Attachment_7_-__Questions_and_Answers_MC_0004.docx

Attachment 7 – Questions and Answers 140R4025Q0008 – BGNDRF Backflow Preventer Replacement

AMENDMENT 0004

Questions and Answers

1. SOW: Install reducing tee (6” x 6” x 4”) with valves on downstream 6” (shutoff for test bays and pads) and 4” (construction water source) lines." The diagram for the 4" construction water source line ends at a valve. Is this valve buried, or does it come to the surface? And is that the intent to just end it at a valve?

- Government Reply – The goal of this work is to have a way to connect to the new 4” shutoff line for construction work. So, the valve supplied should have a way to connect to future piping or hoses. This could mean a flanged connection or have internal threads. The valve would be above ground. The bidders can suggest what they feel is best in their technical proposal.

2. Are DETECTOR ASSEMBLIES on any of the BFPs required?

- Government Reply - The goal is to replace like-for-like on the backflow preventers and to be in compliance with the City of Alamogordo. BFPs should comply with the City's 2022 standards here:

https://ci.alamogordo.nm.us/DocumentCenter/View/9060/Alamogordo-Technical-Standards-PDF?bidId=

Per Article 10-02-080 Cross Connection, Prevention, and Control:

Reduced pressure backflow prevention devices shall be Watts Series LF909 or Engineer Approved Equal.

Refer to Standard Details: W-30 and W-31.

If the bidder recommends detector assemblies, they should indicate the benefit the Government will receive from it.

The bidders can suggest what they feel is best in their technical proposal.

3. In the SOW Principal Components of Work, Item 3 calls for a 2 inch shut off valve to be installed downstream of the BFPD.

a. It is assumed that this is to be installed in the horizontal underground 2 inch piping. Is the type of existing pipe known (PVC, HDPE, etc.)?

-Government Reply – The goal was for the shutoff valve to not be buried for ease of maintenance. The bidders can suggest what they feel is best in their technical proposal.

b. Concerning the valve, does Reclamation have a preference for the type of valve used (Ball, Gate, Resilient Seat Gate, Stop and Waste, Curb Stop, etc.) or the type of enclosure (valve can, curb stop can, landscape box, etc.)?

-Government Reply – Our preference is a quarter full port valve that isn’t PVC. Something along the lines of this Apollo two-way ball valve: https://www.grainger.com/product/APOLLO-Manual-Two-Way-Ball-Valve-2EEK7. The bidders can suggest what they feel is best in their technical proposal.

4. In the SOW Principal Components of Work, Item 5 calls for a 6x4 reducing tee, a 6 inch valve and a 4 inch valve to be installed downstream of the BFPD.

0. It is assumed that this is to be installed in the horizontal underground 6 inch piping. Is the type of existing pipe known? In the pictures of the old vaults it appears that this pipe is C900 PVC, can this be confirmed?

-Government Reply – The 4” valve should be easily accessed (i.e., above ground). The 6” valve can be buried with access to the valve using a tee bar similar to what we have for other valves at the facility. However, the bidder should consider maintenance needs in the future.

As for the pipe, it is likely C900 PVC, however, confirmation may require potholing. Other buried 6” pipe at the facility is C900 PVC.

The bidders can suggest what they feel is best in their technical proposal.

0. Is the 6x4 Tee to be a Tapping Sleeve, a Mechanical Joint Tee, or Mechanical Joint x Flange Tee?

-Government Reply - The bidders can suggest what they feel is best in their technical proposal.

0. Concerning the valves, does Reclamation have a preference for the type and/or brand of valves used?

-Government Reply – Quarter turn valves are preferred for the 2” and 4” valves. These can be ball or butterfly valves. The material should be durable and not PVC or other plastic material. The 4” valve should have a flange or threaded connection that will facilitate connections to future piping or hoses for construction work. All valve handles should be durable and able to withstand outdoor conditions. We do not have a preference on the 6” valve type, however if it is an option to have a reduced amount of turns for closing and opening it could be beneficial. The bidders can suggest what they feel is best in their technical proposal.

0. Concerning the 4” Construction Water service, does this line currently exist? Will the contractor be splicing into both a 6” and a 4” line or is the 4” a new service? Will the contractor be continuing the 4” service beyond the 4” valve or just stubbing out the 4” Tee and Valve for future use?

-Government Reply – The 4” construction water line does not exist. This project will install a new tee on an existing 6” supply line and installing the 6” and 4” valves. The 4” valve should have a flange or threaded connection that will facilitate connections to future piping or hoses for construction work. The bidders can suggest what they feel is best in their technical proposal.