HAHD_RFP Attach 14 - Bulkhead Inspection SOW.pdf

g3endllg Text Box Howard A. Hanson Dam - Fish Passage Facility 35% DDR ATR-BCOES Submittal g3endllg Text Box Attachment 14 g3endllg Text Box Statement of Work :

Existing Bulkhead Inspection g3endllg Text Box

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21 February 2024

SCOPE OF WORK

Bulkhead inspection and analysis

1. TECHNICAL SCOPE

1.1 General: The Contractor shall investigate safety of existing bulkhead structure, by any means necessary, including but not limited to inspection and analysis, for possible use during the construction of the new fish passage facility. The inspection shall be performed in conformance with U.S. Army Corps of Engineers (USACE) EM 385-1-1, Safety and Health Requirements Manual and EM 1110-2-6054, Inspection, Evaluation, and Repair of Hydraulic Steel Structures. Analysis shall be performed in accordance with EM 1110-2- 6054, Inspection, Evaluation, and Repair of Hydraulic Steel Structures, and EM 1110-2- 2107, Design of Hydraulic Steel Structures. For additional clarifications of EM 1110-2-2107 reference ECB 2023-10, Clarification of Policies and Guidance Associated with the Welding of Hydraulic Steel Structures (HSS). If opting to use the bulkhead in construction of the new fish passage facility, the Contractor will ultimately be responsible for the safety of the bulkhead.

1.2 Background: The project site is located at Howard A. Hanson Dam outside of Ravensdale, WA. To construct the new fish passage facility, the Contractor will need a means of dewatering the existing excavation. The bulkhead which separates the reservoir from the fish passage excavation, was constructed and installed around 2007. At the time, there were reports of difficulty getting the bulkhead to fit in the slot, and some field modification was necessary to hammer the bulkhead into place. However, there is limited documentation of what was done, or the as-built condition. The original fish passage contractors worked on the excavation, behind the bulkhead, for several years before the project was stopped in 2010 due to funding constraints. The bulkhead has since remained in place. Currently, the bulkhead does not impound any water, since there are holes in the wall at the bottom, which allow water to pass through freely.

1.3 Detailed Requirements – Base Contract:

1.3.1 The Contractor may choose to remove the bulkhead from the slots prior to inspection or perform a climbing inspection in place. Note, due to previously reported hammering into place, there may be difficulty removing the bulkhead from the slots.

If performing a climbing inspection, one or both sides of the bulkhead may need to be dewatered, or dive inspection may be considered.

1.3.2 Analysis

As-builts for existing bulkhead are incomplete or not legible. Design documentation is not available. Field measurements may be required to verify existing structure and capacity. Provide structural calculations for review by USACE.

1.3.3 Work plan for work execution

Roberto It seem that the excavation started in 2006 and was completed in 2010 (work stopped), so I agree that bulkhead construction and installation started most likely in 2007, but not sure when it finished.

The contractor shall submit a work plan for review and approval by the government 1 month prior to the start of work. The plan shall detail how the contractor plans to complete the required work including personnel, access, equipment, sequencing of work, safety, means of analysis and other pertinent information. For any required testing, non-destructive testing (NDT) is preferred. If destructive testing is required, condition of bulkhead shall be returned to existing condition or better.

1.3.4 Development of Job Hazard Analysis (JHA).

The Contractor shall coordinate with the USACE technical POC to develop and provide the JHA, including rescue plan, and host a pre-work safety briefing before inspection work commences. The JHA shall be developed to the extent possible with information available prior to the start of work and submitted to the USACE as a draft no less than two (2) days prior to the start of work. The JHA shall be completed on site by the Contractor with USACE and facility POC input, reviewed and signed by all applicable parties at the pre-work safety briefing prior to the inspection. Prior to conducting any work and at the start of each shift, the Contractor shall hold documented safety meetings, rescue pre-planning, and complete Job Hazard Analysis forms. The Contractor shall participate in a teleconference (approximately one (1) hour duration) with members of the inspection team and USACE project personnel at least two (2) days prior to the commencement of the work to discuss the work plan, equipment needs, and other logistics.

1.3.5 Green River Watershed access and site access

1.3.6 Isolation of the excavation from the reservoir

The contractor will be responsible for plugging the 10” submerged pipe that currently allows the excavation to equalize with the reservoir water surface and plugging 4 submerged holes in the excavation side wall that connect to the existing trash rack structure (up to 6” in size). If divers are used for this effort, a dive plan will need to be developed and reviewed/approved by Seattle District USACE dive office.

1.3.7 Dewatering the excavation

1.3.8 Excavation wall stability during dewatering

1.3.9 Treatment of pumped water

When dewatering the excavation, pumped water would need to be processed through existing sedimentation ponds to meet water quality standards.

1.3.10 Rewatering/reconnection with the reservoir

1.3.11 Inspection Report

The Contractor shall provide a report of the inspection, documenting findings with notes and photographs.

1.4 Qualifications: All work shall be performed by a licensed professional engineer, experienced in hydraulic steel structures (HSS) inspection and analysis.

1.5 USACE Points of Contact: Seattle District: XXX, XXX-XXX-XXXX

Bulkhead inspection and analysis