ATT 2 RFI_BIGTUJUNGA.docx

AMENDMENT 1

ATTACHMENT

RFQ 127EAW23Q0017

Request for Information (RFIs) for Big Tujunga Water System Repair Contract

A. PRE-BID SITE VISIT

Questions & Responses

1. What is the tank’s thickness for the ladder to be attached? How tall should each ladder be?

The tanks’ thickness is 8-inch. The west tank is 8-feet high and the east tank is 6-feet high. Standard 8-foot ladders can be used for each.

2. What is the size of the interior piping?

Currently, the pipe is 3-inch with one exception of a 2-inch line currently feeding the east tank. New pipe between tanks with the valving will be 3-inch.

3. There is no geotextile fabric referenced for the rip rap at the end od the drain. Will it be required.

A geotextile fabric shall be installed in the excavated area prior to rip rap placement. The price of the fabric will be incidental to the line item for rip rap. See 02661 Part 3 D.

4. How much rip rap should be installed under the drain line?

Rip rap quantity is specified as 0.25 cubic yards. With a trench width of 24 inches, the anticipated length will vary based on the depth of material being placed. The riprap should cover an area approximately 2-feet wide by 3-feet wide and of sufficient depth to allow a vertical drop from the drain outlet not to exceed 12-inches. A geotextile fabric shall be installed in the excavated area prior to rip rap placement.

5. What are the measurements of the area between the tanks?

The tank piping & valve covered area between the tanks is above 8-feet between the tanks and 65 inches wide between the cinder blocks.

6. What is the metal access plate hatch cover dimensions?

Both tanks have a metal access plate hatch cover measuring 31 ¾- inches by 31 ¾-inches.

7. How long does the drain line need to be?

Drain line will not exceed a total length of 25-feet away from the tanks and extend outside of the fenced area. The drain lines for each tank should outflow at the same location.

8. Can drain lines be in the valve box rather than extending from the tank itself?

Yes drain line will be housed in the tank piping & valve covered area rather than coming off from the tank to require less trenching.

9. How many damaged spots need patching?

The west tank has 4 cracks and the east tank has 7 cracks, all on the exterior surfaces.

10. Will debris removal be done?

The Forest Service will have the area within the fence and immediate area around the fence cleared to provide better access to the tanks and the area south of the tanks so drain lines can be installed.

11. Where should the tank levels be located?

Tank level should be located on the south part of the tank so they can be viewable from the fire station in the canyon below rather than the road to the north.

12. What is each tank’s diameter?

The tank’s diameter is 13-feet, 4-inches.

13. Should the same gauge thickness be used for the metal access plate hatch covers?

The metal access plate hatch covers can be replaced in kind.

14. How far is the fence from the covered area?

There is up to 11-feet between the fence and tank piping & valve covered area.

15. How deep does the trench need to be for the drain lines.

Drain lines should be placed between 20-22-inches deep and the excavated material shall be backfilled without a need to remove any excess material.

B. Additional RFIs Questions & Responses

16. Please clarify the scope of work for exterior tank repair specification section 03400 Minor Concrete Repair.

Repairs to the cracks will include exterior patching for 4 cracks and the east tank has 7 cracks, as indicated in Question 8. As stated in the Specification 03400, the work will include materials, supplies, and labor needed to perform the patching on the tank exteriors.

17. Bid schedule line item 0007 calls for 1 hatch cover to be provided, if so, which hatch will it be, (top of east tank or top of west tank) or will you require two?

The Schedule of items has been updated. Both metal access plate hatch covers will be replaced, and the tank piping & valve covered area over the replaced piping will be replaced as well.

18. Section 15010 part 3, 3.1 I -makes reference to a Tank Vent, where is the tank vent on the plans.

No tank vents are present.

19. Dwg sheet D-01, Where does new 2-inch drain line enter the tank? Can the entry point take place at the existing connection points at the top of both tanks?

See revised drawing. The overflow line will use the same input as the current inflow and size to 2-inch.

20. Dwg sheet C-03, has a 1"=30' scale on the dwgs that does not appear to reflect the existing field conditions?

Scale is incorrect and has been removed from the revised drawings. The drawing is not scaled.

21. Quantity of pipe from tank to tank is very high, please verify.

The distance between the existing tanks is 8-feet. The piping line item should take into account the drain lines, fill lines, overflow line, and piping among the isolation valves between the tanks.

22. Can not find size of pipes between tanks, need to know if we are using 2-inch pipe or 3-inch pipe, please clarify if it schedule 80 threaded galvanized steel pipe The 3-inch pipe will be a majority of the piping used between the tank. A 2-inch line can be used for the fill lines and utilize the existing holes. Schedule 80 threaded galvanized steel pipe should be used.

23. Are we to core new holes in tank or are we to use existing holes in tank.

Contractor should use existing holes in tank for overflow line and core new holes for fill lines being used.

24. Section for concrete tank, under product materials, you call for galvanized pipe and cast iron pipe. Where is cast iron pipe used.

Cast iron pipe will not be used for this project and has been removed from the specifications.

25. Section 03100 Concrete Forms and Accessories, How does this specification apply to the project Section 03100 has been removed from the specifications.

26. Section 03200 Concrete Reinforcing How does this specification apply to the project.

Section 03200 has been removed from the specifications.

27. Section 03300 Cast in Place Concrete How does this specification apply to the project.

Section 03300 has been removed from the specifications.

28. Currently the plans show one opening into the tank. According to our High Performance coating installers, you will need two opening to meet safety regulations to clean and install this coating system, how do you plan to proceed.

Need to determine what the applicable safety requirement will be at time of award. For the purposes of bidding this project, please use the defined scope and quantity per current revised plans and specifications.

29. spec section 15010 2.1 c. vent/drain screen is not shown on the plans, please advise.

Not present and spec section removed.

30. spec section 15010 2.1 k. cast Iron pipe is not shown on the plans, please advise.

Not present and spec section removed.

31. Section 15010 3.1 I calls for a Tank Vent, not shown on plans.

Not present and spec section removed.

32. Section 15010 3.1 k. plans do not call for any pipe in the tank to be changed. Please advise Specification has been updated to reflect the pipe to be replaced.

33. Section 02511 2.4 Mechanical joint bell and plain spigot end fittings or 2.5 Push on joint ductile iron fittings, or screw fittings. Which are we to use for the project?

Either can be used for this project and is the contractor’s discretion.