Support healthy plants, biological communities, and water storage and infiltration by planning for soil restoration in the design stage and limiting soil disturbance during construction.
- Create a soil management plan (SMP) prior to construction that provides the following information in a site plan and a worksheet (see Soil Management Plan Worksheet):
- Indicate locations of existing healthy soils on site and any Vegetation and Soil Protection Zones (VSPZs) (See Pre-Design P2.3: Designate and communicate VSPZs) and steps taken to protect these from any disturbance during construction.
- Specify how construction activities are designed to minimize soil disturbance.
- Identify disturbed soils that will be re-vegetated (soil restoration treatment zones):
- For soils disturbed during current construction activity (as required in Construction P7.3: Restore soils disturbed during construction)
- For soils disturbed by previous development (if pursuing Construction C7.4: Restore soils disturbed by previous development)
- Identify severely disturbed soils that will be re-vegetated.
- Describe in detail the planned treatment for each soil restoration treatment zone, including, if applicable, how reference soil characteristics (as identified in Pre-Design P2.2: Conduct a pre-design site assessment) will be met for each zone.
- Communicate the SMP to site contractors through site drawings and written specifications.
Note: Imported topsoils, or manufactured soil blends designed to serve as topsoil, may not be mined from the following locations (unless these soils are a byproduct of a construction process):
- Greenfield sites
- Prime farmland, unique farmland, farmland of statewide importance, or farmland of local importance as defined by the U.S. Natural Resources Conservation Service (or local equivalent for projects outside the United States)
Areas with disturbed soils (as a result of current construction activities) must be restored to a minimum 12-inch (30.48-centimeter) depth per the requirements of Construction P7.3: Restore soils disturbed during construction.
- Before construction begins, the SMP prescribes soil restoration treatments that will be used to restore all soil areas that will be disturbed during construction and re-vegetated at the end of the project, as required by Construction P7.3: Restore soils disturbed during construction.
- Consider existing soil conditions during site design, identify VSPZs and soil restoration treatments for soils that will be disturbed, and communicate clearly with all site contractors to ensure that soil protection and restoration goals are understood and achieved.
- Install fencing or provide other effective physical barriers to protect VSPZs before construction commences (as required by Pre-Design P2.3: Designate and communicate VSPZs).
- Integrate the SMP with site erosion and sediment control planning (e.g., stormwater pollution prevention plan (SWPPP) or erosion and sedimentation control (ESC) plan; see Construction P7.2: Control and retain construction pollutants). For instance, use compost blankets, berms, or socks for erosion and sediment control, and, at the end of the project, reuse the same compost as a soil restoration amendment.
- Limit disturbance during construction to minimize the need for additional restoration. In areas that will be re-vegetated, restore soil characteristics necessary to support the selected vegetation types. Example methods of restoring soils include the following:
- Stockpiling and reusing existing site topsoils, incorporating organic amendments if needed
- Amending site soils with organic matter in place and mechanically correcting compaction, if needed (e.g., by ripping or discing)
- Importing a topsoil or soil blend designed to serve as topsoil
- When selecting a soil restoration strategy, consider the design, site use, and future site maintenance expectation. Potential strategies are:
- Adding mature, stable compost to unscreened soil
- Many un-screened and un-amended soils will drain adequately
- Amending with other earth materials to modify a soil’s gradation/texture and organic matter content
- Best management practices include using soils for functions comparable to their original function (e.g., topsoil is used as topsoil, subsoil as subsoil). In some cases, subsoil can be reused and amended to become functional topsoil.