SedFirst™

SedFirst formulations are developed to stabilize sand-based isolation capping of sediment, minimize dredging-related resuspended sediment, and efficiently transport Organoclay®, Powdered Activated Carbon (PAC) and Granulated Activated Carbon (GAC) amendments through the water column for in-situ placement with a sand matrix. SedFirst can also be used to minimize water turbidity when placing topsoil.

The cohesion formed by SedFirst increases homogeneity of the cap mix during and after placement and significantly reduces loss of high-value amendments due to dispersion (turbidity), ensuring cap performance through erosion resistance and reduced material requirements by optimizing placement of sand and amendments.  

SedFirst decreases the overall project cost by reducing the cost of materials, labor, compliance and oversight associated with over-placement of capping material to account for erosion, scouring and loss to dispersion.  SedFirst treatment also improves water quality during cap placement, thereby decreasing costs associated with management and compliance.

SedFirst can stimulate colonization of sediment cap biota, increasing cap stability and cap life, thereby reducing required cap thickness. SedFirst PPBs can jump-start the natural cohesion-enhancing processes by attracting microphytobenthos and macrobenthos to the cap.

SedFirst has passed the aquatic acute toxicity tests (> 90% survival) in an aquatic toxicity testing conducted at New England Bioassay (NEB) in Manchester, CT. SedFirst formulations are composed of polysaccharides and vegetable protein extracts that are generally recognized as safe (GRAS) by the FDA.