Construction activities in watery environments stir up sediments that can release stored pollutants; clog waterways; and are expensive to store, treat or remove. Blue Boar Contracts, Midlands, England, had a national dredging contract with British Waterways to deepen canals—and extract tons of sediment slurry for removal. The company called on Sedi-filter, a dewatering solution manufactured by DRM Industrial Fabrics Ltd., Bury, Lancashire, England. The system involves pumping the murky water or sludge into geotextile tubes that allow water to drain, but keep sediment in place. When the tubes are 80-percent filled, the dried sediments can be treated or landfilled at a fraction of the cost of wet sludge.
In a three-month trial, the company used Sedi-filter bags to dewater and contain sediments from a two-mile stretch of the Birmingham and Worcester Canal. Blue Boar is now using the geotextile tubes for most of its contaminated sediment projects. The system can incorporate air systems and bacteria that “eat” sediment pollutants, can be used to create artificial berms and reefs, and also work to control erosion in marine environments.