1. SCOPE

The work shall consist of stripping, stockpiling, site preparation, and spreading topsoil in accordance with the applicable specifications.

2. STRIPPING

Strip topsoil only from those areas that will be disturbed by excavation, filling, road building, or compaction by equipment. A 4 to 6 inch stripping depth is common, but depth varies depending on site.

Determine depth of stripping by taking soil cores at several locations within each area to be stripped. Topsoil depth generally varies along a gradient from hilltop to toe of the slope.

All planned erosion and sediment control practices shall be in place and functioning properly prior to stripping.

3. STOCKPILING

Select a stockpile location to avoid slopes and natural drainageways, and to avoid traffic routes. On large sites, respreading is easier and more economical when topsoil is stockpiled in small piles located near areas where they will be used.

Perimeter controls shall be placed around the stockpile immediately. Examples of suitable control measures include DIVERSION DIKE 820, SILT FENCE 920, and STRAW BALE BARRIER 935.

Temporary stabilization of the stockpile shall be completed within seven (7) days of the formation of the stockpile, in accordance with practice standard TEMPORARY SEEDING 965, if it is to remain dormant (undisturbed) for longer than thirty (30) days.

Permanent stabilization of the stockpile shall be completed within seven (7) days of the formation of the stockpile, in accordance with practice standard PERMANENT VEGETATION 880, if it is to remain dormant (undisturbed) for longer than 12 months.

4. SITE PREPARATION

Before spreading topsoil, assure that all necessary erosion and sediment control practices such as diversions, berms, dikes, waterways, and sediment basins are in place and functioning properly. These practices must be maintained until the site is permanently stabilized.

Grading - Maintain grades on the areas to be topsoiled according to the approved plan and do not alter them by adding topsoil.

Liming of subsoil - Where the pH of the existing subsoil is 6.0 or less, or the soil is composed of heavy clays, incorporate agricultural limestone in amounts recommended by soil tests or specified for the seeding mixture to be used (Practice 880 PERMANENT VEGETATION). Incorporate lime to a depth of at least 2 inches by disking.

Roughening - Immediately prior to spreading the topsoil, loosen the subgrade by disking or scarifying to a depth of at least 4 inches, to ensure bonding of the topsoil and subsoil. If no amendments have been incorporated, loosen the soil to a depth of at least 6 inches before spreading the topsoil.

5. SPREADING TOPSOIL

Uniformly distribute topsoil to a minimum compacted depth of 2 inches on 3:1 slopes and 4 inches on flatter slopes. To determine the volume of topsoil required for application to various depths, use Table 1.

Topsoil shall not be spread while it is frozen or muddy or when the subsoil is frozen or muddy.

Irregularities in the surface that result from topsoiling or other operations shall be corrected to prevent the formation of depressions or water pockets.

Compact the topsoil enough to ensure good contact with the underlying soil, but avoid excessive compaction, as it increases runoff and inhibits seed germination and seedling growth. Light packing with a roller is recommended where high-maintenance turf is to be established.

In areas that are not going to be mowed, the surface shall be left rough.

TABLE 1

CUBIC YARDS OF TOPSOIL REQUIRED

FOR APPLICATION TO VARIOUS DEPTHS