Amendment 5 - Final Questions and Answers.pdf

Amendment No. 5 – Final Q&A

Date: 07/24/20

Project: Construct Munitions Inspection Assembly Facility

Project No.: FXSB162207

The following changes, additions, and/or clarifications shall be made to the drawings/specifications for the work of the above project.

This addendum forms a part of the contract documents and in case of a conflict between drawings, specifications, and this addendum, the addendum shall govern.

Question 1:

The response to Am. 4, Question 1 leaves depth of burial of the waterline at the Contractor’s option as long as burial is deeper than 36 inches to top of pipe, as long as the line is covered with 2 inches of blue board for every foot shy of 8 feet of burial. We think the Air Force is making a grave mistake to allow 36 inch burial, even with 5 or 6 inches of insulation: frost penetration on Elmendorf AFB/JBER is typically 7 to 10 feet, and no amount of insulation will protect a line buried at 36 inches: frost will penetrate from the sides and from below the insulation, and almost certainly freeze the pipe. Anchorage Water and Wastewater Utility (AWWU: the civilian utility that manages the water transmission and distribution system and the sewer collection system for the Municipality of Anchorage) has established a Design and Construction Practices Manual (DCPM) for water and sewer installations based on Anchorage’s 105‐year history of water and sewer use: the current 2018 DCPM requires 10 feet of burial to top of pipe for water, and 8 feet of burial for sewer. The DCPM makes an allowance for burial of sewer less than 8 feet deep, but the practice is discouraged. The DCPM makes no provision for depths of cover less than 10 feet for water, except that AWWU’s Engineering department may be petitioned for approval of shallower burial in unusual circumstances. DCPM also allows 4” of insulation as protection if a storm drain pipe that is open to winter air crosses the waterline.

176 CES Response:

Slope and elevation of sewer and water pipes was pre‐determined by existing depth of sewer manhole where new sewer line will tie into and depth of existing water line, so without installing a pump station and taking other means the most cost effective manner to protect this system is via insulation board. Concur that amount of insulation should be calculated based on every foot shy of 10 feet.

Question 2:

“Blue board” is the trademark cover for Dow‐Corning’s extruded polystyrene insulation board. DCPM does not require “blue board” (DOW HI‐60) specifically; it also allows “Pink Board” (Foamular 600), a physically identical extruded polystyrene insulation, and “Insulfoam 60psi” expanded polystyrene insulation board, a functionally equivalent product.

Q2/1: Would Insulfoam 60psi or Foamular 600 be acceptable for insulation over water and sewer lines? Is extruded polystyrene specifically required, or is expanded polystyrene acceptable?

176 CES is not specifically requesting Dow‐Corning’s XPS board be used. The term “blue board” is only meant to be a generic term for XPS. A substitute can be used as long as it has the insulating properties required in the design and specifications produced by Jacobs Engineering.

Question 3:

The response to Am. 4 Questions 2 and 4 do not conform to area‐wide burial/pipe cover standards for Elmendorf/JBER: the Municipality of Anchorage Standard Specifications (MASS) is the civilian building standard that applies in the land areas surrounding Elmendorf/JBER. MASS requires that 10 feet of cover be maintained for waterlines to a point inside the building, with a vertical ductile iron pipe riser to above grade. Connection to the service line and reducers are installed above‐grade as part of the plumbing. MASS requires that sewer service lines enter the building at least 8 feet below the surface adjacent to the outside of the building, with a cleanout 2 feet from the building wall per UBC.

Elmendorf/JBER engineers have reviewed design throughout development process and other than adding insulation board throughout length, as has already been prescribed, for water and sewer lines we elect to make no other changes to design package.

Question 4:

The response to Am. 4 Question 3 to treat the gravity‐flow sewer line like the waterline to maintain cover is not constructible. The sewer line is designed to be constructed at specific grades, which must be maintained to maintain gravity sewer flow. The invert elevation of the sewer line is called‐out periodically on Drawings CS‐101 and CS‐102, but there is absolutely no information concerning the existing or proposed surface elevations called out on sheet CS‐102. There is no way for a bidder to determine how deep the sewer will be installed; therefor there is no way to calculate the cost of excavation and backfill to install the sewer service.

Prospective bidders are responsible for confirming site conditions and no other changes or technical information will be forthcoming from the government.

Question 5:

Plan Sheet CS‐101 shows the sewer line terminating 10 feet west of the northwest corner of the building, in what appears to be a revegetated (grassy) area.

a. How does sewage from the building get to the southern terminus of the sewer line?

b. Will there be a structure at this 90° change if direction of sewage flow?

Please see keynote 7 on Plan Sheet CS‐101 which states provide a cleanout at the point you are referencing