31_22_00_Backfill_and_Grading-Rev20161103.pdf

U.S. General Services Adminstration Mid-Atlantic Region

Public Buildings Service

SECTION 31 22 00

BACKFILL AND GRADING

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PART 1 – GENERAL

1.01 SECTION INCLUDES:

A. Summary B. Laws and Regulations C. Safety D. References E. Submittals F. Quality Control G. Project Conditions H. Common Borrow Fill I. Topsoil J. AOC 15 Cover Soil K. AOC 15 Topsoil L. 1-Inch Crushed Stone M. Open-Grade Stone (OGS) N. Preparation O. Placement of Backfill P. Site Grading Q. Maintenance

1.02 SUMMARY:

A. This Section includes requirements for furnishing and placing the backfill material used to restore the excavated areas, construct the permanent stormwater conveyance systems and construct the AOC 15 consolidation Area.

1.03 LAWS AND REGULATIONS:

A. All work under this Contract shall be accomplished in accordance with regulations of local, county, State and Federal agencies and utility authority standards as they apply.

B. All work under this Contract shall be conducted in accordance with applicable New Jersey Department of Environmental Protection regulation including N.J.A.C.7:26E (Technical Requirements for Site Remediation).

1.04 SAFETY:

A. Methods of operation utilized in work related to these Specifications shall be such as to provide maximum protection against injury or death to workmen or the public.

Requirements of the United States and New Jersey Occupational Safety and Health Acts as to safety regulations and procedures shall be adhered to for all work covered under these Specifications.

1.05 REFERENCES:

A. ASTM D698, Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (Standard Proctor).

Public Buildings Service

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BACKFILL AND GRADING

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B. ASTM D2487, Standard Classification of Soils for Engineering Purposes (Unified Soil Classification System).

C. ASTM D2922, Standard Test Methods for Density of Soil and Soil-Aggregate In-Place by Nuclear Methods.

D. ASTM D3017, Standard Test Methods for Water Content of Soil and Soil-Rock In-Place by Nuclear Methods.

E. New Jersey Department of Environmental Protection’s “Fill Material Guidance for SRP Sites,” dated April 2015.

F. New Jersey Department of Environmental Protection’s “Analytical Laboratory Data Generation, Assessment and Usability Technical Guidance” dated April 2104

G. New Jersey Department of Environmental Protection’s “Data of Known Quality Protocols Technical Guidance” dated April 2014.

H. New Jersey Department of Environmental Protection’s “Data Quality Assessment and Data Usability Evaluation Technical Guidance” dated April 2014.

1.06 SUBMITTALS:

A. For common fill, topsoil, AOC 15 cover soil, AOC 15 vegetative cover topsoil layer, and aggregates, the Contractor shall submit documentation, signed by the material supplier, confirming that the material meets or exceeds the specified requirements along with testing results demonstrating compliance as specified. Information shall be submitted to Construction Manager for review and approval no less than fourteen calendar days prior to scheduled delivery of specified material to the Site.

B. The Contractor shall submit samples of imported topsoil, AOC 15 cover soil, vegetative cover topsoil, and aggregates to Construction Manager for chemical analyses. At least one sample shall be submitted for each source for each material at least three weeks prior to being needed on site.

C. Contractor shall submit written documentation of compaction testing results, showing conformance of the materials and constructed work with the Specifications within five days after test results are obtained.

1.07 QUALITY CONTROL:

A. Contractor shall retain the services of an approved independent Quality Control (QC) Firm licensed in the State of New Jersey to document conformance of backfill material with the Specifications.

B. Property Testing (by Contractor’s QC Firm) of backfill from off-site material sources, shall include:

1. Soil Classification (ASTM D2487) – Minimum of one test for each visible change in material, at least one test for every material source, and one test per 5,000 cubic yards for each source.

Public Buildings Service

SECTION 31 22 00

BACKFILL AND GRADING

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2. Standard Proctor Moisture - Density Curve (ASTM D698) – Minimum of one test for each visible change in material, at least one test for every material source, and one test per 5,000 cubic yards for each source.

C. Chemical Testing (by Contractor’s QC Firm) of backfill from off-site borrow sources shall include:

1. Minimal requirements for all backfill are as follows:

a. The source of the backfill must be clearly established;

b. An initial laboratory sample will be collected and analyzed by the Contractor;

c. Subsequent laboratory analysis will be conducted by the Contractor at a specified frequency; and

d. Visual inspections will be conducted on the material as it is received on-site at a frequency of at each truck load delivered.

2. Default Sampling – Frequency:

Proposed Volume (Cubic Yards)

Default Sampling Scheme without justification (Samples)

Reduced Sampling Scheme with justification (Samples)

0 to 20 1 1

20.1 to 40 2 2

40.1 to 60 3 2

60.1 to 80 4 2

80.1 to 100 5 2

100.1 to 200 6 3

200.1 to 300 7 3

300.1 to 400 8 4

400.1 to 500 9 4

500.1 to 600 10 5

600.1 to 700 11 5

700.1 to 800 12 6

800.1 to 900 13 6

900.1 to 1,000 14 7

1,000.1 to 2,000 15 8

2,000.1 to 3,000 16 9 3,000.1 to 4,000 17 10 4,000.1 to 5,000 18 11

Public Buildings Service

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BACKFILL AND GRADING

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Proposed Volume (Cubic Yards)

Default Sampling Scheme without justification (Samples)

Reduced Sampling Scheme with justification (Samples)

5,000.1 to 6,000 19 12 6,000.1 to 7,000 20 13 7,000.1 to 8,000 21 14 8,000.1 to 9,000 22 15 9,000.1 to 10,000 23 16

10,000.1 to 11,000 * 24 17

With volumes greater than 10,000 cubic yards, the sampling rate is 1 per additional 1,000 cubic yards. The sampling frequency may be reduced with appropriate justification and does not require Department pre-approval.

This includes departure from the default or reduced sampling frequencies.

3. Default Sampling to be conducted by the Contractor - Initial and routine samples shall be sampled after compositing/mixing operations, if applicable, and shall be analyzed by the Contractor for the following:

a. VOC TCL + TICs (SW846 8260B/5035)

b. SVOC TCL + TICs (SW846 8270 sim)

c. NJDEP EPH (SW846 3545)

d. Herbicides (SW846 8151/3550B)

e. Pesticides (SW846 8081A/3545)

f. PCBs (SW846 8082/3545)

g. TAL Metals (SW846 6010B, 6020, 6020B, 7471A)

h. Hexavalent Chromium (SW846 3060A/7196A)

i. Redox Potential (Eh)

j. Percent Solids

k. pH

D. Licensed virgin quarries may be exempt from the default sampling requirements. Without prior written approval from Construction Manager, the default sampling requirements will be mandatory.

E. Results will be compared New Jersey Department of Environmental Protection Soil Remediation Standards (N.J.A.C.7:26D).

Public Buildings Service

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BACKFILL AND GRADING

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F. During performance of the Work, the Contractor shall employ all equipment and services necessary for control of depths, lines, and grades within required tolerances. The Contractor is responsible for any survey required to ensure the grades and limits shown on the Construction Drawings are achieved.

1.08 PROJECT CONDITIONS:

A. Work shall be performed in a manner that does not disturb existing utilities, structures, or other facilities not indicated to be removed within the project limits.

PART 2 – PRODUCTS

2.01 COMMON BORROW FILL:

A. Common Fill shall be hard durable sand and gravel and shall be free from ice, snow, roots, sod, rubbish, and other deleterious or organic matter. It shall be free from chemical contamination. It shall conform to the following gradation requirements:

Sieve Size Percent Passing 3-inch 100 2-inch 90 -100 1-inch 70 - 90 No. 4 80 – 30 No. 200 0 – 10

2.02 TOPSOIL:

A. Topsoil shall be fertile, friable, natural loam, and be free from ice, snow, roots, sod, rubbish, and other deleterious material. It shall be chemically clean, in accordance with New Jersey Department of Environmental Protection’s Soil Remediation Standards (N.J.A.C.7:26D) and the Fill Material Guidance for SRP sites (April 2015 Version 3.0) or the governing fill material guidance.

B. Topsoil shall have the following analysis, or equivalent approved by the Construction Manager:

Sieve Size Percent Passing 2-inch 100 1-inch 85 - 100 ¼ inch 65 - 100 No. 200 20 – 80 Organic Matter 2% and <21% pH 5.5 - 7.6

Public Buildings Service

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BACKFILL AND GRADING

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2.03 WETLAND TOPSOIL:

A. Topsoil shall be fertile, friable, natural loam, and be free from ice, snow, roots, sod, rubbish, and other deleterious material. It shall be chemically clean, in accordance with New Jersey Department of Environmental Protection’s Soil Remediation Standards (N.J.A.C.7:26D) and the Fill Material Guidance for SRP sites (April 2015 Version 3.0) or the governing fill material guidance.

B. Topsoil shall have the following analysis, or equivalent approved by the Construction Manager:

Sieve Size Percent Passing 2-inch 100 1-inch 85 - 100 ¼ inch 65 - 100 No. 200 20 – 80 Organic Matter 2% and <21% pH 5.5 - 7.6

2.04 CONSOLIDATION AREA COVER SOIL:

A. Cover soil (bank run gravel or equivalent) shall be hard, durable sand and gravel, and shall be free from ice, snow, roots, sod, rubbish, and any other deleterious or organic matter. It shall be chemically clean, in accordance with Soil Remediation Standards (N.J.A.C.7:26D) and the New Jersey Department of Environmental Protection’s Fill Material Guidance for SRP sites (April 2015 Version 3.0) or the governing fill material guidance.

B. Cover soil shall consist of soil meeting one of the following Unified Soil Classification System (USCS) designations of the following:

1. SW – Well-graded sands, gravelly sands, little or no fines

2. SM – Silty Sands, sand-silt mixtures

3. GW – Well-graded gravels, gravel-sand mixtures, little or no fines

4. GM – Silty gravels, gravel-sand-silt mixtures

C. Cover soil shall conform to the following gradation requirements:

Sieve Size Percent Passing 3-inch 100 2-inch 90-100 1-inch 70-90 No.4 80-30 No. 200 0-15

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BACKFILL AND GRADING

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2.05 CONSOLIDATION AREA TOPSOIL:

A. Topsoil shall be fertile, friable, natural loam, and be free from ice, snow, roots, sod, rubbish, and other deleterious material. It shall be chemically clean, in accordance with New Jersey Department of Environmental Protection’s Soil Remediation Standards (N.J.A.C.7:26D) and the Fill Material Guidance for SRP sites (April 2015 Version 3.0) or the governing fill material guidance.

B. Topsoil shall consist of the following soil texture classes established by the United States Department of Agriculture Classification system, based upon proportions of sand, silt, and clay particles:

1. Loamy Sand, including Loamy Coarse Sand, Loamy Fine Sand, and Loamy very Fine Sand.

2. Silt Loam, with less than 12 percent clay.

C. Topsoil shall have the following approximate analysis, or equivalent approved by the Construction Manager:

Sieve Size Percent Passing 2-inch 100 1-inch 85 - 100 ¼ inch 65 - 100 No. 200 20 – 80 Organic Matter 2% and <21% pH 5.5 - 7.6

2.06 1-INCH CRUSHED STONE:

A. Stone shall be a No. I-1 crushed stone comprised of individual stone fragments that are dense, sound, and free from cracks, seams and other defects conducive to accelerated weathering. Stone shall be free from ice, snow, roots, sod, rubbish, and other deleterious or organic matter. The stone fragments shall be angular to sub-rounded in shape. The least dimension of an individual stone fragment shall be not less than one-third the greatest dimension of the fragment. Rounded river stone is not acceptable.

B. Stone must be washed of fines.

C. Stone shall have the following approximate analysis, or equivalent approved by the Construction Manager:

Sieve Size Percent Passing 2-inch 70-100 ¾ -inch 50-95 No. 4 30-60 No. 50 5-25 No. 200 0-7

Public Buildings Service

SECTION 31 22 00

BACKFILL AND GRADING

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D. Stone that fails to meet these requirements may be accepted only if similar stone from the same source has been demonstrated to be sound after 5 years or more of service under conditions of weather, wetting and drying, and erosive forces similar to those anticipated.

E. Ensure that the stone is free from elements or chemicals which, in the presence of water, would produce detrimental effects to the environment, construction media and utilities.

F. Stone shall be in accordance with New Jersey Department of Environmental Protection’s Fill Material Guidance for SRP sites (April 2015 Version 3.0) or the governing fill material guidance.

2.07 OPEN-GRADE STONE (OGS):

A. OGS used for riprap lined drainage ditches, shall be composed of coarse aggregate with dense sound stone fragments, free from cracks, seams, and other defects. The stone shall be free from ice, snow, roots, sod, rubbish, and any other deleterious or organic matter.

B. OGS shall be angular to sub-rounded in shape. The least dimension of the individual stone fragment shall be not less than one-third the greatest dimension of the fragment.

Rounded river stone is not acceptable.

C. OGS shall be washed of all fines

D. OGS shall meet the specifications of Coarse Aggregate No. 1, as defined by the New Jersey Department of Transportation (NJDOT), with the following gradation:

NO. Nominal Size 4” 3-1/2” 2-1/2” 1-1/2” 3/4” 1 3-1/2” – 1-1/2” 100 90-100 25-60 0-15 0-5

E. OGS shall have the following properties:

1. Bulk specific gravity (saturated surface-dry basis) not less than 2.5

2. Absorption not more than 2 percent by weight.

3. Fines (No. 10) not more than 2 percent by weight.

4. The bulk specific gravity and absorption shall be determined by ASTM Method C- 127.

F. Stone shall be in accordance with New Jersey Department of Environmental Protection’s Fill Material Guidance for SRP sites (April 2015 Version 3.0) or the governing fill material guidance.

Public Buildings Service

SECTION 31 22 00

BACKFILL AND GRADING

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PART 3 – EXECUTION

3.01 PREPARATION:

A. Backfilling of excavations shall not proceed until Construction Manager has approved the completion of excavation in each area or sub-area of the Site.

B. Do not place backfill on frozen subgrade.

C. Do not place frozen or excessively wet fill or backfill.

D. Verify that subgrade has been accepted by the Construction Manager prior to backfilling.

3.02 PLACEMENT OF BACKFILL:

A. Placement of Material in Consolidation Area

1. Prepare the AOC 15 consolidation Area subgrade by scarifying and re-compacting the upper one foot of material to 90% of the soils maximum dry density as determined by the Standard Proctor Test.

2. Unload and place excavated impacted soils in AOC 15 consolidation area.

3. Soil will be placed within the AOC 15 Consolidation Area in loose lifts not exceeding 12 inches and compacted with several passes of a vibratory roller to a minimum of 90% of the soils maximum dry density as determined by the Standard Proctor Test.

4. Proof rolling may be used to limit the amount of density testing required. Non-recyclable debris (concrete, generated during excavation) may also be placed in the AOC 15 Consolidation Area. This debris material will be spread in thin layers and mixed with soil in order to avoid voids in the fill. It will not be concentrated in a manner that could cause settlement of the cover.

5. The maximum size of the non-recyclable debris will be 6-inches in it maximum dimension.

B. Grading From Excavation Grade to Final Grade Platform

1. Existing soil at the final excavation grade shall be smoothed to fill depressions from clearing and grubbing activities and create a platform on which a uniform thickness of topsoil can be placed to achieve the final grades shown on the Drawings.

2. Graded soils shall be placed in uniform layers not exceeding 12 inches and compacted with at least three passes of a vibratory compactor or other approved equivalent to provide a firm solid surface.

3. Graded soils shall be placed at moisture content adequate to allow effective compaction.

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SECTION 31 22 00

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4. The Contractor shall minimize voids during placement.

5. Tolerance for placement – of the graded material shall be placed within a tolerance of plus or minus 0.1 foot from the locations, elevations, and grades shown on the Drawings.

C. Topsoil Wetland Topsoil Placement

1. Following installation of the vegetative support layer and subsequent Construction Manager approval, the areas designated to receive topsoil shall be scarified or tilled by disking, harrowing, or other approved methods to a depth of approximately 2 inches. Topsoil shall be applied only when the subsoil is in a loose, friable condition.

2. Topsoil material shall be applied to achieve at least 5-inches finish thickness.

Wetland topsoil shall be placed to the thickness shown on the Drawings.

3. The Contractor shall place grade stakes as directed by the Construction Manager prior to topsoil placement in order to verify the final thickness of the topsoil. The method of placement shall be subject to Construction Manager approval to ensure that the stakes do not damage the underlying geosynthetics. The tolerance for acceptance of topsoil placement shall be ± 0.1 foot.

4. Topsoil shall not be spread when the ground and/or the topsoil is frozen, when the soil moisture content is so excessive that unacceptable compaction will occur, or when the soil is so dry that dust will form in the air or clods will not readily break.

5. Topsoil shall not be compacted. Instead, after the topsoil is spread, the Contractor shall remove large, stiff clods, rocks, roots, and other foreign matter over 2 inches in the largest dimension from the surface. If the slopes are tracked from the placement equipment, the cleat marks shall be perpendicular to the anticipated flow direction. When the operation is complete, the area should be in a condition to receive seed without further soil preparation. Areas shall be seeded within 15 days after topsoil is applied.

6. The Contractor shall maintain areas where topsoil has been placed by rolling, raking, and removing ridges and by filling depressions, ruts, low spots, or unsuitable areas which result after settlement and/or rainfall runoff so that the area is suitable for planting and so that the surface of the AOC 15 Consolidation Areas do not pond water. The topsoil surface (especially sloped areas) shall be free of channels that can concentrate stormwater flow and promote erosion.

Channels which form from rainfall runoff shall be repaired by the Contractor until the AOC 15 Consolidation Area is stabilized with a protective vegetative cover.

D. Preparation Of consolidation Area Foundation Soils

1. The upper 12 inches of soil, after vegetation has been cleared, shall be re-compacted to more than 90 percent of the maximum dry density as determined by the Standard Proctor Test (ASTM D698).

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BACKFILL AND GRADING

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2. Locations where soft soils have been identified shall be over excavated and all soft soils shall be re-compacted to more than 90 percent of the maximum dry density as determined by the Standard Proctor Test.

E. Placement Of consolidation Area Cover Soil

1. Cover soil shall have a minimum finished thickness of 18 inches.

2. Cover soil shall be placed in uniform lifts not exceeding 12 inches and compacted to a minimum of 90 percent of the soils maximum dry density as determined by the Standard Proctor Test (ASTM D698) with a minimum of three passes of a vibratory compactor or other approved equivalent.

3. Contractor shall provide field compaction tests for each lift at a minimum of one per every 1,000 square feet.

4. The contractor shall minimize voids during placement.

F. Placement Of Consolidation Area Vegetative Cover Topsoil

1. Topsoil shall have a minimum finished thickness of 6 inches.

2. Topsoil shall be placed in uniform loose lifts and shall not be compacted. The contractor shall remove large clods, rocks, roots, and other objects from the surface.

3. The seed mix shall consist of local, low growing grasses consist of Permanent Upland Wildflower and Grass Seed Mixture as specified in Section 32 92 00 (Turf and Grasses).

4. Care shall be taken when installing the vegetative support layer so that the underlying geotextile is not damaged or displaced. The vegetative support material shall be placed such that minimal slippage of the geotextile on underlying layers occurs and so that excess tensile stresses are not imposed on the geotextile. The method for placement of the vegetative support layer shall be detailed in the Contractor Work Plan submittal and shall be subject to Construction Manager approval.

5. Vegetative support material shall be placed carefully over the geosynthetic materials in a single lift and shall be compacted with a minimum of four passes of a Caterpillar D-6 low ground pressure bulldozer, or Construction Manager-approved equal, such that the compacted thickness measures a minimum of 18 inches.

6. Vehicles operating directly on geosynthetic materials shall be Construction Manager approved low-ground pressure vehicles. Vehicles operating directly on the geosynthetics shall be minimized to the maximum extent possible. Tracked equipment should never come into contact with the geosynthetics. Vegetative support material shall be pushed from areas already having received this material such that approved construction vehicles operate over a minimum of 18

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7. If required, temporary access roads shall be constructed in areas where the vegetative support material has already been installed by increasing the cover soil depth. The cost for temporary access road construction and removal, if necessary, shall be included in the cost for placement of the vegetative support material and shall not be considered a separate scope item.

8. The Contractor shall demonstrate that the vegetative support layer has been installed to the design depth by a method subject to the approval of the Construction Manager. An example would be to establish markers such as placement of pre-cut/pre-marked sections of the inner core of the geosynthetic tubes placed in a grid over the surface of the AOC 15 Consolidation Area to provide guidance to the dozer operators. The Construction Manager may also verify thickness of the vegetative support layer by conducting a series of test holes. The Contractor shall assist the Construction Manager with the hand excavation and is responsible for backfilling and compaction following test hole excavation, if required.

G. Placement Of 1-Inch Coarse Aggregate

1. Coarse aggregate shall have a minimum thickness of 12 inches and graded to the dimensions shown on the construction drawings or specified herein.

2. Coarse aggregate shall not require compaction.

H. Placement Of Open-Grade Stone

1. No. 1 OGS for riprap shall be placed in the proposed drainage ditches as lining in the manner that will produce reasonably well-graded mass of stone.

2. OGS shall be placed to its full coarse thickness in one operation and in such a manner as to avoid displacing the underlying material. Placing of riprap in layers or by dumping into chutes or by other similar methods likely to cause segregation will not be permitted.

3. OGS shall be placed and distributed such that there will be no large accumulation of either the larger or smaller size of stone in any area.

3.03 SITE GRADING:

A. The Contractor shall grade areas to the contours indicated on the Construction Drawings.

The soil surface shall be shaped to provide a smooth transition to existing grade at the limits of the disturbed areas.

B. The Contractor shall shape and compact fill with uniform levels or slopes between points where elevations are shown on the Construction Drawings, or between such points and existing grades.

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C. The Contractor shall smooth the finished surfaces for general site grading within tolerance of two inches above or below the required elevation.

3.04 MAINTENANCE:

A. The Contractor shall protect newly graded areas from traffic and erosion. The Work shall be sequenced to minimize disturbance of completed areas.

B. Where completed areas are disturbed by subsequent project operations or adverse weather, the Contractor shall fill and reshape eroded areas until acceptance of the Work.

END OF SECTION