3_ Dredge Spec 35_20_23.pdf

PNSY Maintenance Dredging

Portsmouth Naval Shipyard, Kittery, ME

Section 35 20 23 Page 1

SECTION 35 20 23

DREDGING

04/06 (Revised 10/2022)

PART 1 GENERAL

1.1 DEFINITION

Hard material is defined as material requiring blasting or the use of special equipment for removal, and includes large boulders and or fragments too large to be removed in one piece by the dredge plant. Boulders and rock fragments less than two tons in weight shall not be considered hard material. The dredge plant shall be capable of removing boulders and rock fragments up to two tons in weight, and be able to dig through stiff clay.

1.2 SUBMITTALS

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

submittals not having a "G" designation are for Contractor Quality Control approval. Submit the following in accordance with Section 01 33 00

SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

Construction Operations Plan; G

Seawater Intake Turbidity Protection Plan; G

Dredge Area Turbidity Protection Plan; G

Lobster Mitigation Plan; G

Marine Mammal Monitoring Plan; G

Hydrographic Survey Methods; G

Pre-Final Design; G

Ready for Construction Documents; G

Material Sampling and Testing Plan; G

Dredge Disposal Plan; G

Method for Computing Quantities; G

Estimated Quantity Calculations; G

SD-02 Shop Drawings

Dewatering Plan; G

Section 35 20 23 Page 2

Soundings; G

SD-11 Closeout Submittals

Material Test Results; G

Post-dredge Hydrographic Survey; G

Quantity Calculations; G

Approved Manifest; G

1.3 MATERIAL TO BE REMOVED

The material to be removed is silt, sand, gravel, clay, cobbles, boulders, artificial obstructions, and other dredge materials. At the dredge locations shown on the contract drawings, all material shall be removed to the target dredge depth or to bedrock, whichever is shallower. Bedrock removal is not required except for the bid option.

Estimated depths to bedrock based on historical borings within and adjacent to the dredge locations are provided on the contract drawings. The depths to bedrock on the plans show the approximate depth to bedrock and a boring number. Boring logs associated with this data are not available. This information is included for general information only; the intent is to help the Contractor understand soil and hard material characteristics and estimated dredge material volumes within the dredge locations. This data reflects the material characteristics at the time of collection and shall not be used as a basis of characterization for disposal. The Contractor is responsible for sampling, testing, and characterization of all material for disposal in accordance with the Government approved upland disposal facility.

In-water dredging activities shall be limited to daylight hours up to a maximum of 12 hours per day.

1.3.1 Hard Material

The removal of hard material is required for the bid option dredge area shown on the contract drawings. Blasting is not permitted under this contract.

If disagreement on the existence of hard materials that can be removed by the dredge plant occur, the Contractor shall demonstrate to the Government's satisfaction that the material is not excavatable by the equipment employed for the work at no additional cost to the government. Demonstration with a clamshell bucket alone is not sufficient and shall not be used as a means to demonstrate the removal capabilities of the dredge plant. The Contractor shall employ a fixed arm excavator or a large backhoe capable of prying hard material as defined for demonstration of the existence of hard material which cannot be removed under the terms of this contract. The Contractor shall identify the limits and elevations of the hard material as directed by the COAR, at no additional cost to the Government.

Hard Material or rock removal will be required for the bid option only and must be accomplished by mechanical means only. Blasting shall not be permitted.

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1.3.2 Hazardous Material

The removal of hazardous material must be completed and removed to the satisfaction of the government prior to any non-hazardous dredging. In the event that the contractor is given permission to dredge non-hazardous material that is near a known hazardous area the contractor must clearly mark the extents of hazardous soils with visible markers. Implementation of the markers must account for all applicable side slopes buffers and tides.

1.4 ARTIFICIAL OBSTRUCTIONS

The Government has knowledge of material, including but not limited to, metal bands, pallets, pieces of broken cable, rope, fire hose, concrete blocks, miscellaneous metal, chain, broken piles, etc. within the area to be dredged. The Government has no knowledge of existing ordnance, wrecks, wreckage, or other material of such size or character as to require the use of explosives or special or additional plant for its safe removal.

Artificial obstructions excavated from the dredged area shall be placed in the dewatering area separate from the dredge materials, and shall be rinsed for review by the Government. All artificial obstructions shall become the property of the Contractor unless otherwise directed or indicated, and shall be properly disposed of at the end of the project at a Government approved facility, at no additional cost to the Government.

1.5 QUANTITY OF MATERIAL

The estimated quantity for bidding purposes shall be as shown on the drawings. The quantities listed are estimates only. The contractor shall carry sufficient funds in their bid that no adjustment will be made to unit pricing if the quantity of material is within 25% above or below the total cubic yard design estimates. Within the limits of available funds, complete the work specified whether the quantities involved are greater or less than those estimated.

1.6 OVERDEPTH DREDGING

To cover unavoidable inaccuracies with the dredging process, where overdepth dredging is indicated, material actually removed to a depth of two feet below the design dredge depth specified and within the dredging limits shall be measured and paid for at the bid unit price with the exception of the bid option. For the bid option there is an overdrege allowance of 10CY. Any material removed as a part of the bid option beyond that shall be nonpayable.

Material excavated below or beyond the limits shown on the drawings shall not be measured or included for payment.

1.7 SIDE SLOPES

Dredging on side slopes shall follow, as closely as practicable, the lines indicated or specified. All side slopes shall be assumed to be a 3:1 slope with the exception of hard material excavation. A two foot allowance will be made for dredging beyond the indicated or specified side slopes, except as provided herein. The amount of material excavated from side slopes will be determined by the approved method for computing dredge quantities.

1.8 PERMITS

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The Contracting Officer has secured the permits for dredging to the permitted depths as indicated on the drawings. The Contractor shall comply with all conditions and requirements in the following permits:

1. Army Corp of Engineers General Permit NAE-2013-00743 issued

October 14, 2020 as revised on October 28, 2020 (corrects time of year restrictions).

2. Maine Department of Environmental Protection #L-21179-26-CC-M and

L-21179-4E-CD-N including issued August 3, 2020:

a. Site Location of Development Act Minor Revision

b. Natural resource Protection Act

c. Coastal Wetland Alteration

d. Water Quality Certification

3. Coastal Zone Management Act concurrence letter dated August 10, Copies of the permits are included as attachment 6 and are part of this contract. All listed permits are in effect throughout the duration of the work.

The permits require upland disposal of dredge materials at a licensed solid waste disposal facility (i.e. landfill). The Contractor shall make arrangements with a Government approved state licensed landfill for disposal of excavated materials. At this time two disposal locations are approved:

(1) Waste Management Inc. (WMI) Turnkey Landfill located in Rochester, NH and (2) Waste Management Inc. Crossroads Landfill located in Norridgewock, ME.

Permit conditions include the following requirements highlighted for the

Contractor’s awareness. This list is not all inclusive; the Contractor shall comply with all permit conditions:

• Dredging operations are restricted to between November 9 and March 14 of any year. Dredging shall not occur outside of this time period.

• Dredge materials shall be cement amended and dewatered on a barge scow prior to transport for disposal. Dredge materials shall be free of liquid as defined by the Paint Filter test prior to transport.

• Dredge material shall meet the approved landfill’s criteria for acceptance for disposal including, but not limited to, physical and chemical characteristics (e.g. compressive strength) as determined by the disposal facility. It is anticipated that dredge materials will need to be cement amended sufficiently to meet an unconfined compressive strength of 1,000 psf. Additional criteria will apply. The

Contractor is responsible for determining the disposal criteria and amending the dredge materials sufficiently to meet the criteria.

• Barge scows used to decant and dewater dredge materials shall be outfitted with a containment system designed to filter and contain sediment from release to the river during the dredging operations. The containment area can consist of concrete barriers wrapped with geotextile fabric surrounding the outer edges of the barge. Dredged

Section 35 20 23 Page 5 materials shall be deposited within the containment area. The geotextile fabric installed shall filter the dredged material prior to its decanting into the river. The containment system shall be maintained throughout the duration of the work.

1.9 CHARGES

The Contractor shall pay all costs associated with amending and dewatering dredge materials, loading and transportation of the dredge materials from the dewatering site to the state licensed landfill, and shall pay all charges required by the landfill for the proper disposal of the dredge material.

The Contractor is responsible for all sampling, testing, segregation and processing of the dredge materials required by the state licensed landfill identified for disposal, as required by the State of Maine Department of

Environmental Protection Solid Waste Division, and as required by the state in which the landfill is located. Costs for this work shall be included in the lump sum contract price for the Base Bid, and in the lump sum contract price for Bid Options. Contractor sampling plan must be approved by the government and sampling must be overseen by a government representative.

Sampling methods must be capable of recovering full dredge depth representative samples, surface grabs will not be permitted.

1.10 ENVIRONMENTAL PROTECTION REQUIREMENTS

Provide and maintain during the life of the contract, environmental protective measures. Provide environmental protective measures required to correct conditions, such as oil spills or sediment releases beyond deminimus quantities that occur during the dredging operations. Comply with Federal, State, and local regulations pertaining to water, air, erosion and sediment control, and noise pollution. Comply with permits applicable to the work.

Turbidity curtains shall be installed and maintained where water velocities and dredge depths make their use practicable and as shown on the contract drawings.

Provide erosion and sediment controls at the offload area to minimize point source pollution in accordance with Section 01 57 19.00 22 and the contract drawings.

1.11 BASIS FOR BIDS

Payment will be at the contract unit price per cubic yard, multiplied by total cubic yards of acceptable dredging. Base bids on total cubic yards of dredging indicated. Include a bid unit price per cubic yard of dredging based on the quantity as specified or indicated. If the Contracting Officer requires an increase or a decrease in total volume of dredging, the contract price will not be adjusted unless the quantity is more than 25% above or below the design volume. Dredging conditions specified and indicated describe conditions which are known. However, the Contractor is responsible for other conditions encountered which are not unusual when compared to conditions recognized in the dredging business as usual in dredging activities such as those required under this contract.

1.12 CONSTRUCTION OPERATIONS PLAN

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Submit a Construction Operations Plan indicating the proposed method by which the dredge work will be conducted. Describe in detail the means by which dredge operations will be conducted so as to avoid damage to benthic resources outside the dredge area. The plan shall include discussion of the following items:

a) Type of dredge equipment and vessels to be used throughout the project,

b) Coordination and communication efforts between site personnel to minimize impact to Portsmouth Naval Shipyard operations,

c) Maintaining horizontal and vertical survey control,

d) Proposed means to avoid damage to adjacent structures, vessels, and moorings, and fenders

e) Proposed means to avoid over dredging,

f) Proposed methods to effectively dewater and remove all dredge material from the dewatering site within the project time limits,

h) Proposed methods to keep unloading site and all haul routes clean, and

i) Proposed methods to prevent spillage from trucks.

1.13 TURBIDITY PROTECTION PLANS

1.13.1 SEAWATER INTAKE TURBIDITY PROTECTION PLAN

Submit a Seawater Intake Turbidity Protection Plan for each dredge location including shop drawings and material specifications detailing how the seawater intake shown on the drawings will be protected from impacts due to turbidity. Example protection measures illustrating the minimum level of effort required are shown on the drawings for reference only. The Contractor is responsible for designing, installing, and maintaining a system that prevents sediment from entering the seawater intake. The Government reserves the right to require the Contractor to verify the function of the turbidity protection by video, divers, or any means necessary upon request. The

Government shall determine if the system employed meets the effectiveness required for the protection of the sweater intake, or require an outage if necessary.

1.13.2 DREDGE AREA TURBIDITY PROTECTION PLAN

Submit a Dredge Area Turbidity Protection Plan including shop drawings and material specifications detailing how the dredge area shown on the drawings will be protected from the release of turbidity from the work area.

Turbidity created by the work shall not migrate from the dredge area.

Example protection measures illustrating the minimum level of effort required are shown on the drawings for reference only. The Contractor is responsible for designing, installing, and maintaining a system that prevents sediment from migrating from the dredge area. The Government reserves the right to require the Contractor to verify the function of the turbidity protection system by any means necessary upon request. The

Government shall determine if the system employed meets the effectiveness required for the prevention of impacts due to turbidity. If it is determined to be unsatisfactory by the government all dredging shall cease at no cost to the government until corrective actions have been taken to the satisfaction of the government.

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1.14 LOBSTER MITIGATION PLAN

Submit a Lobster Mitigation Plan which complies with the requirements and references indicated in Part 3, paragraph entitled "Lobster Mitigation".

Lobster Mitigation activities shall comply with all applicable permits.

1.15 MARINE MAMMAL MONITORING PLAN

Submit a Marine Mammal Monitoring Plan which complies with the requirements and references indicated in Part 3, paragraph entitled "Marine Mammal

Monitoring". This is required for bid option work only.

1.16 DEWATERING PLAN

Submit a Dewatering Plan for the dredge materials. Dewatering operations shall be conducted on the Contractor’s waterborne plant, no land based dewatering site will be provided as part of this contract. The plan shall indicate the steps and methods the Contractor will utilize to ensure the dredge materials are dewatered sufficiently to allow transport and disposal to a licensed solid waste facility within the specified contract completion date.

The Dewatering Plan shall indicate the means and methods for prevention of release of amended dredge materials from entering the river, and for meeting the requirements for transportation of the dredge materials to be liquid free prior to transport. Dredge material ready for transport shall contain no free draining liquids. When there is a question as to whether this standard is met, as determined by the Government, the Paint Filter Liquids

Test (EPA SWA-846 Test Method 9095) shall be used to determine the presence of free draining liquids in a representative sample. The dewatering plan shall be stamped by a Professional Engineer licensed in the state of Maine.

1.17 LAYOUT WORK AND SURVEYS

The Contractor shall employ a licensed land surveyor to layout the limits of the work, establish vertical control using approved datum, and perform surveys as needed to perform the work. The Contractor shall provide all buoys, ranges and other controls necessary to accomplish the work and facilitate inspection of progress.

1.18 HYDROGRAPHIC SURVEYS

The Contractor shall submit pre-dredge and post-dredge hydrographic surveys and quantity calculations. Prior to commencing work, submit hydrographic survey methods to the Contracting Officer’s Representative. Hydrographic surveys shall use multi-beam sonar transducers and shall provide 100% bottom coverage including a method to correct for side slope and beam angle error.

Survey methodology shall conform to the US Army Corps of Engineers specification EM1110-2-1003, as amended. Survey accuracy shall be as follows: horizontal positioning: less than 1 meter; NADIR (vertical): ±0.15 feet. Plans for the Hydrographic Surveys shall include a typical section of the proposed dredge areas.

1.18.1 DELIVERABLES SCHEDULE

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Provide the following design and close-out deliverables in digital ACAD format (2018 or earlier version) and stamped/signed PDF for each deliverable. Approved Post Dredge Survey shall be stamped by a Professional

Engineer and submitted on Mylar.

i) Pre-Final Design deliverable showing hydrographic conditions from

KTRs pre-dredge survey, final grading design, and estimated quantity calculations.

ii) Ready for Construction Documents, incorporating comments from review of Pre-Final.

iii) Post Dredge Survey and Quantity Calculations

All pre- and post-dredge surveys and drawings shall be prepared in accordance with CAD Standards included as attachment to Section 01 78 00.00

22.

Pre-dredge surveys are required to be performed within 30 days for each location to be dredged. Pre-dredge surveys for bid options areas, if awarded, may be completed 45 days prior.

The above described submittal requirement does not relieve the Contractor from conducting interim surveys during the work as described in paragraph

3.6.2 herein entitled "Surveys During Progress of Work". The government may request a progress survey from the contractor at any point at no additional cost to the government.

1.19 METHOD FOR COMPUTING QUANTITIES

Submit Method for Computing Quantities. The method chosen shall be a generally recognized technique using TIN subtraction method of calculation compatible with AutoCAD Civil 3D 2018 software.

1.20 MATERIAL SAMPLING AND TESTING

1.20.1 Material Sampling and Testing Plan

Contractor shall conduct in-situ sampling of the dredge materials as required for disposal of the materials in accordance with state and licensed landfill requirements. Submit a Material Sampling and Testing Plan for

Government approval. Contractor shall allow for a draft submittal review period of 14 days. Contractor shall revise the plan to address Government comments and re-submit for final review and approval. The plan shall not be approved until all Government comments are addressed. Dredging shall not begin until the plan has been approved in writing by the Government.

Contractor shall ensure that a sufficient quantity of samples and tests are performed to meet the state and licensed landfill requirements for acceptance of the material for disposal. The plan shall include sample frequency, sampling methods, compositing methods, testing parameters, detection limits, and quality assurance requirements. Contractor shall assume that samples will need to be taken at full dredge depth, and that a surface sample will not suffice.

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1.20.2 Dredge Material Sampling

Samples of the dredge material shall be collected in accordance with the approved Material Sampling and Testing Plan. Sampling shall be in accordance with standard reference procedures from the US Army Corp of Engineers, the

State of Maine Department of Environmental Protection Solid Waste Division, the Environmental Protection Agency's publication SW-846, "Test Methods for

Evaluating Solid Waste, Physical/Chemical Methods", and the approved state licensed landfill. Dredge material characterization shall be completed by the Contractor in accordance with the disposal facility requirements.

1.20.3 Dredge Material Testing

Testing of the dredge material shall be in accordance with the approved material sampling and testing plan, the State of Maine Department of

Environmental Protection Solid Waste Division, the approved state licensed landfill, and the state in which it is located. Submit Material Test

Results. Sediment free rock does not need to be tested, nor is considered waste as outlined by the Maine Department of Environmental Protection regulations.

1.21 DREDGE DISPOSAL PLAN

The contractor will submit a Dredge Disposal Plan that will detail the different dredge areas and the plan that will be followed for removal, handling and disposal of each area, as well as the method in which inadvertent comingling of different materials will be prevented. Hazardous vs nonhazardous zones including buffers must be called out specifically and delineated in this plan, and the proposed approach to make sure these materials are handled separately. This plan must clearly address how the contractor will ensure that they and their subcontractors correctly documenting, identifying, removing, handling and disposing of each type of dredge material in the contract, or avoiding nearby material that is not in the contract.

1.22 POST-DREDGE HYDROGRAPHIC SURVEY

Submit a Post-dredge Hydrographic Survey and Quantity Calculations. Survey methods shall be in accordance with approved methods designated herein.

Electronic hydrographic surveys shall be submitted in AutoCAD Civil 3D 2016 format. Drawings shall be drawn at 1 foot contour intervals on 22"x34" size

Mylar showing the full length of all piers, berths and dry docks where dredging was accomplished. Plans and quantity calculations shall be stamped and signed by a licensed registered Professional Engineer. Xyz files of the survey data must be submitted for all post dredge surveys.

1.23 MATERIALS TRANSPORTATION

Contractor shall load and transport dewatered and amended dredge materials from barges to the PNSY Hazardous Waste Facility (Building 357), and from

Building 357 to the approved disposal facility. All land transportation shall be conducted in watertight trucks to avoid spillage of dredge material before and after dewatering. Contractor shall transport dredge material from the dewatering barge to the designated location at PNSY for manifesting

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(Building 357) before proceeding to the disposal facility. Contractor shall obtain and submit for each accepted delivery to the disposal facility an

Approved Manifest.

The Contractor shall confirm the operating hours of Building 357 and the approved disposal facility. Contractor shall coordinate transportation of dewatered dredge material with Building 357 personnel. All materials shall be transported on the Shipyard between the hours of 8:00AM and 2:30PM Monday through Friday. Note the disposal facility does not accept deliveries on weekends or holidays.

The allowable trucking routes on the Shipyard are shown on project drawings.

Deviation from Materials Transportation requirements shall not be allowed without written permission from the Government.

1.24 WORK AREA

1.24.1 PROTECTION OF EXISTING WATERWAYS AND SHOALS

The Contractor shall conduct dredge operations in such a manner that the material is not pushed outside of dredging limits or otherwise deposited in existing side channels, basins, docking areas, or other areas being utilized by vessels or moored boats. The Contractor will be required to change his method of operations to comply with the above requirements. Should any bottom material or other dredged material be pushed into areas described above as a result of the Contractor's operations, the material must be promptly removed.

1.24.2 ADJACENT PROPERTY AND STRUCTURES

The Contractor shall conduct the dredging operation such that it does not undermine, weaken, or otherwise impair existing structures located in or near the areas to be dredged. The Contractor shall plan the dredge work accordingly. Contractor shall comply with setbacks from structures and other vessels shown on the drawings. Dredging shall not occur within the setback areas or within 20ft of any structure.

Damage to private or public property or structures resulting from the dredging operations or associated disposal activities shall be repaired promptly by the Contractor at their expense. Damage to structures resulting from the Contractor's negligence require prompt repair at the Contractor's expense.

Contractor shall pay special attention to the unloading site and haul routes presented on the drawings. Contractor shall employ tailgate locks on trucks or other approved methods to ensure sealing against spillage. Contractor will be required to clean Portsmouth Naval Shipyard haul routes as directed, if the trucks do not prevent spillage of the dredge material and water to the satisfaction of the Contracting Officer’s Representative.

PART 2 PRODUCTS

Not used.

PART 3 EXECUTION

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3.1 LOBSTER MITIGATION

Contractor shall carry out lobster mitigation in accordance with the permits and these specifications. The complete requirements for lobster mitigation are presented the document titled “Portsmouth Naval Shipyard, Lobster

Mitigation Plan, Modification and Expansion of Dry Dock 1” prepared by

Stantec Consulting Services, Inc. dated October 25, 2018 included as attachment 7.

The Contractor shall employ the services of a qualified professional to manage/perform all phases of the lobster mitigation effort. The qualified professional shall be familiar with the Maine Department of Marine Resources requirements, protocols and procedures related to lobster mitigation, trapping, and transport. The person(s) performing trapping activities must be properly licensed in the State of Maine for all activities associated with the lobster mitigation efforts. Submit all reports and data for

Government review and acceptance prior to start of dredge operations.

The need for lobster mitigation prior to dredging activities will be determined by the river bottom water temperature within the dredging area.

When the river bottom water temperature is less than 5°C (typically January through late March), no lobster mitigation efforts will be required. When the temperature is above 5°C, lobster mitigation will be required. The objective of the lobster mitigation is to trap and relocate lobsters in the project area until a threshold, as measured by catch per unit effort

(CPUE), of 0.5 lobsters/trap/night set is achieved.

Trapping will target both legal and sub‐legal size lobsters. Legal lobsters typically are retained by the fisherman assisting with the mitigation effort. Sub‐legal lobsters will be transferred to the cove just north of the causeway linking Clark Island to Seavey Island off of the southeast side of

Seavey Island. Based on the above water temperature criteria, lobster mitigation, including trapping and relocation of lobsters, will be completed no more than 14 days prior to the start of project dredging. If dredging has not commenced within 14 days of lobster relocation, the mitigation will be repeated to meet the requirement of dredging within 14 days of completion of mitigation.

The Contractor shall provide the necessary notifications to the Shipyard regarding the in-water work including the following information:

• Copies of the MDMR Special License;

• Coordination for lobster mitigation plan approval and lobster relocation oversight;

• Logistical considerations for site access and working in secure areas/during simultaneous;

• Routine notification of daily sampling activities and general project progress.

3.2 MARINE MAMMAL MONITORING

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Contractor shall submit a Marine Mammal Monitoring Plan in accordance with

Attachment 6, Marine Mammal Monitoring Methodology. This plan must be approved prior to any dredging activities. This requirement is only applicable to the Bid Option (Berth 6 rock removal) for the duration of rock removal activities. The contractor is responsible for all persons, costs and materials necessary to fulfill the requirements in Attachment 2 and the

Marine Mammal Monitoring Plan. Rock removal must immediately stop if a marine mammal approaches/enters the shutdown zones identified in Attachment

6. The shutdown area must be clear of marine mammals or sea turtles for at least 20 minutes before rock removal can begin. Attachment 6 should be carefully reviewed and contains all information regarding Marine Mammal

Monitoring and impacts to the project.

3.3 STURGEON AND SALMON MONITORING

The Contractor shall provide all labor and personnel required to monitor dredging activity for entrapment/ensnarement of Atlantic and/or short-nosed sturgeon species, and Atlantic salmon. A monitor shall be present at all times during dredging operations. The monitor shall be positioned in a location where dredge material can be easily observed. If any of the species of concern become entrapped/ensnared in the dredge bucket or material, all work shall cease, the fish shall be immediately released back to the river, and the NAVFAC PWD-ME Natural Resource Manager (NRM) shall be contacted.

Work shall not commence until the NRM receives written concurrence from the

National Marine Fisheries Service.

The Contractor shall meet with the NRM prior to execution of dredge work for fish species identification, handling, and documentation guidance. The

Contractor shall assume one hour of meeting attendance time for this task and the meeting shall be attended by all employees that will be performing the monitoring. Designated monitor may also perform duties of QCM or SSHO.

3.4 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 transportation for the

Contracting Officer and inspectors to and from the disposal area and between the dredging plant and adjacent points on shore.

3.5 CONDUCT OF DREDGING WORK

3.5.1 Order of Work

The Contracting Officer’s Representative will direct the Contractor on the order of work. The Government reserves the right to change the order of work at any time. The overall period of performance is 303 calendar days, however dredge work will only be allowed between November 9 and March 14. The

Contractor will have 45 days to complete work at each of the two base bid dredge locations. The Government will provide written notice of exact dates

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65 days prior. If the bid option is awarded the Contractor will have 30 days to complete that work, and shall carry costs for that bid option to remobilize offloading equipment at Berth 5 or 6.

Location Estimated (cy) Max Overdredge Duration (days)

Berth 13A/14F 4,261 2,491 45

Berth 5/6A 8,279 4,027 45

Bid Option (Berth 6) 250 10 30

3.5.2 Interference with Navigation

Contractor shall coordinate all marine vessel movements with the Shipyard’s

Port Operations Department. The Contractor shall submit a weekly updated schedule showing proposed dredge locations and vessel movements to the

Contracting Officer’s Representative. The Contractor shall meet with

Contracting Officer’s Representative and Shipyard Port Operations

Representatives weekly to review the schedule.

The Contractor shall minimize interference with the use of channels and passages. The Contracting Officer’s Representative will direct the shifting or moving of dredges or the interruption of dredging operations to accommodate the movement of vessels and floating equipment, if necessary.

Contractor shall maintain a minimum of 100’of standoff distance from berthed submarines, minimum 25’ to caisson at dry dock entrance, 10’ from any structure (e.g. the port security barriers and berth/pier face), and a minimum of 25’ from berthed barges or support vessels.

3.5.3 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.

3.5.4 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.

3.5.5 Plant

Maintain the plant, scows, coamings, barges, pipelines, and associated equipment to meet the requirements of the work. Promptly repair leaks or

Section 35 20 23 Page 14 breaks along pipelines. Remove dredged material placed due to leaks and breaks.

3.5.6 Disposal of Excavated Material

Provide for safe transportation and disposal of dredged materials to

Building 357, and from the Building 357 to the approved landfill.

Transportation shall include measures to prevent loss of material during movement, including water that might separate from the dredge material during movement. Contractor is responsible to follow all haul restrictions and requirements imposed by the towns or municipalities in which the haul routes are located. The deposit of dredged materials in unauthorized places is forbidden.

3.5.7 Method of Communication

Provide a system of communication between the dredge crew, the Port

Operations of the Portsmouth Naval Shipyard, and the crew at the disposal area. A portable two-way radio is acceptable.

3.5.8 Salvaged Material

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

3.5.9 Safety of Structures

The prosecution of work shall ensure the stability of caissons, piers, berths, bulkheads, fender systems, mooring hardware, and other structures lying on or adjacent to the site of the work, insofar as structures may be jeopardized by dredging operations. Repair damage resulting from dredging operations.

3.5.10 Plant Storage

When not in use, plant equipment shall be stored at an approved location.

Stored plant equipment shall not interfere with Portsmouth Naval Shipyard operations.

3.5.11 Plant Removal

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

3.6 MEASUREMENT

Contractor shall complete soundings before and after dredging.

3.6.1 Method of Measurement

The material removed will be measured by cubic yard in place, by means of soundings taken before and after dredging. The drawings represent existing

Section 35 20 23 Page 15 conditions based on current available information, but shall be verified and corrected, if necessary, by soundings completed before dredging in each locality. Soundings shall be taken by Multi-Beam Sonar methods; as approved by the Contracting Officer, no sooner than 30 days prior to dredging. Post dredge surveys shall be completed immediately following, and in no case greater than 5 business days upon, completion of dredging activity for each designated location. Results of soundings shall be the basis for payment.

3.6.2 Surveys During Progress of Work

Contract depth will be determined by soundings as work progresses. The

Contractor shall be able to produce drawings with hydrographic survey data at any time during dredging operations if requested by the Contracting

Officer.

3.6.3 Monthly Estimates

Monthly estimates of work completed will be based on the result of hydrographic surveys taken during the progress of the work. Deductions will be made for dredging and disposal not completed in accordance with the contract documents.

3.7 FINAL EXAMINATION AND ACCEPTANCE

Contractor shall ensure that existing drains, catch basins, and drainage structures located within the vicinity of the offload site or impacted by the work are free of sediment and debris upon completion of the work. All structures shall maintain the ability to freely transport runoff to the outfalls.

When areas are found to be in a satisfactory condition, the work therein will be accepted as complete. Final volumes will be subject to deductions or correction of deductions previously made because of excessive overdepth dredging, dredging outside of authorized areas, or disposal of material in an unauthorized manner. All material (including hard bottom) shall be removed down to the design dredge depth to receive payment.

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