2amnarr.pdf

Amendment No. 0002 W912P9-16-B-0013

AMENDMENT OF SOLICITATION

Specifications and drawings are amended as follows:

GENERAL REQUIREMENTS

SECTION 00 08 00 – Delete this section and replace with the like numbered section which includes changes to paragraph 1.22 (j).

SECTION 01 15 00 – Delete this section and replace with the like numbered section which includes changes to paragraph 2.1.

SECTION 01 22 00 – Delete this section and replace with the like numbered section which includes changes to paragraph 1.1, subparagraphs d, e and f.

GRAVITY DRAIN/ACCESS ROAD TECHNICAL REQUIREMENTS

SECTION 31 24 00.11 - Delete this section and replace with the like numbered section which includes changes to paragraphs 1.2, and 3.2.1 and its subparts.

SECTION 32 15 00.00 09 - Delete this section and replace with the like numbered section which includes changes to paragraph 2.1.2.

SECTION 35 20 16 - Delete this section and replace with the like numbered section which includes changes to paragraph 2.5.8.1.

SECTION 35 31 19 - Delete this section and replace with the like numbered section which includes changes to paragraph 2.1.2.6.

SOUTH UNIT TECHNICAL REQUIREMENTS

SECTION 03 31 01.00 10 - Delete this section and replace with the like numbered section which includes the deletion of 1.4.1 and subsequent renumbering of following paragraphs.

SECTION 31 24 00.11 - Delete this section and replace with the like numbered section which includes changes to paragraphs 1.2, and 3.2.1 and its subparts.

SECTION 32 15 00.00 09 - Delete this section and replace with the like numbered section which includes changes to paragraph 2.1.2.

SECTION 35 20 16.02 09 - Delete this section and replace with the like numbered section which includes changes to paragraphs 1.9, 2.2.2 and 2.2.10.

GRAVITY DRAIN/ACCESS ROAD CONTRACT DRAWINGS

Delete and replace the drawings with like numbers as shown below:

Deleted Drawing Replacement Drawing C-105 C-105.1 C-301 C-301.1

Amendment No. 0002 W912P9-16-B-0013

SOUTH UNIT CONTRACT DRAWINGS

Delete and replace the drawings with like numbers as shown below:

Deleted Drawing Replacement Drawing C-501 C-501.1 S-101 S-101.1 S-104 S-104.1 S-105 S-105.1 S-106 S-106.1 S-202 S-202.1 S-203 S-203.1 S-204 S-204.1 S-205 S-205.1 S-206 S-206.1 S-304 S-304.1 S-305 S-305.1 S-306 S-306.1 S-505 S-505.1 S-506 S-506.1 S-507 S-507.1 S-601 S-601.1

CONTRACTOR QUESTIONS

See attached questions and responses.

1. Will a tax exemption certificate be provided?

Yes, after contract award.

2. There are two CLINS for Mobilization/Demobilization. One for the base bid and one for the option.

252.236-7004 states that 60% will be paid upon mobilization and 40% paid upon demobilization.

Will the 40% for the base bid be paid at the end of the base bid features of work? Or will the 40% for both CLINS be paid when the entire project is complete and all equipment is demobilized?

The 40% for the base bid demobilization will be paid upon completion of demobilization of the base bid work and the 40% for the optional items demobilization will be paid upon completion of the demobilization of the optional items.

3. Do road repairs need to be done at the end of the three years as stated “at the end of the contract”? Or will the contractor be expected to keep the roads repaired during the course of the contract?

Interim road repairs prior to the end of the contract may be required depending on the severity of the damage and impact to public or staff using the roads. The government's intention is that minor damage can be repaired at the end of the contract or sooner if a particular access road is no longer being utilized by the contractor. Requirements for interim repairs and minor repairs performed before the end of the contract will be determined by the contracting officer.

4. 000800-1.22 there is no sequence of work required. Is this correct? Contractor can work on any features that have been awarded?

Correct, there is no sequence identified. The sequence of work will be determined by the efforts associated with the features as awarded. With regard to the gravity drain structure, please review the final paragraph in 1.22 regarding the overshot gate transmittals.

5. Please explain “Design of the Overshot Gate Structure”. Will the various items described need to be designed and stamped by a professional engineer?

See Section 35 20 15. In paragraph 2.2.2, very end: "All calculations shall be performed under the supervision of and sealed by a licensed professional engineer." Please note that the intent of the specification is for the design of the gate and associated items to be performed by the gate manufacturer (for manufacturer qualification requirements see paragraph 2.2.1). This is also to include design of the operating equipment anchorage to the concrete per paragraph 2.5.9.7, for which the manufacturer may have to engage the services of a separate entity. Supervision and seal requirements would also apply to that work. We have not asked for sealed drawings, but all items are subject to warranty per paragraph 1.9.

6. Same question for design of the cofferdams?

Stamped drawings are not required for South Unit work, but are for Gravity Drain work. Care of water is up to the contractor as long as it meets the requirements in the Care of Water spec section 31 23 19.02.

7. Is there any surveying required other than for layout?

No other surveys required by the government. See revised Section 31 24 00.11 included in this amendment.

8. 01 15 00 states that the contractor is to provide a job trailer “for use by the government”. Can one trailer be provided and shared by the contractor and government or will two trailers be required?

Does the government really need for the contractor to provide a computer as specified?

Yes, only one trailer will be required and no computer. See revised Section 01 15 00 included in this amendment.

9. 01 22 00 states that the removal of existing structure is paid under both the subunit degrade and water control structure CLINS. Which one?

For locations where an existing water control structure is being replaced with a new one, the removal is paid under that water control structure CLINS. When a structure is being removed as part of a berm degrade, or removed and backfilled, it is paid under the berm degrades for that subunit.

10. 03 31 01.00 10-What would constitute a “prequalified cement/pozzolan source”? For testing at the batch plant is this testing to be performed by a Corps certified testing lab or can the plant QC personnel perform the testing?

See revised Section 03 31 01.00 10 per this amendment for cement and pozzolan requirements. See Section 01 14 40-3.7.1 for testing requirements.

11. Clarify the number of staff gages required (plan sheet S-508). The notes indicate that three of the structures have gages on the managed side only. Would we assume that the others would have gages on the channel side as well?

There is one staff gate on each of the C2, SW2, and BP2 managed sides. There is one staff gate on each of the PS1, PS3, and PS4 structures. There is one staff gate on each side of the overshot gate gravity drain structure. All staff gages location will be coordinated with the local sponsor.

12. The specifications state that the borrow area shall be excavated over the entire footprint. Can portions be excavated as the project progresses to alleviate the borrow area filling with water? Will the stripped topsoil from the borrow area be placed back into the borrow area? How is the unsuitable material hauled to the borrow area to be placed?

Yes, the borrow area excavation can be done as the project progresses. No, the government will not require the topsoil to be placed back into the borrow area. It may be used as embankment material if it meets the requirements. Unsuitable embankment material should spoiled in the area designated on the plans. See revised Order and Coordination Section (J) included in this amendment.

13. Please clarify embankment testing requirements. Is the embankment semi compacted? 31 24 00.11 paragraph 3.3.2 for both projects states that in place density testing shall be done within 4 feet of any concrete and or steel and every 24 inches of completed fill. Should we assume that the only testing required will be within 4’ of all structures?

No. Embankment shall be tested every 24 inches, especially the outer embankment surrounding the gravity drain as this embankment is also a levee protecting the managed area. Small berms on the interior of the managed unit do not need to be tested.

14. Does the earthen material placed in existing ditches during the berm degrade fall under the same specification for embankment construction? The specification states that no embankment shall be placed in water. This would require “unwatering” of the ditches. In addition, the specifications state that the “foundation material consisting of soft, wet, or organic material or debris upon which embankment is to be placed shall be removed”. This would require excavation of all of the ditches prior to placing degrade material.

No. The earthen material placed on ditches does not qualify as embankment and can be placed in water.

The ditch is not a structure that requires a specific foundation condition.

15. This contract requires that bedding stone is to be used as the “crushed stone base”. On previous similar contracts, much courser stone has been used as the base. Please verify.

Coarser stone is to be used. See revised Section 32 15 00.00 09 included in this amendment.

16. Please confirm that the specification for the seed mix on the embankment areas is correct. On previous similar contracts, a different seed mix was used.

The seed mix in section 32 92 00.00 is correct.

17. It appears as though “dewatering” may be required to lower the piezometric level 3’ below the lowest excavation (430.74) at the gravity drain. Can you provide hydrographs with the relationship between the nearest gage and the mouth of Bryant Creek?

Bryants Creek is located along the southern border of the refuge, and is a tributary of the Mississippi River. Bryants Creek enters the Mississippi River near river mile 261.1 above the mouth of the Ohio River.

A gaging station of the Mississippi River at Mosier Landing, Illinois, is located at river mile 260.3 above the mouth of the Ohio River. Data are available for this gage from August 1939 to the present. Another gaging station of the Mississippi River at Rip Rap Landing, Illinois, had been located at river mile 265.0 above the mouth of the Ohio River. Data are available for this gage from August 1939 to the year 2000.

Available data for these two gages beginning with the year 1941 were used to calculate, by linear interpolation, the Mississippi River average daily elevation for river mile 261.1. In performing the calculation, it was recognized that different periods of record were used for the gages at Rip Rap Landing and Mosier Landing. It was decided to accept this shortcoming since the Rip Rap Landing period of record was 81 percent of the length of that used for the Mosier Landing gage, the Rip Rap Landing gage was much closer to the mouth of Bryants Creek than is the next-closest gage with a long-duration period of record (Lock & Dam No. 24 tailwater, river mile 273.2), and the mouth of Bryants Creek is relatively close to the Mosier Landing gage.

Mississippi River average daily elevation data for three locations near the refuge are shown in FIGURE

1. The three locations are the site of the former Rip Rap Landing gage, the mouth of Bryants Creek and the site of the Mosier Landing gage. The average daily elevation for each of these three locations varies significantly with time of year, reaching maximum values for each gage during late April. The data used to create each of the plots shown in FIGURE 1 can be provided.

FIGURE 1. Mississippi River Average Daily Elevation Data near the Refuge.

18. Would the government allow over-excavation of 1’ under all structure base slabs to place a layer of clean rock for the purpose of controlling water in the excavation?

Yes, with the proviso that the properties of the material proposed would be submitted for approval.

19. Is there any boring information for the borrow area?

No, plan sheet B-101 in the South Unit Water Control Structures and Berm Degrades set shows the locations of all borings drilled within the unit.

20. Could the government provide any topographic information of the berm degrade areas?

Lidar survey data of existing site can be provided by the government after award of contract upon request. See CCNWR Site 1’ Contours pdf included in this amendment for additional berm degrade information.

21. Nowhere in the specification does it list the required Cable to Drum Ratio – Example if the design calls for a 1.0 in diameter cable and the specification calls for a cable to drum ratio of 12 that would require the cable hoist to have a 12 inch diameter drum – Please note the smaller the drum the less torque it takes to drive the hoist – In summary the Cable to drum ratio on a cable hoist is very important as one cable manufacture may use a small ratio therefore having a hoist with much less capacity versus on that uses a higher ratio and a hoist with much more capacity – Also note the tighter a cable wraps around the drum the more cable fatigue is caused.

The minimum cable to drum ratio will be as recommended in Table 9 of the Wire Rope Technical Board

– Wire Rope User’s Manual for the type of wire rope proposed in the design. Verbiage added to the spec to clarify.

22. Move the gate 6.0 inch per minute using a manually operated handwheel – is just not possible with the many reductions needed to get down to a 40 Lb-Pull when you have a hoist that is requiring 91,385 lbs of total lift. We can get down to only 1 to 1.5 inches per minute using a handwheel at 50 rpm – using the powered drill that spins at 250 rpm we can achieve the require 6 inches per minute.

I’m assuming this is in reference to paragraph 3.3.2.1 and 3.3.2.2; these paragraphs do not require the gate to be operated at 6.0 inches per minute using a manually operated handwheel. These paragraphs say that during the field tests the gate shall be operated 6 inches of travel using the operator without the drill and no time constraint.

23. Some of the structures are not that large. Do all structures formwork drawings require formwork to be stamped by PE and checked by another?

Engineering approval is a standard requirement for the design of structural reinforced concrete. The intent is that the engineer sealing the work has a self-mandated quality control process to catch errors, omissions and so forth, thus requiring another engineer to check the work. This requirement does not require the checker to seal the calculations or formwork design.

24. Is dust control required on public (county) roads?

Yes, dust control should be considered situationally when traffic dictates.

25. Please clarify which embankment areas require compaction to 95% and density testing. The embankment section for the water control structures implies only within 4’ of the pipes and structures, but the embankment section in the gravity drain section of the specs implies all areas require testing.

The interior embankment berms for the water control structures do not have to be tested, however, the embankment section around the gravity drain does have to be tested every 24” as this embankment is also acting as a levee.

26. The specs state the precast beams must meet the IDOT requirements. Is this the intent or MoDOT?

IDOT is correct. MoDOT does not have standard details for the desired items.

27. 05 50 14, 2.3.3.2, d mentions weld testing on H-Pile and flowmeters. These are not included in this project. Please clarify which items require weld testing.

No testing is required unless indicated under paragraph 2.3.1.

28. 31 24 00, 1.2 , 8 states quantity surveys are required for embankment Quality Control. Are surveys required since excavation and embankment are by the job?

No other surveys required by the government. See revised Section 31 24 00.11 included in this amendment.

29. Are Access roads that are to receive surfacing to be graded prior to rock placement to remove ruts and obtain a uniform top? Or shall rock be placed on existing?

Yes, some grading prior to rock placement may be required to remove ruts and obtain a uniform top.

The government’s intention is for the rock to be placed on existing unless there are specific areas of damage or rutting that should be graded before rock placement.

30. Due to the length of the contract and the uncertainty on the release of funding will future consideration be given to large price swings on fuel, concrete, etc.? Or should the contractor include these contingencies in their bid?

The contracting officer will consider contract modifications if necessary due to changing conditions.

31. It was stated at the pre-bid that access must be maintained for a landowner that borders the refuge.

Does this mean limiting work areas, or providing access (i.e. cofferdams with driving surface)?

Work areas will not be limited. The Contractor shall provide access for agriculture equipment and vehicles throughout the duration of work, including driving surfaces over cofferdams if warranted.

32. Plan page C-106 shows the final grading at the gravity drain. The work includes a new levee alignment setting back the existing levee. The new alignment crosses an area of ponded water. The pond of water is substantial and is present in multiple satellite photos taken over different times.

The embankment spec states that no placement in water is allowed. Please advise the intent for this area. Should contractors plan to have contingencies to unwater this area in their proposals?

Yes. A contingency to unwater this area, if needed, to meet the Embankment spec should be included.

It is the government’s intent that it would be part of the contractor designed cofferdam.

33. Also regarding the same area will the setback have to be completed to plan protection level before the existing levee can be degraded?

The new setback embankment will have to be completed to at least the spillway elevation of 448.0 before degrading the existing levee.

34. The PS1 structure as can be seen on S-101 has a radius in the box culverts. Can the contractor use small forms segmented to produce the desired radius or does the radius have to be a smooth transition?

Contractor can form the radius using segmented forms to establish the radius as shown on the drawings.

The final configuration will need to be coordinated with and approved by the government.

35. On plan page C-106, Gravity Drain Final Grading, the existing road appears to run into the ACB mats of the new structure. How should contractors plan on handling the intersection of the existing road to the new structure?

The existing road surfacing should be removed within the footprint of the gravity drain embankment grading. See revised sheet C-105.1 included in this amendment.

36. The rock to be placed on the access road shown on C-101 and typical section C1 on C-301 is incidental to CLIN 0002 is this correct? All of the other surfacing stone on the project are unit priced items. What is the reason for this being by the Job?

The rock to be placed on the pump station access road in the Gravity Drain package is covered by CLINs 6006 and 6007. Crushed Stone Base and Crushed Stone Surfacing CLINs under each water control structure covers the road surfacing on the new embankment in each of the structure areas. CLIN 0002 under the South Unit Water Control Structures covers the rock that is to be placed on the rest of the access road between the structures in the South Unit Water Control Structures plan set.

37. The structure removal at location X=743476.45; Y=1247836.36, shown on page C-105, is on a road with a rock surfacing. The note just states that it should be graded to “match adjacent berm grade”.

Does the surfacing have to be replaced? If yes what are the required materials and depth?

Surfacing does not need to be replaced in this area.