C7.4: Restore Soils Previously Disturbed by Development – Above Green

(3-5 points)

INTENT

Support healthy plants, biological communities, water storage, and infiltration by restoring soils in areas disturbed by previous development.

REQUIREMENTS

Restore soils on site disturbed by previous development. These requirements apply only to previously disturbed areas that will be re-vegetated. Areas with soils that were previously developed and restored per requirements in Construction P7.3: Restore soils disturbed construction may also be included here.

To count towards this credit, restored soils must cover a minimum of 500 square feet (46.46 square meters) or five percent of the total project area. Credit point values are based on the surface area of soil disturbed by previous development that will be re-vegetated and the degree of disturbance of those soils (disturbed or severely disturbed). See Point Value Table 7.4-A below.

Locate reference soils to guide and determine performance criteria that are appropriate for the site’s vegetation, intended program, and site elements.
- If identified reference soils are not appropriate for the design intent, explain why and describe the soil characteristics that will guide soil restoration treatment efforts. (See Pre-Design P2.2: Conduct a pre-design site assessment and Soil+Veg P4.1: Create and communicate a soil management plan.)
Restore disturbed existing soils to a minimum depth of 12 inches (30.48 centimeters)
- Where planting trees, restore soils to a greater depth and volume to support (biologically, structurally, hydrologically, and geotechnically) the intended mature tree canopy.
Test restored (final) soil conditions to ensure the following soil restoration criteria are met (see Construction P7.3: Restore soils disturbed during construction for details):

1. Organic matter (required)

2. Compaction (field test or undisturbed core sample only)

Infiltration (field test only)

3. Soil chemical characteristics

Soil biological function

Required tests per project area:

Restored Vegetated Area	Minimum Number of Soil Tests Required
≤ 0.5 acre (0.20 hectares)	1 set for each soil restoration treatment zone type (see Soil+Veg P4.1)
> 0.5 acre (0.20 hectares) to ≤ 1 acre (0.40 hectares)	2 sets for each soil restoration treatment zone type
> 1 acre (0.40 hectares) to 2 acres (0.81 hectares)	3 sets for each soil restoration treatment zone type
> 2 acres (0.81 hectares) to ≤ 20 acres (8.09 hectares)	1 set per acre for each soil restoration treatment zone type
> 20 acres (8.09 hectares)	1 set per 3 acres for each soil restoration treatment zone type

Note: If multiple soil restoration treatment zones have the same soil restoration methods, treat them as one type.

TABLE 7.4-A: Point Value Table

Percent or total site area that will be re-vegetated
500 sq ft to 0.5 acres (46 square meters to 0.20 hectares) OR at least 5%	0.5 acres to 5 acres (0.20 to 2.02 hectares)OR 10% or more	More than 5 acres (2.02 hectares) OR 30% or more
Disturbed	3 points	3 points	4 points
Severely disturbed	3 points	4 points	5 points

Note: Soils must be reused for functions comparable to their original function (i.e., topsoil is used as topsoil, subsoil as subsoil, or subsoil is amended to become functional topsoil).

Structural or engineered media:

These specialized media are exempt from meeting the soil restoration criteria above when used for applications such as the following. However, all other requirements must be met and documentation submitted accordingly:

Athletic fields
Green roofs
Raingardens
Vertical green walls
Trees in paving
Bioswales
Green vehicle easements
Steep slopes
Food gardens
Constructed wetlands

Note: Imported topsoils, or manufactured soil blends designed to serve as topsoil, may not be mined from the following locations (unless 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)

RECOMMENDED STRATEGIES

Please see detailed recommended strategies for soil restoration in Construction P7.3: Restore soils disturbed during construction.