Environmental Dredging on the Birmingham Canals: Water Quality and Sediment Treatment

Abstract

ABSTRACTSediments in sections of the central Birmingham canals are heavily contaminated with heavy metals and mineral oils. The sediments promote high levels of metals within the water column, which suppress the establishment of aquatic vegetation and fisheries. Sediment disturbance by boat traffic results in the release of mineral oils which cause unsightly surface oil sheens.Studies into a variety of treatment methods indicated that removal and ex‐situ treatment of the contaminated sediments would significantly improve water quality and result in environmental benefits.Funding from Birmingham City Council and British Waterways enabled the award of a contract with a value of approximately £800000 and commencement in February 1993 for the removal and processing of about 24 000 m3 of sediments by soil washing prior to off‐site disposal. The nature of the sediments and water are reviewed, and the results of the soils washings are discussed. The impact of the dredging operations on water quality was monitored during the works and generally observed to be localized. An environmental management plan is now being implemented and the objectives for this are discussed.