Turn-Key Dewatering Management: Design, Feasibility, and Operations

Walter and Son Waste Hauling was tasked to hydraulically dredge 11,468 m3 (15,000 yd3) of river sediments (25-percent solids) from a backwater slough adjacent to the La Crosse Wisconsin Municipal Airport for subsequent backfill and taxiway construction using geogrids. Geotextile tubes and a site-specific chemical conditioning program were identified and subsequently implemented as a high volume, high flow containment option that provided efficient, cost effective, and environmentally friendly dewatering. The objective of this project was to design and operate a turn-key dewatering project that used a site-specific chemical conditioning program to expedite dewatering of sediments in geotextile tubes and safely return filtrate water back to area surface waters. Management included a comprehensive design with geotextile tube containment area specifications, weir design, liner and geotextile recommendations, and drawings. Feasibility testing included identification of a site-specific plan, fabric selection, hanging bag performance, Wisconsin DNR use permit applications and additional toxicological evaluation for full-scale operations. Management included technical support for construction, mobilization and start-up, daily and weekly reports, and personnel training for both chemical optimization and geotextile tube management. Overall, turn-key management helped the contractor optimize performance in a timely manner which ultimately led to realized profitability.