26094 - Addendum 04 - 09.02.2026.pdf

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Date: September 2, 2026 Project: Fivemile Hydroelectric - Phase 1 Construction Solicitation No.: ITB 26094 Addendum No.: 04

TO ALL PLAN HOLDERS:

The following changes, additions, clarifications, and/or deletions are hereby made part of the ITB Documents for the above noted project, as if fully contained therein. All other terms, conditions, and specifications of the original Invitation to Bid remain unchanged.

Bidders must acknowledge receipt of this Addendum by email prior to the bid due date and time.

The ITB Package is hereby clarified, changed or modified by the following:

CONTRACT PROVISIONS AND SPECIFICATIONS

The ITB Due date and time of September 9, 2026, at 2:00 PM AKST remains unchanged.

QUESTIONS AND ANSWERS:

1. Question: Is there any geotechnical data available for contractors to use and if not, can HDR provide an estimate of approximate volume of rock to be blasted for the project?

Answer: No, there is no geotechnical data. Contractors are expected to estimate volume of rock excavation.

2. Question: Spec section 40 20 44 - 4 3.2.B.3 states that the fusion bead on the inside of the piping is to be removed. Based on contractor's experience, the inside bead from welding is typically not removed, especially for longer 50' pipe sections indicated. Can the specification be modified to remove this requirement?

Answer: No, removing the bead is still required. Contractor may purchase and install 40 ft sticks of pipe rather than 50 ft sticks.

3. Question: How long does AEA anticipate taking from bid submission deadline to award the contract and issue the NTP?

Answer: Bid close to contract award varies, assume 2 to 4 weeks. NTP will now be issued at time of DOE approval of prospective awardee.

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4. Question: Special notice to bidders indicates achieving intake access no later than 20 October 2026 and substantial completion no later than 20 June 2027. With the anticipated NTP date likely to not occur until mid-late September and then the period for the submittal and approval of pre-construction submittals, these timeline dates are likely to not be feasible. Will the Period of Performance be extended based on award dates and seasonal freeze/thaw times for the area as the steep slopes of the project will make the roads impassable for rock truck use on snow/ice.

Answer: Bidders should prepare their bids with a new target for heavy equipment access to the intake site by July 1, 2027, and substantial completion by August 1, 2027.

5. Question: With nothing else in the area to be protected, will the contractor be allowed to forgo the use of a blanket for rock blasting?

Answer: Yes, except Contractor must keep public users of the trail safely far away. Also, any blasting at the powerhouse area would need blankets due to proximity to the highway.

6. Question: General Note 8 states that the majority of the tree clearing for the project has been completed, and most trees have been chipped except for those on steeper terrain.

Upon visiting site, it was noted that the entirety of the phase one areas past the diversion from the jeep trail has only been felled with no chipping performed and all trees left intact where they had fallen. What salvage requirements for the disposal of trees are there for the remaining trees felled in the construction area of phase one?

Answer: Contractors should assume no salvage requirements but should include cost to relocate felled material to the edge of project limits.

7. Question: Section 31 00 00 states that the clearing and grubbing are to be stockpiled for reuse, with the limited area for staging of material will the contractor be allowed to place the trees and grubbing on the downhill areas of the project site.

Answer: Yes, but coordinate locations with Engineer and Owner.

8. Question: Will contractors be allowed to pull water from the culvert stream at the start of the jeep trail by the Edgerton Hwy. For use in compaction?

Answer: Contractor must obtain its own DNR Temporary Water Use Authorization to do so.

9. Question: Will contractors be allowed to make modifications to the jeep trail on the section to the project site as needed for equipment and material access?

Answer: Yes, but coordinate modifications with Engineer and Owner.

10. Question: For bidding purposes is the contractor to assume that all blasted material is to be suitable as fill material for the embankments?

Answer: Yes.

11. Question: Will the overburden that is to be removed from high spots be suitable for subbase fill of the low spots on the road?

Answer: Yes, except for the top organic mat layer.

12. Question: Page 92 (PDF page number) states that a copy of the wage determination is included in the solicitation, but we have not seen one in any of the issued documents.

Could the required wage determination be provided?

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Answer: Contractor should use the higher of the State and Federal wage determination for each role. Relevant determinations are available here:

• State: https://labor.alaska.gov/lss/forms/Pamphlet_600_Issue_52.pdf?q=041026

• Federal: https://sam.gov/wage-determination/AK20260006/1#document

13. Question: Section 5.4 states that Builder's Risk Insurance will be required. Since this phase will not include any buildings or significant storage, does this need to be required?

Spec Section 31 23 00 Earthwork

14. Question: 2.1 A.2 - Filter Blanket is specified but not indicated on drawings. Section 31 37 00 3.1B Calls for Filter Blanket under all Rip Rap. Typical sheets C-220 call out class 2 Rip Rap 2’ thick placed directly on Class 1+ geotextile. Which is correct?

Answer: Use Class 1 geotextile below riprap.

15. Question: 2.1 A.3-Surface Course is called out as meeting gradation for Surface Course

D-1, with exception that material does not need to meet LA wear of Degradation values.

Drawings call out surface Course Grading C-1. Which is correct?

Answer: Use C-1 and the same exception applies that material does not need to meet LA wear of Degradation values.

16. Question: 2.1 A.4- Porous Backfill Material- noted in specifications but not called out in plan sheets. Is Porous Backfill incorporated on Phase 1 of this project?

Answer: No.

17. Question: 3.4 B.1- Rock Excavation- ‘Employ an independent surveyor to determine rock quantities before removal operation begins’. – No unit price for Rock Excavation is listed in contract documents.

Answer: Disregard. Rock excavation is required as part of the lump sum bid.

18. Question: 3.4 C.3- Rock Excavation- ‘Contract unit price for rock excavation shall….’ –

No unit price for Rock Excavation is listed in contract documents.

Answer: Disregard. Rock excavation is required as part of the lump sum bid.

19. Question: 3.6 B- Excavation for Structures- Does phase 1 of this contract include excavation and backfill procedures for proposed future structures?

Answer: Yes, the powerhouse, sheet C-216.

Spec Section 31 25 00 Soil Erosion and Sediment Control

20. Question: 3.1 A – During Construction Period- If encountered, and are excavated or blasted rock embankments expected to be seeded or stabilized as part of phase 1 contract?

Spec Section 40 20 44 Polyethylene Pipe

21. Question: Neither the plans nor specifications call out a specified SDR thickness for the upper penstock line being installed as part of Phase 1, please provide SDR thickness.

Answer: SDR 13.5

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22. Question: 2.1 A- Owner Supplied Materials- ‘contractor shall supply all other materials necessary for pipe installation…’ Is owner providing HDPE piping for phase 1?

Answer: No. Contractor to supply HDPE pipe.

23. Question: Hilfiker, the listed supplier of the MSE wall, only recently sent a quote for an expanded version of the MSE wall that shows embedment depth below the surface shown on the plans. Our DBE subcontractor has requested an additional two days to make a site visit on Thursday and Friday of this week to evaluate surface and inferred subsurface conditions for the additional embedment depth called out by the supplier, Hilfiker. We feel an extension until Tuesday, August 25, would be beneficial getting the most competitive pricing and not impact planned mobilization in September. The concern is evaluating potential blasting that may be required to extend the wall beyond the depths shown in the initial plans, which was originally called out to be on the existing grade.

Answer: Procurement was extended.

24. Question: Will AEA retain a compaction tester on site at all times when fill is being placed to avoid delays due to testing requirements?

Answer: Compaction testing is the responsibility of the contractor.

25. Question: Are there any requirements for disposal of any unused spoils from rock blasting?

Answer: Generally, no, but coordinate with Engineer and Owner.

26. Question: Will the contractor be allowed to expand the lower staging area should it be requested for additional room to stage material?

Answer: Possibly, depending on how much larger. There are also wide spots along the existing trail that could be used for additional contractor staging. One is about 800 feet up the trail from the Edgerton Highway, the other is about 1000 feet up the trail from the highway.

27. Question: Page C220 and C221 contains details for ditch widening around the culverts, but there is no ditch shown in any of the soil and rock cut details. Does the designer/AEA require a ditch line through the entire access road on the uphill side or the road?

28. Question: Where is the access control gate to be installed along the road?

Answer: Station 23+00.

29. Question: Page C210 shows a proposed 24" culvert in the access road profile at approximately station 2+00 but does not contain length, is this culvert still to be installed?

Answer: No. Do not install a culvert there.

30. Question: What are the inverts at the inlets and outlets of all culverts?

Answer: Contractor to field fit culvert inverts.

31. Question: What PSI rating is required for the concrete for the access gate posts?

Answer: Use Alaska DOT&PF Class B concrete in accordance with Standard Specs for Highway Construction, section 550-2.02, Table 550-1. 4,000 psi.

32. Question: Can you confirm the wage scale determinations to be utilized for this project?

Answer: See above.

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33. Question: In order to complete quantity verification, could AEA please provide cross sections, designers quantity computations, and the Designers original ground surface file in an .xml format.

END OF ADDENDUM #04