USES: Cap Amendment Placement, Mudflats, Sediment Cap Stabilization, Topsoil

What is SedFirst™?

Fish swimming in the ocean above ocean plants

SedFirst™ Sediment Stabilizer is an innovative technology that enhances cohesion of sand, sediment and soil. SedFirst mimics natural processes to increase sediment stabiliity.

In nature, biota emit organic secretions which increase the cohesion of sediment by forming biofilm on sand and sediment particle grains. This cohesion increases the erosion resistance of sediment. When SedFirst is placed in sand, sediment, or soil, it abiotically coats the surfaces, thereby enhancing cohesion and shear strength and cohesion.

This in-situ technology uses a formulation of Protein and Polysaccharide Biopolymer (PPBs). The SedFirst products are GRAS (Generally Recognized As Safe) due to the non-toxic food-grade nature of their ingredients. The products are biodegradable and are formulated based on site characteristics and stabilization and placement objectives.

Benefits of 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.  

Cost Benefits

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.

Bringing Life to your Cap

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.

Toxicity Testing

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.

Our Process

EcoStable will evaluate your site and assist in establishing the best course of action. A site-specific product formulation will be designed and a treatment program will be developed for your project.


  • Site Evaluation

    Site characteristics, objectives for stabilization and placement methods are evaluated in order to develop the optimal SedFirst formulation. Bed shear stress data from hydrodynamic studies are reviewed to determine strength requirement for the capping material. Cap design requirements such as chemical isolation performance, thickness and armoring also may be reviewed.  


  • Laboratory Testing

    Laboratory testing is conducted on a sample of the cap material and amendments to optimize the SedFirst formulation for the intended application, e.g. erosion resistance, homogeneous amended cap placement and water turbidity reduction. Testing may include turbidity measurements in a water column and direct shear testing of treated specimen.

  • Product Preparation

    Based on the laboratory testing, the site-specific SedFirst formulation is manufactured and shipped to the site.

  • Product Application

    EcoStable will work with the Engineer and/or  contractor to select the most appropriate SedFirst field application method for the site. EcoStable will provide technical assistance and data analysis, as necessary, to ensure a successful application of SedFirst.

  • Monitoring

    EcoStable will work with the Engineer and/or contractor to develop a SedFirst field application monitoring plan. Cores from the cap may be collected to determine that the placement meets the specifications of the SedFirst-enhanced cap design.