Intake_Pre_Bid_Q_A_Final_2015_07_20.pdf

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Lower Yellowstone Diversion Dam Replacement Weir and Fish Passage Channel Pre-Bid Contractor Site Visit – 15 July 2015 Contractor Questions & Answers

1. Has the Government identified potential rock sources for the riprap to be installed on this project?

The Government received pricing information from two potential rock suppliers for use in preparing the Government cost estimate: Fischer Sand & Gravel and L.G. Everist. However, the Government has not approved any riprap sources for this project. The contractor will be responsible for identifying an acceptable riprap source in accordance with Specification Section 35 31 19.00, Part 2.1.1.

2. Is the rock that is currently located downstream of the existing weir from placement of rock on the weir crest over the years to remain in place, and if so, why?

Yes, this rock will remain in place because it is important for allowing native fish species other than pallid sturgeon to successfully pass the existing and new weirs as they migrate upstream.

3. Is there a more direct route of access from the north side of the Intake Diversion (headworks) to the south side (new bypass channel) other than the route indicated in the design drawings, which requires travel through Glendive to use the I-94 bridge over the Yellowstone River?

No, there is not a more direct route.

4. Why is relocation of the existing rock placement trolley system cable and south tower included in the solicitation as an option?

Relocation of the cable and south tower will be required in order to construct the bypass channel, but these are optional items because they may be relocated by the Bureau of Reclamation under a separate contract rather than under this contract.

5. How should the contractor establish the baseline for the new weir?

The point of departure for the new weir is the center of the first sluice gate on the north abutment (historic headworks structure) as specified. The azimuth of the new weir baseline is 8.15°. The azimuth was omitted from the design drawings (Drawing CW302), and it will be added by amendment to the solicitation.

6. Specification Section 31 62 16.00 25, Part 3.1.1.1 states in part, “Obtain driving energy by use of a heavy ram and a short stroke with low impact velocity, rather than a light ram and a long stroke with high impact velocity.” May the contractor use a light ram/long stroke hammer to drive the W36x150 piles contrary to this specification requirement?

This specification language is general guidance to prevent overstressing the W36x150 piles during driving. The contractor may use any combination of ram weight and stroke length to drive these piles, as long as it will not overstress the piles. Prior to constructing the weir, the contractor will be required to demonstrate, through the required WEAP analysis submittal and weir test section, that the chosen combination of ram weight and stroke length will not overstress the piles.

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7. May the contractor use a vibratory drive hammer to start driving the W36x150 piles, and then finish driving these piles with an impact hammer?

Yes, the contractor may use a vibratory drive hammer to drive the W36x150 piles to a tip elevation of 1970 ft. Beyond this tip elevation, use of an impact hammer will be required to finish driving the piles. (Note: this revises the Government’s response to Bidder Inquiries 6150463 and 6150466.)

8. May the contractor use a vibratory drive hammer to drive the sheet piles for the cofferdams?

Yes, the contractor may use a vibratory drive hammer for driving all sheet piles on this project.

9. May the contractor use water from the Yellowstone River for construction purposes (e.g. dust control)?

If the contractor wished to pump water out of the Yellowstone River for construction purposes, they would need to secure a temporary water right. See the Montana statute related to short-term leases of an appropriation right at http://leg.mt.gov/bills/mca/85/2/85-2-410.htm. The contractor could also use water obtained by dewatering of the bypass channel excavation during construction.

10. How should potential bidders know how much excavated material from the bypass channel they will need to process to produce the cobbles required for the channel cobble layer? May potential bidders perform test pits on Joe’s Island during the solicitation period for use in preparing bids?

The Government will amend the solicitation to add a Bid Schedule line item for the number of cubic yards of excavated material potential bidders should expect to process to produce the cobbles required for the channel cobble layer. Potential bidders may not perform test pits on Joe’s Island during the solicitation period.

11. Will use of a turbidity curtain be required for in-river work performed outside of the cofferdams?

Yes, the contractor will be required to control turbidity for all in-river work performed outside of the cofferdams in order to comply with the environmental protection requirements of the Specifications.

12. Does the Government have a geotechnical report it can provide to potential bidders? Specifically, the information from in-river borings would be useful for determining soil parameters (e.g. shear strength) for use in cofferdam design.

The Government used correlations with the Standard Penetration Test N-Value (SPT-N) to establish shear strength parameters for coarse grained soils. For soils with cohesion, the government used Atterburg limits and blow counts to assess relative consistency, both of which were correlated to shear strength. No specific laboratory shear strength testing was performed to support the Government’s expectations regarding cofferdam construction. Specification Section 31 52 00.00 25, Part 3.1a requires that the temporary works for the weir, including the cofferdam, be designed by a Montana licensed professional engineer. Selection of the appropriate soil parameters for use in designing the cofferdam is a matter of professional judgment for the contractor’s engineer.

http://leg.mt.gov/bills/mca/85/2/85-2-410.htm

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13. May the contractor operate heavy equipment on the new riprap to be placed between the existing and new weirs?

Yes, the contractor may operate heavy equipment on the new riprap in an allowable 20 foot wide travel lane measured offset downstream from the new weir centerline. The solicitation will be amended to show this travel lane on Drawing SW302.

14. Who will be responsible for any damage to the new weir from natural forces (e.g. water or ice) that occurs prior to completion of the weir? Who will be responsible for any damage that occurs after completion of the weir but prior to completion of the entire project?

The contractor will be responsible for any damage to the new weir from natural forces that occurs prior to the Government’s acceptance of the weir. The Government is open to partial acceptance of the new weir if it is completed prior to final acceptance of the entire project. Upon partial acceptance of the weir by the Government, the construction warranty period for the weir would commence, and the Government would be responsible for any damage to the weir from natural forces that is not covered by the construction warranty.

15. Why does the bid schedule require pricing of riprap material by the ton and pricing of riprap placement as a lump sum instead of pricing both material and placement by the ton?

This discrepancy is an error. The solicitation will be amended to revise the Bid Schedule so that both riprap material and placement will be priced by the ton.

16. Will the due date for bids be extended?

The solicitation will be amended to extend the due date for bids one week to 06 August 2015.

17. Are any topsoil amendments required, or is the existing topsoil to be reused without amendments?

The existing topsoil is to be reused. Topsoil amendments are not explicitly required; however, please see Specification Section 32 92 19, Part 3.1.1, which states that soil conditioners shall be used as required to achieve the required stand of seed.

18. Has the Corps made any agreement with Dawson County for maintenance of any of the access or haul routes, or is this maintenance strictly a contractor responsibility?

All required access and haul route maintenance is the contractor’s responsibility.

19. Are all road improvements required for construction to remain in place after contract completion?

Yes, all access roads and haul routes are to remain in place after contract completion. Please see the notes on Drawing G-004.

20. Have all required project permits been obtained by the Government?

All required project permits for permanent improvements have been obtained by the Government, except for the Montana DEQ Section 401 Water Quality Certification and the Corps Section 404

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Clean Water Act Permit. (Note that there will be no Section 404 Permit issued for this project, but the Corps will still complete the permitting process.) The Corps expects both of these permits to be issued prior to contract award. The Corps is also pursuing a Montana Section 124 Stream Protection Act Permit as a courtesy, but this permit is not required for construction.

21. The contractor is responsible for obtaining permits for temporary works for construction. Will new permits be required, or will the contractor be allowed to amend the existing permits?

The contractor may file their permit applications as amendments to the existing permits, provided that the permitting agency will allow this. Alternatively, the contractor could file new permit applications that reference the existing permits.

22. The contract documents do not specify the new weir construction sequencing (e.g. the number of sections in which the weir should be placed). Will the Government provide an assumed number of sections for weir placement that potential bidders may use as a baseline for preparing bids?

No, the Government will not provide any assumed weir construction sequencing or number of weir sections for use as a baseline. Per Specification Section 31 52 00.00 25, the contractor is responsible for investigating and determining existing and anticipated conditions, determining an appropriate weir construction sequence, and designing all temporary works for weir construction. Note: for information only, the available construction record indicates that the existing weir was constructed in five sections; however, the existing weir creates different river conditions at Intake than what existed at the time it was constructed.

23. Is there a required width for the new weir cofferdam?

No, the width of the new weir cofferdam is not specified. Per the note on Drawing SW101, Typical Weir Section Plan View, the cofferdam width is to be determined by the contractor. Note that the cofferdam sheet piles shall not interfere with the existing weir. The solicitation will be amended to require that the maximum offset of the downstream row of sheet piles from the new weir centerline will be 6’-4” and the maximum offset of the upstream row of sheet piles from the new weir centerline will be 6’-4”. Note also that the upstream row of sheet piles is to be cut off and remain in place upon completion of the weir.

24. The Bid Schedule indicates that leveling concrete will be measured by cubic yard, but Specification Section 01 22 00 (Measurement and Payment), Part 24 indicates that leveling concrete will be measured by Job. Which is correct?

Leveling concrete should be measured by cubic yard. The solicitation will be amended to correct the Measurement and Payment section of the specifications.

25. Who will be responsible for any additional cost if an obstruction is encountered while driving a W36x150 steel pile?

Please see Bidder Inquiry 6150505.

26. Who will be responsible for any additional cost if an obstruction is encountered while driving a steel sheet pile?

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If an obstruction is encountered while driving a steel sheet pile, the contractor should pull the sheet and jog or realign it to attempt to avoid the obstruction. Note that the upstream and downstream extents of the sheet pile, beyond the minimum footprint of the leveling concrete, are to be determined by the contractor (see Number 23 above). If attempts to avoid an obstruction within the alluvial layer of the soil fail, or if the obstruction is riprap previously placed by the Bureau of Reclamation, then this may constitute a differing site condition subject to negotiation between the contractor and Contracting Officer to determine a technical remedy and any required compensation.

27. The contract documents indicate that the Government will provide the Digital Terrain Model (DTM) for the bypass channel to the contractor after contract award. Will the DTM for the waste channel grading also be provided? What will be the format of the DTM?

The Government will provide the DTM for all parts of this project (bypass channel, waste channel, cofferdams) after contract award. Note, however, that per Note 7 on Drawing CG112, the final waste channel grading is to be designed by the contractor. The grading plans were prepared using InRoads, and the DTM will be provided in MicroStation format.

28. Is the waste channel grading shown on the contract drawings intended to handle all of the bypass channel excavation spoil material?

Yes, although the final waste channel grading is to be designed by the contractor, the approximate waste channel grading shown on the contract drawings should handle all of the spoil material. The extent of the waste channel fill should not need to extend farther downstream than shown on the drawings.

29. Will electronic bids be accepted?

No, electronic bids will not be accepted. Per Specification Section 00 21 00, Part 1.18, bids must be either mailed or hand-carried. This section provides all applicable details related to the required bid format and submittal of bids.

30. What is the required format for as-built drawings?

Please refer to Specification Section 01 78 39.00 24 for as-built drawing requirements.

31. Will grazing of cattle on Joe’s Island continue throughout the contract performance period?

The Bureau of Reclamation has the authority to restrict grazing of cattle on Joe’s Island during the contract performance period. Any required restrictions on cattle grazing will be determined by discussion between the contractor and Contracting Officer on an as-needed basis depending upon the particular phase of construction, and these restrictions will be instituted by the Bureau of Reclamation.

32. Will there be any restrictions on recreational access to Joe’s Island or to the Yellowstone River and both river banks both upstream and downstream of Intake during the contract performance period?

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The Bureau of Reclamation has the authority to restrict recreational access to Joe’s Island during the contract performance period. Any required restrictions on recreational access will be determined by discussion between the contractor and Contracting Officer on an as-needed basis depending upon the particular phase of construction, and these restrictions will be instituted by the Bureau of Reclamation. It will be more difficult to restrict recreational access to the Yellowstone River because boats can launch from various points both upstream and downstream of Intake. The contractor will be required to clearly mark restricted areas during in-river work, and any problems with recreational users entering restricted areas will need to be addressed on a case-by-case basis. Potential bidders should be aware that the Intake area is an extremely popular paddlefish fishing spot, and the contractor and Contracting Officer will need to work with the Montana Department of Fish, Wildlife, and Parks to ensure that work plans for the paddlefish season (generally May 15 to June 30) will neither unduly impact sport fishing at Intake nor result in unsafe conditions for either contractor personnel or sport fishers.

33. The contract specifications require that the contractor’s Site Safety and Health Officer (SSHO) and Contractor Quality Control (CQC) System Manager be separate people, both of whom are required to be on the site at all times during construction and neither of whom may have any other responsibilities. Will the Government consider changing this requirement to allow the SSHO and CQC System Manager roles to be filled by the same person?

No, the requirements in Specification Sections 01 35 26 and 01 45 00.10 10 regarding the SSHO and CQC System Manager will not be changed.

34. Is the contractor required to dewater the waste channel prior to placing excavation spoils into it?

No, dewatering of the waste channel prior to placement of fill is not required.

35. Is there an area on Joe’s Island near the proposed bypass channel where the contractor may set up a screening plant to process material for the required cobble layer?

Yes, a cobble processing location is identified on Drawing G-004.

Other General Guidance Offered by Government Personnel During the Site Visit

1. There is an identified cultural resource area that the contractor will be required to protect during construction. Required protection will be avoidance of this area. This area is located near where the access road across the existing high-flow channel onto Joe’s Island branches off from Dawson County Road 303. The exact location will be provided by amendment to the solicitation.

2. The contractor will be required to minimize disturbance to trees on Joe’s Island. Please see specification Section 01 57 20.00 10, Part 3.2.

3. The Government’s hydrographic survey information indicates that there is a deep hole in the

Yellowstone River bed at the approximate location of the downstream end of the new bypass channel. Potential bidders are advised to pay particular attention to the grading at this location (e.g. Drawing CG101A and CG101).

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4. Potential bidders are advised to pay particular attention to the Typical Weir End/Joint Detail Plan View on Drawing SW101. Per Note 3, the cofferdam sheeting at the joints must either be pulled or be cut off at the top surface of the leveling concrete prior to placement of adjacent structural concrete. In other words, the cofferdam end sheet may not be left in place in the joint between adjacent sections of structural concrete.