QA_22_September_2016.pdf

Questions and Answers

Q: Is this requirement under Full and Open Competition or set aside for Woman Owned Small Business?

A: This requirement is set aside for Woman Owned Small Business.

Q: Will the tanks be empty and available prior to cleaning activity or will diving/inspection be required?

A: Paragraph 2 of the PWS states: “The contractor shall accomplish this project without disruption of the distribution systems and the tanks shall not be drained.”

Q: Does this work require prevailing wages to be used in our calculations?

A: Yes. A wage determination has been attached to this solicitation.

Q: What amount and type of sediment should we base our pricing on so all bidders are quoting the same and you have a solid comparison? We base our calculations on the removal of 3 inches or less as this is the maximum amount of sediment of a normal consistency that can be removed in an hour.

A: 9 CES/*CEOI estimate was a total calculation for all tanks based on surface area and previous recorded sediment depths for each tank. Estimates are provided next to the tank specifications below.

Q: What is the diameter and height of the on-grade tanks?

A:

B22694 (Main reservoir); 3.0 MG, Dia. 132’ Height 30’/Estimate 1”solids

B5750 (pave Paws); 0.5 MG, Dia. 60, Height 24/Estimate 1” solids

B4800 (MFH); 0.5 MG, Dai 60’, Height 24’/Estimate 1” solids

B4802 (MFH); 1.0 MG, Dai 85’, Height 24’/Estimate 1” solids

B1150 (Elevated storage); 0.25 MG, Dia. 40’, Height 40’/Estimate 1” solids

11025 (WTP Decant tank); 0.15 MG, Dia. 35’, Height 16’/Estimate 36” solids

11025 (Sump wet well); 0.089 MG, 34’X22’X16’/Estimate 3’ solids

Q: What is the diameter or length and width and the depth of the below-grade tanks?

A: 11025 (Sump wet well); .089 MG, 34’X22’X16’/Estimate 3’ solids

Q: What is the diameter and depth of the tank on the tower and what is the distance from the ground to the top of the tank?

A: B1150 (Elevated Tank); Dia. 40’, Depth 40’, height to top of tank is 101’

The entrance hatch is approx 5’ below the top of tank

Q: Please clarify exactly what work is required to complete “h” as listed in the Performance Work Statement. Is this asking us to clean the support columns in each tank? If so how many columns are in each tank and what are their diameters? To calculate the time require will be very difficult without knowing exactly what we will find and we are hardly ever asked to clean a column as sediment does not collect on vertical surfaces.

A: This requirement for cleaning is only the sediment on the bottom of the tank. (Surface area)

Q: Does each tank have a hatch opening 24 inches or larger?

A: YES

Q: Does each tank other than the below grade tank have an exterior ladder?

Q: Does each tank have an interior ladder?

Q: Are all tanks steel welded or concrete? Please identify per tank.

A: Above ground tanks are welded steel. The B11025 (wet well) at the water treatment plant is concrete

Q: How far from each tank is the area where the sediment bags can be placed and the discharge water can be released?

A: All tanks approx within 100’ of tank

Q: Initially the sediment bags will be heavy and hard to move. Can they be left to dry out and removed at a later date? At Travis AFB we were allowed to leave the bags and base personnel disposed of them.

Might this be possible?

A: Bags may be left to dry out and removed once dry.

Q: If we are given a defined sediment depth upon which we will base our pricing where on the quote sheet can we show the cost per hour or day for additional work? Prevailing wage requires that we pay our divers a minimum of 8 hours for any day or part thereof they work; therefore, we cannot quote an hourly cost for additional work. We will always ask for written approval before additional work is performed.

A: Our estimate of solids was based on reported depths from previous tank cleanings. Most Above ground tanks had anywhere from a ¼” – 1” of sediment. I based my calculation on 1” of surface coverage so I’m thinking my calculation is high for those tanks.

We do have a filter backwash tank at the water treatment plant. The last inspection had 36” of sediment. This is solids in suspension. I estimated this as 36 “, so my estimate should also be high for this tank.

Q: We do not use disinfecting agents. Cleaning is accomplished by moving a vacuum across the floor.

A: We are asking that divers and equipment be cleaned and disinfected prior to entry into the tanks.

Pervious contractor have provided this service in accordance with established diver tank cleaning guidelines.

Q: The tower (bldg. 1150) is listed first with a 35ft diameter and depth of 16ft and in a follow-up answer the diameter is shown as 40ft and depth of 35ft. Which is correct?

A: B1150 (Elevated Tank); Multi Column (Capsule Tank) Dia.; 40’ Height; 40’ Height to top of tank; 101’ Gallons; .25 MG The entrance hatch is approx 5’ below the top of tank

Q: The WTP Decant tank (backwash tank) is listed on the bid sheet as .25MG and the answer shows .15MG. Google Earth measurements confirm the 35ft diameter, but we question the overall tank height to be more than 16 feet. Is .25MG correct and is the overall height closer to 30 feet?

A: B 11025 (Decant Tank) Dia.; 35’ Height; 16” Gallons; .115 MG

Q: The Sump Wet Well tank (underground storage tank) is listed on the bid sheet as .25MG and the answer shows .08MG. The dimensions listed would place the tank capacity close to .08MG. Is .08MG the correct capacity?

A:

Length; 34’ Width; 22’ Depth; 16’ Gallons; .089 MG

Note; these are reconfirmed sizes/volumes. It should be noted. All volumes are based on the tanks when full. We usually keep our tanks between 75% - 95% full at all times. Exception would be the B11025 (Decant tank) which is anywhere from 25%-90% depending on when last backwash was performed.

Q: How far from the base is the location where the sediment bags can be disposed? What is the name of the site?

A: It is incumbent upon the contractor to research locations for proper disposal.

Q: Can the sediment bags be left for removal by base personnel?

A: No. Sediment bags will be disposed of by the contractor.