S01 Amendment 003 - Attachment 2 - Questions and Responses.pdf

CONTRACTOR QUESTIONS WITH NRCS RESPONSES - 5/05/2021

Solicitation Number: 12FPC321B0006

Project: BARATARIA BASIN LANDBRIDGE PROJECT - BA-27 Repair

1. The industry standard for the manufacturing of articulating concrete block mats is 4.5” thickness. On page 15 of the drawings it calls out a thickness of 5” on the articulating concrete block mat. Will a 4.5” thickness be allowable?

NRCS Response: The word “nominal” will be removed from Drawing Sheet 15. The requirement will be a minimum thickness of 5” with a tolerance as specified in Construction Specification 65 Item 7.A.2)ii which states, “The dimensional tolerance of each concrete element shall be +/- one-quarter (1/4) of an inch.” There are several suppliers that have sizes available that meet this specification.

2. On page 15 of the drawings it shows images of an open-cell design on the articulating concrete block mat, but the specifications calls out a closed-cell design. Which one is accurate?

NRCS Response: The correct requirement is as stated in Construction Specification 65, Articulating Concrete Block, which requires the open area of the entire articulated concrete mat shall not exceed ten percent. The project requires closed cell.

3. On page 16 in the notes section of the drawings it calls out the warning light color to be white, but the specifications call out a yellow light. Which one is accurate?

NRCS Response: NRCS will change warning light color to white and the relevant specifications will be updated accordingly.

4. Are there any design allowances of the geotextile fabric?

NRCS Response: The requirements for the geotextile will be as described in Construction Specification 95 and Material Specification 592.

5. The Continuation Sheet on pg. 4 states 9216 SY of Geotextile, but pg. 5 “THE SCHEDULE” has 9216 CY of Geotextile. Which one is accurate?

NRCS Response: The correct unit is Square Yards (SY). “The Schedule” will be revised and provided an amendment.

6. For the geotextile fabric specifications will there be allowances on Permittivity and Apparent Opening Size such as; #30 sieve for AOS and 0.5 sec on permittivity?

NRCS Response: Allowable maximum and minimum values for geotextile are those stated on page 592-2 of Material Specification 592.

7. Is there a specific Louisiana contractor’s license required for this project? Will a license in Coastal Restoration, and Habitat Enhancement be accepted?

NRCS Response: The federal government has no specific licensing requirements, other than what is generally required to do business in Louisiana.

8. For item No. 6 – Articulating Concrete Blocks, the quantity is listed at 768 Linear Feet. Typically, these types of items are listed in square feet or square yards, since the area is what drives the item quantity. Can you please provide the area of the articulating concrete blocks required?

NRCS Response: Due to the variability of the bag sizes that a contractor may choose to use, a specified width of Articulating Concrete Block (ACB) cannot be determined by NRCS. Therefore, based on the cross sections shown in the drawings, the contractor must determine the number of Lightweight Aggregate (LWA) bags required and estimate the square footage of ACB needed to cover the LWA from toe to toe for the entire length of repair.

9. Where will a magnetometer survey be required?

NRCS Response: A magnetometer survey, as described in Construction Specification 7, Construction Surveys, will only be required within the work limits for each repair site as shown on the drawings.

10. Are there any pipelines in the area?

NRCS Response: Known utilities are shown in the construction drawings. It is possible that some pipelines and/or utilities exist that have not been shown. The Contractor shall perform a magnetometer survey to locate pipelines within 150 feet of the proposed access channels. Pipelines located within 150 feet of the access channels shall be marked in the field prior to construction and shall remain marked throughout construction. The Contractor shall be on the alert for such pipelines and utilities and shall report them immediately to the Contracting Officer (CO).

11. Is the project tax exempt?

NRCS Response: No. The government is tax exempt, but that tax exempt status does not pass on to the contractor in their purchase of supplies and materials. Contractors are responsible for paying any applicable sales tax on supplies or materials.

12. Is Access Channel excavation required?

NRCS Response: Access Channel Excavation is only required to the extent that the contractor can mobilize their equipment to the repair sites. It depends on the contractor’s means and methods.

13. If possible, can we receive the soil borings and logs for the location of the repair project? This is needed to size the anchors that are required.

NRCS Response: Yes. The geotechnical report will be provided.

14. After reviewing the drawings and specifications there is no timber pile specification on treatment or design. All that is called out is length and diameter.

NRCS Response There is no specific requirement to remove or install any timber pile. The dimensions are provided in the event that the Contractor damages the existing piling while doing their work.

Special Provisions Item 12 states that Contractor will repair or replace, in like manner, anything damaged. It further goes on to state that if the Contractor should damage or remove and lose the permanent warning signs and/or timber piles, then the Contractor shall replace at no cost to the Government. Construction Specification 13 – Piling will be provided with full details on the piling requirements (Material Specifications 512 - Wood Piles, Material Specification 583 - Coal Tar-Epoxy Paint and Material Specification 585 - Wood Preservatives and Treatment).

15. Through extensive research on the lightweight aggregate there is no available material that meets the required specification given. Can the USDA give out an alternate material or specification and a recommended supplier?

NRCS Response: Gradation standard in table 1 of ASTM C330 (Coarse Aggregate, 12.5mm to 4mm) may be substituted for gradation standard of ASTM C 136. The relevant specifications will be updated accordingly.

16. What is the engineering estimated value of this project?

NRSC Response: The magnitude of construction is between $1,000,000 and $5,000,000

17. Are there any as built drawings available from the original dike construction, if yes are they available for reference?

NRCS Response: As-built drawings will be made available.

18. Is a barge stability analysis required for the crane barge? (Naval Architectural Analysis) NRCS Response: NRCS has no requirement for this but the Contractor is required to comply with all OSHA, US Coast Guard, and other applicable safety regulations.

19. If the existing elevation is higher than a 2.5 or higher, and the contractor is not allowed to install a LWA bag, then how does the contractor meet the finish elevation limit of 3.5+NAV by only installing a 5” nominal ACBM?

NRCS Response: Note 3 on Drawing Sheet 2 provides a -0.5’ tolerance on final top elevation of +3.5. This can result in an acceptable final top elevation of +3.0. However, as observed in the above question, placing a 5” ACB mat on top of an existing elevation of +2.5 will result in a final top elevation of +2.92 (+ 2.5’ plus 0.42’ (5”) ACBM) which is outside the allowable tolerance of -0.5’. Therefore, the maximum elevation above which no LWA bags can be placed will change from +2.5’ to +2.7’. The relevant drawings and/or specifications will be updated accordingly. Please refer to question and response #1 concerning the use of the word “nominal” as it pertains to the thickness of the ACB mats.

20. Can the contractor remove rock from the existing dike to get the elevation lower?

NRCS Response: No

21. Is the specification section Construction Specification 25 – Rockfill compaction of rock fill and compaction of bedding a requirement for this project?

NRCS Response: Construction Specification 25 requires that compaction of rockfill be Class III compaction in Section 7 (see Item 10.A.3) i). Compaction of bedding is not a requirement and is not allowed.

22. Construction Specification 95 – Geotextile: Is surface preparation required before geotextile is installed under the LWA?

NRCS Response: No. A statement to Section 7, ITEMS OF WORK AND CONSTRUCTION DETAIL stating that “Section 4, Surface Preparation, does not apply” will be included in revised specification.

23. Is compaction of the subgrade required prior to installing geotextile of the articulating concrete block mats?

NRCS Response: No.

24. Is it a requirement to fill the open area of the ACB system with soil or granular material before the occurrence of any rainfall runoff or other event that may damage or contaminate the subgrade?

NRCS Response: No.

25. The specification states that the LWA Bags must be enclosed after filled with the lightweight aggregate. Are there other methods to enclose the bags? If not, is there a recommended service to field close the LWA bags?

NRCS Response: The Contractor shall choose their means and methods, the NRCS does not dictate this. Contractors have performed this on past projects using various methods, one of which filled/closed the bags at an offsite staging area and brought the filled bags to the project site via barge. The lightweight aggregate (LWA) must be in the bag prior to the bag being enclosed. The NRCS does not recommend any particular service.