SECTION_35_20_23_DREDGING__REV_A.pdf

FY17 Atlantic Intracoastal Waterway Charleston Harbor to W912HP-B-17-0005 Port Royal Maintenance Dredging

SECTION 35 20 23 PAGE 1

1.1.1.1. SECTION 35 20 23

DREDGING

PART 1 GENERAL

1.1. SUMMARY

1.2. REFERENCES

1.3. DEFINITIONS

1.3.1. Required Dredging Prism

1.3.2. Allowable Overdepth Prism

1.3.3. Side Slopes

1.3.4. Excessive Dredging

1.3.5. Acceptance Section

1.3.6. Floating Pipeline

1.3.7. Submerged Pipeline

1.4. MEASUREMENT AND PAYMENT

1.4.1. Continuity of Work

1.4.2. Work Covered By Contract Price

1.4.3. Estimated Quantities

1.4.4. Variations In Estimated Quantity – Dredging

1.4.5. Shoaling

1.5. SUBMITTALS

1.6. CHARACTER OF MATERIALS

1.6.1. Debris

1.7. CONSOLIDATED REPORT

PART 2 PRODUCTS

2.1. WOOD MATERIALS

PART 3 EXECUTION

3.1. ORDER OF WORK

3.2. INSPECTION

3.2.1. Inspection Requirements

3.2.2. Noncompliance

3.3. PLANT

3.3.1. Equipment and Machinery

3.3.1.1. Capacity of Plant

3.3.1.2. Walkways and Guardrails

3.3.1.3. Signal Lights

3.3.1.4. Communications

3.3.1.5. Automatic Identification System

3.3.1.6. Use of More Than One Dredge

3.3.2. Pipelines

SECTION 35 20 23 PAGE 2

3.3.2.1. Submerged Pipeline

3.3.2.1.1. Floating Pipeline

3.3.2.1.2. Marking the Location of the Pipeline

3.3.3. Buoys

3.3.3.1. Lights, Lighted Buoys and Dredging Aids Markers

3.3.4. Noncompliance

3.3.5. Plant Removal

3.4. NAVIGATION AIDS AND DREDGING AIDS

3.4.1. Relocation of Navigation Aids for Dredging

3.4.2. Aids to Navigation within the Dredging Areas

3.5. MISPLACED MATERIAL

3.5.1. Dredged Material

3.5.2. Equipment

3.6. PROTECTION OF OYSTER BEDS

3.7. PLACEMENT OF EXCAVATED MATERIAL IN UPLAND PLACEMENT AREA

3.7.1. Use and Operation of Placement Area

3.7.2. Discharge Points and Discharge lines

3.7.3. Use of Spillways

3.7.3.1. Stoplogs

3.7.4. Monitoring of Dikes and Spillways

3.7.5. Monitoring Discharges from Spillways

3.7.6. Maintenance of Upland Placement Area

3.7.6.1. Existing Drainage Ditches

3.7.6.2. New Drainage Ditches

3.7.6.3. Maintenance and Repair of Dikes

3.7.6.4. Maintenance and Repair of Spillways

3.7.7. Drainage of Surface Water

3.7.8. Completion Inspection of Placement Areas

3.8. SURVEY

3.8.1. Quantity Surveys

3.8.1.1. Survey Specifications

3.8.1.2. Horizontal Positioning of Surveys

3.8.1.3. Vertical Positioning of Surveys

3.8.1.4. Government Equipment

3.8.1.5. Datum and Bench Marks

3.8.1.5.1. Horizontal Datum

3.8.1.5.2. Vertical Datum

3.8.1.6. Dispute of Surveys Performed by Government

3.9. EXAMINATION AND ACCEPTANCE

3.9.1. Examination

3.9.2. Acceptance of Work

3.10. ACCOMMODATIONS AND MEALS FOR INSPECTORS

3.10.1. Office

3.10.2. Subsistence

SECTION 35 20 23 PAGE 3

PART 1 GENERAL

1.2. SUMMARY

The work covered by this section consists of furnishing all plant, equipment, labor and materials, and performing all work required for the removal and placement of all material, layout and accomplishment of all dredging work, and the movement of plant in accordance with these specifications and as indicated on the contract drawings.

1.3. REFERENCES

U.S. ARMY CORPS OF ENGINEERS (USACE)

EM 385-1-1 Safety and Health Requirements Manual

EM 1110-2-1003 Hydrographic Surveying Manual

1.4. DEFINITIONS

1.4.1. Required Dredging Prism

The dredging prism shall be defined as the area down to the required depth and the associated side slopes as specified on the contract drawings. The dredging prism does not include the allowable overdepth in the channel or allowable overdepth in the associated side slopes.

1.4.2. Allowable Overdepth Prism

To cover inaccuracies of the dredging process, material actually removed from within the specific areas to be dredged below the required dredging prism to a depth not more than shown on the contract drawings will be computed and paid for at the contract price. This material is considered to be optional and shall not be considered for purposes of determining any variation in quantity. See Paragraph “Variations In Estimated Quantity – Dredging”.

1.4.3. Side Slopes

Dredging of side slopes is not required. Material actually removed from the required side slope section shown on the contract drawings will be computed and paid for at the dredging unit cost per cubic yard for that acceptance section. For the purpose of dredging, the side slopes constitute a design criteria. Side slopes may fall flatter than those shown on the contract drawings. However, no payment will be made for material removed outside these specified limits.

1.4.4. Excessive Dredging

Material taken from beyond the limits as extended in the provisions of Paragraphs "Allowable Overdepth Prism" and "Side Slopes" above will be considered as excessive dredging for which payment will not be made. Nothing herein shall be construed to prevent payment for the removal of shoals performed in accordance with Subsection EXAMINATION AND ACCEPTANCE or Paragraph “Shoaling” and as applicable and as further set forth under Subsection MEASUREMENT AND PAYMENT.

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1.4.5. Acceptance Section

For the purpose of acceptance, each shoal shall comprise an acceptance section. Acceptance sections may be modified as described in Paragraph “Acceptance of Work”.

1.4.6. Floating Pipeline

Floating pipeline is any pipeline which is not anchored on the channel bottom.

1.4.7. Submerged Pipeline

Submerged pipeline is any pipeline which is anchored on the channel bottom.

1.5. MEASUREMENT AND PAYMENT

The Contractor shall dredge all shoals to the required depths as indicated on the contract drawings. The Contractor is required to cut the channel vertically to the required depth along each toe. However, the Contractor will be paid for material removed from the side slopes as described in Paragraph “Side Slopes” below. This material shall be considered for purposes of determining any variation in quantity. See Paragraph “Variations In Estimated Quantity – Dredging”. The required amount of material removed and placed by dredging according to contract specifications will be measured and paid for by the cubic yard in situ.

The volume computation method used will be determined according to the most accurate method for each acceptance section and the type of survey performed and may include: the TIN to Channel Single TIN method for before dredge (BD) volumes and the TIN to Channel Dual TIN method for after dredge (AD) volumes, the Philadelphia Pre-dredge Side Slope Non-contour method for BD volumes and the Philadelphia Post-dredge Side Slope Non-contour method for AD volumes, or the Cross Sections and Volumes Philadelphia Predredge method for BD volumes and the Cross Sections and Volumes Philadelphia Postdredge method for AD volumes. After dredge volumes will be calculated from a survey made within 14 days (weather permitting) after dredging in the Acceptance Section that has been completed. This includes the area within the limits of the allowable overdepth and side slopes described in Paragraph “Allowable Overdepth Prism” and Paragraph “Side Slopes”, less any deductions that may be otherwise required by these specifications. Payment will be made using the after dredge method based on the before dredge survey and after dredge survey for each acceptance section. The net required and net overdepth volumes will be used for payment.

All volume calculations will be computed using HYPACK software. Calculations will be made using multi-beam data, binned to a 3-foot by 3-foot matrix using the average soundings within each cell. The corresponding soundings and contours, when plotted, will be generated from a reduced resolution 30-foot by 30-foot matrix that is plot-scale dependent using the average sounding of the 3-foot by 3-foot matrix within the cell. The subsequent depth contour generated for the plotted soundings sheet is not to be used for either the calculation of square footage or volumes. All raw survey data and data used for volume computations will be available to the Contractor upon request.

Payment items for the work of this contract will be made as listed in the Bidding Schedule and described below. All costs for items of work, which are

SECTION 35 20 23 PAGE 5

not specifically mentioned or are incidental to completion of the work, are to be listed in a particular lump sum or unit price payment item that is most closely associated with the work involved. The lump sum price and payment made for each item listed shall constitute full compensation for furnishing all plant, labor, materials, and equipment, and performing any associated Contractor quality control, environmental protection, meeting safety requirements, testing and reports, and for performing all work required for which separate payment is not otherwise provided.

Progress payments shall be made monthly in accordance with the contract clause PAYMENTS UNDER FIXED-PRICE CONSTRUCTION CONTRACTS. Progress payments shall be based on a mutually agreeable percentage of completed work. Monthly progress payments will be based on approximate quantities estimated and agreed on with the construction representative using information taken from the surveys as described in Subsection SURVEY.

Within the limit of available funds, the Contractor will be required to excavate the entire quantity of material necessary to complete the work specified herein, be it more or less than the amounts above estimated, and as modified by Subsection EXAMINATION AND ACCEPTANCE and Paragraph “Shoaling”.

All work to be done in accordance with the contract at the contract price or prices, except as may be affected by Paragraph “Variations In Estimated Quantity – Dredging”.

Final acceptance of the whole or a part of the work and deductions or corrections of deductions made thereon will not be reopened after having once been made, except on evidence of collusion, fraud or obvious error, and the acceptance of a completed section shall not change the time of payment of the retained percentages of the whole or any part of the work.

1.5.1. Continuity of Work

No payment will be made for work done in any area designated by the Contracting Officer until the full depth required under the contract is secured in the whole of such area, nor will payment be made for excavation in any area not adjacent to and in prolongation of areas where full depth has been secured except by decision of the Contracting Officer. Should any such nonadjacent area be excavated to full depth during the operations carried on under the contract, payment for all work therein may be deferred until the required depth has been made in the area intervening. The Contractor may be required to suspend dredging at any time when for any reason the vertical and horizontal control systems cannot be seen or properly followed.

1.5.2. Work Covered By Contract Price

ITEM 0001, MOBILIZATION AND DEMOBILIZATION (SHOALS 1-7), shall include all costs connected with the mobilization and demobilization of all dredging plant and equipment required to complete the work to and from the project site. Sixty percent (60%) of this CLIN will be paid when scheduled mobilization work has been completed, and the remaining forty percent (40%) will be paid when scheduled demobilization has been completed. All effort associated with moving the plant and equipment within the project site shall be included in the unit price for the shoals being worked and not in the mobilization and demobilization CLIN 0001.

ITEMS 0002-0008, DREDGING WORK (SHOALS 1-7, 11’+1’), shall include the cost of removal and placement of all material and the layout and accomplishment of

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all work, as specified herein or indicated on the contract drawings. The movement of plant between shoals, as indicated on the contract drawings, shall be included in the unit price. The contract price per cubic yard for dredging shall be applicable to quantities in any extensions of the dredging limits except as provided Paragraph “Variations In Estimated Quantity – Dredging”. Calculated volumes for cubic yardage will be determined according to Subsection SURVEY for payment purposes.

OPTIONAL ITEMS 0009, DREDGING WORK (SHOAL 2 – DAWHOO 1, 12’+2’), shall include the cost of removal and placement of all material and the layout and accomplishment of all work, as specified herein or indicated on the contract drawings. The movement of plant between shoals, as indicated on the contract drawings, shall be included in the unit price. The contract price per cubic yard for dredging shall be applicable to quantities in any extensions of the dredging limits except as provided Paragraph “Variations In Estimated Quantity – Dredging”. Calculated volumes for cubic yardage will be determined according to Subsection SURVEY for payment purposes.

OPTIONAL ITEMS 0010, DREDGING WORK (SHOAL 3 – DAWHOO 2, 12’+2’), shall include the cost of removal and placement of all material and the layout and accomplishment of all work, as specified herein or indicated on the contract drawings. The movement of plant between shoals, as indicated on the contract drawings, shall be included in the unit price. The contract price per cubic yard for dredging shall be applicable to quantities in any extensions of the dredging limits except as provided Paragraph “Variations In Estimated Quantity – Dredging”. Calculated volumes for cubic yardage will be determined according to Subsection SURVEY for payment purposes.

1.5.3. Estimated Quantities

The total estimated quantity of material necessary to be removed from within the specified limits to complete the work are as follows:

SHOAL

NO. LOCATION

REQUIRED

DREDGING PRISM

CY PL. MEAS. *

ALLOWABLE

OVERDEPTH PRISM

CY PL. MEAS. **

TOTAL CY

PL. MEAS.

BASE

Rantowles (11’+1’) 7398+00 to 7420+00

24,000

8,000

32,000

2 Dawho River 1 (11’+1’)

8284+00 to 8346+00 121,000 33,000 154,000

3 Dawho River 2 (11’+1’)

8372+00 to 8388+00 20,000 8,000 28,000

4 Watts Cut (11’+1’)

8534+00 to 8680+00 208,000 74,000 282,000

5 Fenwick Cut (11’+1’)

9055+00 to 9069+00 9,000 5,000 14,000

6 Rock Creek (11’+1’)

9281+00 to 9302+00 33,000 11,000 44,000

SECTION 35 20 23 PAGE 7

Ashepoo Coosaw Cutoff (11’+1’)

9313+00 to 9400+00

198,000 52,000 250,000

OPTIONS

2 Dawho River 1 (12’+2’) 8284+00 to 8388+00

33,000

35,000

68,000

3 Dawhoo River 2 (12’+2’) 8372+00 to 8388+00

8,000 8,000 16,000

TOTALS 654,000 234,000 888,000

NOTE:

* 1. Required depth will be as shown on the contract drawings. The required dredging prism quantities include the optional side slope material associated with the required depth.

** 2. The allowable overdepth quantities include optional side slope materials associated with the allowable overdepth.

1.5.4. Variations In Estimated Quantity – Dredging

In reference to contract Clause FAR 52.211-18 VARIATIONS IN ESTIMATED QUANTITY, consideration for equitable adjustment will be determined as follows:

Where the quantity of a pay item in this contract is an estimated quantity and where the actual quantity of material within the dredging prism varies more than fifteen percent (15%) above or below the stated estimated quantity within the dredging prism, an equitable adjustment in the contract unit price will be made upon demand of either party. The equitable adjustment will be based upon any increase or decrease in costs due solely to the variations above one hundred fifteen percent (115%) or below eighty-five percent (85%) of the estimated quantity within the dredging prism. No consideration for an adjustment in the contract unit price will be given for any variation in quantities of material below the dredging prism or outside the associated side slope lines; such quantities will not be subject to any adjusted unit price.

1.5.5. Shoaling

In order to allow for shoaling which will occur between the time of surveys shown on the contract drawings and pre-dredging surveys, the computed quantities for maintenance dredging have been increased based on historical shoaling rates for the individual shoals. The resulting increased quantities are shown above.

If before the contract is completed, shoaling occurs in any section previously accepted, including shoaling in the finished channel because of the natural lowering of the side slopes, dredging at contract price, within the limits of available funds, may be done if agreeable to both the Contractor and the Contracting Officer. This will include the dredging of adjacent horizontal extensions to the shoals included under this contract.

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1.6. SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. Submit the following in accordance with this section.

SD-01 Preconstruction Submittals

Plant & Equipment Schedule (Reference Paragraph “Equipment and Machinery)

SD-05 Design Data

Work Plan (Reference Subsection ORDER OF WORK)

SD-07 Certificates

Stoplog Certification (Reference Subsection WOOD MATERIALS)

SD-11 Closeout Submittals

Consolidated Report (Reference Subsection CONSOLIDATED REPORT)

1.7. CHARACTER OF MATERIALS

Materials to be excavated are principally those which accumulated as a result of shoaling that has occurred since the areas were last dredged. The Contractor shall remove all material which is within the dredging areas.

Bidders are expected to examine the site of the work, conduct their own investigations and decide for themselves the character of the materials and the difficulties of performing the work.

1.7.1. Debris

The Government recognizes that debris may be encountered during dredging operations such as, but not limited to, logs, misplaced riprap, chains, buoy anchors, cables, miscellaneous trash, pipes, ropes, and other artificial obstructions. The Government has no knowledge of existing wrecks, wreckage, or other material of such size or character as to require the use of explosives or special or additional plant for its economical removal. If in the judgment of the Contracting Officer the debris can be removed during normal dredging operations, it shall be removed by the Contractor. Debris removed from the dredged area shall be removed from the water. Disposal shall be the responsibility of the Contractor and placement shall be outside the limits of government property. The removal and placement of this debris shall be accomplished at no additional cost to the Government. Disposal of debris will not be permitted on the riverbanks, in navigable waterways or placement areas unless otherwise specified. In case the actual conditions differ from those stated or shown, an adjustment in contract price or time of completion, will be made in accordance with "FAR 52.236-2, Differing Site Conditions."

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1.8. CONSOLIDATED REPORT

The Contractor shall submit a consolidated report within 30 days after completion of all work associated with this contract and shall include, as a minimum, the information listed on the form, CONSOLIDATED REPORT provided in the ATTACHMENTS. Final payment to the Contractor will not be made until this report has been received by the Contracting Officer.

PART 2 PRODUCTS

2.1. WOOD MATERIALS

Lumber and timber piles shall be fabricated before preservative treatment.

Each piece of treated lumber or timber shall be branded, by the producer, in accordance with AWPA M6. All wood will be in contact with salt water or salt water splash and therefore shall be treated in accordance with AWPA U1 (Material Subject to Marine Borer Exposure) with water-borne preservative.

The Contractor shall be responsible for the quality of treated wood products.

Stoplogs shall be 3" x 6" tongue and groove lumber, Southern Yellow Pine #2 or approved equal. Style of tongue and groove shall be submitted to the Contracting Officer for acceptance. Stoplog certification is required and shall be submitted to the Contracting Officer for confirmation or compliance to the specifications listed.

PART 3 EXECUTION

3.1. ORDER OF WORK

For all shoals identified under this contract, there is no set order of work.

The Contractor will submit a plan for performing the work. The plan shall include a schedule, equipment list and description, and description of how the work is to be accomplished. The work plan shall be submitted for Contracting Officer’s approval a minimum of 14 days before any construction is to be performed.

Approval of the Contracting Officer must be received by the Contractor before dredging may commence on the next shoal prior to the completion and acceptance of the previous shoal.

3.2. INSPECTION

All work will be conducted under the general direction of the Contracting Officer and shall be subject to full-time inspection by his appointed Representative to ensure strict compliance with the terms of the contract.

3.2.1. Inspection Requirements

The presence of a Quality Assurance Representative shall not relieve the Contractor of responsibility for the proper execution of the work in accordance with the specifications.

The Contractor shall:

(a) Furnish, on the request of the Contracting Officer or any Quality Assurance Representative, the use of such boats, boatmen, laborers, and material forming a part of the ordinary and usual equipment and

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crew of the dredging plant as may be reasonably necessary in inspecting the work. However, the Contractor will not be required to furnish such facilities for the surveys prescribed in the Subsection

EXAMINATION AND ACCEPTANCE.

(b) Furnish, on the request of the Contracting Officer or any Quality Assurance Representative, suitable transportation from all points on shore designated by the Contracting Officer to and from the various pieces of plant, and to and from the placement area.

3.2.2. Noncompliance

Should the Contractor refuse, neglect, or delay compliance with these requirements, the specific facilities may be furnished and maintained by the Contracting Officer and the cost thereof will be deducted from any amounts due or to become due the Contractor.

3.3. PLANT

The Contractor agrees to keep on the job sufficient plant to meet the requirements of the work. The plant shall be in satisfactory operating condition and capable of safely and efficiently performing the work as set forth in these specifications. Inspection of equipment listed in Paragraph "Equipment and Machinery" shall be made prior to commencement of work in order to determine if it is satisfactory so as to meet the requirements of work. The plant shall be subject to inspection by the Contracting Officer and the U.S. Coast Guard at all times. The plant list is the minimum which the Contractor agrees to place and maintain on the job unless otherwise determined by the Contracting Officer, and its listing thereon is not to be construed as an agreement on the part of the Government that it is adequate for the performance of the work.

3.3.1. Equipment and Machinery

A complete listing of all dredging plant and machinery to be used in the work, including booster pumps, barges, skiffs, and other related equipment, shall be submitted with the Plant and Equipment Schedule prior to beginning work. The plant list, as specified in Section 00 45 00 Representations & Certifications, shall include manufacturer and year of manufacture, operational capacities, safety features, operating and licensing requirements for operators, and a description of where and how the item of equipment or plant is to be employed in the work.

3.3.1.1. Capacity of Plant

No reduction in the capacity of the plant employed on the work shall be made except by written permission of the Contracting Officer. The measure of the "capacity of the plant" shall be its actual performance on the work to which these specifications apply.

3.3.1.2. Walkways and Guardrails

All floating plant and pipelines used as access ways or working platforms shall be equipped with walkways and guardrails conforming to Corps of Engineers Manual EM 385-1-1 and meet OSHA requirements for worker safety.

3.3.1.3. Signal Lights

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The Contractor shall display signal lights and conduct his operations in accordance with the General Regulations of the Department of the Army and of the Coast Guard governing lights and day signals to be displayed by towing vessels with tows on which no signals can be displayed, vessels working on wrecks, dredges, and vessels engaged in laying cables or pipe or in submarine or bank protection operations, lights to be displayed on dredge pipe lines, and day signals to be displayed by vessels of more than 65 feet in length moored or anchored in a fairway or channel, and the passing by of other vessels of floating plant working in navigable channels, as set forth in Commandant U.S. Coast Guard Instruction M16672.2, Navigation Rules:

International-Inland (COMDTINST M16672.2), or 33 CFR 81 Appendix A (International) and 33 CFR 84 through 33 CFR 89 (Inland) as applicable.

3.3.1.4. Communications

The Contractor will be required to furnish, maintain, and operate one FM narrow-band radio transmitter-receiver with a capacity of not less than (1) watt, equipped for operating on maritime channels 13 and/or 16 at 156.65 MHz.

This frequency shall be used for communications with passing vessels, harbor pilots, and bridge operators and has been approved by the Federal Communications Commission for this purpose. It is not required that this frequency be disabled after termination of the contract. Contractor will be required to maintain a Contractor owned cellular phone for communication with Corps of Engineers personnel.

3.3.1.5. Automatic Identification System

The Contractor is required to have the Automatic Identification System (AIS).

The Contractor shall have AIS transponders on all floating plants at all times when working in Charleston Harbor. The AIS provides a means for ships to electronically exchange ship data including: identification, position, course, and speed with other nearby ships and VTS stations. AIS is intended to assist the vessel's watch standing officers and allow maritime authorities to track and monitor vessel movements.

3.3.1.6. Use of More Than One Dredge

No more than one dredge working under this contract shall discharge into each placement area at any given time.

3.3.2. Pipelines

The Contractor will be responsible to ensure that all pipelines are properly maintained during this contract. All pipelines for hydraulic machines must be kept in good condition at all times and any leaks or breaks along their length must be promptly and properly repaired. Dredge pipelines that are floating, to include rubber discharge hoses, or supported shall display lights at night and in periods of restricted visibility in accordance with U.S. coast Guard regulations and 33 CFR 88.15.

3.3.2.1. Submerged Pipeline

Submerged pipeline shall rest on the channel bottom. Where a submerged pipeline crosses a navigation channel, the top of the pipeline and any anchor securing the pipe shall be no higher than the authorized channel depth in which the pipe is placed. Pipelines shall not be permitted to fluctuate between the water surface and the channel bottom or lie partially submerged.

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Routine inspections of the submerged pipe shall be conducted to ensure anchorage.

3.3.2.1.1. Floating Pipeline

The dredge operator will assure that the pipeline remains fully submerged and on the bottom; however, when it is necessary to raise the pipeline, proper clearances shall be made and maintained and the entire length of the pipeline will be adequately marked.

3.3.2.1.2. Marking the Location of the Pipeline

Submerged pipeline shall be marked in accordance with local USCG requirements and approved by the Government Designated Authority (GDA).

(c) Unless otherwise specified by the USCG, submerged pipelines are considered to require special marks and shall have a USCG approved flashing yellow light.

(d) Indicators, such as signs or buoys that state “DANGER SUBMERGED PIPELINE” will be placed at the beginning and end of the pipeline.

In addition, indicators are required beginning in areas which reduce the charted depth by more than 10 percent and, as a minimum, every 1000 ft. (304.8 m) to clearly warn of the pipeline length and course.

(e) If barges or other vessels are used to anchor the beginning and/or end of the submerged pipeline, they shall be lighted in accordance with 33 CFR 88.13.

(f) Within a navigation channel, each end of the pipeline shall be identified with a regulatory marker buoy.

(g) Lengths of submerged pipeline located outside of the navigation channel, which reduce the charted depth by more than 10 percent, will be identified with high visibility buoys marked with 360 degree visibility retro-reflective tape, such as orange neoprene buoys, placed at an interval not to exceed 500 ft. (152.4 m) to clearly show the pipeline length and course.

(h) All submerged pipeline or fittings with less than six (6) feet of clearance between the top of the pipeline and mean low water will be marked with the same type of light meeting the requirements of this subsection and spaced approximately one hundred (100) feet apart.

3.3.3. Buoys

All marker buoys shall be painted yellow and display the same yellow flashing light as required for floating or supported dredge pipelines meeting the requirements of this subsection.

(1) Buoys used to anchor booster pumps

(2) Buoys used to anchor or mark stored equipment i.e. (barges, pipeline etc.)

(3) Buoys used to mark or anchor dredge pipelines and this includes floating and submerged pipeline leading to placement areas.

(4) Any other buoys the U.S. Coast Guard or Contracting Officer requires to insure a safe harbor free from hazards to navigation must be marked and display yellow flashing lights meeting the requirements stated in this subsection.

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3.3.3.1. Lights, Lighted Buoys and Dredging Aids Markers

All lights, lighted buoys and dredging aids markers must be maintained, operable and on station at all times to insure a safe harbor. The placement, markings and lighting shall meet all US Coast Guard Regulations, EM 385-1-1 and the Special Requirements found in this specification.

3.3.4. Noncompliance

The Contracting Officer will notify the Contractor in writing of any noncompliance with the foregoing provisions. Such notice, when delivered to the Contractor or his authorized representative at the site of the work, shall be deemed sufficient for the purpose. Within 24 hours after receipt of such notice, the Contractor shall mail, or personally deliver to the Contracting Officer, a complete proposal of the prompt correction of the noncompliance. The Contracting Officer will review the proposal and return it to the Contractor approved, subject to such changes or conditions as he finds necessary to assure correction of noncompliance. Immediately upon receipt of such approval, the Contractor shall begin the corrective work and shall carry it to completion. If the Contractor fails or refuses to submit his proposal or to proceed with the corrective work, the Contracting Officer may suspend all or any part of the work until satisfactory corrective action has been taken. No part of the time lost due to any such suspension shall be made the subject of a claim for extension of time nor for excess costs or damages by the Contractor. If he so elects, the Contracting Officer may cause the corrective work to be accomplished by others, in which event the cost thereof shall be chargeable against moneys otherwise due the Contractor from the Government.

3.3.5. Plant Removal

Upon completion of the work, the Contractor shall promptly remove all plant, including all pipelines, pipeline anchors, ranges, buoys, piles, and other markers or obstructions.

3.4. NAVIGATION AIDS AND DREDGING AIDS

3.4.1. Relocation of Navigation Aids for Dredging

The USCG requires notification sixty (60) days in advance to remove or relocate any navigation aids to facilitate dredging operations. Due to time constraints the Government will notify the USCG in advance of an estimated time and location that dredging operations will be accomplished. However, after award and prior to commencement of dredging it is the responsibility of the Contractor to coordinate with the USCG for the actual removal or relocation of any navigation aids within or near the areas to be dredged. The Contractor will also notify the Contracting Officer in advance of the time and location of the aids that will require relocation. The Contractor shall coordinate the removal or relocation of navigation aids with the following:

Commander, 7th Coast Guard District (OAN) Brickell Plaza Federal Bldg., Room 406 909 S.E. 1st Avenue Miami, Florida 33131-3050 ATTN: Chief of Planning and Marine Information Phone: (305) 350-5621

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Commander, Sector Charleston US Coast Guard 196 Tradd Street Charleston, South Carolina 29401 ATTN: Aids to Navigation Officer Phone: (843) 740-3180 Fax: (843) 740-3189 Email: secchasn-wm@uscg.mil

3.4.2. Aids to Navigation within the Dredging Areas

The Contractor shall be responsible for any damage to aids to navigation within the dredging areas or areas adjacent thereto caused by his operations.

3.5. MISPLACED MATERIAL

Any material that is deposited or allowed to flow elsewhere than in places designated or approved by the Contracting Officer will be considered as misplaced material and will not be paid for.

3.5.1. Dredged Material

Should the Contractor deposit any material outside the designated placement areas approved by the Contracting Officer, the Contractor shall give immediate notification of the location of the misplaced material and when required, mark or buoy this location. If in the opinion of the Contracting Officer this misplaced material will in any way be a hazard to navigation and requires removal, the Contractor shall be required to remove the misplaced material immediately and deposit said material in an area designated by the Contracting Officer at no additional cost to the Government.

3.5.2. Equipment

Should the Contractor, during the progress of the work, lose, dump, throw overboard, sink, or misplace any material, plant, machinery, or appliance, which in the opinion of the Contracting Officer may be dangerous to or obstruct navigation, the Contractor shall recover and remove the same with the utmost dispatch. The Contractor shall give immediate notice, with description and location of such obstructions, to the Contracting Officer or Quality Assurance Representative, and when required shall mark or buoy such obstructions, until the same are removed. Should he refuse, neglect, or delay compliance with the above requirements, such obstructions may be removed by the Contracting Officer, and the cost of such removal may be deducted from any money due or to become due the Contractor, or may be recovered under his bond. The liability of the Contractor for the removal of a vessel wrecked or sunk without fault or negligence shall be limited to that provided in Sections 15,19, and 20 of the River and Harbor Act of March 3, 1899 (33 U.S.

C. 410 et seq.).

3.6. PROTECTION OF OYSTER BEDS

The Contractor shall investigate the location of all oyster beds in the sections of the waterway where work is to be conducted; the Contractor will be held responsible for any damage to oyster beds outside the canal prism and

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the disposal areas that may be caused by dredging operations under this contract. In the vicinity of oyster beds, greater care shall be taken to prevent the deposit of dredged material or the runback of dredge discharge water within the beds.

3.7. PLACEMENT OF EXCAVATED MATERIAL IN UPLAND PLACEMENT AREA

Material dredged under this contract shall be transported to and placed in the applicable placement area(s) as shown on the contract drawings and in accordance with these specifications. In the event of dike breaching, the pumping of material into the placement area shall be immediately stopped until repairs are implemented.

3.7.1. Use and Operation of Placement Area

The Contractor shall assume all responsibility for use and operation of the placement areas such that they contain all the material to be dredged under this contract. This responsibility includes but is not limited to controlling or limiting inflow rate, proper operation of effluent control structures (spillways), maintaining adequate freeboard (one foot (1’) minimum at all times), and maintaining specified effluent water quality at all times. It shall be the Contractor’s responsibility to shut down or use intermittent dredging if his inflow rates exceed the water/solids retention capacity of the designated placement area.

3.7.2. Discharge Points and Discharge lines

The Contractor shall locate the discharge lines at the discharge point as indicated on the drawings. The Contractor shall be responsible for locating the discharge lines in such a manner as to prevent run back of dredged material into the channel or outside the designated placement area limits. As material builds up, the discharge line shall be extended, moved or relocated as necessary to prevent topping of the dike. Relocation of the discharge point to other than locations indicated on the drawings shall have prior approval of the Contracting Officer.

3.7.3. Use of Spillways

Unless shown otherwise on contract drawings, the Contractor shall board up the spillway(s) nearest to the discharge point and use the spillway(s) located the maximum distance from the discharge point for outflow from the area.

3.7.3.1. Stoplogs

The contractor shall supply enough weir boards to provide for an adequate spillway operation. All spillways and surrounding areas shall be maintained as required to ensure proper spillway operation. Stoplogs shall provide a reasonably watertight fit and it is the Contractor’s responsibility for a tight seal between all stoplogs. Warped stoplogs shall not be used. Large sheets of polymer/plastic sheeting or plywood shall not be used in weirs to prevent leaking. However, filter fabric or other approved materials may be utilized to prevent escape of solids from the spillways. In addition, the Contractor shall inspect all existing stoplogs below the existing fill or mud line and shall be responsible for ensuring that they are sound and watertight.

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Stoplogs shall be cut to proper lengths (minimum 47") to fit the spillways to prevent binding in spillway channels (guides) and to prevent leakage around the ends.

3.7.4. Monitoring of Dikes and Spillways

The Contractor shall provide full-time monitoring of the dikes and the discharges over the spillways to assure retention of dredged material within the placement areas. Full-time monitoring shall be defined as having a minimum of two (2) competent Contractor Quality Control personnel on the placement area at all times when the dredge is operating. These personnel shall have a portable radio or cell phone with them at all times while monitoring the dikes and spillways. They shall maintain constant communication with the dredge regarding weir operations, effluent quality, remaining freeboard around the entire placement area, and any other relevant conditions.

3.7.5. Monitoring Discharges from Spillways

During the duration of the contract, the Contractor shall visually monitor discharges from all the spillways and outfall pipes and take necessary action to minimize discharge of total suspended solids (TSS). Should concern arise regarding the occurrence of an excess of TSS caused by improper management of the spillways or dredging operations, samples will be collected by the Contractor at locations and quantities chosen by the Government. All samples will be collected by the Contractor and sent directly to a laboratory for analysis. Following receipt of the laboratory analysis, the Contractor may be required to modify his operations to reduce the TSS below 110 mg/l. The costs for sampling and analysis will be borne by the Contractor.

Discharge of clarified water shall be so regulated as to prevent runback of dredged material from obstructing natural drainage and the deposit of dredged material in navigable channels. The Contractor will be required to remove without cost to the United States Government any deposits in such channel as a result of dredge discharge and will be responsible for any damage to other areas and to existing facilities or private property caused by dredged material.

3.7.6. Maintenance of Upland Placement Area

The Contractor will be responsible to patrol, maintain and repair any damage to drainage culverts and spillway pipes under the roads and dikes. At the completion of dredging operations all roads and the tops of dikes will be left in an undisturbed condition or a smooth and graded condition. The Contractor will use only rubber-tired four-wheel drive vehicles for transportation around top of dikes. Tracked equipment should not be used on top of dikes for transport of personnel. All pot holes, ruts, and areas with ponded water which are caused by traffic from the Contractor's personnel and/or equipment will be repaired to the original condition or better. The Contractor will grade and crown the roads in a manner so as not to leave berms (windrows) on the shoulders of the road or top of the dike. The Contracting Officer's Representative will designate a borrow area if fill material is necessary for road fill.

3.7.6.1. Existing Drainage Ditches

Prior to commencement of dredging, existing drainage ditches outside or

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around the placement areas shall be examined with a representative of the Contracting Officer to assess their condition. Before the work is accepted by the Government, the Contractor will be required to remove any shoaling which has occurred in the drainage ditches due to his dredging operations.

3.7.6.2. New Drainage Ditches

The Contractor may cut shallow drainage ditches inside the placement area as necessary to drain water or dredged material which has become trapped behind spoil mounds or discharge points. The Contracting Officer shall approve all such ditching.

3.7.6.3. Maintenance and Repair of Dikes

Minor dike maintenance may be required in order to contain all the material to be dredged under this contract. The Contractor shall be responsible for maintenance and sandbagging of existing dikes as necessary in order to contain all the material to be excavated under this contract. The Contractor shall provide for a minimum of one foot (1’) of freeboard at all times. Any minor dike maintenance, to contain dredged material as defined in this paragraph, shall be made by the Contractor and their costs shall be included in the dredging unit price.

3.7.6.4. Maintenance and Repair of Spillways

Minor spillways maintenance may be needed, such as re-opening channel guides for weir boards, replacing pipe support boards, etc and should be inspected by the prospective bidders prior to submitting bids. All necessary maintenance shall be made by the Contractor with prior approval of the Contracting Officer at no additional expense to the Government.

3.7.7. Drainage of Surface Water

Prior to completion of the contract, and after the dredged material has stabilized, the Contractor shall reduce the spillway stoplogs to an elevation below the surface of any clarified water to permit drainage of the surface water only. Upon completion of each acceptance section or move from a placement area, the Contractor shall begin surface water drainage from the containment area by removing the stoplogs to an elevation below the surface of the clarified water. All excess stoplogs will become the property of the Contractor and shall be removed from the premises.

3.7.8. Completion Inspection of Placement Areas

Upon completion of placement the Contractor shall inspect the entire placement area to determine if all requirements of these specifications have been met. Inspection shall be in accordance with SECTION 01 45 04.00 10, subsection entitled COMPLETION INSPECTION.

3.8. SURVEY

3.8.1. Quantity Surveys

The maps and/or drawings already prepared, as stated in Section 00 73 00, contract clause CONTRACT DRAWINGS, MAPS AND SPECIFICATIONS, are believed to represent accurately conditions existing at the time surveyed but the depths shown thereon will be verified and corrected by before dredging sounding

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taken of the entire area to be dredged under this contract. The before dredging survey shall be sounded in the first acceptance section not less than 30 days after Notice to Proceed has been given the Contractor or sooner if requested in writing by the Contractor. The before dredging surveys for the remaining acceptance sections will be sounded commencing not more than 14 days prior to the arrival of the Contractor on the section to be dredged. The Contractor shall notify the Government a minimum of ten days prior to estimated time of arrival on each section to allow time for before dredging surveys to be conducted. The estimated time of arrival shall be determined by the Contractor. The request for acceptance surveys on any shoal shall be given at least five (5) days in advance of the estimated time of completion.

The estimated date of completion shall be determined by the Contractor. The request for all Government surveys shall be in writing by the Contractor and shall include the shoal number(s), stationing, and the estimated date of arrival on or departure from the shoal(s) to be surveyed. Determination of quantities removed and the deductions made therefrom to determine quantities by place measurement to be paid in the area specified after having once been made, will not be reopened except on evidence of collusion, fraud, or obvious error. Note: The Government will be available at the request of the Contractor to run check surveys between the Contractor's and Government's survey vessels prior to the start of work. Check surveys will require a seven days’ notice.

3.8.1.1. Survey Specifications

Hydrographic surveys will be conducted by the Government to meet USACE Performance Standards as defined in the Hydrographic Surveying Manual EM 1110-2-1003. Surveys will generally be performed by singlebeam or multi-beam type surveys, or both. However, the same method will be used for the pre and post survey of a given reach. The Government reserves the right to take soundings by any method, including: lead line and calibrated staff if conditions permit. Bottom soundings will be obtained by the echosounder operating at a frequency ranging from 180 to 250 Khz. As specified by the Contracting Officer, 24 KHz low frequency depth may be used. All fathometers will be calibrated following procedures outlined in the aforementioned EM.

Accuracy will be in accordance with stated quality control values in USACE Hydrographic Surveying Manual.

3.8.1.2. Horizontal Positioning of Surveys

Electronic horizontal positioning systems shall be used for conducting hydrographic surveys. The electronic horizontal positioning system for the survey processes shall be differential GPS with a minimum horizontal positioning system accuracy of 2 meters or RTK real time carrier phase positioning as required by EM 1110-2-1003, Hydrographic Surveying, dated 1 January 2002. USACE will use the South Carolina Geodetic Survey’s VRS system.

The horizontal datum is specified in Subparagraph “Horizontal Datum.”

3.8.1.3. Vertical Positioning of Surveys

Vertical Positioning for hydrographic surveys shall be calibrated to a government-installed tide gauge set to the datum specified in Subparagraph “Vertical Datum”. Orthometric height corrections shall be derived in accordance with Subparagraph “Vertical Datum.”

3.8.1.4. Government Equipment

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The following survey equipment may be used by the Government Survey Crew during the collection of sounding data and will be considered the standard for which data is obtained:

• R2Sonic 2022 Multibeam Echosounder

• Applanix POS MV V4

• Odom Echotrack CV200 Echosounder

3.8.1.5. Datum and Bench Marks

The Contracting Officer will provide benchmark and tide gage location information to the Contractor at the preconstruction meeting.

3.8.1.5.1. Horizontal Datum

North American Datum of 1983 (NAD83) State Plane Coordinate System South Carolina (3900) using the NAD83 datum and International Survey Feet. Any control network established under this task shall be properly connected to National Spatial Reference System (NSRS) control points with established network accuracy values.

3.8.1.5.2. Vertical Datum

All depths shall be referenced to MLLW (Mean Lower Low Water) using North American Vertical Datum 1988 (NAVD88). Ellipsoid heights acquired by GPS should be converted to Orthometric heights NAVD88 using GEIOD12a and reduced to MLLW using NOAA (National Oceanographic and Atmospheric Administration) datum corrections. Orthometric height corrections are found on NOAA’s website https://vdatum.noaa.gov/download/php.

3.8.1.6. Dispute of Surveys Performed by Government

In the event that the Contractor disputes the accuracy of any survey performed by the Government, the Contractor shall immediately notify the Contracting Officer or the Contracting Officer’s Authorized Representative, in writing, concerning the nature of the dispute. If the dispute cannot be resolved immediately, the Contractor shall immediately resurvey the shoal, or all remaining area that has not been dredged or unaffected portions of the shoal with a Government representative onboard the Contractor’s survey boat.

At the conclusion of the survey, the Contractor shall provide copies of all raw and edited data files for that shoal. The files shall be in Hypack format. The Contractor shall submit the following information (as a minimum) in support of his survey data:

(1) Edited survey data in X-Y-Z format; coordinates shall be SC State Plane Coordinates, NAD 1983.

(2) Method of horizontal positioning.

(3) Date, time, and stage of tide.

(4) Water surface conditions.

(5) Plan showing the edited depth soundings.

(6) Plotted cross sections of the latest Contractor survey compared with the Government survey. The individual cross sections shall be provided at a scale of 1 inch equals 10 feet horizontal and 1 inch equals 10 feet vertical.

(7) Plan of channel showing areas that were worked by the…