ATT_8_Amendment_2_Questions_0002.pdf

Additional Questions for GC River Outlet Works Relining

09/19/2023

1. Per Q&A in Addendum No. 1, Item No. 5 We are aware that the project consists of relining the outlet pipes and we are aware that caulking’s and fillers must be compatible with the coating system.

You did not respond to how the fillers or caulking is quantified. Without quantities how do we address material and labor costs other than guessing. Please quantify areas for caulking and fillers in each outlet pipe.

We are anticipating minimal quantity for caulks or fillers. The pipes are weld construction, with minimal discontinuities, such as expansion joints, or sleeve couplings. The pipes do not appear to have severe pitting. It is anticipated there will be less than a 100 cubic inches of epoxy filler/ caulking material required per outlet pipe. If there is any cavitation damage, it should be communicated to the onsite Government representative. These repairs will be completed with Government crews, after this contract is complete.

2. For welding repairs how do we quantify stand by time/delays for equipment and personnel during welding repairs if no other work can be performed?

The weld inspection is planned for two days, once the original lining is completely removed. If any weld repair is identified, holdbacks will be required while the remainder of the pipe is relined. After the contractor has relined the pipe, the Government will perform weld repairs, and perform lining repair at the holdbacks.

3. Where is the termination point for interior coatings in the 6” drainpipes in Outlets 1 and 2? Does the coating stop at the valve or continue? Per the drawings sheet 557-D-522 under Drain Plan and Profile A-A and B-B it is difficult to tell were the drain ends to determine how we would capture the spent water from hydro blasting.

The lining of the 6-inch diameter drainpipes starts in the outlet pipe and goes to the valve. If more access is required, there is a sleeve coupling just downstream of the valve.

4. Per page 15 of Section 09 96 20 Coatings, Tabulation No. 2, Item 5, “States that valves will be replaced in-kind by facility. Are we to assume that the Facility will remove this valve then we can use this as a access point to the interior and when our work is complete the Facility would reinstall the valves.

The Government will remove this 6-inch diameter valve and re-install the valve upon completion of the relining.

If more access is required, there is a sleeve coupling just downstream of the valve.

5. How much time is needed for the owner to install and remove bulkhead gates?

Two days to move the bulkhead gate and install on the next pipe.

6. Per Q&A in Addendum No. 1, response to question No. 2 we will assume the water will be diverted through the 6” upper drain by the bellmouth or through the drain in F level and capture of the water will not be required as it will be diverted back into the river/reservoir.

No water treatment is required since both drains lead to a sump pump.