Dewatering of Geotextile Fabric Containers Upon Impact with the Sea Floor: Environmental Monitoring Implications

A permeable geotextile fabric container (GFC), used for containing dredge spoils or sewage sludge, may expel contaminated water after its release due to impact with the sea floor. By extrapolating from reported permeabilities and flow rates for GFC fabrics to expected impact conditions, we demonstrate that water-filled GFCs may lose 10–30% of their content. Sediment filled GFCs, however, will experience water loss on the order of 0.0024% of total GFC volume as a result of immediate clogging of fabric pores during GFC impact. Thus, any significant release of contaminated water from GFCs will be caused by initial rupture or long-term failure. Monitoring scenarios should focus mainly on these issues.