35 20 23_AM0001.pdf

Maurice River Maintenance Dredging Ammendment No. 1

IFB W912BU25BA005

SECTION 35 20 23

DREDGING

PART 1 GENERAL

1.1 WORK COVERED BY CONTRACT PRICE

The contract price per cubic yard for dredging shall include the cost of removal and disposal of all materials as specified herein or indicated on the drawings, with the exception of ledge rock, large boulders, rock fragments, wrecks, snags, stumps, and piles which cannot be removed or buried below project depth without blasting. Should ledge rock or other material which cannot be removed without blasting be encountered, the Contractor shall remove therefrom all overlying material which in the judgment of the Contracting Officer can be removed. Nothing in this paragraph shall be construed as prohibiting the removal of excepted material by special means at prices agreed upon and approved in accordance with FAR 52.236-2 "DIFFERING SITE CONDITIONS".

1.2 REFERENCES

The publications listed below form a part of these specifications to the extent referenced. The publications are referred to in the text by the basic designation only.

U.S. NATIONAL ARCHIVES AND RECORDS ADMINISTRATION (NARA)

33 CFR 156 (2010) Navigation and Navigable Waters, Oil and Hazardous Material Transfer Operations

U.S. ARMY CORPS OF ENGINEERS (USACE)

EM 1110-2-1003 (2002; Change 1 April 2004) Hydrographic Surveying

1.3 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. The following shall be submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

NOTE: Any submittals classified as "SD-01 Preconstruction Submittals" are submittals required to be submitted and approved prior to mobilization to the contract work site. All other submittals, classified as "SD-02" through "SD-11," shall be submitted and approved prior to commencing the particular task to which the submittal is associated.

SD-01 Preconstruction Submittals

Beneficial Use Placement Area Plan; G,COR Vessel and Equipment List; G,COR Spill Response Plan; G,COR Discharge Pipe Support Plan; G, COR

SECTION 35 20 23 Page 1

SD-02 Shop Drawings

Submerged Pipeline

SD-03 Product Data

Turbidity Barrier; G, DO

SD-06 Test Reports

Daily Dredgehead Positioning Records; G,COR Fuel Usage Disposal Area Effluent Measurements; G,COR Daily Report of Operations; G,COR

1.4 ORDER OF WORK AND DREDGING TIME RESTRICTIONS

Unless otherwise directed by the Contracting Officer, the dredging work shall commence in Acceptance Section 1 and proceed upstream to Acceptance Section 4. Dredging under this contract shall be subject to the requirements specified in Section 01 57 19 TEMPORARY ENVIRONMENTAL CONTROLS and the following seasonal time restrictions:

a. Dredging will only be permitted from 15 September through 1 March to minimize impacts to birds and migratory fish.

b. Dredged material from Acceptance Sections 1, 2, 3, and 4 shall be placed in Placement Area 1 and dredged material from optional Acceptance section 5 shall only be placed in Placement Area 2. During dredging of Acceptance Sections 1 and 4, the Government reserves the right to direct the Contractor to move, extend, or relocate piping from Placement Area 1 to Area 2, if the Placement Area 1 reaches capacity, at no additional cost to the Government. If this change of placement area occurs, the Contractor shall use Area 2 for all remaining placement of material under this contract.

1.5 CHARACTER OF MATERIALS

a. The material to be removed to restore the depth within the limits called for in the specifications and drawings, is that composing the shoaling that has occurred since the channel was last dredged as noted in Section 01 30 00 ADMINISTRATIVE REQUIREMENTS. The character of the material is believed to be as indicated by the results of the Government-conducted sampling. An abstract of bottom samples is included as Appendix B40 of this specification. This Delaware Bay region is a prolific source of oysters and other bivalves. Relict oyster beds and other shells may be encountered during the dredging process in addition to the sediments noted in Appendix B40.

b. It is the Government’s position that sufficient information has been provided in this contract package to enable the Contractor to establish the type and quantity of material to be removed. USACE Survey and Mapping hydrographic survey information is available online through the eHydro link at http://navigation.usace.army.mil/Survey/Hydro . Data on this or other websites are not appropriate for volume computations. Full datasets are available upon request. However, prior to bidding, the Contractor may, at his discretion and expense, conduct additional investigation to further determine conditions at the site.

SECTION 35 20 23 Page 2

1.6 BENEFICIAL USE PLACEMENT AREA PLAN

Submit a plan for usage or modification of the beneficial use placement areas prior to the use of the area. This plan shall show the areas or portions thereof to be used, and the manner in which the dredged material will be distributed in the area. Plans for materials and equipment to be used, vehicle access, means of placement, and manner in which existing conditions will be protected shall also be submitted for approval by the Contracting Officer.

1.7 SCHEDULE OF DREDGING OPERATIONS

1.7.1 Hours of Work

Dredging operations are allowed 24 hours per day, 7 days per week. Conduct land-based disposal area equipment operations during daylight hours only.

1.8 DREDGE

Dredge(s) used under this contract shall have a dredge pump with at least a 12-inch, but not larger than a 20-inch, inside diameter discharge flange.

1.9 VESSEL AND EQUIPMENT LIST

Submit a complete list of all vessels and equipment to be used during the contract, including all dredging plants, supporting vessels, and equipment. The vessel list shall contain the types, the numbers of each, the draft of each, dredge production capacities, and all other pertinent information.

1.10 DAILY DREDGEHEAD POSITIONING RECORDS

For all dredging and for each dredge employed under this Contract, a computerized positioning system capable of representing the horizontal and vertical position of the hydraulic cutterhead, at all times throughout the dredging cycle, shall be utilized. Horizontal and vertical positioning of the cutterhead shall be recorded at intervals not greater than one minute in duration. The horizontal and vertical (x,y,z) positions of the cutterhead, shall be provided to the COR in an approved electronic format. Commercially available systems such as those offered by companies under the registered trademarks of Dredgepak, Winops, or similar proprietary systems developed by the Contractor would be considered satisfactory. The system shall produce a record of the working locations, horizontal and vertical, of the cutterhead, in a continual display and in a submittal satisfactory to the COR. Records of position during dredging shall be recorded on a computer disk every 15 minutes.

Submittals of this information shall be transmitted electronically to the COR daily at the same time as the Daily Operations Report.

1.11 FUEL OIL HANDLING

Ensure that fuel oil transfer operations to or from the plant comply with all Federal, state, and municipal laws, codes and regulations.

Incorporate in the Accident Prevention Program, submitted in compliance with the Contract Clause: "ACCIDENT PREVENTION", sufficient information to demonstrate compliance with 33 CFR 156 and other applicable laws, codes, and regulations. Submit on or before the last day of each month, a Fuel Usage report listing the totals of fuels consumed by the dredging plant and supporting vessels. Separately list the quantities of each type of

SECTION 35 20 23 Page 3 fuel used. Each report shall cover the period from the 25th of the preceding month to the 25th of the current month.

PART 2 PRODUCTS

2.1 HAY BALES

Hay bales shall be 18 inches by 36 inches by 14 inches, and wrapped with biodegradable twine and held down with wooden stakes.

2.2 COIR LOGS

Coir logs shall be 100 percent biodegradable, coconut fiber, high density, 9 pounds per cubic foot, and encased in coir twine netting. Coir logs shall be 12 inches in diameter by 10 feet in length.

2.3 TURBIDITY BARRIER

a. The turbidity barrier shall consist of a floating, bottom-sealed, permeable curtain capable of preventing suspended sediment from impacting sensitive environmental habitats.

b. Design Requirements:

(1) The turbidity barrier shall consist of a bottom-sealed turbidity barrier system that extends full water depth with a freeboard of 10 inches or more above the water given the performance requirements specified below. The bottom seal shall be ballasted with sufficient weight or jetted into the bottom to maintain contact with the bottom at all times while conforming with the bottom contours. Turbidity barrier system (including all connections) shall be designed to resist maximum loading.

(2) Performance Requirements. Minimum requirements of the turbidity barrier system are as follows:

(a) Fully functional in wind-driven wave action up to 2 feet and water currents of 1.5 knots (3 feet per second).

(b) Curtain fabric grab tensile strength of 300 lbs.

(c) Fully functional during a tidal range of approximately 6 feet and respective water currents.

c. Should the turbidity barrier fail to meet the performance requirements specified, modify the turbidity barrier to meet the project performance requirements at no additional cost to the Government.

PART 3 EXECUTION

3.1 INSPECTION

Inspect the work, keep records of work performed, and ensure that gages, targets, ranges, and other markers are in place and usable for the intended purpose. Furnish, at the request of the Contracting Officer, boats, boatmen, laborers, and materials necessary for inspecting, supervising, and surveying the work. When required, provide

SECTION 35 20 23 Page 4 transportation for the Contracting Officer and inspectors to and from the disposal area and between the dredging plant and adjacent points on shore.

3.2 CONDUCT OF DREDGING WORK

3.2.1 Lights

Each night, between sunset and sunrise and during periods of restricted visibility, provide lights for floating plants, pipelines, ranges, and markers. Also, provide lights for buoys that could endanger or obstruct navigation. When night work is in progress, maintain lights from sunset to sunrise for the observation of dredging operations. Lighting shall conform to United States Coast Guard requirements for visibility and color.

3.2.2 Ranges, Gages, and Lines

Furnish, set, and maintain ranges, buoys, and markers needed to define the work and to facilitate inspection. Establish and maintain gages in locations observable from each part of the work so that the depth may be determined. Suspend dredging when the gages or ranges cannot be seen or followed. The Contracting Officer will furnish, upon request by the Contractor, survey lines, points, and elevations necessary for the setting of ranges, gages, and buoys.

3.2.3 Plant

Maintain the plant, scows, coamings, barges, pipelines, and associated equipment to meet the requirements of the work. Promptly repair leaks or breaks along pipelines. Remove dredged material placed due to leaks and breaks.

3.2.4 Obstructions and Debris

The Government has no knowledge of cables, pipes, or other artificial obstructions or of any wrecks, wreckage, or other material that would necessitate the use of explosives or the employment of additional equipment for economical removal. Contractors should however exercise due diligence in determining the existence of any obstructions within proposed work areas during bid preparation.

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.

3.2.5 Misplaced Material

Material deposited in places other than those designated or approved by the Contracting Officer, or which escapes from such places, is prohibited, and will not be paid for. The Contractor may be required to remove such misplaced material in accordance with Contract Clause titled: "OBSTRUCTION OF NAVIGABLE WATERWAYS", and deposit it where directed at no additional cost to the Government.

3.2.6 Hopper Dredging

Hopper dredging will not be permitted under this contract.

SECTION 35 20 23 Page 5

3.2.7 Hydraulic Dredging

a. Excavate material by hydraulic pipeline dredge and transport the material by pipeline to final discharge position in the approved disposal area(s) without the use of rehandling basins or placing in scows or other similar vessels. Turn off the dredge cutterhead while moving anchors, until the anchors are relocated and the derrick is out of the cutterhead swing radius of the dredge. Keep pipelines in good condition at all times, and promptly and properly repair leaks or breaks. Clear and remove materials that leak from pipelines on or around access roads, and place within the limits of the disposal or placement areas by a means which will preclude any loss of material to the waterway prior to deposition in the disposal or placement areas.

b. Submit discharge pipe support plan with the proposed method for supporting the discharge pipe inside the beneficial use placement area as required by these specifications, to include sketches showing plan and elevation views and details for the proposed method, and data on the materials to be used.

3.2.8 Bucket Dredging

Bucket dredging will not be permitted under this contract.

3.2.9 Government Quality Control Monitor

The Government may place a Government monitor aboard the Contractor's dredge or supporting vessels to monitor quality control conditions during dredging and disposal operations. See Section 01 30 00 ADMINISTRATIVE REQUIREMENTS, paragraph titled "ACCOMMODATIONS AND MEALS FOR GOVERNMENT

INSPECTORS".

3.2.10 Submerged Pipeline

If a leak occurs in the discharge pipeline, immediately discontinue using the line until leaks are repaired. Remove material placed due to leaks or breaks.

3.2.11 Floating Pipeline

Should the Contractor's pipeline not rest on the bottom, it will be considered a floating pipeline and shall be visible on the surface and clearly marked. In no case will the Contractor's pipeline be allowed to fluctuate between the surface and the bottom, or lie partly submerged.

Lights shall be installed on the floating pipeline as required in Section 01 30 00 ADMINISTRATIVE REQUIREMENTS, paragraph titled "SIGNAL LIGHTS".

3.2.12 Navigation Warnings

Furnish and maintain navigation warning signs along the pipeline.

3.2.13 Method of Communication

Provide a system of communication between the dredge crew and the crew at the disposal area. A portable two-way radio is acceptable.

3.2.14 Salvaged Material

Anchors, chains, firearms, and other articles of value, which are brought

SECTION 35 20 23 Page 6 to the surface during dredging operations, shall remain or become the property of the Government and shall be deposited on shore at a convenient location near the site of the work, as directed.

3.2.15 Plant Removal

Upon completion of the work, promptly remove plant, including ranges, buoys, piles, and other markers or obstructions.

3.3 OTHER EQUIPMENT

3.3.1 Paragraph Deleted

3.3.2 Control of Plants and Equipment

Equipment included above shall be under the control of the Contracting Officer, or his authorized representative, with regard to hours of work, location of work, and work to be accomplished. A representative of the Contracting Officer will be available, at a minimum, by telephone, at all times to issue instructions regarding the work; however, the actual supervision and direction of work operations shall be the responsibility of the Contractor.

3.3.3 Capability

Provide sufficient equipment, and personnel to work 7 days per week as directed by the Contracting Officer.

3.3.4 Condition of Plants and Equipment

Equipment shall be in satisfactory operating condition and capable of safely and efficiently performing the work as set forth in these specifications, and shall be subject to inspection by the Contracting Officer at all times.

3.3.5 Contractor Representation

The Contractor, or a representative with full authority to act for him in regard to care and operation of the equipment, shall be on the site of the work at all times and available by telephone, or equivalent, at all times. Designate a qualified representative to act on the Contractor's behalf in the case of his absence.

3.3.6 Inspection

The Contractor's equipment require inspection and approval by the Government, prior to the start of work. The Contractor must give the Contracting Officer at least 48 hours notice prior to inspection of equipment.

3.3.7 Unserviceable Equipment

If, at any time during the life of the contract, the Contracting Officer determines that any item of equipment, or part thereof, is inadequate for the service required, is not being operated at full capacity, has become unserviceable or unsafe, is incapable of efficient work, or is not being efficiently operated because of insufficient or incompetent crew, he will notify the Contractor in writing of his decision and direct that the item of plant or part thereof be removed from the worksite until the defects

SECTION 35 20 23 Page 7 are corrected. The Contractor may substitute other equipment of similar capacity and power, satisfactory to the Contracting Officer, for any item of equipment or part thereof condemned or ordered removed from the work as unfit.

3.3.8 Operation and Repair

Furnish, at no additional expense to the Government, all labor, fuel, necessary equipment for transportation of fuel to the equipment, material, and subsistence and supplies, and bear all expense incident to the efficient operation of the equipment in connection with the work. The Contractor shall also bear all direct, overhead, and collateral expenses incident to the operations, upkeep and repair of all equipment. Maintain the equipment in a good state of repair, arrange for a supply of renewal parts to be on hand when needed for the equipment, and provide and maintain efficient crews for each item of equipment employed in connection with the work.

3.4 DEVELOPMENT AND OPERATION OF PLACEMENT AREAS

3.4.1 Beneficial Use Placement Areas

3.4.1.1 Contractor Coordination

a. Conduct a beneficial use placement area prep meeting and site visit prior to starting work in the placement area.

b. Contact project engineer and COR 15 days prior to use of the placement area.

3.4.1.2 General

a. Submit a beneficial use placement area plan prior to the use of the placement area. Conduct work in accordance with the approved beneficial use placement area plan. Maintain and repair of all Government-owned and State managed land, roads and facilities used under this contract. Remove all Contractor-owned dredging pipe used in the contract work, from the site within 30 days of completion of all dredging work.

b. Dredging involves the placement of dredged material to elevate existing marsh and create new natural and nature-based features. Placement shall be within the areas shown on the drawings, or as directed by the Contracting Officer based on environmental sensitivities and dynamic conditions at the placement sites.

c. Contractor-furnished pipelines shall enter the placement area only within the limits shown on the drawings. The Contracting Officer reserves the right to direct the extension of Contractor-furnished pipelines beyond the discharge limits shown on the contract drawings if required for efficient management of the area. The ends of all discharge pipes shall be located inside the placement area limits at the approximate location.

Location is to be coordinated with COR and Beneficial use placement plan.

d. Use only low pressure equipment with a 3-psi maximum ground pressure that limit impact within the sensitive marsh placement area when moving pipelines or when performing other work. Equipment with a 4.5-psi rating such as a D-4 type dozer (or equivalent) will be permitted if methods that reduce the loading to the 3-psi maximum ground pressure can be demonstrated. Include the type of equipment, load rating, and methods to

SECTION 35 20 23 Page 8 limit the impact within the placement area, in the Beneficial Use Placement Area Plan.

e. Equipment must only be used in areas of phragmites vegetation and harder surface marsh areas, avoiding native marsh and soft sediment areas, unless specifically authorized. To avoid rutting, do not track equipment over the same alignment repeatedly. Identify in the Beneficial Use Placement Area Plan, the means of travel and methods to be used that reduce the impact to the marsh surface.

f. Use only non-toxic environmentally friendly lubricants for hydraulic oil and machine grease for equipment operating in the beneficial use placement area.

g. Submit a Spill Response Plan detailing the steps to be taken in the event of a spill. Locate spill response kits containing oil booms and pads on each piece of equipment.

h. During daylight hours, provide a minimum of 2 personnel at the placement area when work (disposal or other) is being done at the site.

Provide radio communication between the placement area personnel and the dredge at all times.

i. Obtain required right-of-ways for work operations, including, but not limited to, the placement and use of pipelines. Obtain written permission from the Contracting Officer prior to entering on or utilizing property owned or leased by the Government, other than the placement area shown.

j. Hay Bales and Coir Logs: Install and maintain optional hay bales and coir logs during placement operations and as agreed upon on the beneficial use placement plan. Hay bales and coir logs shall be placed between the dike, discharge pipe and optional turbidity curtain, with the exact location agreed upon during the Beneficial Use Placement Plan submittal or as directed by the Contracting Officer. Install coir logs as recommended by the manufacturer for the intended purpose. The Contractor may be required to manually carry the hay bales several hundred feet.

k. Turbidity Barrier: Install and maintain a turbidity barrier during placement operations if option is awarded and as directed by Contracting Officer.

3.5 OVERDEPTH, SIDE SLOPES, AND EXCESSIVE DREDGING

3.5.1 Overdepth

Material removed to a depth of not more than 1 foot below the required depth, limited by a vertical plane through the required depth contour, will be estimated and paid for at the contract unit price for removal and disposal of material.

3.5.2 Side and End Slopes

No side or end slopes are specified for this contract (box cut).

3.5.3 Excessive Dredging

Material taken from beyond the limits specified in the Paragraphs titled:

"Overdepth" and "Side and End Slopes", will be deducted from the total amount dredged as excessive dredging for which payment will not be made.

SECTION 35 20 23 Page 9

Nothing herein shall be construed to prevent payment for the removal of shoals performed in accordance with the applicable requirements of Paragraph "FINAL EXAMINATION AND ACCEPTANCE" and Section 01 30 00 ADMINISTRATIVE REQUIREMENTS, paragraph titled "SHOALING".

3.6 ESTIMATED QUANTITIES

The total estimated quantity of material necessary to be removed within the specified limits as shown on the drawings, including allowable overdepth and areas outside the channel limits as previously specified, is as follows for each of the potential work areas:

Required Allowable Dredging Overdepth Acceptance Station to to 8 ft. 8 ft. to Section Station MLLW (cy) 9 ft. MLLW (cy) Total (cy)

Base Bid AS#1 0+500 to 2+300 4,261 6,148 10,409 AS#2 2+300 to 4+000 7,506 9,450 16,956 AS#3 4+000 to 5+528 6,464 8,418 14,882 AS#4 5+528 to 8+000 6,435 13,209 19,644

Total Base Bid 24,666 37,225 61,891

Option 1 AS#5 8+000 to 10+000 10,312 11,079 21,391

Total Base plus options 34,978 48,304 83,282

All depths specified for dredging are referenced to mean lower low water

(MLLW).

3.7 LIMIT OF DREDGING

3.7.1 General

The areas to be dredged in within the limits indicated on the Contract Drawings and specified in paragraph "FINAL EXAMINATION AND ACCEPTANCE", as defined by dredging prism indicated in the paragraphs titled: "OVERDEPTH, SIDE SLOPES, AND EXCESSIVE DREDGING" and "MEASUREMENT AND PAYMENT" of this section.

3.7.2 Quantity Acceptance

Complete all dredging requirements for each acceptance section prior to its acceptance by the Government. In any portion of an acceptance section, when the before dredging survey indicates dredging is required, remove material found to be remaining above the required depth by the after dredging survey, by dredging, unless such dredging is waived by the Contracting Officer. Dragging of a bar or other device will not be allowed. All material removed from within the dredging prism, whether accomplished by initial dredging or redredging, will be paid for at the contract unit price and as determined by the quantity calculation resulting from the difference between the before dredging survey and the final after dredging survey. In any portion of the area of work, when the after dredging survey indicates dredging is required that was not indicated by the before dredging survey, remove such material to the

SECTION 35 20 23 Page 10 required depth, unless waived by the Contracting Officer. Such work will be paid for at the contract unit price and any additional quantity calculation will be made based on the after dredging survey, provided that the material is not determined by the Contracting Officer to be misplaced material.

3.8 CONTRACTOR QUALITY CONTROL

Prepare, maintain, and submit daily, the Daily Report of Operations forms and furnish signed copies thereof with the Daily Construction Quality Control Reports required in Section 01 45 00 QUALITY CONTROL to the Contracting Officer. A copy of the Daily Report of Operations forms to be used is attached at the end of this section. Further instructions regarding the preparation and submittal of this form will be provided at the Pre-Dredging Coordination Meeting. Submittals for the Daily Report of Operations are available to the public.

3.9 FINAL EXAMINATION AND ACCEPTANCE

a. As soon as practicable after the completion of areas, which in the opinion of the Contracting Officer, will not be affected by further dredging operations, each area will be examined by the Government by sounding or sweeping, or both. Remove shoals and lumps by dragging the bottom or by dredging. However, if the bottom is soft and the shoal areas form no material obstruction to navigation, removal may be waived at the discretion of the Contracting Officer. The Contractor will be notified when soundings or sweepings are to be made and will be permitted to accompany the sounding or sweeping party and to inspect the data and methods used in preparing the final estimate. When areas are found to be in a satisfactory condition, the work therein will be accepted as complete. Final estimates will be subject to deductions or correction of deductions previously made because of excessive overdepth, dredging outside or authorized areas, or disposal of material in an unauthorized manner.

b. Should more than two soundings or sweeping operations by the Government over an area be necessary by reason of work for the removal of shoals disclosed at a prior sounding or sweeping, the cost of such third and any subsequent sounding or sweeping operations will be charged against the Contractor. The rate of each day in which the Government plant is engaged in such sounding or sweeping operations and/or is enroute to or from the site or held, for the Contractor's convenience, at or near the site for these operations shall be $5,500.00, except on Saturday, Sunday and holidays when the rate shall be $6,000.00.

3.10 MEASUREMENT AND PAYMENT

3.10.1 Mobilization and Demobilization

All costs connected with the mobilization and demobilization of all the Contractor's dredging plants and equipment will be paid for at the contract lump sum price for the Bid Item titled "Mobilization and Demobilization". Sixty percent of the lump sum price will be paid to the Contractor upon completion of his mobilization at the work site. The remaining forty percent will be included in the final payment for the work under this contract.

SECTION 35 20 23 Page 11

3.10.1.1 Contractor's Cost Data

In the event the Contracting Officer considers that the amount in this item (60 percent) which represents mobilization, does not bear a reasonable relation to the cost of the work in this contract, the Contracting Officer may require the Contractor to produce cost data to justify this portion of the bid. Failure to justify such price to the satisfaction of the Contracting Officer will result in payment of actual mobilization costs, as determined by the Contracting Officer at the completion of mobilization, and payment of the remainder of this item in the final payment under this contract. The determination of the Contracting Officer is not subject to appeal.

3.10.1.2 Mobilization and Demobilization Costs

a. All costs connected with the mobilization and demobilization of the Contractor's dredging plant and equipment as defined below, shall be included in the contract lump sum price for Base Bid Item titled "Mobilization and Demobilization", as listed in the Bidding Schedule.

(1) Mobilization shall include all costs for operations accomplished prior to commencement of actual dredging operations; i.e., transfer of dredge, attendant plant, and equipment to site; initial installation of pipe; preparation of disposal areas, including construction of walkways at disposal areas as required; and other incidentals in advance of the actual dredging operations.

(2) Demobilization shall include general preparation for transfer of plant to its home or standby base, removal of pipelines, and cleanup of disposal areas.

3.10.2 Dredging

3.10.2.1 Channel Clearance Surveys

a. The material to be removed above project depth within each acceptance section will be determined by a before dredging survey conducted by the Government. See drawings for required depth template.

b. The material remaining above contract depth within each acceptance section will be determined by an after dredging survey conducted by the Government following the completion of an acceptance section by the Contractor.

c. The sorted XYZ datasets will be generated for review utilizing the methods described in the Paragraph "Plotting". Surveys will be conducted as outlined in EM 1110-2-1003 . Raw data will not be available, however, the edited files will be available upon request and the processed and sorted XYZ dataset provided to the Contractor.

d. The sorted datasets cannot used for the calculation of square footage or dredging volumes.

3.10.2.2 Volume Calculations

a. The total amount of material to be removed and paid for under the contract will be measured by the cubic yards in place. Measurement of the number of cubic yards in place will be made by computing the volume between the bottom surface shown by soundings of the before dredging

SECTION 35 20 23 Page 12 survey and the final after dredging survey of the acceptance section once it has been cleared. The volume for measurement will include the material within the limits described in the paragraph "OVERDEPTH, SIDE SLOPES, AND EXCESSIVE DREDGING", less any deductions that may be required for misplaced material described in the paragraph "DISPOSAL OF EXCAVATED MATERIAL" of this Section.

(1) The volume of material removed will be generated by using the TIN (Triangulated Irregular Network) computation as outlined in the Hydrographic Survey Manual EM 1110-2-1003 . An XYZ file will be generated from the edited multi-beam data using the average sounding within the cell of a 3 foot by 3 foot matrix to perform the TIN volume calculations. If single beam method is used, all depths will be utilized for volume computations.

b. The sorted XYZ dataset generated for volume computations cannot to be used for clearance of an acceptance section or for plotting.

3.10.2.3 Plotting

The primary method of surveying under this contract will be singlebeam.

Data will be plotted using a sort radius appropriate to the scale of the drawings. Longitudinal lines may be run through the designated dredging areas and included in the plot. If multibeam is used, plotting of before dredging and after dredging surveys will be the XYZ dataset generated from the 3x3 average dataset used to compute quantities utilizing the minimum sounding shifted to the center of the cell of a 15 foot by 15 foot matrix.

The contour depicting all data (singlebeam) or 3x3 average XYZ dataset (multibeam) will also be plotted.

3.10.2.4 Surveys for Acceptance

The Government will perform pre and post dredging surveys for each acceptance section. Notify the Government of the need for acceptance surveys at least three days in advance of the date for each survey (Saturdays, Sundays and holidays are excluded), and confirm the need by telephone between 0630 and 0700 hours on the day of each survey by calling the Technical Support Branch, O & M Contracts Section at 215-656-6750, and by email to both Jason.M.Gray@usace.army.mil and Stephen.A.Farrell@usace.army.mil. The time for any redredging to remove shoals and for second and subsequent surveys in any acceptance section is the responsibility of the Contractor, and must be accomplished within the completion period established for the contract. The Contractor may accompany the survey party to observe if redredging is required. The Contracting Officer will notify the Contractor if any redredging is required.

3.10.2.5 Existing Conditions

Hydrographic surveys will be taken by the Government before dredging.

Determination of quantities removed, and the deductions made therefrom, to determine quantities by in-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. The hydrographic surveys for this contract, containing all edited x,y,z data, will be available on CD by request.

SECTION 35 20 23 Page 13

3.10.2.6 Hydrographic Survey Equipment

Hydrographic surveys will be conducted to meet USACE Performance Standards as defined in the Hydrographic Surveying Manual EM 1110-2-1003 . Surveys will be performed by single transducer sounding techniques, multi-beam sweep type surveys or both. When using single beam technology, the operating frequency will range from 190 to 210 Khz in hard bottom areas.

When utilizing multi-beam technology, the operating frequency will range from 180 to 250 Khz in hard bottom areas. In soft bottom areas, 24 KHz low frequency depth may be used. All fathometers will be calibrated following procedures outlined in the aforementioned EM.

3.10.2.7 Tide Corrections - Government Surveys

Horizontal and vertical vessel positioning for all hydrographic surveys conducted under this contract by the Government, will be based upon Real Time Kinematic (RTK) Global Positioning System, a Real Time Network (RTN), or Post Processed Kinematic (PPK) techniques. All soundings will be corrected to Mean Lower Low Water (MLLW) based upon differences shown in the chart on the drawings.

3.10.2.8 Payment

Payment for dredging will be made at the contract unit prices for the Bid Items titled "Removal and Satisfactory Disposal of Material", for the various dredging locations, as listed in the Bidding Schedule, for the number of cubic yards which are removed and satisfactorily disposed of in the disposal and placement areas.

3.10.3 Hay Bales

Hay Bales will be measured for payment by the number installed. Payment will be made at the contract price per unit under the Option Bid Item titled "Hay Bales", which shall include compensation to the Contractor for all transportation, installation, and removal costs associated with the hay bales.

3.10.4 Coir Logs

Coir logs will be measured for payment by the linear foot installed.

Payment will be made at the contract price per unit under the Option Bid Item titled "Coir Logs", which shall include compensation to the Contractor for all transportation, installation, and removal costs associated with the coir logs.

3.10.5 Turbidity Barrier

The use of turbidity barrier will be measured for payment by the linear foot installed. Payment will be made at the contract unit price under the Option Bid Item titled "Turbidity Barrier", which shall include compensation to the Contractor for all transportation, installation, and removal costs associated with the turbidity barrier.

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