### **ITEM T‑905  TOPSOILING**

DESCRIPTION

**905‑1.1**   This item shall consist of preparing the ground surface
for topsoil application, removing topsoil from designated stockpiles or
areas to be stripped on the site or from approved sources off the site,
and placing and spreading the topsoil on prepared areas in accordance
with this specification at the locations shown on the plans or as
directed by the Engineer.

MATERIALS

**905-2.1 TOPSOIL.**  Topsoil shall be the surface layer of soil with no
admixture of refuse or any material toxic to plant growth, and it shall
be reasonably free from subsoil and stumps, roots, brush, stones (2
inches or more in diameter), and clay lumps or similar objects.  Brush
and other vegetation that will not be incorporated with the soil during
handling operations shall be cut and removed.  Ordinary sods and
herbaceous growth such as grass and weeds are not to be removed but
shall be thoroughly broken up and intermixed with the soil during
handling operations.  The topsoil or soil mixture, unless otherwise
specified or approved, shall have a pH range of approximately 5.5 pH to
7.6 pH, when tested in accordance with the methods of testing of the
association of official agricultural chemists in effect on the date of
invitation of bids.  The organic content shall be not less than 3% nor
more than 20% as determined by the wet‑combustion method (chromic acid
reduction).  There shall be not less than 20% nor more than 80% of the
material passing the 200 mesh (0.075 mm) sieve as determined by the wash
test in accordance with ASTM C 117.

Natural topsoil may be amended by the Contractor with approved materials
and methods to meet the above specifications.

**905-2.2 INSPECTION AND TESTS.**  Within 10 days following acceptance
of the bid, the Engineer shall be notified of the source of topsoil to
be furnished by the Contractor.  The topsoil shall be inspected to
determine if the selected soil meets the requirements specified and to
determine the depth to which stripping will be permitted.  At this time,
the Contractor may be required to take representative soil samples from
several locations within the area under consideration and to the
proposed stripping depths, for testing purposes as specified in 905‑2.1.

CONSTRUCTION METHODS

**905‑3.1  GENERAL.**  Areas to be topsoiled shall be shown on the
plans.  If topsoil is available on the site, the location of the
stockpiles or areas to be stripped of topsoil and the stripping depths
shall be shown on the plans.

Suitable equipment necessary for proper preparation and treatment of the
ground surface, stripping of topsoil, and for the handling and placing
of all required materials shall be on hand, in good condition, and
approved by the Engineer before the various operations are started.

**905-3.2 PREPARING THE GROUND SURFACE.**  Immediately prior to dumping
and spreading the topsoil on any area, the surface shall be loosened by
discs or spike‑tooth harrows, or by other means approved by the
Engineer, to a minimum depth of 2 inches (50 mm) to facilitate bonding
of the topsoil to the covered subgrade soil.  The surface of the area to
be topsoiled shall be cleared of all stones larger than 2 inches (50 mm)
in any diameter and all litter or other material which may be
detrimental to proper bonding, the rise of capillary moisture, or the
proper growth of the desired planting.  Limited areas, as shown on the
plans, which are too compact to respond to these operations shall
receive special scarification.

Grades on the area to be topsoiled, which have been established by
others as shown on the plans, shall be maintained in a true and even
condition.  Where grades have not been established, the areas shall be
smooth‑graded and the surface left at the prescribed grades in an even
and properly compacted condition to prevent, insofar as practical, the
formation of low places or pockets where water will stand.

**905-3.3 OBTAINING TOPSOIL.**  Prior to the stripping of topsoil from
designated areas, any vegetation, briars, stumps and large roots,
rubbish or stones found on such areas, which may interfere with
subsequent operations, shall be removed using methods approved by the
Engineer.  Heavy sod or other cover, which cannot be incorporated into
the topsoil by discing or other means shall be removed.

When suitable topsoil is available on the site, the Contractor shall
remove this material from the designated areas and to the depth as
directed by the Engineer.  The topsoil shall be spread on areas already
tilled and smooth‑graded, or stockpiled in areas approved by the
Engineer.  Any topsoil stockpiled by the Contractor shall be rehandled
and placed without additional compensation.  Any topsoil that has been
stockpiled on the site by others, and is required for topsoiling
purposes, shall be removed and placed by the Contractor.  The sites of
all stockpiles and areas adjacent thereto which have been disturbed by
the Contractor shall be graded if required and put into a condition
acceptable for seeding.

When suitable topsoil is secured off the airport site, the Contractor
shall locate and obtain the supply, subject to the approval of the
Engineer.  The Contractor shall notify the Engineer sufficiently in
advance of operations in order that necessary measurements and tests can
be made.  The Contractor shall remove the topsoil from approved areas
and to the depth as directed.  The topsoil shall be hauled to the site
of the work and placed for spreading, or spread as required.  Any
topsoil hauled to the site of the work and stockpiled shall be rehandled
and placed without additional compensation.

**905-3.4 PLACING TOPSOIL.**  The topsoil shall be evenly spread on the
prepared areas to a uniform depth of 2 inches (50 mm) after compaction,
unless otherwise shown on the plans or stated in the special
provisions.  Spreading shall not be done when the ground or topsoil is
frozen, excessively wet, or otherwise in a condition detrimental to the
work.  Spreading shall be carried on so that turfing operations can
proceed with a minimum of soil preparation or tilling.

After spreading, any large, stiff clods and hard lumps shall be broken
with a pulverizer or by other effective means, and all stones or rocks
(2 inches (50 mm) or more in diameter), roots, litter, or any foreign
matter shall be raked up and disposed of by the Contractor.  after
spreading is completed, the topsoil shall be satisfactorily compacted by
rolling with a cultipacker or by other means approved by the Engineer. 
The compacted topsoil surface shall conform to the required lines,
grades, and cross sections.  Any topsoil or other dirt falling upon
pavements as a result of hauling or handling of topsoil shall be
promptly removed.

METHOD OF MEASUREMENT

**905-4.1**  Topsoil obtained on the site shall be measured by the
number of cubic yards (cubic meters) of topsoil measured in its original
position and stripped or excavated.  Topsoil stockpiled by others and
removed for topsoiling by the Contractor shall be measured by the number
of cubic yards (cubic meters) of topsoil measured in the stockpile. 
Topsoil shall be measured by volume in cubic yards (cubic meters)
computed by the method of end areas.

**905-4.2**  Topsoil obtained off the site shall be measured by the
number of cubic yards (cubic meters) of topsoil measured in its original
position and stripped or excavated.  Topsoil shall be measured by volume
in cubic yards (meters) computed by the method of end areas.

BASIS OF PAYMENT

**905-5.1**  Payment will be made at the contract unit price per cubic
yard (cubic meter) for topsoiling (obtained on the site).  This price
shall be full compensation for furnishing all materials and for all
preparation, placing, and spreading of the materials, and for all labor,
equipment, tools, and incidentals necessary to complete the item.

**905-5.2**  Payment will be made at the contract unit price per cubic
yard (cubic meter) for topsoiling (obtained off the site).  This price
shall be full compensation for furnishing all materials and for all
preparation, placing, and spreading of the materials, and for all labor,
equipment, tools, and incidentals necessary to complete the item.

Payment will be made under:

Item T‑905‑5.1 Topsoiling (Obtained on Site or Removed from
Stockpile---per cubic yard (cubic meter)

Item T‑905‑5.2 Topsoiling (Furnished from Off the Site)---per cubic yard
(cubic meter)

TESTING MATERIALS

ASTM C 117 Materials Finer than 75-m (No. 200) Sieve in Mineral
Aggregates by Washing

**END OF ITEM T-905**

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