W912DW20B0005- Kenmore Dredging Transloading-Disposal.pdf

FY20 Kenmore Navigation Channel Maintenance Dredging 20014 Kenmore, WA

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SECTION 35 20 24

UNSUITABLE MATERIAL TRANSPORTATION, TRANSLOADING, AND DISPOSAL

PART 1 GENERAL

1.1 GENERAL

Contractor is responsible for identifying a Transload facility/location permitted to handle this dredged material.

Contractor is responsible for identifying an upland Disposal facility permitted to accept this dredged material.

The sediment shall be dredged and managed in accordance with SECTION 35 20 23 DREDGING.

1.2 SUBMITTALS

Government approval is required for submittals with a “G” designation; submittals having an “F” are for information only. The following shall be submitted in accordance with SECTION 01 33 00.

SD-01 Preconstruction Submittals

Transload, Transport, and Disposal (TTD) Plan; G

Transload Facility/Location; G

Disposal Facility; G

1.3 DESCRIPTION OF WORK

Approximately 38,000 cubic yards of material in the Kenmore navigation channel has been classified as unsuitable for open water placement. The required work consists of removing the unsuitable material from the channel, transporting unsuitable dredged material (soil, sediment, rock, debris and water (free and entrained in the dredge material) from the channel to a permitted Transload facility/location identified by the Contractor and approved by the Government, transloading the material from the barge to transport vehicles/containers, and disposing and discharging the material at a permitted upland Disposal facility identified by the Contractor and approved by the Government. All water (free and entrained in the dredge material) on the dredge barge shall be discharged into Lake Washington after onsite treatment, which includes filtration to reduce particulates. All water removed after material is removed from the barge must be treated on-site and properly disposed. Transloading consists of all work activity required to accomplish upland disposal of unsuitable dredged material from the point at which it is placed on the barge in the Kenmore channel in Lake Washington. Requirements for dredging and disposal are provided in Section 35 20 23 – DREDGING.

1.4 TRANSLOAD, TRANSPORT, AND DISPOSAL WORK PLAN

The Contractor shall submit a Transload, Transport, and Disposal (TTD) Plan within fourteen (14) calendar days of Notice to Proceed (NTP). The TTD Plan shall describe all elements of execution for transport, transloading, and placement of unsuitable material. This TTD Plan may be included as an appendix of the Dredging and Disposal Work Plan (Work Plan). The TTD Plan shall be a separate document from the Work Plan submittal that is required per Section 35 20 23. Dredging shall not begin until: 1) the TTD Plan has been reviewed and approved by the Government and applicable regulatory agencies; 2) agency-required notifications have been completed in accordance with the WQC; and 3) the Contractor schedules and attends a preconstruction conference with the

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Government, which might include regulatory personnel from Washington State Department of Ecology and other agencies. At a minimum, the TTD Plan shall contain the following:

a) Work Sequence and Equipment

1. Order in which the work is to be performed indicating the work sequence.

2. Number, types and capacity of all land-based equipment to be used as well as names of derrick barges, dredge barges, and other marine vessels to be used.

3. A construction schedule shall be prepared that identifies the timing and sequencing of the major activities to set up, operate, and clean up the dewatering, transit, transloading, and disposal. These shall include, but not be limited to, mobilization, site setup including any environmental protection such as splash shields, start of transloading operations, anticipated material delivery and processing rates, duration of transloading, cleanup, and demobilization. The transloading schedule shall be coordinated with the dredge schedule required for submittal per Section 35 20 23.

b) Means and Methods for Transporting, Offloading, Handling, Dewatering, and Disposal of Unsuitable Dredge Material

1. Methods, procedures, and controls to be used to offload, segregate, handle, dewater both at the barge and once removed from the barge, transport, and dredged sediment and debris disposal.

2. Methods, procedures, and equipment to be used to provide containment of dredged material on disposal barges. Drawings shall be submitted that show the proposed concept for providing containment of all dredged material en route from the Kenmore channel to the Transload facility and subsequent Disposal facility.

3. Methods, procedures, and equipment to be used to transport the disposal barge from the Kenmore channel to the Transload facility/location and subsequent Disposal facility.

4. Methods to be used for record keeping related to transport, transloading and disposal of dredged material.

5. Methods, procedures, and controls to protect transloading facility/location and other facilities and structures encountered against damage, including installation of temporary structures to protect the existing system(s).

6. Methods, procedures, and controls to be used to prevent water from entering existing storm drain system(s).

7. Methods, procedures, and controls to be used to provide containment, collection, and conveyance of all dredged water and surface water to the onsite water treatment system, including water collected during offloading of dredged material.

8. Methods, procedures, and controls to be used to collect and convey dredged water from the dredge barge to the onsite treatment system.

9. A site plan(s) shall be submitted that clearly depicts the Contractor’s proposed setup and use of the Transload facility/location and Disposal facility, including details depicting the proposed water containment, collection, conveyance, and treatment system

c) Dewatering Treatment System Information

1. Description of water treatment system, both barge and land based, product details, and process and instrumentation details.

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2. System scaling calculations, including dredge rates, transload rates, barge dewatering rates, sediment dewatering rates, water treatment rates, stormwater accumulation, and storage requirements.

3. System monitoring, control, and response plan.

d) A Stormwater Pollution Prevention Plan (SWPPP) for operation of the Transload facility/location and Disposal facility that shall meet National Pollutant Discharge Elimination System (NPDES) substantive requirements. The SWPPP shall describe operational and source control BMPs related to dredge material transloading at the transloading facility/location and Disposal facility and shall describe the routing and ultimate disposal of any water from the dredged material, all stormwater collected within the Transload facility/location, all water that is used for wash-down of trucks and equipment, and any water that may come in contact with the dredged material or dredged material handling equipment. The SWPPP shall also discuss the design storm criteria and the contingency for overflows in excess of the design storm and controls to minimize stormwater contributing to the sediment dewatering process. See Section 01 57 20.00 10 – Environmental Protection.

e) Notification procedures to United States Coast Guard (USCG) for barge operations within Lake Washington, Elliot Bay, and other body of water used for transporting dredged material.

f) Environmental monitoring, including procedures for emergency spill containment and removal operations. Spill containment and removal procedures shall be provided that address spills that occur while transiting dredged material to the Transload facility/location, while offloading at the Transload facility/location, and while in route to the upland Disposal facility.

g) Water Quality Monitoring and Notification Procedures

1. The Contractor shall be subject to the requirements and procedures specified in the Water Quality Monitoring Plan (WQMP) Attachment 01 57 20.00 10-A. Provide written acknowledgement of understanding of all requirements and procedures contained in these documents with respect to water quality monitoring, dredging best management practices (BMPs), and notification procedures associated with transload operations. Written acknowledgement shall be provided in the form of a signed letter from the Contractor to the Government.

2. Proposed methods and procedures for monitoring water quality in strict compliance with the Water Quality Monitoring Plan (WQMP).

3. The personnel and equipment that will be used to monitor water quality during the course of the project

4. Contingency measures to be implemented if water quality violations occur.

h) Prevention of Interference with Navigation

1. Notification and procedures to be used for moving transloading equipment to accommodate inbound and outbound commercial vessel traffic using the surrounding waterway.

i) Contractor Quality Control and Organization Plan

1. Organization chart with key personnel and supervisory chain. At a minimum, the Contractor shall identify the following key personnel: superintendent, quality assurance representative, health and safety representative, equipment operator(s), water quality monitoring supervisor (or firm that the Contractor has hired to conduct monitoring), water treatment supervisor, and other key personnel deemed necessary by the Contractor for the successful implementation and completion of this work. Provide 24-hour direct telephone

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numbers for key staff that will be responsible during off hours work periods (5 pm to 8 am the following day and on non-working days).

2. Quality control methods and procedures

1.5 TRANSLOAD FACILITY/LOCATION

Contractor shall identify and propose a Transload facility/location, capable of accepting and handling this dredged material. The Contractor and/or Transload facility/location shall have all the necessary plant, labor, materials, appliances, services, and incidentals, and performing all operations necessary to transload the dredged material from the barge to the transportation equipment that will be used to transport the dredged material to the Disposal facility.

Contractor shall provide complete Transload facility/location documentation showing the facility/location is capable of handling this material. Documentation must include the Transload facility/location’s permits.

Contractor shall provide details of the Transload facility/location’s plant, labor, materials, appliances, services, and incidentals, and all operations necessary to transload the dredged material from the barge to the transportation equipment.

The Government must approve the Transload facility/location (preconstruction submittal required) prior to the start of dredging.

1.6 DISPOSAL FACILITY

Contractor shall identify and propose a Disposal facility, capable of accepting and handling this dredged material. The Contractor and/or Disposal facility shall have all the necessary plant, labor, materials, appliances, services, and incidentals, and performing all operations necessary to transload the dredged material from the transportation equipment to the upland Disposal facility.

Contractor shall provide complete Disposal facility documentation showing the facility is capable of handling this material. Documentation must include the Disposal facility’s permits.

Contractor shall provide details of the Disposal facility’s plant, labor, materials, appliances, services, and incidentals, and all operations necessary to transload the dredged material from the transportation equipment to the upland Disposal facility.

The Government must approve the Disposal facility (preconstruction submittal required) prior to the start of dredging.

1.7 MISPLACED MATERIALS

See Section 01 00 02 SUPPLEMENTARY REQUIREMENTS, paragraph MISPLACED

MATERIAL.

1.8 REGULATORY COMPLIANCE

Permits and Compliance. The Contractor shall be responsible for obtaining all permits necessary from entities for use of the Transload facility/location, Disposal facility and roads and/or rails. The Contractor shall be responsible to adhere and conform to all applicable provisions, conditions and requirements as required within the WQMP (attachment 01 57 20.00 10-A). The Contractor is responsible for notifying the regulatory agencies prior to commencing transloading, discharge of treated dredged water, and upland disposal of dewatered sediment. Any conflicts between these contract specifications and issued permits will be brought to the attention of the Contracting Officer Representative (COR).

PART 2 PRODUCTS

NOT USED

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PART 3 EXECUTION

3.1 ORDER OF WORK

Handling and management of dredged material shall be performed in sequence with dredging at the Kenmore channel and shall be performed in compliance with the work sequence defined in the Work Plan and TTD Plan. See Section 35 20 23 for work sequence requirements for dredging. All unsuitable dredge material shall be processed for disposal through the Transload facility/location.

The Contractor shall set up the transload plant and Transload facility/location to accommodate the proposed means and methods for offloading, dewatering, hauling, and disposal of dredged debris, sediment, and water. The Transload facility/location shall be setup as described in the Contractor-prepared TTD Plan and as approved by the Government.

The Contractor shall outfit his dredge disposal barge(s) to provide containment of dredged material as described in the Contractor-prepared TTD Plan and as approved by the Government. The Contractor shall use of filter fabric covering the scuppers and filter fabric-wrapped hay bales or other containment techniques to control run-off and turbidity from the barges.

Transport of the dredged material from the work area to the Transload facility/location shall only be performed after all standing surface liquid has been removed from the barge.

The Contractor shall perform transloading operations only after approval has been received from the Government that Transload facility/location setup and barge containment has been completed in accordance with the approved TTD Plan.

Transloading activity shall be coordinated and performed in strict accordance with project-specific BMPs and permit requirements. This specification section does not include all required protection measures, mitigation measures, and BMPs associated with this project. The Contractor shall pay particular attention to the conditions of issued permits, the WQMP, and applicable regulations and authorizations associated with this project. All protection measures, mitigation measures, and BMPs included in these documents shall be implemented by the Contractor.

The water treatment system shall be removed only after all cleaning of the site and equipment is complete. All wash-down water including equipment cleaning shall be processed through the water treatment system.

3.2 TRANSLOAD SITE ACCESS AND SETUP

It is the Contractor’s responsibility to coordinate with or operate the Transload facility/location.

A pre-transload meeting shall be held prior to Contractor mobilization to the Transload facility/location to coordinate proposed transloading operations.

At a minimum, the Contractor shall coordinate Transload facility/location access activity on a daily basis with the Transload facility/location. Changes to access routes within the terminal to the Transload facility/location may be required depending on the Transload facility/location operations.

No separate payment will be made for changes that occur due to the Transload facility/location’s operations.

All water that enters the Transload facility/location shall be treated before discharge into the local body of water associated with the Transload facility/location. A site drainage and collection system shall be available to establish complete containment within the Transload facility/location of all surface water and dredge water and to deliver water to the treatment system. The containment system shall include exclusion zones to prevent migration of dredged material from the Transload facility/location via vehicle, equipment, or personnel access leaving the site. Exclusion zones shall include features such as wheel washes, vehicle and equipment wash-down areas, boot washes, etc.

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3.3 DREDGE RETURN WATER TREATMENT

Dredge return water includes the water collected in the enclosed bucket during mechanical dredging and placed on barges, and the entrained water within the dredged sediment. Dredge return water shall include water pumped from the barges. Dredged return water shall be filtered to remove suspended dissolved solids and reduce turbidity to below discharge limits prior to discharge back into the harbor. The Contractor shall bear responsibility for the effectiveness, efficiency, and reliability of the filtration system and for consequential project delays attributed to exceedance of water quality turbidity criteria. The Contractor shall bear costs for additional project delays due to system shutdown because of maintenance or monitoring conditions that warrant subsequent re-evaluation of performance. The Water Quality Monitoring Plan (WQMP – Attachment 01 57 20.00 10-A) defines the monitoring.

3.4 DREDGED MATERIAL DEWATERING

The Contractor shall place dredged material in a fully fenced and sealed haul barge where it will be dewatered and filtered to control run-off from the barges and turbidity in water returning to Lake Washington. Prior to transport of the material to the Transload facility/location, standing surface water above the dredged material in the barge shall be removed and filtered to remove suspended solids. All dredged material shall be sufficiently dewatered in the barge at the dredge to avoid water slopping out of the barge, prior to transport to the Transload facility/location. Dewatering during transit is not allowed. Additionally, if standing water above the dredged material in the barge develops during transit and/or off-loading, the standing water shall be removed and filtered to remove suspended solids before off-loading resumes. Details of the Contractor's strategy to meet the dewatering criteria shall be included in the TTD Plan. All water removed from dredged sediment at the Transload facility/location shall be collected and conveyed to the onsite treatment system to remove suspended solids.

3.5 BARGE TRANSIT TO TRANSLOAD SITE

Barges transporting dredged material from the Kenmore channel to the Transload facility/location shall provide containment of all dredged material during barge loading, transit, and unloading.

Dredged material includes water, soil, sediment, and debris. Dredged material shall not be piled above the barge sidewalls at any time. Geotextile fabric and fences shall be used to line the interior of the barge to prevent soil, sediment, and debris seepage during loading, transit, and offloading.

The Contractor’s proposed method for providing containment of dredged material on transit barges shall be included in the TTD Plan submittal. All repairs or modifications to the Contractor’s proposed dredged material containment system that are necessary to demonstrate containment shall be performed at the Contractor’s expense.

Any barge that exhibits unsatisfactory containment during transloading shall be removed from the equipment utilized on the project until satisfactory repairs are made. Costs and penalties associated with delays due to repair or failure of the containment system shall be paid for by the Contractor.

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3.6 UNLOADING OF DREDGED MATERIAL FROM BARGE

Unloading of dredged material from the barge shall only occur at the designated Transload facility/location and shall be done in such a manner as to prevent spillage of dredged material into the water. All dredged material shall remain contained either within the barge or within the confines of the contained Transload facility/location.

Transfer of dredged material shall occur in a fashion that minimizes splash and splatter of the dredged material. Sheeting or equivalent impermeable lining shall be placed under the travel area of the offloading between the barge and placement site to capture any spills.

There shall be no path for dredged material to fall into the water during off-loading operations. Spill aprons or other containment devices shall be used to prevent the release of spilled material into the waterway or on uncontained landside work areas.

Spill aprons shall be impermeable, uninterrupted, and structurally adequate to catch any falling material, including rain water, and hold or deflect it back into a contained area, either on shore or on the barge. Spill aprons shall be able to provide protection throughout the full tidal range and shall be wide enough that caught material will not fall off the sides. Dredged material shall not be allowed to accumulate on the spill apron.

Transload facility/location sediment control (e.g., sweeper trucks, shoveling, sweeping, wash down) shall occur as often as necessary to avoid tracking of sediment by vehicles and personnel and to generally maintain a clean site.

The Government shall be notified immediately if a spill of dredged material into the waterway occurs. Spill response procedures shall follow those described in the approved TTD Plan.

3.7 WATER QUALITY MONITORING

The Contractor is responsible for all water quality monitoring and is responsible for meeting Water Quality criteria as defined in the approved WQMP.

3.8 TRANSLOAD REPORTS

Daily Transload Report: The Contractor shall keep a daily record of the estimated quantity of dredged material delivered to the Transload facility/location, the number of barge trips made to the site, the quantity of material delivered to the Transload facility/location, the volume of water treated through the onsite treatment system, the volume of treated water discharged back into Lake Washington, results from water quality monitoring, and a summary of other details of the work.

This daily record shall be submitted to the Government with a transmittal letter the morning following completion of work on the date of the Daily Report. The Daily Report shall be signed by the Contractor's transloading superintendent or quality control manager.

Transload Closure Report: The Contractor shall prepare a closure report that summarizes all the daily reports and identifies Contractor estimates of the total volume of transloaded dredge material, including the total volume of treated water discharged into any body of water, to include Lake Washington, Elliot Bay, and Duwamish River.

3.9 SITE CLEANUP

At the conclusion of the transload operation the Contractor shall return the site to its pre-construction condition. All deposited material shall be back graded to stabilize the positioning of the material within the designated footprint shown in the Drawings. Site cleanup shall include, but not be limited to, the following:

Removal of all Contractor-installed temporary structures, utilities, protection devices, etc.

a) Repair of any existing structure that was damaged during the transload operation.

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b) Repair of any pavement damaged during the transload operation.

c) Unplugging of stormwater pipes at existing catch basins.

d) Removal of pier deck drain plugs.

e) Removal of temporary fender/mooring piles installed in front of the dock.

f) Removal of temporary curbing or flow control structures

g) Removal of treatment system, including discharge piping and temporary outfall structures.

h) Removal of Contractor-installed fences and traffic control measures.

Government approval that the site has been restored to its pre-construction condition must be obtained prior to the Contractor vacating the site.

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