Dredging contractor uses cost effective and innovative dewatenng technology to contain and dewater marine sediments.
A build-up of organics, sediments, very fine silt and clay created a major navigational problem for members of the Queens Lake Marina Association, in York County, VA. A contract was issued to dredge and dewater sediments in the boat slips and outside the enclosed slip area. Site preparation, permitting, transportation, and disposal were handled by the Marina Association. The filling and consolidation phase took place over a two-week period. Dredging/pumping was approximately 1,500 gpm at an average feed solids concentration of 6% - 8%.
TenCate develops and produces materials that function to increase performance, reduce cost, and deliver measurable results by working with our customers to provide advanced solutions. The unique high volume, low cost Geotube dewatering system, provides a very effective way of dewatering marine sediments.
Watersolve's WSLP-2400 Polymer System made down and activated Solve 9330 emulsion polymer at 0.5% concentration. Onsite confirmation of the previously identified chemical conditioning program confirmed 166-ppm Solve 9330 for full-scale operations. A good, tight floe was achieved inline with release of clear filtrate. Clear filtrate from the dewatering Geotube units flowed back into the river. Polymer usage was in line with original usage estimates of 3 to 5 lbs of polymer per dry ton of sediment.
This project was started in November '07 and dredging was completed within two weeks. The Geotube units were pumped to the maximum allowable height of 7.5', allowed to dewater and consolidate and then pumped to the maximum 7.5' height again. The material was left in the Geotube containers through the winter. The dredged sediments continued to desiccate over the winter and were successfully transported off-site.