4-02912 Topsoil Sub-Soil.pdf

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SECTION 02912

TOPSOIL AND SUBSOIL

PART 1 GENERAL

1.1 DESCRIPTION

A. The Work of this Section describes the subgrade compaction for lawn and planting areas, and final preparation and placing of topsoil.

B. Removal of roots, root mat, brush, trash and stones larger than 2 inches shall be the responsibility of the Landscape Trade Contractor so that topsoil is clean and will facilitate vigorous plant growth.

C. Provide labor and materials complete as indicated on drawings and specified including but not limited to:

1. Testing existing on-site soils and/or topsoil acquired from off-site.

2. Amending and preparing soil for lawn, meadows and planting areas.

3. Preparing subgrade.

4. Spreading topsoil.

5. Placing planting soil in beds.

6. Guarantee

7. Disposal and Clean-up

1.2 RELATED WORK ELSEWHERE

A. Exterior Plants - Section 02930

1.3 REFERENCES

A. The following references apply to this section.

1. Agricultural Chemist: qualified, experienced public or private soils testing laboratory, capable of providing test results as specified and approved by the Architect.

2. ASTM: American Society for Testing and Materials

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a. Modified proctor density in accordance with ASTM 01557.

3. AASHTO: American Association of State Highway and Transportation Officials.

a. Modified Proctor Density in accordance with AASHTO T180.

1.4 DEFINITIONS

A. Topsoil is defined as the existing top layer of earth on the site, which produces heavy growths of crops, grass or other vegetation, and free from clay lumps and toxic substances harmful to plant growth.

1.5 SUBMITTALS TO PROJECT LANDSCAPE ARCHITECT

A. General: Render submittals and receive approval prior to delivery or installation.

1. Approval by the Architect of submitted product data, samples, test reports, and certificates does not constitute final acceptance.

B. Testing: Submit written statement from proposed agricultural chemist that required tests can be performed in accordance with the specifications.

C. Product Data: Submit product literature or tear sheets giving name of product, manufacturer's name, and compliance with specifications.

1. Peat Moss: Include pH, content of woody material, water absorbing capacity, and moisture content by weight.

2. Ground Limestone: Include guaranteed analysis and weight for packaged material.

3. Dehydrated cow manure. Include guarantee that cow manure is pure, sterilized, organic cow manure that is well composted and not fresh.

D. Samples

1. Sand: Two pound bag.

2. Peat Moss: One pound bag.

E. Test Reports: Submit certified reports by an agricultural chemist. Make submittals at least three

(3) weeks prior to delivery of materials to site.

1. Topsoil: Test all existing topsoil or topsoil acquired off-site, for compliance with material specifications. Coordinate with this 2.1.A. Have one composite sample tested from each stockpile intended for use in lawn and planting work. Include

02912 -3 the costs of tests and amendments, if required, in the bid price. Owner reserves the right to have soil tested independently.

a. If topsoil does not meet specified requirements, submit a program of amendments for bringing the topsoil up to the minimum standards.

b. Perform the following tests:

i. Fertility analysis - pH, soluble salts, nitrate, phosphate, potassium, calcium, and magnesium.

ii. Cation exchange capacity.

iii. Organic matter content (% ovendry weight of soil).

iv. Particle size analysis.

c. Promptly submit written reports of each sample tested. Each report shall include:

i. Date issued.

ii. Project title and Landscape Trade Contractor name.

iii. Testing laboratory name, address, telephone number, and name of laboratory inspector.

iv. Date and time of sampling or test including temperature and weather conditions.

v. Location of topsoil stockpile or off-site source.

vi. Type of test.

vii. Results of tests and interpretation of test results.

viii. Recommendations for soil additives, proportions, and methods for preparing soil for optimum lawn and planting conditions.

2. Sand: Provide sieve analysis report and salt content.

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1.6 QUALITY ASSURANCE

A. Testing shall be performed by a single laboratory.

B. Installer: Perform Work with personnel totally familiar with planting soil preparation and lawns and planting installation under the supervision of an experienced landscape foreman. Notify the Construction Manager of the name and phone number of the foreman five (5) business days in advance of the first day of lawn construction.

C. Arrange a pre-construction meeting between the Architect, Construction Manager and Landscape Trade Contractor. Such meeting shall seek to review the soil testing and soil work schedule, phasing, review of specifications, and construction procedures.

1.7 REGULATORY REQUIREMENTS

A. Comply with all rules, regulations, laws, and ordinances of local, State, and Federal authorities having jurisdiction. Provide labor, materials, equipment, and services necessary to make Work comply with such requirements without additional cost to Owner.

B. Investigate the conditions of public thoroughfares and roads as to availability, clearances, loads, limits, restrictions, and other limitations affecting transportation to and ingress and egress at the site. Conform to all governmental regulations regarding the transportation of materials.

C. Procure and pay for permits and licenses required for Work.

1.8 DELIVERY, STORAGE AND HANDLING

A. All stockpiled topsoil, whether from on-site or off-site sources, shall be protected from erosion.

Provide temporary seeding and/or erosion control measures.

B. Before topsoil is redistributed from topsoil stockpiles to areas to be seeded or planted, rehandle and re-pile stockpiled topsoil to be spread in the following manner:

1. Homogenize the topsoil to make a uniform mix, free of subsoil lenses and other irregularities.

2. Aerate the topsoil to make a friable planting medium.

3. Separate out all clay lumps, stone, stocks, and other debris.

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1.9 PROJECT CONDITIONS

A. Environmental Requirements: Perform soil work only during suitable weather conditions. Do not disc, rototill, or work soil when frozen, excessively wet, or in otherwise unsatisfactory condition.

B. Existing Conditions

1. Carefully examine the site before submitting a bid. Be informed as to the nature and location of the Work, general and local conditions including climate, adjacent properties and utilities, conformation of the ground, the nature of subsurface conditions, the character of equipment, and facilities needed prior to and during execution of the Work.

2. Should the Landscape Trade Contractor in the course of Work find any discrepancies between drawings and physical conditions or any omissions or errors in drawings or in layout as furnished by the Architect, it will be his duty to inform the Construction Manager immediately in writing for clarification. Work done after such discovery unless authorized by the Construction Manager shall be done at the Landscape Trade Contractor's risk.

1.10 SEQUENCING AND SCHEDULING

A. Coordinate Work of this section with Work of all other sections of specification.

B. Coordinate earthwork, soil preparation, and seed work. Do not allow subgrade or topsoil to be exposed for longer than 15 days without temporary or permanent cover or other erosion control cover.

1.11 GUARANTEE

A. The Landscape Trade Contractor shall obtain in the Owner's name the standard written manufacturer's guarantee of all materials furnished under this section where such guarantees are offered in the manufacturer's published product data. All these guarantees shall be in addition to and not in lieu of other liabilities which the Landscape Trade Contractor may have by law or other provision of the contract Documents.

PART 2 PRODUCTS

2.1 MATERIALS

A. Topsoil - On-site topsoil or topsoil acquired from off-site, plus required additives. Topsoil shall be acquired in accordance with all applicable federal, state, and local regulations.

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B. Should on-site topsoil be insufficient in quantity to provide specified thickness in areas shown, provide additional screened topsoil from approved off-site sources as required to complete the Work. Off-site topsoil shall meet the following minimum requirements:

1. Topsoil shall be screened, fertile, friable, well drained, pH range of 6.0 to 6.5, free of sub-soil, toxic substances harmful to plant growth, without clay lumps, stones, roots, or debris.

Analysis of content shall be as follows:

Sand 35% to 40% Clay 15% to 20% Organic Matter 2.5% Minimum Silt Balance

2. When topsoil from off-site sources is required, have this soil tested by the local County Agricultural Agent and submit copy of test report for approval.

3. On-site topsoil may be used only if it meets the requirements of this specification. On-site topsoil shall be screened on-site, prior to spreading, to remove all lumps, roots, and debris greater than 1 inch diameter and not contain toxic substances harmful to plant growth.

4. The samples of topsoil shall be submitted by the Landscape Trade Contractor to a private testing laboratory for testing and analysis. No topsoil shall be used until test results have been received and approved by the Landscape Architect and any and all amendments have been made.

5. Chemical Analysis

a. Organic matter content (% ovendry weight of soil)

i. Sandy Loam 1.5 to 3.0

ii. Loam or Silt Loam 2.5 to 5.0

iii. Soil Reaction (pH) 5.5 to 6.5

iiii. Soluble salt content (conductivity) Less than 0.5 mmhos/cm for a 1:2 soil:water ratio.

6. Nutrient Analysis: Have nutrient levels (nitrate, nitrogen, phosphorous, potassium, magnesium, calcium, etc.) tested and request testing laboratory recommendations for fertilizer requirements for lawn areas and planting areas if nutrient levels are below average.

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C. Subsoil: Dry compatible portions of the excavated site soils which are free of organic matter, rubble and all deleterious substances and have a maximum particle size of 6” inches. Additional select fill required shall consist of clean imported relatively well-graded sand and/or gravel containing less than 15 percent passing a No. 200 sieve and having a maximum particle size of four inches or off-site materials from approved stockpiles which are sufficiently graded and are free of organic matter, rubble, and all deleterious substances and have a maximum particle size of 6 inches. The suitability of these materials will be evaluated and certified by the Geotechnical Engineer at the time of construction.

D. General Fill: Any soil material free of deleterious matter which can be spread to achieve the desired grades and be sufficiently compacted to support the construction equipment, its own weights, and the desired construction. The suitability of materials proposed as general fill will be determined by the Geotechnical Engineer.

2.2 SOIL AMENDMENT MATERIAL

A. Ground Limestone: Minimum of 88% of calcium and magnesium carbonates. Total of 100% passing the 10 mesh sieve; minimum of 90% passing the 20 mesh sieve; minimum of 60% passing the 100 mesh sieve.

B. Water: Potable, clean, fresh, and free from harmful materials. Water shall be furnished by Construction Manager. Provide all hoses and other irrigation equipment required by the Work shall be furnished by the Landscape Trade Contractor.

C. Lawn Fertilizer: Complete fertilizer recommended for grass and a standard product complying with State and Federal Fertilizer laws. Deliver fertilizer to the site in the original unopened containers bearing the manufacturer's name and guaranteed statement of analysis. At least 50% by weight of the nitrogen content of the fertilizer derived from organic materials, of the following preparation unless otherwise indicated by topsoil test results:

1. Nitrogen: 10%

2. Phosphorus: 20%

3. Potash: 10%

D. Sand: Natural, medium to course grained in texture, free from decomposed organic matter like roots, sticks, leaves, paper, and of any other undesirable trash like glass, plastic, or metal fragments that could interfere with soil drainage and plating operations. Sand shall be salt free.

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2.3 ORGANIC MATTER

A. Peat Moss: Baled sphagnum moss with an acid reaction approaching pH 4.5. Low content of woody material, free of mineral matter harmful to plant life, water absorbing capacity of 1,100% to 2,000% by weight containing not more than 35% moisture by weight.

B. Composted Cow Manure: Sterilized, unleached horse or cow manure containing not more than 15% bedding materials such as straw, wood chips, shavings; free from chemicals used to hasten decomposition artificially and other injurious substances; containing not more than 60% of moisture by weight.

1. Compost at least six months with added nitrogen prior to delivery in bulk to the site.

PART 3 EXECUTION

3.1 STRIPPING, STOCKPILING, AND STABILIZING TOPSOIL

A. If required, strip topsoil from areas where the finished Work of the Project will result in changes in existing grades. Strip topsoil to a depth that will expose subgrade. Do not mix subgrade soil with topsoil.

B. Provide initial cleaning by removing roots, root mat, brush, trash, and stones larger than 2 inches in any dimension.

C. Stockpile topsoil in one or more approved locations on the site, or adjacent to the site.

D. If not used within two weeks after stockpiling, stabilize stockpiled topsoil by temporary seeding, netting, or other covering, and maintain in non-eroding and non-dusting conditions (See Civil Engineering Drawings and Specifications for details).

B. Surplus topsoil, if any, at completion of the Project Work, shall be removed from the site, and disposed of by the Landscape Trade Contractor.

3.2 PLANTING SOIL MIXES

A. For Lawns and Planting Beds

1. 70% topsoil improved as per soil test recommendations.

2. 20% peat moss.

3. 10% sand.

4. Dehydrated cow manure, 5 pounds per cubic yard of mix.

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5. Bring to pH of 6.0 to 6.5.

6. Bring to pH of 5.0 to 5.5 for non-ericaceous plants. Verify pH by testing.

7. Uniformly mix ingredients (soil, organic matter, sand) by wind rowing/tilling on an approved hard surface area. Keep organic matter moist during mixing.

3.3 SUBGRADE PREPARATION TO RECEIVE TOPSOIL

A. Site grading shall be as specified on Civil Engineering Drawings.

B. Before the start of grading and excavation, establish the location and extent of underground utilities in the work area. Exercise care of underground utilities during earthwork operations. Perform excavation work near utilities by hand. Protect active utility services uncovered by excavation.

C. Prior to dumping and spreading topsoil, verify subgrade elevations and do whatever additional grading is necessary to bring the subgrade to a true, smooth slope parallel to the finished grade for all areas to receive soil.

D. Do not compact existing subsoil.

E. Have subgrade observed by Construction Manager prior to placing soil. Request observation at least one week in advance. Clean up subgrade and dispose of all debris and garbage prior to observation.

F. Loosen subgrade uniformly to depth of 6 inches.

G. Correct variations, bumps, ridges, depression, and smooth to final subgrade elevation and contours.

H. Spray all vegetation on subgrade with an emergent weed killer at a rate of application accepted by the Architect and approved by government agencies with jurisdiction.

I. Keep unnecessary equipment off the prepared subgrade.

J. After acceptance of subgrade, loosen subgrade in lawn area by discing or scarifying to a depth of at least 6 inches to permit bonding of the topsoil to the subsoil. Additionally, loosen subsoil in shrub/tree planting areas to a depth of 2 feet and then roll lightly to help soil settle. Do not compact to greater than 85% density as determined by the Modified Proctor Test. Within canopies of existing trees, loosen soil to a maximum depth of 2 inches by hand method.

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3.4 PLACING PLANTING SOIL MIX IN LAWN AND GRASS MEADOWS

A. Place and spread topsoil over approved areas to a depth sufficiently greater than the depth required for lawn and meadow areas so that after natural settlement and light rolling, the complete work will conform to the lines, grades, and elevations indicated. Minimum required depth: 6 inches.

B. In areas seeded with fine lawn seed mix, remove all large clods, lumps, brush, roots, stumps, litter, and other foreign material and stones over one (1) inch in diameter and dispose of legally off-site.

Roll the whole surface with a hand roller weighing approximately one hundred pounds per square foot of width. Do not compact to greater than 85% density as determined by the Modified Proctor Test. During the rolling, fill all depressions caused by settlement with additional topsoil and then regrade and roll until the surface presents a smooth, even, and uniform finish and is up to the required grade.

3.5 TOPSOIL AMENDMENTS FOR LAWN AREA

A. Applying Fertilizer: Apply commercial fertilizer and work thoroughly into the topsoil within one week before seeding at the rate of 35 pounds per 1,000 square feet or at rate determined by soil test results. Harrow into the top two (2) inches of sod or seed bed.

B. Applying Limestone: Apply limestone to bring the pH to range of 6.5 to 7.0 at rate determined by the soil test results.

3.6 PREPARING AND PLACING TOPSOIL

A. The topsoil (from each source) shall be tested to ensure acceptable level of fertility so as to promote and ensure healthy plant growth. Acceptable level shall be determined by soil tests conducted by the Agricultural Extension Agent as provided for by Landscape Trade Contractor.

Topsoil shall be amended as necessary to comply with the results of the tests.

B. The topsoil shall be free of trash, debris, twigs, root mat, stones larger than 2 inches and other matter detrimental to lawn development.

C. Place topsoil in areas indicated to receive lawns, shrubs, groundcovers, trees, annuals and perennials.

D. Provide sufficient topsoil so that after cleaning, rolling and settlement, topsoil will have uniform minimum specified thickness.

3.6 TOPSOIL THICKNESS

A. For Seeded or Sodded Lawns - minimum 6-inch thickness.

B. For Other Planted Areas -

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1. Around trees, topsoil with a minimum thickness of 12 inches shall be installed in an area with a minimum radius of 10' around trunk locations.

2. Around shrubs and groundcovers, topsoil with a minimum thickness of 12 inches shall be installed in an area with a minimum radius of 18 inches around plant center.

3. See construction details for dimensions of planting mix that is to be placed directly next to plants.

3.7 COMPACTION FOR SHRUB/TREE AREAS

A. Do not compact existing subsoil.

B. See Civil Engineering Drawings for compaction of fill material.

B. For subsoil or fill that has been compacted to greater than 85% (by any means), loosen top 18" to a range of 80-85% maximum dry density.

D. Spread planting soil in ground cover, perennials, annuals, and bulb areas to a depth of 12 inches.

3.8 FINAL SUBSOIL PREPARATION TO RECEIVE TOPSOIL IN SHRUB/TREE PLANTING AREAS

A. Loosen subsoil in lawn areas uniformly to depth of 6 inches. Additionally, loosen subsoil in shrub/tree planting areas to a depth of 2 feet and then roll lightly to help soil settle.

B. Correct variations, bumps, ridges, depressions and smooth to final subsoil elevation and contours.

C. Keep unnecessary equipment off the prepared subsoil. If compaction occurs, repeat items 3.02, "B" and "C".

3.9 DISPOSAL AND CLEANUP

A. Legally dispose of off-site all refuse and debris from these operations. Do not dump or burn materials on site.

B. Maintain the site in an orderly condition during the progress of the Work. Continuously and promptly remove excess waste materials; keep lawn areas, walks, and roads clear. Store materials and equipment where directed. Promptly remove equipment, surplus materials, debris, and trash resulting from operations under this contract upon completion and prior to initial acceptance of Work. Leave the site in a neat, orderly condition, "broom clean."

END OF SECTION