Leavenworth_Contractor_Q-A_7-9-2021_ANSWERS_0003.pdf

# Contractor Question Government Answer

The specifications mention a video inspection previously performed on the pipe where the CIPP is going to be installed. Are you able to provide the CCTV footage from that inspection?

Historical Video Inspection Footage referred to in the specification will not be provided during the solicitation period. It may be provided to the successful awardee if requested during performance of the contract.

After attending the site visit, the proximity to the river and the high water table gave us concerns about infiltration and heat sinks, especially with the very long liners. If aquatically-friendly UV cured liners provide a better solution for this application, will UV be considered as an approved curing method?

Method must be ASTM approved and comply with all other specification requirements

To meet the provided specifications, CIPP liner is likely to be limited to 1,000 foot shots. We anticipate up to 3 additional access pits will be needed to successfully install the CIPP without overlapping liner or requiring manned entry. Please confirm this will be covered under the CIPP Pre-Work pay item

Contractor work is limited to the Contractor Use Areas (CUA) shown in the specification.

Section 33 11 10-13, 2.02. The products we intend to use for the CIPP lining will be NSF-61 approved for use in municipal and private drinking water systems and are certainly safe for human consumption. The specifications call for “Fish friendly” materials to be used. Can it be assumed that if the products have been deemed safe for public drinking water pipes that they are thereby safe for “fish”? Testing specific to fish and marine animals is not common and may not be available, but we want to clarify if using “human safe” products that are NSF-61 certified can be assumed to be “fish friendly”?

YES, if NSF-61 meets the requirements of 33 11 10 it would be acceptable

Section 33 11 10 - What sources can be utilized for obtaining curing water for the CIPP lining that are “local” to the project?

With advance coordination with the USFWS' Leavenworth Fisheries Complex Manager or the LNFH Hatchery Manager, a fire hydrant at the LNFH can be used as a source of water for curing CIPP lining.

Section 33 11 10 - Does the Government recommend any locations where the curing water from the NSF-61 lining can be disposed or processed?

The Bureau of Reclamation will not recommend any location for disposing of curing water from the CIPP lining project.

140R1021B0015 Leavenworth Fish Hatchery SWISP II Pipe Rehabilitation

QUESTIONS AND ANSWERS

Section 33 11 10-15, 2.05.B.2 – The specification states “The liner shall be capable of curing in the presence of water”. Epoxy resins, which are the preferred resin system as stated in 2.05.B.1, are not compatible with water and will dilute and lose physical properties when mixed with water. We are not aware of any manufacture that has an epoxy for CIPP lining that is compatible with water. However, for clarification, if there is water flowing into the host pipe by way of a crack/hole, etc, these areas are typically grouted to stop the flow or a mechanical seal can be installed to stop the water flow. If this is not possible, then it is also possible to install a water barrier, such as a rubber pre-liner which will keep the flow of the water external to the epoxy impregnated CIPP liner. We feel that there is no epoxy product that “cures in the presence of water” and this statement should be removed or further clarified.

This statement was included to facilitate the use of curing hot water of steam, consistent with the material chosen (styrene-free VER, epoxy, etc.) which was left up to the Contractor.

Flowing water from leaks inside the host pipe is not expected, but could occur, and should be investigated during the pre-work video survey. Additionally, standing water may be present in the sag portion of the profile, which should be addressed during installation. It is up to the Contractor to determine means and methods for installation of materials if their epoxy won't cure or will dissipate in the presence of water.

Section 33 11 10-18, 2.06.B.7 – The specifications state “The modulus of soil reaction for design shall be 200 to 500 psi.” This soil modulus is extremely low and impractical for any roadway that would be considered for HS20 load conditions. The soil modulus should reflect soils that vehicles would actually drive on or the external loading should be modified to only reflect external soil and water loading. The specifications as written, will result in a unreasonably thick liner due to the combination of these two polar opposite specifications and create additional material and installation costs that may be unwarranted.

The Modulus of Elasticity for uncompacted soil, if used in the design of the CIPP lining system, shall vary between 200 and 500 psi, as identified in the Specifications. The Modulus of Elasticity for compacted soil shall be taken as ranging from 1,500 to 2,000 psi when used for design of the CIPP lining system. The soil backfill around the existing CCP (pipe) may be considered compacted for this project

Section 33 11 10-28, 3.10.F.1 – The specifications disallow UV curing for the project, but in section 2.05.B.1.b, it states that vinyl ester resins, which are not harmful to fish and aquatic life may be used (subject to approval). UV cured products are very suitable for this application, and we feel there inclusion is warranted. The UV products eliminate the challenge of finding, transporting, and disposing of cure water, are NSF approved for public drinking water systems, and have physical properties that are 2 to 5 times that of traditional epoxy & glass composite CIPP liners. However, the only NSF- 61 products we are aware of are in UV cured products that are currently manufactured in Germany, and imported by the USA division of the same company, SAERTEX. Would it be possible to consider a potable grade, UV cured CIPP lining system?

Method must be ASTM approved and comply with all other specification requirements

The as-builts show a blow off valve at sta. 18+45, and an air valve at sta.

28+08. Are these to be reinstated following CIPP installation? What is the diameter of these openings at the host pipe?

Yes, these (2) features shall be reinstated following CIPP lining. The diameters of these features are not known, but shall be discovered during the pre-work video and survey work.

Are intermediate excavations and contractor use areas allowed to facilitate CIPP installation, if required?

Contractor work is limited to the CUA's shown in the specification.

Section 33 11 10-30, C, 4, c. This section references chemical resistance testing of installed liner. Chemical resistance testing is an expensive and lengthy process that is generally performed only by manufacturers of the CIPP materials. Will chemical resistance testing previously performed on the product installed be acceptable?

If all materials used are similar or identical to products being installed, then previous chemical resistance testing results would be acceptable. Must comply with Section 33 11 10.

Contractor Use Area #2 & #3 have fire hydrants in near proximity. Is this water available for contractor use?

No, the only hydrant available for use is on Hatchery grounds with advanced notification

Please clarify Work Restrictions 01 14 12 F. 4, Is the juvenile fish release from April 17 to May 13 and the contractor shall maintain 20 cfs after that?

No. Fish release is prior to April 17. The Contractor shall maintain 20 cfs between April 17 to May 13.

Please clarify, does Work Restrictions 01 14 12, G. 1,2 &3 place further restrictions on performing work during the low flow work window of April 17th to May 13th.

Work Restrictions 01 14 12, G, 1, 2, & 3 gives notice that the Contractor shall coordinate any work in the Spillway Pool to respect the Tribal fishing window and Tribal fishing scaffolding repairs that may occur. This does not limit the work during the low flow work window of April 17 to May 13, but raises awareness of other activities that may occur during the same time, in the same area, and encourages increased coordination with Tribal entities.