What are Hydraulic Biotic Soil Amendments (HBSAs)?

A HBSA is a manufactured, pre‐packaged material that is mixed with water and hydraulically‐applied as a uniform slurry. HBSAs are engineered to foster the development of top soil in deficient substrates within the rhizosphere, promote faster seed germination, and provide long term nutrient cycling that enhances sustainable vegetation establishment. HBSAs are designed to be used as topsoil or compost alternatives when topsoil is not present, soil is lacking organic matter, or there is little to no biological activity. In order to meet the criteria of replacing the compost or topsoil growth media, HBSAs typically contain a blend of organic and natural fibers with soil building components and soil enhancing chemistry. These materials are manufactured under controlled conditions with specific formulations that ensure product consistency. The components increase the water and nutrient holding capacity of the soil and create an environment for growth of beneficial microorganisms while allowing seed germination and vegetation establishment.

HBSAs shall be a pre‐packaged, commercially available, hydraulically applied blend of natural fibers, growth media and other biologically active material.

HBSAs offer some level of erosion protection, but typically do not replace the use of hydraulic or rolled erosion control products (HECPs or RECPs). HBSAs are typically installed beneath and complement HECPs or RECPs as a growing media. Refer to Erosion Control Technology Council HECP and RECP specifications for proper erosion control.

ECTC has developed a specification for HECPs to help assist designers and specifiers use these products. Click here for a copy of the HBSA specification.