ATT_6_Amend_001_-_Site_Visit_Questions_0001.pdf

140R4023R0010 River Outlet Works Pipe Relining at Glen Canyon Power Plant

Pre-Site Questions

1. Where are the entry points into each pipe? Looks like there are only 2 – 20” manholes?

This is correct, plus the pass-through space at the hollow jet valves.

2. If there is leaking water where can the water, be diverted to?

Drawing 557-D-578 shows there is a drain in the bell mouth just downstream of the bulkhead gate. The volume of water that leaks around the bulkhead is unknown but should be less than 100 gallons per minute as stated in the specification section 02 04 10,

1.06 Project Conditions. If there is too much water for the drain to handle, water can be pumped to the F level and put down the drain.

3. Can we weld on the interior of the pipe?

Glen Canyon personnel will perform the post cleaning weld inspection and will perform any needed weld repairs.

4. Per 3.09 Coating Tabulation, Blasting and Lining, In the tabulation box it states Sherwin

Williams Duraplate 235 / Sherloxane 800. If we are lining the interior of the Outlet pipe using this product there are some safety concerns, I have. One by using this product or any other product that is not a 100% solid material or is a solvent base coating you are introducing solvents into a confined space which could create an LEL above 10 percent and even LEL’s below 10 percent does not mean it is necessarily safe. With limited ingress and egress and locations for ventilation, which is a big safety concern, using a

100% solid epoxy coating like Sherwin Willaims SherPlate PW 100% solid epoxy would not introduce solvents and remove that safety issue. My second part to this is what is the

Sherloxane 800 being used for? Is this to be placed over the top of the SW Duraplate

235? Also keep in mind that these products have to be applied in multiple applications and will require time for coatings to set up to get back on top of them to apply any additional coats to achieve the DFT requirements. This will add time and substantial costs and safety issues. Using 100% solid coating can be applied in one application and has least amount of time to cure prior to submerge the coating.

The coating was selected based on the extreme service conditions due to the maximum water velocity being 75 ft/s. It has been observed that some 100% solids epoxy chip off at 25 ft/s water flow rates and complete are removed in higher water velocities within 1 year. If the outlet works linings are to be successful, a different lining system was required. The epoxy/ polysiloxane system has been evaluated at 75 ft/s water velocities and there was no delamination. The polysiloxane provides increased corrosion protection compared to a 100% solids epoxy and solvent borne epoxy.

It is recommended to use robotics equipment to reduce risk. Any lining can be applied using robotics application equipment, not just 100% solids. By using robotics it will reduce the number of employees within the confined space.

The contractor is responsible for using the appropriate environmental controls and to provide a safe work environment.

The contractor can provide substitute materials, but will require prior testing in water velocities at 75 ft/s.

5. Being the site walk is on August 22nd and this bids September 11, plus the Labor Day holiday and people taking vacation and the complexity of this project plus this doesn’t allow us a lot of time to secure subcontracting quotes. Can the bid date be pushed out a week or two?

Solicitation is extended to 2 October 2023 at 5:00 PM MD.

Questions from Site Visit – 22 August 2023

1. There might be the Possibility that a couple of swing stage connection points be required in upper section of Pipe at the Elbows at around Elevation 3374. Would the Bureau allow this and if so, what might be required from the contractor… possibly size, configuration, and engineering?

The contactor would be allowed to weld brackets to the interior of the bypass tubes with the provision that all brackets be removed when the job is finished, and the surface returned to a pre work condition or better. The contractor will be responsible for their own engineering of the brackets.

2. Is potable water or electricity available onsite? If power is available is 480-3 phase available?

Potable water and 480V 3 phase power is available on site in the form of hose bibs and

480V 30-amp plugs. Please see Section 01 51 00 Temporary Utilities.

3. Per page 119 of the specifications how do we quantify under cuts and filling of welds?

Glen Canyon personnel will perform the post cleaning weld inspection and will perform any needed weld repairs.

4. Per page 119 How is the pitting of the steel to be quantified for Outlet Pipes 1 thru 4?

Who is responsible for measuring the pits? Who is repairing/welding the pits?

Glen Canyon personnel will perform the post cleaning weld inspection and will perform any needed weld repairs.

5. Per Page 120 of the specifications how is the caulking or fillers to be quantified for crevices, gaps, and seams on the interior or exterior of Outlet Pipes 1 thru 4? What materials are to be used for these locations?

The entire project is relining the interior of the river outlet works pipes. The fillers and caulks shall be compatible with the coating manufacturer’s product.

6. Currently there are only 2 – 20” access points to the Outlet pipes, one in the gate

Chamber and one just passed the bottom of the slope in the pipe. Can the general contractor install a new manhole in all 4 Outlet Pipes?

Reclamation prefers not to add additional penetrations to the tubes. If the Contractor proposes to add a manhole to outlet pipe it shall be in an alternate proposal for consideration.

7. Can the hollow jet be fully opened to allow personnel to enter and exist and allow ventilation?

Reclamation can open the hollow jet valves to 60% for an additional access point.

8. Concerning the solvent base coating system for the interior lining as specified in Section

09 96 20, 3.09 Coating Tabulations, Blasting and Relining, which specifies solvent base coating system. The coating systems specified will introduce solvents into a confined space which can create an environment that can exceed the LEL limits therefore could create an environment that if there was a source of ignition could cause a fire or worse yet an explosion. Due to limited access and the complications of ventilation for this project we are requesting to use a 100% solid coating system to eliminate this safety issue in lieu of the proposed coatings system. Is this acceptable?

The coating was selected based on the extreme service conditions due to the maximum water velocity being 75 ft/s. It has been observed that some 100% solids epoxy chip off at 25 ft/s water flow rates and complete are removed in higher water velocities within 1 year. If the outlet works linings are to be successful, a different lining system was required. The epoxy/ polysiloxane system has been evaluated at 75 ft/s water velocities and there was no delamination. The polysiloxane provides increased corrosion protection compared to a 100% solids epoxy and solvent borne epoxy.

It is recommended to use robotics equipment to reduce risk. Any lining can be applied using robotics application equipment, not just 100% solids. By using robotics, it will reduce the number of employees within the confined space.

The contractor is responsible for using the appropriate environmental controls and to provide a safe work environment.

The contractor can provide substitute materials, but shall provide prior testing in water velocities at 75 ft/s.

9. Per Drawings sheet 557-D-522 for the 6” drain line in Outlet Pipes 1 and 2 how will the contractor access the interior of this pipe? Mechanical methods will be next to impossible to use with 90-degree bends, turns and valves and to reach 140’. We do not believe these drainpipes can be adequality coated. We are aware of the drain openings on the interior of the outlet pipes but not exactly sure where the pipe drains to. Can this work be omitted due to it being impractical to perform this work?

Drawing 557-D-522 shows access to the 6” diameter drain line are inside outlet pipes 1 and 2 approximately 47.5 ft upstream from the hollow jet valve. Inside each pipe, there is a 90-degree bend attached to the 8’ diameter outlet pipes. Outlet pipe no.1 has a 24.66’ section of 6” diameter straight pipe, a 45-degree bend, then a 45.75’ of straight pipe to a flanged valve in a pit between hollow jet valves 1 and 2. Outlet pipe no. 2 has a 21.5’ section of 6” diameter straight pipe, a 22-degree bend, then a 45.75’ of straight pipe.

Waterjet cleaning is specified due to the complexity of abrasive blast cleaning. Valves can be removed for access.

10. How much water leakage can the contractor anticipate there will be for Outlets 1, 2,3, and

4. Can the water be discharged or diverted back into the reservoir or river?

Drawing 557-D-578 shows there is a drain in the bell mouth just downstream of the bulkhead gate. The volume of water that leaks around the bulkhead is unknown but should be less than 100 gallons per minute as stated in the specification section 02 04 10,

1.06 Project Conditions. If there is too much water for the drain to handle, water can be pumped to the F level and put down the drain.

11. Per the Solicitation and the specifications, it states there is asbestos removal. Per the

Solicitation, on page 40, it states that per I.23 WBR 145.223-80 – Asbestos-Free

Warranty – Bureau of Reclamation (Aug 2021) (a) The contractor warrants that all items delivered, or work required by the contract, shall be free of asbestos in any form whatsoever.

The clause WBR 1452.223-80 –Asbestos Free Warranty- Bureau of Reclamation

(August 2021) Requires contractor to not use any asbestos containing material on this project.

12. Please identify where the asbestos work/removal is to be done so it can be quantified.

Please note the exterior of the drain valves do have lead based paint that will need to be removed and disposed of properly.

All linings were non-detectable for asbestos. There is no asbestos work/ removal on this project.

13. Is the coating system to be dechlorinated prior to the Outlet pipes being put back into service?

This is not a requirement in the specification.

14. Is Mil Scale present under the existing coating?

Reclamation has assumed that the mil scale was removed during original lining application.

15. RFP Attachment 1, Specification, Foreword, page 3, states the “principal components of work include removal of existing linings, hazardous materials abatement, and relining of the river outlet works piping.” Attachment 1, Specification, Section 01 11 00, 1.02 lists

“Principal Components of Work” in items A-H that differ from the list on page 3. In addition, Section L.10(f), page 69, states “Provide a brief narrative describing the approach to performing and accomplishing the principle components of the work …

Principle components include:

• Access to all work areas and use of containment where applicable

• Control of water

• Complete lining removal and re-lining of river outlet pipes interiors

• Surface preparation

• Application techniques for coatings and linings

• All major equipment required”

Please clarify which list of “principal components of work” offerors are to use when developing our index, cross reference matrix, and technical proposal.

Section B lists all the specific components of the work. CLIN A1-6, B1-65, C1-3, D1-3.

Section 01 11 00 Principal Components of Work A-H match the CLIN items.

Technical proposal components are intended for the Contractor to show their approach and knowledge and understanding of the project to accomplish the required components listed in Section “B” and in Section 01 11 00 of the specification.

16. Can you identify where the closest waste disposal facilities are and the name of the facility? We are assuming your folks dispose of materials regularly.

Republic Services Transfer Station of Page, 3004 Coppermine Rd, Page, AZ 86040,

(928) 645-3885. Please note, providing this information is not Reclamation requiring this facility be used, this is for information only.