Frequently Asked Questions

Engineered soils are blended, manufactured soils with specific ratios of components.  The sand component can is often specified by gradation, for example ASTM c33.  The topsoil component may include a certain percentage of organic matter, pH, or texture.  The compost component may have to include a certain percentage of organic matter or meet the USCC STA requirements.  Once the key components are acquired the best way to blend the components is with a precision blending system.  Each component must be measured by volume or weight (scaled) prior to loading into the mixing system.  It is best to do a large quantity or the whole project’s quantity at a single run so that the entire mix is homogenous with no variability.  Sampling the components and final stockpile of engineered soil will ensure that the soil is compatible with the project prior to installation.

Engineered soil is a soil designed and blended, or manufactured, for a specific purpose or with specific physical and chemical characteristics.  Often, the engineered soil is a blend to meet a texture including a target percentage of sand, silt, and clay particles including a percentage of organic matter within those components.  Engineered soils are typically used in stormwater applications such as bioretention areas and bioswales, but can include any type of topsoil for a project. 

Applications where engineered soils may be required include:

• Bioretention ponds, basins, and cells
• Rain Gardens
• Detention and retention ponds for stormwater
• Parking lot infiltration
• Pervious pavers and pervious pavement
• Vegetated roof systems or Green Roof Soil
• Upslope from channels, ditches, streams, and other water bodies
• Treating runoff from impervious surfaces such as roads, highways, parking lots, and other land disturbing activities
• Structural soil for planting near curbs, sidewalks, and roads
• Rootzone for athletic fields
• Topsoil for reclamation areas or landscaping

Engineered topsoil is a topsoil that is designed to meet a specification.  Typical blends of engineered topsoil have parameters for pH, organic matter content, soluble salt, texture, and nutrients. 

There are very few soil suppliers that are capable enough to handle large quantities of soil blending properly and keep soil components in stockpiles.  River Sand, Inc. produces both the components and the engineered soil you need.  You can pick up or we can deliver.  We also provide support for answering questions from engineers, architects, or owners and laboratory analysis on our soils.