3-Colonel Estill Technical Specifications.pdf

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COLONEL ESTILL DRAINAGE IMPROVEMENTS

SPECIAL CONDITIONS

SECTION 01600

PART 1 – PROJECT DESCRIPTION

The project is in the unincorporated Chatham County on Isle of Hope along Colonel Estill Avenue.

The work consists of removal of existing pipes and structures, installation of stormwater pipes and structures, construction or modification of open channels, utility adjustments, and associated work as shown on the plans. Traffic will be impacted but roadway and property access must be maintained unless otherwise directed. Capacity for stormwater flow must be maintained, although temporary blockages are acceptable. Erosion and sedimentation control plans are provided and must be implemented prior to and maintained during construction. Coordination with utility providers is also included.

PART 2 – CONTRACT DOCUMENTS

2.1 Technical Specifications:

02200 Excavation, Filling and Grading 02210 Erosion Control 02221 Excavation, Trenching and Backfilling for Utility Systems 02400 Storm Drainage System 02480 Grassing and Sodding

2.2 Drawings:

C0.1 Cover Sheet, Vicinity Map, and Schedule of Drawings C0.2 Construction Notes and Legend C0.3 Paving, Grading and Drainage Plans C0.4 Construction Details EC0.1–EC0.2 Erosion and Sedimentation Control Notes EC0.3 Erosion and Sedimentation Control Plan EC0.4 Erosion and Sedimentation Control Details

PART 3 – PRE-CONSTRUCTION INSPECTIONS

The contractor is responsible for a pre-construction conditions video. Special emphasis shall be given to recording pre-disturbance condition of roadways, driveways, buildings, mailboxes, fences, utilities, and other improvements located within and 100 feet adjacent to the project limits. This is in addition to other inspections and surveys required of the contractor or performed by the County.

Still photographs with a detailed description log may be substituted for the video if level of coverage is similar.

PART 4 - STAKING

The County shall engage a surveyor registered by the State of Georgia to provide initial project control. Ongoing control of the project work shall be the responsibility of the Contractor. The cost to reestablish initial project controls damaged or lost due to construction activities shall be paid for by the Contractor. The Contractor shall provide access and schedule all work to accommodate the survey work by the County’s surveyor.

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PART 5 – DOCUMENTATION

In addition to the documentation described elsewhere in the Contract Documents, the Contractor shall submit with each request for payment the following:

1. Copies of material delivery tickets. The Contractor shall be responsible for collecting these documents at the time of delivery. The delivery tickets shall not relieve the Contractor of his responsibility to ensure the materials are in accordance with the contract with the contract documents. Missing or incomplete documentation of delivered materials may be cause for delay/denial of payment.

2. Copies of soil erosion and sedimentation, including NPDES, reports and forms completed during the pay period.

3. Prior to submitting a request for payment, the Contractor shall review the extent of work completed with the County’s representative for accuracy and completeness.

PART 6 – EROSION AND SEDIMENTATION CONTROL

The Contractor shall be fully responsible for compliance with the Georgia Water Quality Control Act and compliance with the approved sediment and erosion control plan contained in the contract documents.

1. The County shall perform the initial inspection of the Best Management Practice (BMP) system installation. The Contractor shall perform no land disturbing activities (other than that which is necessary for installation of the BMPs) until approval of the initial BMP installations.

PART 7 – FINES AND LIQUIDATED DAMAGES

1. A $500 per day fee shall be assessed against the Contractor and withheld from the

Contract Price for each day that the erosion and sedimentation control plan is not in proper operation. This fee shall be in addition to any penalties or assessments made against the Contractor for non-compliance with the Georgia Water Quality Control Act.

2. Liquidated Damages shall be assessed at $500 per calendar day for work not completed within the Contract period. The full amount of liquidated damages will be deducted from the final payment to the Contractor.

PART 8 – ALLOWANCE

The Field Condition Allowance shown on the bid sheet shall belong to Chatham County. The purpose of this Allowance is to allow the County to designate actions associated with completion of the project which are not indicated on the plans, but which are dictated by field conditions.

Bidders shall not use this Allowance to assume any Contractor costs known or unknown at the bidding. Chatham County must approve use of the Allowance. All bidders shall include this Field Condition Allowance within their base bid. Any unused allowance shall revert to Chatham County.

PART 9 – SPECIAL REQUIREMENTS OF CONSTRUCTION

1. The County will pay for all materials testing as required by the contract. Testing will be performed by an independent testing lab that is hired by the County. The County will not pay for testing in support of contractor operations/schedule. The contractor will be required to pay for failed tests.

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2. Clearing debris may not be chipped and spread on the project site.

3. It is understood that the location and nature of the project will result in some soil migration to pavement. This is to be kept to a minimum and cleaned up on a regular basis.

4. The Contractor shall comply with all local, state, and federal regulations as they pertain to construction activities (erosion control, etc.).

5. All efforts have been made to identify every underground and above ground utility;

however, the contractor has the ultimate obligation to proceed with caution when a suspected utility line is present in the excavation. Any lines which are not shown to be abandoned shall be repaired immediately if broken during construction.

6. Work hours shall be limited to 7:00 am to 7:00 pm Monday through Friday and shall exclude weekends and holidays unless otherwise approved by Chatham County.

7. The Contractor shall obtain an Encroachment permit from the Department of Public Works prior to any work within County rights of way. All work is to be performed within the existing rights of way and easements as shown on the plans unless coordinated with others.

8. Watering past the date of substantial completion of the work shall be provided on grassed areas to achieve full coverage to match existing conditions and as accepted by Chatham County.

9. A detailed construction schedule for the project shall be provided to and approved by Chatham County prior to beginning demolition or construction.

10. The contractor shall develop a traffic control plan for review and approval by the County. No work shall commence on the site until the plan has been approved. The work shall be completed in a manner which allows one lane of traffic to remain in service during the construction period; however, temporary road closures will be permissible for short periods for crossings. All temporary road closures must be approved by the County prior to the closure. The contractor is responsible for providing all measures of traffic control including, but not limited to, flagmen, warning and directional signs, channelization devices, and barriers. If a closure is approved, the contractor shall develop the detour plan for County review and implement the detour if accepted. The County reserves the right to limit the time of closure.

11. Submittals for the following items are required:

Storm drain pipe Storm drain structures Silt fence Grassing

12. The contractor shall be responsible for the continued functioning of the storm drainage system throughout the course of the work.

13. The contractor shall be responsible for the design, installation, maintenance, and removal of any sheeting, shoring, or other soil support measures required to facilitate construction.

Any damages or additional costs due to the failure of supported or unsupported cut faces shall be the responsibility of the contractor.

PART 10 – MEASUREMENT AND PAYMENT

1. Measurement

The items listed in the proposal shall be considered as sufficient to complete the work in accordance with the drawings and specifications. Any portion of the work not listed in the

01600 - 4 bid form shall be deemed to be a part of the item which it is associated with and shall be included in the cost of the unit shown on the bid form. Payment for the unit shown on the bid form shall be considered to cover the cost of all labor, material, equipment and performing all operations necessary to complete the work in place. The unit of measurement shall be the unit shown on the bid form. Payment for unit price items shall be based upon the actual quantity multiplied by the unit prices. Where work is to be performed at a lump sum price, the lump sum shall include all operations and elements necessary to complete the work. No payment will be made for any material wasted, unused, rejected or used for the convenience of the Contractor.

2. Payment

A. Mobilization Mobilization of equipment and commencement of project. Payment shall be based on the lump sum price in the Bid Proposal and shall not to exceed 5% of the total price bid for the project.

B. Remove Existing Drainage Structure

Payment shall be at the unit price in the Bid Proposal for each size structure and shall include all labor, materials and equipment required to remove. Measurement shall be based on the actual number of structures removed as shown on the plans or as directed by the owner.

C. Remove Existing Pipe, All Sizes

Payment shall be at the unit price in the Bid Proposal and shall include all labor, materials and equipment required to remove existing pipes and dispose of them off-site. Measurement shall be based on the actual linear feet of pipe, of whatever size and type, removed as shown on the plans or directed by the owner.

D. General Clearing

Clearing shall include removal of all vegetative materials such as trees, shrubs and grass which do not have an individual item on the Bid Schedule, and which is required to complete the work as shown on the plans. Removal of stumps and roots is a part of clearing unless stump retention is directed by the owner. Demolition is included in this item and shall include the removal of all manmade items required to complete the work as shown on the plans, except for items specifically listed in the Bid Schedule. For both clearing and demolition, the removal of debris is also included in this item. Payment shall be at the lump sum price in the Bid Proposal.

E. Grading

Payment shall be at the lump sum price in the Bid Proposal and shall include all labor, materials and equipment required. The item shall include excavation or filling not associated with conduit installation or drainage channel modifications, finish grading of drainage channels, and finish grading of shoulders and swales to be created above storm pipes. The item shall also include construction staking, bonds, insurance, supervision/project management and all other work required to complete the project, and which is not covered by a separate item.

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F. Remove Unsuitable Material materials and equipment required to remove the material as directed by the owner and to dispose of it off the site of the work. Measurement shall be based on the actual number of cubic yards of unsuitable material removed and shall be based on before and after cross sections or such other method as may be acceptable to the owner.

G. Foreign Borrow equipment and materials required to obtain, transport, and install borrow material to serve as backfill for pipes or to fill the existing channel when on-site material is not suitable or not available. Measurement shall be by trench sections, or such other method as may be accepted by the owner. Only the cost of obtaining the material and transporting it to the site shall be included in this item; placement and compaction shall be included in the cost of pipe installation or in the cost of filling the existing channel.

H. Storm Drain Pipe, All Sizes

Payment shall be at the unit price in the Bid Proposal for each size and type of storm drainage pipe and shall include all material, labor and equipment required to install and backfill the pipes (except for foreign borrow) in accord with the plans and specifications. The length of pipe will be paid for on a linear foot basis, as measured along the centerline, from end of pipe to end of pipe. Cost of bedding to be included in price bid for pipe.

I. Storm Drain Structures

Payment shall be made at the contract unit price for each type and size of structure.

Payment should include all material, equipment and labor required to install the structures in accord with the contract documents. Structures include grate inlets, weir inlets, and storm manholes.

J. Utility Coordination measures associated with coordinating the installation of the new storm drain with existing public and private utilities. This will include arranging for location and adjustments.

K. Traffic Control materials and labor required to control and maintain traffic movement through the work zone. This includes, but is not limited to, signs, barricades, flagmen, temporary and permanent markings, and channelization devices.

L. Maintenance of Flow

01600 - 6 materials, labor, and equipment necessary to maintain the flow of stormwater, sanitary sewer and water as shown on the plans or directed by the owner.

M. Concrete Drive

Payment shall be at the unit price in the Bid Proposal and shall include all labor materials and equipment required to construct the concrete drive as shown on the plans or directed by the owner. Measurement shall be based on the actual number of square yards installed.

N. Remove and Replace Asphalt Pavement materials and equipment required to remove the existing pavement as required for storm drain installation, dispose of it offsite and install the replacement section shown on the plans. The owner will determine whether proposed removal limits are acceptable; excessive pavement removal will not be paid.

O. Remove and Replace Concrete Drive materials and equipment required to remove and reconstruct the concrete drive as shown on the plans or directed by the owner. Measurement shall be based on the actual number of square yards installed.

P. Remove and Replace Concrete Sidewalk materials and equipment required to remove and reconstruct the concrete sidewalk as shown on the plans or directed by the owner. Measurement shall be based on the actual number of square yards installed.

Q. Remove and Replace Mailbox materials and equipment required to remove the mailbox and reinstall it in the same location as shown on the plans or as directed by the owner. Measurement shall be based on the actual number of mailboxes removed and replaced.

R. Remove and Replace Traffic Sign materials and equipment required to remove the sign, store it during construction and reinstall it in the same location as shown on the plans or as directed by the owner. Measurement shall be based on the actual number of signs removed and replaced.

S. Relocate Water Meter / Water Service Line materials and equipment required to relocate the water meter or water service line

01600 - 7 as shown on the plans or as directed by the owner. Measurement shall be based on the actual number of relocated water meters and water service lines.

T. Riprap materials and equipment required to install the riprap as shown on the plans or as directed by the owner. Excavation required for flush installation and filter fabric underlay is included. Measurement shall be based on the actual number of square yards of riprap installed.

U. Inlet Sediment Trap materials, and equipment required to install the trap as shown on the plans, maintain it during the construction period, and remove it when the construction is complete.

V. Tree Protection Fence equipment, and materials to install tree protection fence as shown on the plans or directed by the owner, maintain the fence during the construction period, and remove the fence when work is complete. Measurement shall be based on the actual linear feet of fence installed.

W. Silt Fence Payment shall be at the unit price for each type in the Bid Proposal and shall include all labor, materials, and equipment required to install the silt fence, maintain it during the construction period, remove it when stabilization is completed, and restore the area where the fence was installed. Measurement shall be based on the actual number of linear feet of each type of silt fence installed as shown on the plans or directed by the owner.

X. Floating Sediment Barrier materials and equipment required to install the floating silt barrier, maintain it during the construction period and remove it when construction is complete. Measurement shall be based on the actual number of linear feet installed as shown on the plans or directed by the owner.

Y. Grassing

Payment shall be at the unit price in the Bid Proposal for each type of grassing and shall include all labor, materials and equipment required to establish the temporary / permanent vegetation on the disturbed areas. This shall include watering and mowing until acceptance by the County. Measurement shall be based on the actual number of square yards of temporary / permanent grassing in place.

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SECTION 02200

EXCAVATION, FILLING AND GRADING

1) SCOPE:

Under this heading shall be included the following:

a) Excavation required for structures.

b) Sub-cut excavation as required or designated.

c) Shoring, sheeting, and bracing as required

d) Wasting and disposal of excess or unsuitable materials.

e) Furnishing and placing borrow material.

f) Furnishing and placing granular foundation material.

g) Compaction of all materials.

h) Dewatering or unwatering as necessary to complete the excavations to the required depths and as necessary to maintain the excavation sufficiently dry so that all work can be accomplished.

i) Site grading as required, including excavation and backfill.

j) All other work specified herein.

Excavation and backfill for outside utility systems and other underground piping is specified in Section 02221 of these Specifications.

2) GENERAL:

The Contractor shall accept the site in its existing condition and shall assume the risk of encountering whatever materials as may occur. Chatham County will hire a third-party testing firm to perform required geotechnical testing and field observations. Contractor shall coordinate his work and schedule through the County for the necessary testing.

3) SOILS:

No geotechnical investigation has been performed. The Contractor shall make his own determination of the soil structure and site conditions as they may affect the work.

4) DEWATERING AND PROTECTION AGAINST WATER:

The Contractor shall remove water from the site and shall lower the ground water level as necessary to complete the excavations to the required depths and as required to maintain the excavations sufficiently dry so that all required work can be accomplished. The Contractor shall do such well construction, well pointing, sheeting, ditching, diking and pumping and shall construct necessary drains, channels, sumps and cofferdams to keep his excavations and new structures clear of ground water, storm water or sewage and to keep his construction areas dry during the progress of the work and until the finished work is accepted by the Owner, except as otherwise specified.

The Contractor shall be responsible for the effect of dewatering operations on adjacent property and for the effects on water supplies located in the vicinity of the project.

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Adequate measures and protection shall be provided by the Contractor to protect his work from damage from uplift due to ground water, storm water, or flood water. Any damages which may result shall be the Contractor's responsibility.

The Contractor shall accept all responsibility for damage to the work of this Contract because of floods and water pressures and other water damages and shall accept all risks of floods and other events which may occur.

All water discharged by pumping operations shall be discharged so as not to interfere with work under this Contract or with existing structures and operations. Route of dewatering pipe shall be subject to the Owner’s review. Discharge facilities and water quality shall comply with applicable regulations of State and Federal agencies.

Dewatering operations shall be uninterrupted and continuous during the course of the work so as not to endanger any construction in place or to present a hazard to workmen in and around the site. The Contractor shall take all measures necessary including, but not limited to, standby equipment and constant attendance to ensure that the dewatering system remains operational and effective throughout the period of time that it is required.

5) MATERIALS:

a) Earth Fill.

Earth fill shall consist of all suitable materials from required excavations. Suitable materials for earth fill shall generally be composed of sands, clay-sand mixtures and silt-sand mixtures classified as SW, SP, SM or SC (low plasticity only) by the Unified Soil Classification System.

Clay-sand and silt-sand mixtures must be approved by the soil technician prior to being incorporated in fills. Clays, silts, and organic soils will be considered as unsuitable materials.

b) Excavated Materials.

All suitable materials from excavations shall be used in the permanent construction required under these Specifications. Suitable materials shall be excavated separately from materials to be wasted and the suitable materials shall be segregated by loads during the excavation operations and shall be placed in temporary stockpiles and later placed in the designated locations. Excavated materials, which, after drainage, are suitable for the embankment but which, when excavated are too wet for immediate compaction in the embankment, shall be placed temporarily in stockpiles until the moisture content is reduced sufficiently to permit them to be placed in the earth fills.

c) Excess Materials.

All excess material from required excavations shall be removed from the site unless written authorization is given by the Owner’s representative to stockpile the material on the site.

6) EXCAVATION:

Excavation shall include the loosening, loading, removing, transporting, stockpiling and disposing of all materials, wet or dry, necessary to be removed to construct all structures included in this Contract to the lines and grades, and at the locations, shown on the Contract

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Drawings. Excavation for outside piping, storm sewers and utilities systems is included in other Sections of these Specifications.

Excavation for structures shall conform to the depth and dimensions necessary for the proper installation of all structures detailed on the Contract Drawings. Unless shown on the Drawings excavation shall not be carried below the elevations shown on the Drawings. Where bottoms of excavations are slightly unstable and the Drawings do not require a stabilized granular back-fill and the Engineer does not direct additional excavation and replacement, the Contractor may provide a gravel course, but such work will be considered as for the Contractor's convenience and will not be considered as extra work.

Where any unauthorized excavation is made below the elevation indicated on the Contract Drawings, the excavation shall be restored to the proper elevation with compacted, well graded granular backfill. Such backfill shall be compacted as specified in the Article entitled "Compaction".

Excavation for pipes under and adjacent to structures shall be made after the installation of the granular backfill. Excavations shall be made to the required depths, grades, alignment, and trench widths required for the installation of the pipe. Temporary sheeting and bracing shall be used as required to confine the trench size and width. Trench size and width shall conform to the requirements in Section 02221.

Excavation shall be made for site work to the required depths, grades, and alignment.

Excavations, where conditions require, shall be properly shored, sheeted and braced by the Contractor to maintain excavation in a condition to permit the safe and efficient installation of all items of Contract work. Upon completion of the various Contract items, all temporary forms, shores and bracing shall be removed. While being withdrawn, all voids left by the sheeting and bracing shall be carefully filled with sand and compacted.

7) UNSUITABLE MATERIAL:

Where material encountered is unsuitable for subgrade construction of roads, buildings and walks, such material shall be excavated to the required depth of compaction (generally two feet below pavement base course), disposed of off the site and property of the Owner and replaced with suitable material. Unsuitable materials are those classified as MH, CH, OH, OL, and Peat in accordance with the Unified Soil Classification System. Excess water in material will not be a basis for establishing unsuitable material regardless of gradation. The Owner’s representative shall be notified immediately upon encountering of unsuitable material.

8) BORROW:

It is anticipated that suitable material for required fill and backfill can be obtained from required excavation. Suitable materials shall be secured by the Contractor from off-site sources if required.

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9) BACKFILLING:

All excavation shall be backfilled to the lines and grades shown on the Contract Drawings.

Backfill adjacent to structures shall not be placed until forms, form lumber and all debris from construction have been entirely removed from around the work. No backfilling shall be done in unsuitable weather or over ground that is frozen or too wet.

Backfill shall not be placed against structures until the concrete has cured at least 7 days.

Backfill, in general, shall be placed in horizontal layers not in excess of 12 inches in thickness, except in the cases of embankment construction around structures and under roadway and piping locations, where backfill shall be placed in 6 inch layers, with each layer thoroughly compacted as specified hereinafter, prior to the addition of the succeeding layer.

Fill immediately adjacent to walls shall be hand tamped and special care shall be taken to prevent any wedging action or eccentric loading against the walls.

Fill material shall be free of organics, roots or other deleterious materials, including frozen material, stones or cobbles over 6 inches in maximum dimension. It shall be non-plastic granular material containing less than 25 percent fines passing the No. 200 sieve.

10) COMPACTION:

a) General.

Compaction of earth fill and all pavement subgrades shall be performed to the percentages of maximum standard or modified dry densities and to the depths as shown on the drawing or as follows:

1. Subgrades Under Paved Areas and Structures.

100 Percent Standard (ASTM Test D698) 24 inches

2. Pedestrian Traffic Subgrades.

95 Percent Standard (ASTM Test D698) 12 Inches

3. Unpaved Areas To Be Grassed Or Sodded.

95 Percent Standard (ASTM Test D698) Full Depth

b) Moisture Content.

All compaction shall be performed at material moisture contents within 3 percentage points, plus or minus of optimum. Compaction and proof rolling equipment shall be as may be required for the type of fill being compacted.

11) TESTING:

The Owner will select an approved independent testing laboratory for the purpose of identifying soils, checking densities, and classifying soils materials during construction.

Payment for the testing will be by the Owner. The Contractor shall coordinate need for testing services with the Owner’s representative. Copies of all test results shall be furnished to the

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Contractor and the Owner’s representative.

b) Moisture Density Tests.

Testing shall be in accordance with ASTM Methods D698 or such other test as may be accepted by the Owner. A test shall be performed on each type of material used in the work regardless of source. Tests will be accompanied by particle-size analyses of the soils tested (ASTM Methods D421 and D422). Changes in color, gradation, plasticity or source of fill material will require the performance of additional tests. Copies of all test results shall be furnished to the

c) Field Density Tests.

Tests shall be made in accordance with ASTM Method D1556 and/or ASTM Method D 2922 or such other test as may be acceptable to the owner. If any compaction test reveals that fill or backfill is not compacted as specified, the Contractor shall scarify and recompact as required to achieve the specified density. Additional compaction tests shall be made to verify proper compaction. These additional tests, required due to failure of the original test, shall be paid for by the Contractor.

d) Submittals.

The soils technicians will submit formal reports of all compaction tests and retests to the Con-tractor and Owner’s representative as soon as possible upon completion of the required tests.

This report information is to include but not be limited to the following:

1. Date of the test and date submitted.

2. Location of test.

3. Wet weight, moisture content and dry weight of field sample.

4. Description of soil.

5. Maximum dry density and moisture content of the lab sample which best matches the field sample in color, texture, grain size and maximum dry density.

6. Ratio of field dry density to maximum lab dry density expressed as a percentage.

7. Comments concerning the field density passing or failing the specified compaction.

8. Comments about recompaction if required.

e) Compaction Results.

The soils technician is to advise the Owner’s representative and Contractor immediately of any compaction tests failing to meet the specified minimum requirements. No additional lift is to be placed on a lift with any portion failing.

12) GRADING:

Upon completion of other construction operations, the entire site, within the limits shown on the Drawings, shall be brought to the finished grades shown. All surfaces shall be sloped to the grades indicated and which will provide proper drainage. All surfaces shall be raked smooth and shall be free of all vegetable matter, debris, and stones larger than 2-1/2 inches.

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SECTION 02210

EROSION CONTROL

This Section includes all measures both temporary and permanent to control erosion and sedimentation and protect all surface waters and property both on and off site. This includes all labor, materials, and equipment necessary to meet the requirements of this Section.

It is the intent of this Specification that the Project and the Contractor comply with all applicable requirements of the Erosion and Sedimentation Act of 1975, local regulations and ordinances, and the current edition of the Manual for Erosion and Sediment Control in Georgia.

Chatham County will hire a third party NPDES firm to perform the required rainfall/ storm water sampling and reporting if required. Contractor shall provide qualified personnel to perform the daily inspections and complete the reports as indicated on the plans or required by the Georgia General Permit.

The Manual for Erosion and Sediment Control in Georgia further defines practices and requirements. The Contractor is responsible for maintaining all sediment and erosion control measures on the project site during construction. The Contractor is responsible for any damage caused due to failure to implement these requirements. A Soil Erosion and Sedimentation Control Permit has been obtained by the Owner so that periodic inspections may be made by the County. The Contractor is to cooperate with the person performing these inspections.

3) PLANS:

A Soil Erosion and Sedimentation Control Plan is included in the Contract Documents and is to be implemented as a part of the procedures necessary to implement requirements of the Act and applicable local regulations.

4) IMPLEMENTATION:

Implementation of the requirements of the Act is based on the following principles:

a) The disturbed area and the duration of exposure to erosion elements should be minimized.

b) Stabilize disturbed areas immediately.

c) Retain or accumulate runoff.

d) Retain sediment.

e) Do not encroach upon watercourses.

5) SYMBOLS:

The Soil Erosion and Sedimentation Control Plan contains standard symbols for the different types of measures for implementing the Act. These symbols are defined for conditions, design criteria and construction specifications in Sections II and III of the Manual.

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6) SPECIFIC REQUIREMENTS:

a) All disturbed areas shall be grassed by sodding or seeding, fertilizing, mulching and watering to obtain a ground cover which prevents soil erosion.

b) A temporary construction egress pad shall be installed and maintained at any point where construction vehicles enter a paved road, street or parking area. The pad shall be used to prevent mud from leaving the construction area. The pad shall be constructed as shown in the Manual for Erosion and Sediment Control.

c) All measures installed for sediment control shall be checked at the beginning and end of each day when construction is occurring to ascertain that the measures are in place and functioning properly.

d) Erosion control measures shall be inspected by the Contractor after each rainfall event and at least daily during prolonged periods of continuous rainfall. Contractor shall make repairs and adjustments as necessary to maintain the effectiveness of all sediment and erosion control measures.

e) All temporary erosion control measures shall be removed and disposed of off-site once final inspections are complete and vegetative cover is established. Final payment and/or retainage may not be released until the temporary measures are removed.

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SECTION 02221

EXCAVATION, TRENCHING AND BACKFILL FOR UTILITY SYSTEMS

Under this heading shall be included the excavation, trenching and backfilling required for all underground utility systems.

Utility systems include sanitary sewers, storm sewers, water piping and force mains.

Underground piping and utility systems which are to be installed in trenches whose lowest point of excavation is below the existing ground level, and which are unaffected by an excavation for structures, may be installed at any time during the course of the work. Piping and systems to be installed in or over fill, backfill or new embankments shall not be installed until all earthwork has been completed to rough grade, nor until settlement of the fill or embankment has taken place.

Braced and sheeted trenches and open trenches shall comply with all state laws and regulations, and local ordinances relating to safety, life, health, and property. Also, this shall conform to the Occupational Safety and Health Standards for Excavations, Final Rule (29 CFR Part 1926) as printed in the October 31, 1989, issue of the Federal Register.

The sides and bottoms of the trenches shall be protected against any instability which may interfere with the proper laying of the pipe and as necessary for the safety of the workmen and others and as may be necessary to protect adjacent structures. Protective systems for trenches shall be utilized by the Contractor and shall conform with Section 1926.652, 29 CFR Part 1926, Final Rule.

3) LOCATION AND PROTECTION OF UTILITIES AND STRUCTURES:

It shall be the responsibility of the Contractor to acquaint himself with the location of all utilities and structures both present and proposed, also all existing surface structures which may be affected by work under the Contract. The location of any underground structures furnished, shown on the Plans or given on the site are based upon the available records but are not guaranteed to be complete or correct, and are given only to assist the Contractor in making a determination of the existence of underground structures.

Overhead utilities, poles, etc., shall be protected against damage by the Contractor, and if damaged by the Contractor, shall be replaced by him. The Contractor shall notify those who maintain utilities sufficiently in advance of the proposed construction so that they may locate, uncover and disclose such work. If the progress of construction necessitates the removal or relocation of poles, overhead utilities and obstructions, the Contractor shall make all arrangements and assume all costs of the work involved.

The Contractor shall provide for the continuance of the flow of any sewers, drains, water pipes, and water courses, and the like. Where such facilities, water courses, or electric overhead wires

02221-2 or conduits are interfered with by the work of the Contractor, the interruption shall be a minimum and shall be scheduled in advance with the owner and the utility owner.

The Contractor shall restore all facilities interfered with to their original condition or acceptable equivalent. The cost of such restoration or damage caused directly by his work shall be paid for by the Contractor and shall be included in the prices bid for the items to which it pertains.

4) EXCAVATION AND TRENCHING:

a) Excavation.

Excavate all materials encountered. See Article 9 for payment for removal of unsuitable materials.

b) Caution in Excavation.

The Contractor shall proceed with caution in the excavation and preparation of the trench so that the exact location of underground structures in the trench zone may be determined before being damaged. He shall be held responsible for the repair or replacement of such structures when broken or otherwise damaged because of his operations.

c) Subsurface Explorations.

The Contractor shall make explorations and excavations at no additional charge to the Owner to determine the location of existing underground structures.

d) Depth of Trench.

Utilities and other piping shall be laid in open trenches as shown and specified. Trenches shall be excavated to the designated lines and grades, beginning at the outlet end and progressing toward the upper end in each case. Trenches for pipe shall be shaped to the lower 1/3 of the pipe and provide uniform and continuous bearing. Bell holes shall be dug to allow ample room for working fully around each joint.

e) Width of Trench.

Trenches shall be of minimum width to provide ample working space for making joints and tamping backfill. Width on each side of barrel of pipe shall be as shown on the Plans. Sides of trenches shall be closely vertical to top of pipe and shall be sheet piled and braced where soil is of unstable nature. Above the top of the pipe, trenches may be sloped. The width of the trench above this level may be wider for sheeting and bracing and the performance of the work.

f) Alignment and Grade.

Trenches shall be excavated on the alignments shown on the Plans, and to the depth and grade necessary to accommodate the pipes at the elevations shown. Where elevations of the invert or centerline of a pipe are shown at the ends of a pipe, the pipe shall be installed at a continuous grade between the two elevations.

g) Over Excavation.

Excavation in excess of the depth required for proper shaping shall be corrected by bringing to

02221-3 grade the invert of the trench with compacted coarse, granular material at no additional expense to the Owner. Bell holes shall be excavated to relieve bells of all loads, but shall be small enough to ensure that support is provided throughout the length of the pipe barrel.

Excavation in excess of the depths required for manholes and other structures shall be corrected by placing a subfoundation of 1500 psi concrete, at no additional expense to the Owner.

If trenches are excavated to widths more than those specified, or if the trench walls collapse, the pipe shall be laid in accordance with the next better class of bedding at the expense of the Contractor.

5) TRENCHES:

Trenches shall be maintained in a safe condition to prevent hazardous conditions to persons working in or around the trench.

Braced and sheeted trenches and open trenches shall comply with all State and Federal Laws and Regulations, and local ordinances relating to safety, life, health, and property.

The top portion of the trench may be excavated with sloping or vertical sides to any width which will not cause damage to adjoining structures, roadways, utilities, etc. The bottom of the trenches shall be graded to provide uniform bearing and support each section of the pipe on undisturbed soil at every point along its entire length, except for the portions of the pipe sections excavated for bell holes and for the sealing of pipe joints. Bell holes and depressions for joints shall be dug after the trench bottom has been graded and in order that the pipe rests upon the trench bottom for its full length and shall be only of such length, depth and width for making the particular type of joints. The bottom of the trench shall be rounded so that at least the bottom one-third of the pipe shall rest on undisturbed earth for the full length of the barrel as jointing operations will permit. This part of the excavation shall be done manually only a few feet in advance of the pipe laying by workmen skilled in this type of work.

The sides of all trenches and excavation for structures shall be held by stay bracing, or by skeleton or solid sheeting and bracing according to conditions encountered, to protect the excavation, adjoining property and for the safety of personnel. Bracing and shoring may be removed when the level of the backfilling has reached the elevation to protect the pipe work and adjacent property.

6) DEWATERING AND PROTECTION AGAINST WATER:

The Contractor shall remove water from the site and shall lower the ground water level as necessary to complete the excavations to the required depths and so that all required work can be accomplished in the dry. The Contractor shall do such well construction, well pointing, sheeting, ditching, and pumping, and shall construct necessary drains, channels, and sumps to keep his excavations and new structures clear of ground water, storm water or sewage and to keep his construction areas dry during the progress of the Work.

Adequate measures and protection shall be provided by the Contractor to protect his work from

02221-4 damage from uplift due to ground water, storm water, or flood water. Any damages which may result shall be the Contractor's responsibility.

The Contractor shall accept all responsibility for damage to the work of this Contract because of floods and water pressures and other water damages and shall accept all risks of floods and other events which may occur.

All water discharged by pumping operations shall be discharged so as not to interfere with work under this Contract or with existing structures and operations. Water from dewatering operations shall be conveyed to the existing drainage features, using piping and pumping facilities provided by the Contractor.

Route of dewatering pipe shall be subject to the Owner’s review. Discharge facilities and water quality shall comply with applicable regulations of State and Federal agencies.

Dewatering operations shall be uninterrupted and continuous during the course of the work so as not to endanger any construction in place or to present a hazard to workmen in and around the site. The Contractor shall take all measures necessary including, but not limited to, standby equipment and constant attendance to ensure that the dewatering system remains operational and effective throughout the period of time that it is required.

No water shall be allowed to run over any uncompleted portions of the work. No units of the work shall be constructed under water. The cost of dewatering shall be included in the price bid for the item of work for which it is required.

7) PILING EXCAVATED MATERIALS:

All excavated material shall be piled in a manner that will not endanger the work and that will avoid obstructing roadways.

8) LIMIT TO LENGTH OF OPEN TRENCH:

The routine of operation shall be so organized to keep the length of open trench to a practicable minimum.

9) REMOVAL OF UNSUITABLE BEDDING MATERIAL:

Where, in the opinion of the Owner’s representative, the subgrade of the pipe trench is unsuitable material, the Contractor shall remove the unsuitable material 6” deep and furnish and place stone backfill in the trench to stabilize the subgrade. Attention is invited to the fact that the presence of water does not necessarily mean that stone backfill is required. If well points or other types of dewatering will remove the water, the Contractor shall be required to completely dewater the trench in lieu of stone backfill. Stone backfill will be limited to areas where well pointing and other conventional methods of dewatering will not produce a dry bottom. Stone shall be placed 6” deep and 18” wider than the pipe at the barrel. The pipe shall be carefully bedded in the stone as specified or in accordance with the manufacturer’s recommendations. Should overdepth excavation be necessary to remove unsuitable material below the specified bedding and to replace it with satisfactory material, the Contractor will be

02221-5 paid for this work, based on the following requirements:

a) Unsuitable materials for bedding are those classified as MH, CH, OL, OH and PT in accordance with the Unified Soil Classification System. Excavated soils that are too wet to compact shall not be classified unsuitable due to high moisture content alone.

b) When the trench is excavated to the plan depth or as required by these Specifications, and soft or other material not suitable for bedding purposes is encountered in the trench, the Contractor shall immediately notify the Owner’s representative for inspection and measurement of the unsuitable material to be removed.

c) No overdepth excavation or backfilling of the overdepth excavated trench shall start until proper measurements of the trench have been taken by the Owner’s representative for the determination of the quantity in cubic yards of unsuitable material excavated. Backfill material and backfilling shall conform to the requirements specified in Article 12 below.

d) No payment will be made for any overdepth excavation of soft unstable material due to the failure of the Contractor to provide adequate means to keep the trench dry.

e) No payment will be made for any overdepth excavation of the unsuitable material and replacement not inspected and measured by the Owner’s representative prior to excavation.

10) BEDDING OF CONCRETE PIPE:

Pipe shall be laid on foundations prepared in accordance with ASTM C12 as modified herein and in accordance with the various classes of bedding required by the trench width and trench depth for the size of pipe to be laid. Bedding shall be included in the appropriate unit price bid for concrete pipe.

a) Class “A” Bedding.

Class “A” Bedding shall be achieved by either of the following two construction methods:

i) Concrete Cradle.

The pipe shall be bedded in a monolithic cradle of plain or reinforced concrete having a minimum thickness under the pipe barrel of one-fourth the inside diameter of the pipe but in no case less than 4 inches and extending up the sides to a height of at least one-fourth of the pipe outside diameter. The cradle shall have a width equal to the full width of the trench as excavated. The pipe shall be laid to line and grade on concrete blocking after which the concrete shall be placed to the limits described. Concrete shall be 3,000 psi concrete.

ii) Concrete Arch.

iii) The pipe shall be bedded in crushed stone or rounded gravel bedding material having a minimum thickness under the pipe barrel of one-fourth the outside diameter of the pipe but in no case less than 4 inches and shall extend up the sides of the pipe to the horizontal centerline. The top half of the pipe shall be covered with a monolithic plain or reinforced concrete arch having a thickness of one-fourth the inside diameter of the

02221-6 pipe but in no case less than 4 inches at the crown of the pipe. The arch shall have a width equal to the full width of the trench as excavated.

b) Class "B" Bedding.

Class "B" Bedding shall be achieved by either of two construction methods:

i) The bottom of the trench excavation shall be shaped to conform to a cylindrical surface with a radius at least 2 inches greater than the radius of the outside of pipe with a width sufficient to allow 6/10 of the width of the pipe barrel to be bedded in fine granular fill placed in the shaped excavation. Carefully compacted backfill shall be placed at the sides of the pipe to a thickness of at least 12 inches above the top of the pipe.

ii) The pipe may be bedded in compacted crushed stone, placed on a flat trench bottom.

The crushed stone bedding shall have a minimum thickness of 1/4 the outside pipe diameter and shall extend halfway up the pipe barrel at the sides. The remainder of the side fills and a minimum depth of 12 inches over the top of the pipe shall be billed with carefully compacted material.

c) Class "C" Bedding.

Class "C" Bedding shall be achieved by either of two construction methods:

i) The pipe shall be bedded in an earth foundation formed in the trench bottom by a shaped excavation which will fit the pipe barrel with reasonable closeness for a width of at least 50 percent of the outside pipe diameter. The side fills and area over the pipe to a minimum of 12 inches above the top of the pipe and shall be filled with compacted fill.

ii) The pipe shall be bedded in compacted granular material placed on a flat trench bottom.

The granular bedding shall have a minimum thickness of 4 inches under the barrel and shall extend 1/6 of the outside diameter up the pipe barrel at the sides. The remainder of the side fills and to a minimum depth of 12 inches over the top of the pipe shall be filled with compacted backfill. Class "C" Bedding shall be used except where the use of Class “A” or Class "B" bedding is shown on the Plans.

d) Class "D" Bedding.

Class "D" Bedding is achieved by shaping bell holes only on a flat trench and no care is taken to secure compaction at the sides and…