573 SECTION 651 FURNISHING AND PLACING TOPSOIL
651.1 -DESCRIPTION : This work shall consist of acquiring sites outside the right -of-way from which topsoil can be obtained and the hauling and placing of such material, or hauling and placing of tops oil from stockpiles within the right -of-way, all in accordance with these Specifications and at locations indicated on the Plans or designated by the Engineer.
651.2 -MATERIALS : Topsoil shall consist of the uppermost layers of fertile and friable soil that contains humus material. This material varies in thickness in accordance with soil groups and usually possesses a darker color than the subsoil. The texture of the topsoil may vary within the range o f natural loam, silty clay loam, and sandy loam. Acceptable topsoil shall contain organic matter in the range of 2% to 20% and be sampled at least once per project using AASHTO T 267 method; multiple sources or change of sources shall also be sampled.
CON STRUCTION METHODS
651.3 -STRIPPING TOPSOIL : Prior to removal from the site, the soil will be tested by the Division to determine the humus and nutrient value. Care shall be exercised as to th e depth of stripping, and any loads with an excess of subsoil shall be discarded. The Contractor shall mow or otherwise remove all heavy grass, weeds, or other vegetation over the areas before stripping. Approval by the Engineer must be obtained prior to transporting any material from the stripping site.
651.4 -TRANSPORTING : Topsoil material shall not be placed until the entire roadway (including surfacing) has been completed, unless otherwise provided for on the Plans or approved in writing. During hauling operations, the surface of the highway shall be kept reasonably clean to avoid creating a traffic hazard.
651.5 -PLACING AND MANIPULATING : Areas to be topsoiled shall be brought reasonably close to the lines and grades shown on the Plans or established by the Engineer. The Contractor shall scarify the surface of the subsoil before the topsoil is placed, unless otherwise permitted, for bonding the topsoil layer with the subsoil. Scarification shall be accomplished by disking, harrowing, raking, or other approved methods. Depressions and ridges formed by construction equipment, during final grading or scarifyin g, shall be parallel to the contours. Topsoil shall not be spread to a greater depth than that required to make the work conform to the natural terrain after shrinkage and settlement have taken place. After spreading the soil, all deleterious materials ( large lumps or clods, brush, litter, or other foreign material, and stones exceeding two ( 2) inches approximately in any dimension) shall be raked up and removed from the site. The Contractor shall take all reasonable precautions to avoid injury to existing plant growth, structures, and roadway surface.