Appendix A - Trenchless Specifications.pdf

SECTION 3010 - TRENCH EXCAVATION AND BACKFILL

PART 1 - GENERAL

1.01 SECTION INCLUDES

A. Trench Excavation for Pipe Systems

B. Trench Foundation Stabilization

C. Pipe Bedding and Backfill

1.02 DESCRIPTION OF WORK

A. Excavate trench for pipe installation.

B. Stabilize trench and install pipe bedding materials.

C. Place backfill material in trench.

1.03 SUBMITTALS

Comply with Division 1 - General Provisions and Covenants, as well as the following:

A. Gradation reports for bedding materials.

B. Results of required testing.

C. Dewatering plan.

1.04 SUBSTITUTIONS

Comply with Division 1 - General Provisions and Covenants.

1.05 DELIVERY, STORAGE, AND HANDLING

1.06 SCHEDULING AND CONFLICTS

1.07 SPECIAL REQUIREMENTS

None.

1.08 MEASUREMENT AND PAYMENT

A. General: The following items are incidental to the underground utility being installed and will not be paid for separately:

1. Standard trench excavation.

2. Removal and disposal of excess backfill material resulting from pipe installation.

3. Removal of abandoned private utilities encountered during trench excavation.

4. Furnishing and placing granular bedding material.

5. Placing and compacting backfill material.

6. Dewatering including, but not limited to, all equipment such as generators, pumps, rock for sump pits, discharge piping, and any extra excavation needed to facilitate dewatering according to stormwater regulations, as applicable.

7. Sheeting, shoring, and bracing.

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8. Adjusting the moisture content of excavated backfill material to the range specified for placement and compaction.

9. Temporary support for existing water, sewer, gas, telephone, electric, and other utilities or services that cross the trench.

B. Rock Excavation:

1. Measurement: Measurement will be by cubic yards of rock removed.

2. Payment: Payment will be at the unit price per cubic yard for the quantity of rock removed.

3. Includes: Unit price includes, but is not limited to, furnishing the equipment and labor to break up, remove, and properly dispose of rock encountered in the trench.

C. Trench Foundation:

1. Measurement: Measurement will be in tons for the quantity of stabilization material required to replace material removed by over-excavation. Measurement will be based on the scale tickets for the material delivered and incorporated into the project. Trench foundation required to correct unauthorized over-excavation will not be measured.

2. Payment: Payment will be at the unit price per ton for the quantity of stabilization material furnished and placed.

3. Includes: Unit price includes, but is not limited to, removal and disposal of over- excavated material required to stabilize trench foundation; and furnishing, hauling, and placing stabilization material.

D. Removal, Disposal, and Replacement of Unsuitable Backfill Material:

1. Measurement: Measurement will be in cubic yards for the quantity of backfill material required to replace unsuitable backfill material removed during standard trench excavation.

Measurement will be based on compacted material in place.

2. Payment: Payment will be at the unit price per cubic yard for the quantity of the suitable replacement backfill material furnished.

3. Includes: Unit price includes, but is not limited to, removal, hauling, and disposal costs of the unsuitable material and the furnishing, hauling, and placing of the suitable replacement backfill material. Unit price does not include landfill costs for contaminated materials.

E. Special Pipe Embedment or Encasement:

1. Measurement: Measurement will be by the linear foot along the centerline of pipe for each type of special embedment or encasement.

2. Payment: Payment will be at the unit price per linear foot for each type of special pipe embedment or encasement.

3. Includes: Unit price includes, but is not limited to, furnishing and placing all required special pipe embedment or encasement materials.

F. Trench Compaction Testing: If the contract documents specify that the Contractor is responsible for trench compaction testing, measurement and payment will be as follows.

1. Measurement: Lump sum item; no measurement will be made.

2. Payment: Payment will be at the lump sum price for trench compaction testing.

3. Includes: Lump sum price includes, but is not limited to, all payments associated with retesting resulting from failure of initial tests.

PART 2 - PRODUCTS

2.01 MATERIALS EXCAVATED FROM A TRENCH

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A. Standard Trench Excavation: All materials encountered during trench excavation, except rock and over-excavation.

1. Suitable Backfill Material: Class II, Class III, Class IVA, or Class IVB as defined in

Section 3010, 2.02.

2. Unsuitable Backfill Material: Includes, but is not limited to, the following materials:

a. Soils not classified as suitable backfill material, as defined in Section 3010, 2.02.

b. Individual stones or concrete chunks larger than 6 inches and averaging more than one per each cubic foot of soil.

c. Frozen materials.

d. Stumps, logs, branches, and brush.

e. Trash, metal, or construction waste.

f. Soil in clumps or clods larger than 6 inches, and without sufficient fine materials to fill voids during placement.

g. Environmentally contaminated soils.

h. Materials removed as rock excavation or over-excavation.

3. Topsoil: Class V material. Comply with Section 3010, 2.03.

B. Rock Excavation: Boulders or sedimentary deposits that cannot be removed in trenches without continuous use of pneumatic tools or blasting.

C. Over-excavation: Excavation of unsuitable or unstable material in trenches below the pipe zone, comply with Figure 3010.101.

2.02 BEDDING MATERIAL

A. Class I Material:

1. Crushed stone complying with the following gradation:

Sieve Percent Passing 1 1/2” 100

1” 95 to 100 1/2" 25 to 60

No. 4 0 to 10 No. 8 0 to 5

2. The Engineer may allow the use of gravel or authorize a change in gradation subject to materials available locally at the time of construction.

3. The Engineer may authorize the use of crushed PCC for pipe sizes up to 12 inches.

4. Use aggregates having a percentage of wear, Grading A or B, not exceeding 50%, determined according to AASHTO T 96.

2.03 BACKFILL MATERIAL

A. Class II Material: Manufactured and non-manufactured open-graded (clean) or dense-graded

(clean) processed aggregate, clean sand, or coarse-grained natural soils (clean) with little or no fines. Class II materials are further described in Table 3010.01.

Table 3010.01: Class II Materials

Type Soil Group

Symbol

ASTM D 2487

Description Percentage Passing Sieve Sizes

1 1/2 in. No. 4 No. 200

Coarse-Grained Soils, clean

GW Well-graded gravels and gravel-sand mixtures; little or no fines.

100%

< 50% of "Coarse Fraction"

< 5%

GP

Poorly-graded gravels and gravel-sand mixtures; little or no fines.

SW Well-graded sands and gravelly sands; little or no fines. > 50% of

"Coarse Fraction"SP Poorly-graded sands and gravelly sands; little or no fines.

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Coarse-Grained Soils, borderline clean to with fines e.g. GW-GC, SP-SM

Sands and gravels that are borderline between clean and with fines.

100% Varies 5% to 12%

B. Class III Material:

1. Natural coarse-grained soils with fines. Class III materials are further described in Table 3010.02.

2. Do not use where water condition in trench may cause instability.

Table 3010.02: Class III Material

Table

Symbol

ASTM D 2487

Description

Coarse-Grained Soils, with fines

GM Silty gravels, gravel-sand-silt mixtures.

GC Clayey gravels, gravel-sand-clay mixtures.

SM Silty sands, sand-silt mixtures.

SC Clayey sands, sand-clay mixtures.

C. Class IVA Material:

1. Natural fine-grained inorganic soils. Class IVA materials are further described in Table 3010.03.

2. The Engineer will determine if material is not suitable for use as backfill material under deep fills, surface applied wheel loads, heavy vibratory compactors, tampers, or other conditions.

3. Do not use where water conditions in trench may cause instability.

4. Material is suitable for use in dry trench conditions only.

Table 3010.03: Class IVA Material

Symbol

ASTM D 2487

Description

Fine-Grained Soils (inorganic)

ML Inorganic silts and very fine sands, rock flour, silty or clayey fine sands, silts with slight plasticity.

CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clay, lean clay.

D. Class IVB Material:

1. Natural fine-grained inorganic (high elastic silts and plastic clays - fat clay) with a liquid limit greater than 50%. Class IVA materials are further described in Table 3010.04.

2. When approved by the Engineer, material may be used as final trench backfill in a dry trench.

3. Do not use in the pipe embedment zone.

Table 3010.04: Class IVB Material

Symbol

ASTM D 2487

Description

Fine-Grained Soils (inorganic)

MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts.

CH Inorganic clays of high plasticity, fat clays.

2.04 TOPSOIL

A. Class V Material:

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1. Organic soils. Class V materials are further described in Table 3010.05.

2. Use only as topsoil outside of the pavement, unless otherwise specified or allowed by the

Engineer.

3. Do not use in the pipe embedment zone.

Table 3010.05: Class V Material

Type Soil Group Symbol ASTM D 2487 Description

Organic Soils (unsuitable for backfill)

OL Organic silts and organic silty clays of low plasticity.

OH Organic clays of medium to high plasticity, organic silts.

Highly Organic (unsuitable for backfill) PT Peat and other high organic soils.

2.05 STABILIZATION (FOUNDATION) MATERIALS

A. Clean 2 1/2 inch crushed stone with the following gradation:

Table 3010.06: Stabilization Materials

Sieve Percent Passing 2 1/2” 100

2” 90 to 100 1 1/2” 35 to 70

1” 0 to 20 1/2” 0 to 5

B. If specified, meet Iowa DOT Section 4128 for Gradation No. 13a screened over a 1 inch screen or the Engineer may authorize a change in gradation depending on materials available locally at time of construction.

C. Crushed concrete may be used, if approved by the Engineer, if it is within + 5% of the gradation for each size of material.

2.06 SPECIAL PIPE EMBEDMENT AND ENCASEMENT MATERIAL

A. Concrete Cradle, Arch, or Encasement: Use Iowa DOT Class C concrete.

B. Flowable Mortar: Comply with Iowa DOT Article 2506.02.

C. CLSM:

1. Approximate quantities per cubic yard:

a. Cement: 50 pounds

b. Fly ash: 250 pounds

c. Fine aggregate: 2,910 pounds

d. Water: 60 gallons

2. A compressive strength of at least 50 psi compressive strength at 28 calendar days can be expected.

3. Comply with material requirements of Iowa DOT Article 2506.02.

D. Foamed Cellular Concrete:

1. If specified or approved by the Engineer, foamed cellular concrete may be substituted for flowable mortar.

2. Comply with Iowa DOT Article 2506.02.

3. Submit mix design to the Engineer. Include base cement slurry mix per cubic yard, expansion factor from the foaming agent, and wet density.

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PART 3 - EXECUTION

3.01 TRENCH EXCAVATION

A. Notify the Engineer prior to the start of excavation activities.

B. Remove topsoil to a minimum depth of 12 inches and stockpile.

C. Excavate trench to required elevations and dimensions. Comply with Figure 3010.101.

1. Protect existing facilities, trees, and shrubs during trench excavation.

2. Place excavated material away from trench.

3. Grade spoil piles to drain. Do not allow spoil piles to obstruct drainage.

D. Unsuitable Backfill Material:

1. If unsuitable backfill material is encountered, notify the Engineer.

2. Remove rock, rubbish, boulders, debris, and other unsuitable backfill materials at least 6 inches below and on each side of the pipe.

3. Keep unsuitable backfill material separated from suitable backfill material and topsoil.

4. Restore trench to design dimensions using bedding or stabilization material.

3.02 ROCK OR UNSTABLE SOILS IN TRENCH BOTTOM

A. Notify the Engineer prior to over-excavation.

B. The Engineer will determine the need for over-excavation and trench foundation stabilization prior to installation of pipes and structures.

C. Comply with Figure 3010.101 for over-excavation of rock and wet or soft foundations.

3.03 TRENCH PROTECTION

A. Install adequate trench protection (sheeting, shoring, and bracing) to prevent ground movement or damage to adjacent structures, pipelines, and utilities.

B. Move trench boxes carefully to avoid disturbing pipe, bedding, or trench wall.

3.04 DEWATERING

A. Maintain water levels below the bottom of trench excavation.

B. Perform the dewatering operation according to the dewatering plan approved by the Engineer.

The dewatering plan may be modified to meet actual field conditions, with approval of the

C. Ensure operation of the dewatering system does not damage adjoining structures and facilities. Cease dewatering operations and notify the Engineer if damage is observed.

D. Discharged Water:

1. Do not discharge water into sanitary sewers.

2. Discharging water into storm sewers requires Engineer's approval.

3. Obtain permission of adjacent property owner prior to discharging water onto their property.

4. Maintain and control water discharge as necessary to prevent a safety hazard for vehicular and pedestrian traffic.

5. Direct water discharge away from electrical facilities or equipment.

6. Use dewatering equipment that will minimize disturbance from noise and fumes.

7. Protect discharge points from erosion. Provide sediment control for sediment contaminated water discharged directly from trench.

3.05 PIPE BEDDING AND BACKFILL

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A. General: Comply with Figures 3010.101, 3010.102, 3010.103, 3010.104, and 3010.105, as appropriate.

1. Bedding and backfill used for pipe installation will depend on:

a. Type of installation (water main, sanitary sewer gravity main, sanitary sewer force main, or storm sewer).

b. Pipe material.

c. Depth of bury.

d. Pipe diameter.

2. After pipe installation, place remaining bedding material and immediately place backfill in trench.

3. Adjust the moisture content of excessively wet, but otherwise suitable, backfill material by spreading, turning, aerating, and otherwise working material as necessary to achieve required moisture range.

4. Adjust the moisture content of excessively dry, but otherwise suitable, backfill material by adding water, then turning, mixing, and otherwise blending the water uniformly throughout the material until the required moisture range is achieved.

5. Hydraulic compaction (flooding with water) is not allowed unless authorized by the

6. Special Pipe Embedment and Encasement Materials:

a. If specified, use concrete, flowable mortar, CLSM, or foamed cellular concrete as a substitute for pipe bedding, haunch support, or primary and secondary backfill.

b. Secure pipe against displacement or flotation prior to placing special pipe embedment and encasement material.

c. Place Class IV clay material for a waterstop and compacted to 90% of Standard Proctor Density. Obtain required compaction within a soil moisture range of optimum moisture to 4% above optimum moisture content. If trench stabilization material is used, extend waterstop through stabilization material to the bottom of the trench.

B. Pipe Bedding:

1. Granular Material:

a. Class I granular bedding material is required for all gravity mains. Use when specified for pressure pipes.

b. Comply with Figures 3010.101, 3010.102, 3010.103, 3010.104, and 3010.105.

c. Place bedding material in the bottom of the trench in lifts no greater than 6 inches thick.

Consolidate and moderately compact bedding material.

d. Shape bedding material to evenly support pipe at the proper line and grade, with full contact under the bottom of the pipe. Excavate for pipe bells.

e. Install pipe and system components.

f. Place, consolidate, and moderately compact additional bedding material adjacent to the pipe to a depth equal to 1/6 the outside diameter of the pipe.

2. Suitable Backfill Material:

a. Only use with pressure pipe. Comply with Figure 3010.104.

b. Use suitable backfill material to shape trench bottom to evenly support pipe at the proper line and grade, with full contact under the bottom of the pipe. Excavate for pipe bells.

C. Haunch Support: Place from the top of the pipe bedding to the springline of the pipe.

1. Granular Material:

a. Place Class I material in lifts no greater than 6 inches thick.

b. Consolidate and moderately compact by slicing with a shovel or using other approved techniques.

2. Suitable Backfill Material:

a. Place in lifts no greater than 6 inches thick.

b. For Class II backfill material, consolidate and moderately compact by slicing with a shovel or using other approved techniques.

c. For Class III and Class IVA backfill materials, compact to at least 90% of Standard

Proctor Density. Obtain required compaction within a soil moisture range of optimum moisture to 4% above optimum moisture content.

D. Primary and Secondary Backfill:

1. General:

a. For primary backfill, place from the springline of the pipe to the top of the pipe.

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b. For secondary backfill, place from the top of the pipe to 1 foot above the top of the pipe.

2. Granular Material:

b. Compact to at least 65% relative density.

3. Suitable Backfill Material:

b. For Class II backfill material, compact to at least 65% relative density.

c. For Class III and Class IVA backfill materials, compact to at least 95% of Standard

Proctor Density. Obtain required compaction within a soil moisture range of optimum moisture to 4% above optimum moisture content.

E. Final Trench Backfill:

1. Place suitable backfill material from 1 foot above the top of the pipe to the top of the trench.

a. Use no more than 8 inch thick lifts for backfill areas more than 3 feet below the bottom of pavement.

b. Use no more than 6 inch thick lifts for backfill areas less than or equal to 3 feet below the bottom of pavement.

2. Place backfill material after recording locations of connections and appurtenances or at the Engineer’s direction.

3. Class I and Class II Backfill Material:

a. Compact to at least 65% relative density within right-of-way.

b. Compact to at least 50% relative density outside right-of-way.

4. Class III and Class IVA Backfill Material:

a. Compact to at least 95% of Standard Proctor Density within right-of-way.

b. Compact to at least 90% of Standard Proctor Density outside right-of-way.

c. Obtain required compaction within a soil moisture range of optimum moisture to 4% above optimum moisture content.

5. In areas to remain unpaved, terminate backfill material 8 inches below finished grade. Use topsoil for the final 8 inches above trench backfill material.

6. Terminate backfill material at subgrade elevation in areas to be paved.

3.06 TRENCH COMPACTION TESTING

A. General: When trench compaction testing is specified in the contract documents as the

Contractor’s responsibility, provide testing of trench backfill material using the services of an independent testing laboratory approved by the Engineer.

B. Soil Testing:

1. Cohesive Soils:

a. Determine moisture-density relationships by ASTM D 698 (Standard Proctor). Perform at least one test for each type of cohesive soil used.

b. Determine in-place density and moisture content. Use ASTM D 1556 (sand-cone method) and ASTM D 2216 (laboratory moisture content), or use ASTM D 6938 (nuclear methods for density and moisture content).

2. Cohesionless Soils:

a. Determine maximum and minimum index density and calculate relative density using ASTM D 4253 and ASTM D 4254.

b. For Class I granular bedding material, determine gradation according to ASTM C 136.

C. Field Testing:

1. Testing Frequency and Locations: Perform testing of the final trench backfill, beginning at a depth of 2 feet above the top of the pipe, as follows:

a. Coordinate the timing of testing with the Engineer.

b. The Engineer will determine the location of testing.

c. For each 2 vertical feet of consolidated fill, provide tests at a maximum horizontal spacing of 200 feet and at all street crossings.

d. Additional testing may be required by the Engineer in the event of non-compliance or if conditions change.

e. If necessary, excavate to the depth and size as required by the Engineer to allow compaction tests. Place backfill material and recompact.

2. Test Failure and Retesting: Rework, recompact, and retest as necessary until specified compaction and moisture content is achieved in all areas of the trench. In the event of failed tests, the Engineer may require retesting as deemed necessary.

END OF SECTION

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SECTION 4010 - SANITARY SEWERS

A. Sanitary Sewer Gravity Mains

B. Sanitary Sewer Force Mains

C. Sanitary Sewer Services

A. Construct sanitary sewer gravity and force mains.

B. Construct or relocate building sanitary sewer services, stubs, and connections.

A. Sanitary Sewer Gravity Main:

1. Trenched:

a. Measurement: Each type and size of pipe installed in a trench will be measured in linear feet along the centerline of the pipe from center of manhole to center of manhole.

b. Payment: Payment will be made at the unit price per linear foot for each type and size of pipe.

c. Includes: Unit price includes, but is not limited to, trench excavation; dewatering;

furnishing and installing pipe; pipe lining (if specified); furnishing, placing, and compacting bedding and backfill material; wyes and other fittings; pipe joints; pipe connections; testing; and inspection.

2. Trenchless:

a. Measurement: Each type and size of pipe installed by trenchless methods will be measured in linear feet along the centerline of pipe.

b. Payment: Payment will be made at the unit price per linear foot for each type and size of pipe.

c. Includes: Unit price includes, but is not limited to, furnishing and installing pipe;

pipe lining (if specified); trenchless installation materials and equipment; pit excavation; dewatering; placing and compacting backfill material; pipe connections;

testing; and inspection.

B. Sanitary Sewer Gravity Main with Casing Pipe:

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a. Measurement: Each type and size of pipe installed with a casing pipe in a trench will be measured in linear feet along the centerline of the casing pipe, from end of casing to end of casing.

b. Payment: Payment will be made at the unit price per linear foot for each type and size of carrier pipe.

c. Includes: Unit price includes, but is not limited to, furnishing and installing both carrier pipe and casing pipe; pipe lining (if specified); trench excavation;

dewatering; furnishing, placing, and compacting bedding and backfill material;

furnishing and installing annular space fill material; casing spacers; pipe

a. Measurement: Each type and size of pipe installed by trenchless methods with a casing pipe will be measured in linear feet along the centerline of the casing pipe from end of casing to end of casing.

b. Payment: Payment will be made at the unit price per linear foot for each type and size of carrier pipe.

c. Includes: Unit price includes, but is not limited to, furnishing and installing both carrier pipe and casing pipe; pipe lining (if specified); trenchless installation materials and equipment; pit excavation; dewatering; and placing and compacting backfill material; casing spacers; furnishing and installing annular space fill material; pipe connections; testing; and inspection.

C. Sanitary Sewer Force Main:

a. Measurement: Each type and size of pipe installed in an open trench will be measured in linear feet along the centerline of the pipe from the outside wall of the pumping station to the center of manhole, or from the center of manhole to the center of manhole.

b. Payment: Payment will be made at the unit price per linear foot for each type and size of pipe.

c. Includes: Unit price includes, but is not limited to, trench excavation; dewatering;

furnishing and installing pipe; furnishing, placing, and compacting bedding and backfill; wyes and other fittings; pipe joints; testing; and inspection.

measured in linear feet along the centerline of the pipe.

b. Payment: Payment will be made at the unit price per linear foot for each type and size of pipe.

c. Includes: Unit price includes, but is not limited to, furnishing and installing pipe;

trenchless installation materials and equipment; pit excavation; dewatering; placing and compacting backfill material; pipe connections; testing; and inspection.

D. Sanitary Sewer Force Main with Casing Pipe:

will be measured in linear feet along the centerline of the casing pipe.

b. Payment: Payment will be made at the unit price per linear foot for each type and size of pipe.

c. Includes: Unit price includes, but is not limited to, furnishing and installing both carrier pipe and casing pipe; trench excavation; dewatering; furnishing, placing, and compacting bedding and backfill material; furnishing and installing annular space fill material; casing spacers; pipe connections; testing; and inspection.

casing pipe will be measured in linear feet along the centerline of the casing pipe.

b. Payment: Payment will be made at the unit price per linear foot for each type and size of carrier pipe.

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c. Includes: Unit price includes, but is not limited to, furnishing and installing both carrier pipe and casing pipe; trenchless installation materials and equipment; pit excavation; dewatering; placing and compacting backfill material; casing spacers;

furnishing and installing annular space fill material; pipe connections; testing; and inspection.

E. Sanitary Sewer Service Stub: The portion of the sanitary sewer service from the main to a point 10 feet outside of the right-of-way line or as specified in the contract documents (comply with Figure 4010.201).

1. Measurement: Each type and size of pipe will be measured in linear feet along the centerline of the pipe from the end of the pipe to the centerline of the sewer main.

2. Payment: Payment will be made at the unit price per linear foot for each type and size of sanitary sewer service stub.

3. Includes: Unit price includes, but is not limited to, trench excavation; furnishing and installing pipe; furnishing, placing, and compacting bedding and backfill material; tap;

fittings; testing; and inspection.

F. Sanitary Sewer Service Relocation: The portion of an existing sanitary sewer service in a zone of conflict.

1. Measurement: Each completed relocation will be counted.

2. Payment: Payment will be made at the unit price for each relocation.

3. Includes: Unit price includes, but is not limited to, removal of existing pipe, trench excavation, furnishing new pipe and bedding material, placing and compacting bedding and backfill material, connection back to existing service, compaction, testing, and

G. Sewage Air Release Valve and Pit:

1. Measurement: Each completed installation, including valve, accessories, and pit, will be counted.

2. Payment: Payment will be made at the unit price for each sewage air release valve and pit.

3. Includes: Unit price includes, but is not limited to, excavation; furnishing, placing, and compacting bedding and backfill material; and testing.

H. Removal of Sanitary Sewer:

1. Measurement: Each type and size of pipe removed will be measured in linear feet from end to end.

2. Payment: Payment will be at the unit price per linear foot for each type and size of pipe.

3. Includes: Unit price includes, but is not limited to, removal, disposal, and capping (if specified) of pipe; and furnishing, placing, and compacting backfill material.

I. Sanitary Sewer Cleanout:

1. Measurement: Each sanitary sewer cleanout will be counted.

2. Payment: Payment will be made at the unit price for each cleanout.

3. Includes: Unit price includes, but is not limited to, plug at the end of the main, fittings, riser pipe, cap with screw plug, casting, and concrete casting encasement.

J. Connection to Existing Manhole: Comply with Section 6010, 1.08, G.

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K. Sanitary Sewer Abandonment, Plug:

1. Measurement: Each plug will be counted.

2. Payment: Payment will be made at the unit price for each plug installed.

3. Includes: Unit price includes, but is not limited to, trench excavation (if necessary), cutting pipe (if required), furnishing and placing plug materials, and placing and compacting backfill material.

L. Sanitary Sewer Abandonment, Fill and Plug:

1. Measurement: Each size of sanitary sewer to be abandoned by filling and plugging will be measured in linear feet.

2. Payment: Payment will be at the unit price per linear foot for each size of pipe filled and plugged.

3. Includes: Unit price includes but is not limited to, trench excavation (if necessary), cutting pipe (if required), furnishing and placing pipe fill material, furnishing and placing plug materials, and placing and compacting backfill material.

2.01 SANITARY SEWER (Gravity Mains)

A. Solid Wall Polyvinyl Chloride Pipe (PVC) 8 inch to 15 inch:

1. Comply with ASTM D 3034, SDR 26, unless SDR 35 is specified.

2. Pipe stiffness per ASTM D 2412.

a. SDR 26: Minimum pipe stiffness of 115 psi.

b. SDR 35: Minimum pipe stiffness of 46 psi.

3. PVC plastic meeting ASTM D 1784, Cell Classification 12454 or 12364.

4. Integral bell and spigot joints with elastomeric seals complying with ASTM D 3212 and

ASTM F 477.

B. Solid Wall Polyvinyl Chloride Pipe (PVC) 18 inch to 27 inch:

1. Comply with ASTM F 679.

2. Pipe stiffness per ASTM D 2412, 46 psi.

3. PVC plastic meeting ASTM D 1784, Cell Classification 12454 or 12364.

C. Corrugated Polyvinyl Chloride Pipe (PVC) 8 inch to 36 inch:

1. Comply with ASTM F 949, smooth interior, corrugated exterior.

2. Pipe stiffness per ASTM D 2412.

a. 8 inch to 10 inch: Minimum pipe stiffness of 115 psi, unless 46 psi is specified.

b. 12 inch to 36 inch: Minimum pipe stiffness of 46 psi.

3. PVC resin meeting ASTM D 1784, Cell Classification 12454.

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D. Closed Profile Polyvinyl Chloride Pipe (PVC) 21 inch to 36 inch:

1. Comply with ASTM F 1803.

2. Pipe stiffness per ASTM D 2412, 46 psi.

3. PVC plastic meeting ASTM D 1784, Cell Classification 12364.

E. Polyvinyl Chloride Composite Pipe (truss type PVC) 8 inch to 15 inch:

1. Comply with ASTM D 2680. Pipe constructed with truss-type structure between inner and outer PVC walls with voids filled with lightweight concrete.

2. Pipe stiffness per ASTM D 2412, 200 psi.

3. PVC plastic meeting ASTM D 1784, Cell Classification 12454.

F 477.

F. Reinforced Concrete Pipe (RCP) 18 inch to 144 inch:

a. Comply with ASTM C 76 (AASHTO M 170).

b. Minimum Class IV (3000D), Wall B.

c. Tongue and groove joints.

d. Rubber O-ring or profile gasket flexible joint complying with ASTM C 443.

2. Pipe Lining:

a. Epoxy Coal Tar:

1) Coat interior pipe barrel and all joint surfaces with two-component coal-tar epoxy-polyamide black paint or approved equal.

2) Lining Material: Steel Structures Painting Council (SSPC) Specification No. 16, Table 1.

a) Minimum epoxy resin content 34% to 35% by dry film weight.

b) Minimum sag resistance 40 mils.

c) Minimum solids 80% by volume.

3) Apply according to lining material manufacturer’s recommendations.

b. PVC:

1) Minimum thickness of 0.65 inch.

2) Locking extensions extruded from the same material as the liner a minimum of

0.375 inches tall spaced a maximum of 2.5 inches.

3) Liner to cover the entire interior of the concrete pipe.

4) Minimum tensile strength of liner is 2200 psi with a minimum elongation of

200% at breaking.

5) Meet EPA 9090 for chemical resistance.

6) Free of cracks, cleavages, pinholes, or other defects.

7) Joint sealer strip to be from the same material as the liner.

c. HDPE:

1) Minimum thickness of 0.064 inches according to ASTM D5199.

2) Minimum density of 0.90 g/cm3.

3) Meet EPA 9090 for chemical resistance.

4) Locking extensions made from the same material as the liner with minimum pullout strength of 14,000 pounds per square foot.

5) Free of cracks, cleavages, pinholes, or other defects.

6) Joint sealer strip to be from the same material as the liner.

7) If gasketed joints, comply with ASTM F 477 and ability to withstand a minimum groundwater pressure equal to that of the pipe liner or 20 psi, whichever is greater.

G. Ductile Iron Pipe (DIP) 8 inch to 54 inch:

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a. Comply with AWWA C151.

b. Minimum thickness Class 52.

2. Interior Linings:

a. Provide interior lining for ductile iron pipe and fittings used for all gravity sewers and drop connections.

b. Use linings specifically designed for sanitary sewer applications, such as ceramic epoxy. Other lining types may be allowed upon approval of the Engineer.

c. Apply lining to interior of unlined ductile iron pipe and fittings according to the published specifications from the manufacturer.

d. Seal all cut ends and repair field damaged areas according to the manufacturer’s recommendations.

3. Exterior Coating: Asphalt.

4. Joints: Push-on complying with AWWA C111.

5. Fittings: Mechanical complying with AWWA C110 or AWWA C153.

6. Polyethylene Encasement:

a. Comply with AWWA C105.

b. Minimum thickness of 8 mils.

c. Use for all ductile iron pipe and fittings in buried service.

H. Vitrified Clay Pipe (VCP) 8 inch to 42 inch:

1. Pipe and fittings complying with ASTM C 700.

2. Compression joints complying with ASTM C 425 for plain end pipe or bell and spigot pipe.

3. Test according to ASTM C 301.

I. Double Walled Polypropylene Pipe 12 inch to 30 inch:

1. Comply with ASTM F 2764.

2. Minimum pipe stiffness per ASTM D 2412, 46 psi.

3. Integral bell and spigot joint complying with ASTM D 3212 and ASTM F 477.

J. Triple Walled Polypropylene Pipe 30 inch to 36 inch:

1. Comply with ASTM F 2764.

2. Minimum pipe stiffness per ASTM D 2412, 46 psi.

3. Integral bell and spigot joint complying with ASTM D 3212 and ASTM F 477.

2.02 SANITARY SEWER FORCE MAINS

A. Ductile Iron Pipe (DIP) 4 inch to 54 inch: Comply with the DIP requirements in Section

4010, 2.01. If joint restraints are specified, comply with Section 5010, 2.03.

B. Polyvinyl Chloride Pipe (PVC): Comply with the requirements in Section 5010, 2.01 for

PVC pipe. Provide restrained joints when specified.

C. Fusible PVC and HDPE Pipe: Comply with the requirements in Section 5011, 2.01.

D. Sewage Air Release Valve:

1. General: Consists of an elongated tapered or conical body and a float to operate (open and close) under pressure without spillage. Provide valves suitable for pressures up to 150 psi. Use a float with a linkage connection to the seal plug

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2. Materials:

a. Body and Cover:

1) Stainless Steel: ASTM A 351.

2) Cast Iron: ASTM A 126, Grade B.

3) Ductile Iron: ASTM A 536, Grade 65-45-12.

4) Other corrosion resistant materials.

b. Internal Metal Components: Stainless steel.

c. Float: Stainless steel, ASTM A 240, Type 304 or Type 316, or foamed polypropylene.

d. Seal Plug Assembly: Stainless steel, foamed polypropylene, EPDM rubber, Nitrile

(Buna-N) rubber, and reinforced nylon.

3. Tapping Saddle: Stainless steel or nylon.

4. Pit: Construct according to Figure 4010.202.

E. Tracer Wire: Comply with Section 5010, 2.05. Tracer wire will be required on all force mains.

F. Tracer Wire Station:

1. Two internal terminals with shunt.

2. Five to six foot plastic post (color as specified by the Jurisdiction).

3. Removable top cap with lock.

4. Decals indicating “Sewer Force Main” or similar language.

2.03 CASING PIPE

Comply with Section 3020, 2.02 for casing pipe requirements.

2.04 SANITARY SEWER SERVICES

A. Connection to Main:

1. PVC Main:

a. Preformed wye or tee service fitting with integral bell and spigot joints with elastomeric seals complying with ASTM D 3034 or ASTM F 949.

b. Preformed saddle wye or saddle tee for service tap complying with ASTM D 3034 or ASTM F 949.

c. PVC plastic meeting ASTM D 1784, Cell Classification 12454.

2. PVC Composite Main:

a. Preformed wye or tee service fitting with integral bell and spigot joints with elastomeric seals complying with ASTM D 3212.

b. Preformed saddle wye or saddle tee for service tap complying with ASTM D 2680.

3. RCP Main: Preformed saddle wye or saddle tee service tap designed for use with

RCP.

4. VCP Main:

a. Precast VCP wye or tee service fitting complying with ASTM C 700 for pipe and ASTM C 425 for compression joints.

b. Preformed saddle wye or saddle tee service tap designed for use with VCP.

5. DIP Main:

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a. Use DIP wye or tee fittings complying with AWWA C110 or AWWA C153.

b. Preformed saddle wye or tee services tap designed for use with DIP. Cut the hole for the tap with equipment designed for application.

B. Wye and Tee Pipe Stop: All saddle wye or saddle tee fittings must provide integrally molded pipe stop in the branch for positive protection against service pipe insertion beyond the inside of sewer main pipe wall.

C. Service Pipe: Use products as required by local plumbing code or regulations, if applicable. Otherwise, use the following:

1. PVC:

a. Comply with ASTM D 3034, minimum thickness SDR 23.5 minimum pipe stiffness of 153 psi as per ASTM D 2412.

b. PVC plastic meeting ASTM D 1784, Cell Classification 12454.

c. Integral bell and spigot type rubber gasket joint complying with ASTM D 3212.

2. DIP: As specified for sanitary sewer force main, including polyethylene encasement.

D. Connection to Existing Service: Comply with Section 4050, 2.06.

2.05 SANITARY SEWER SERVICE RELOCATIONS

A. Comply with Section 4010, 2.04 for all materials used for sanitary service relocation.

B. Use the same nominal size as the existing service being relocated.

2.06 SANITARY SEWER CLEANOUT

Comply with Figure 4010.203.

3.01 EXAMINATION

A. Verify measurements at site. Make necessary field measurements to accurately determine pipe makeup lengths or closures.

B. Examine site conditions to ensure construction operations do not pose hazards to adjacent structures or facilities.

3.02 GRAVITY SEWER INSTALLATION

A. General:

1. Install watertight plug to prevent water from entering the existing sewer system.

2. Clean pipe interior and joints prior to installation. Keep pipe clean during construction.

3. Begin at the lowest point in the line. Lay groove or bell end pointing upstream unless otherwise specified.

4. Assemble joints according to Section 4010, 3.04.

5. Use a saw to cut ends of pipe flush with inside wall of manholes and structures. Do not use hammer or other means to break pipe.

6. Provide manholes as specified in the contract documents.

7. Install cap, plug, or bulkhead at exposed ends of pipe upon completion of construction or whenever pipe installation is not in progress.

B. Trenched:

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1. Excavate trench and provide pipe bedding and backfill material as specified in Section 3010.

2. Prepare trench bottom to design line and grade so that only minor movement of the pipe is necessary after installation.

3. Lay pipe to design line and grade. Set field grades to invert of pipes.

4. Provide uniform bearing for full pipe barrel length. Excavate bell holes as necessary for uniform support of pipe barrel on bedding material.

5. Do not lay pipe in water or on saturated soil or bedding, or allow water to rise in trench around pipe prior to placing backfill material.

6. Do not disturb installed pipe and bedding when using movable trench boxes and shields. Block or anchor pipe as necessary to prevent joint displacement.

7. Install wye or tee service fitting at each location specified in the contract documents.

C. Trenchless: Comply with Section 3020.

3.03 SANITARY SEWER INSTALLED WITHIN A CASING PIPE

Comply with Section 3020, 3.04 for installation of sanitary sewer within casing pipe.

3.04 GRAVITY MAIN PIPE JOINTING

1. Clean joint surfaces to remove soil or foreign material prior to jointing pipe.

2. Assemble joints according to pipe manufacturer¢s recommendations. Use equipment that does not apply damaging forces to pipe joints.

B. Polyvinyl Chloride Pipe (PVC) and Polyvinyl Chloride Composite Pipe (truss-type):

1. Coat rubber gasket and joint with soap-based lubricant immediately prior to closing joint.

2. Seal ends of PVC composite and closed profile pipe at manholes with the coating recommended by the manufacturer.

C. Reinforced Concrete Pipe (RCP): Coat rubber gasket and joint with soap-based lubricant immediately prior to closing joint.

D. Ductile Iron Pipe (DIP):

1. Push-on Joint: Coat gasket and joint with soap-based lubricant immediately prior to closing joint.

2. Mechanical Joint: Wash plain end, bell socket, and gasket with soap solution. Press gasket into socket, set gland, and tighten bolts uniformly.

E. Polypropylene Pipe: Coat gasket and bell with lubricant immediately prior to closing joint.

F. Connections between Dissimilar Pipes:

1. Use manufactured adapters or couplings approved by the Engineer.

2. Where adapters or couplings are not available, the Engineer may authorize use of a

Type PC-2 concrete collar as shown on Figure 4020.211.

3.05 FORCE MAIN INSTALLATION

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A. General: Install according to Section 5010.

B. Tracer Wire:

1. Required for all force main installations. Comply with Section 5010.

2. Install tracer wire station at each end of the force main and at additional locations specified in the contract documents.

3. Bury end of tracer wire station 2 feet and compact.

3.06 SANITARY SEWER SERVICE STUBS

A. Provide sanitary sewer service stubs at locations specified in the contract documents.

B. Install wye or tee for each service connection.

1. Connection of sanitary service to new sewer main, except RCP:

a. Use only factory wye or tees.

b. Install according to manufacturer’s requirements and Section 4010, 2.04 and 3.04 for joints.

2. Connection to existing sewer main and new RCP:

a. Cut sewer main for service tap with hole saw or sewer tap drill.

b. Use preformed saddle wye or saddle tee for service tap. Use a gasketed saddle with rigid pipe mains and a solvent-cemented saddle with PVC mains.

c. Install according to the manufacturer’s requirements, but always attach with at least two stainless steel band clamps.

C. Install service stub from sewer main to a location 10 feet beyond the right-of-way line or as specified in the contract documents. Comply with Figure 4010.201.

1. Install according to Section 4010, 3.02.

2. Install service stub with a slope between 2% and 5% for 4 inch pipes, and between 1% and 5% for pipes 6 inches and greater.

3. Terminate end of service stub 10 to 12 feet below finished ground elevation or as specified in the contract documents.

4. If the depth of the sewer main causes the service to exceed a depth of 12 feet or a slope of 5%, install a service riser.

5. For undeveloped properties, place watertight stopper, cap, or plug in end of sanitary sewer service. Mark the end of the service line as required by the Jurisdiction or as

6. For reconnection of new service pipe with existing service pipe, comply with the

Jurisdiction’s plumbing code.

3.07 SANITARY SEWER SERVICE RELOCATION

A. Relocate existing sanitary sewer services that conflict with new storm or sanitary sewer installations. Existing services located within a conflict zone from 6 inches below the bottom of the proposed sewer pipe to 2 inches above the top of the proposed sewer pipe require relocation.

B. When a conflicting service is encountered:

1. Determine grades and elevations of the existing service and proposed main.

2. Determine the extent of service replacement necessary to relocate the service outside of the conflict zone while maintaining a minimum 1% slope on the sewer service.

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3. If it is not feasible to maintain a minimum slope of 1% on the relocated service, a special design and additional work may be required. Stop work and contact the Engineer. Do not remove sewer service unless directed by the Engineer.

4. If service relocation with a minimum slope of 1% is feasible, proceed with removal and replacement of the existing sanitary sewer service.

a. Length of replacement varies. Remove the existing service to the extent necessary to move the service out of the conflict zone.

b. Use all new materials complying with Section 4010, 2.04.

c. Re-install the service according to Section 4010, 3.02.

d. Maintain a minimum 1% grade on relocated service.

3.08 SANITARY SEWER ABANDONMENT

A. Plug:

1. Prior to placing the sewer plug, the Engineer will verify the sewer line is not in use.

2. Construct sewer plug by completely filling the end of the pipe with concrete. Force concrete into the end of the pipe for a distance of 16 inches, or one-half the pipe diameter, whichever is greater.

B. Fill:

1. Prior to filling the sewer, the Engineer will verify the sewer line is not in use.

2. If specified in the contract documents, fill the line to be abandoned with flowable mortar, foamed cellular concrete, or CLSM (comply with Section 3010) by gravity flow or pumping.

3. Batching, mixing, and placing may be started when temperature is 34°F and rising.

Cease mixing and placing when temperature is 38°F or less and falling.

3.09 CONNECTION TO EXISTING MANHOLE

Comply with Section 6010, 3.05.

3.10 SANITARY SEWER CLEANOUT

Provide cleanouts where specified in the contract documents. Comply with Figure 4010.203.

3.11 TOLERANCES

Apply the following tolerances to utilities installed by open trench construction. For trenchless construction, comply with Section 3020.

A. Gravity Main:

1. Do not allow horizontal and vertical alignment to vary from design line and grade at any structure by more than 1% of the inside diameter of the pipe or 1/4 inch, whichever is larger.

2. Do not allow the horizontal alignment of the pipe to vary from design line at any point along the pipe by more than 1% of the inside diameter of the pipe.

3. Low spots holding water exceeding the following depths for each pipe size will be considered unacceptable and must be removed and reinstalled to proper grade.

Pipe Diameter Maximum Low Spot Depth 8” 1/2” 10” 1/2” 12” 3/4” 15” 3/4”

18” and Larger 5% of Pipe Diameter*

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* Measured to the nearest 1/2”

B. Force Main: Do not allow horizontal and vertical alignment of trenched force mains to vary from design line and grade by more than 3 inches.

3.12 CONFLICTS

A. Horizontal Separation of Gravity Sanitary and Combined Sewers from Water Mains:

Separate gravity sanitary and combined sewer mains from water mains by a horizontal distance of at least 10 feet unless:

1. The top of a sewer main is at least 18 inches below the bottom of the water main, and

2. The sewer is placed in a separate trench or in the same trench on a bench of undisturbed earth at a minimum horizontal separation of 3 feet from the water main.

3. When it is impossible to obtain the required horizontal clearance of 3 feet and a vertical clearance of 18 inches between sewers and water mains, provide a linear separation of at least 2 feet and one of the following:

a. Construct sanitary and combined sewers of water main materials meeting the requirements…