses and incorporates runoff-control systems. The series of treatment stages of each system comprises an oil interceptor, silt trap, grassy slope and constructed wetland. In December 1998, a monitoring programme was initiated for one of the systems to evaluate the removal and behaviour of pollutants, and this paper presents the initial results. Future work will examine the mechanisms involved in metal removal and the fate of other pollutants.