QA Elkhorn Creek EWP.pdf

Elkhorn Creek EWP (Gabions & Grouted Riprap)

Elkhorn Site & Northfork Church Site in McDowell County, WV

Solicitation Number 12FPC326B0002

Questions and answers

1. Q: Does excess material have to be hauled off?

A: Yes, excess material must be hauled off to an approved landfill or dump site located outside the floodplain. A signed release is needed from any private dump site landowners prior to hauling material off site. Any fees associated with disposal of excess material is the sole the responsibility of the contractor.

2. Q: Will rebar anchoring or riprap foundation be required for the gabion baskets?

A: Bid Item 3B, Foundation Preparation on Shallow Bedrock (Rebar Anchoring) and Bid Item 4B, Riprap Foundation Protection may or may not be installed. The NRCS Engineer will determine if Bid Item 3B, Bid Item 4B, or a combination of both will need to be installed.

Contractors are instructed to bid these items as if they will be needed. Any unbalanced bids will be rejected.

3. Q: Will rebar anchoring be required for the grouted rock riprap?

If bedrock is encountered during excavation for the riprap keyway (at bottom of the slope below streambed grade), then rebar anchoring will likely be required. The NRCS engineer will make the final determination. Reference sheet 7 of the drawings for details. Rebar anchoring for grouted rock riprap is paid for as a subsidiary item under bid item 3A Rock Riprap.

3. Q: Can riprap truck beds be lined with fines for truck bed protection?

A: Yes, but only riprap meeting the gradation requirements stated in the contract will be allowed to be placed in the work areas of the project. All unused riprap materials, truck bed linings shall be hauled off site to an approved disposal location (see question 1). A tonnage of truck bed lining material will be agreed to between the on-site superintendent and the inspector for a deduction from the load ticket. A copy of the riprap load tickets will be provided to the inspector for each load delivered to the site.

4. Q: Will there be a concern if grout gets in the stream?

A: Yes. Grout can not be installed in standing water, so the contractor’s dewatering plan needs to keep the stream or standing water from entering the work area as grout is being placed. Provisions also need to be in place to keep fresh grout or grout residue from entering the stream. Once grout has reached its initial set, water can be allowed to come into contact with the grouted riprap.

5. Q: Can the performance time be extended if weather doesn’t allow grout placement in a timely matter?

A: A request would need to be submitted in writing to the contracting Officer (CO) for approval. Bad weather days should be kept track of by the COR and the contractor. Plan ahead on weather to ensure that grout can be installed properly and with the site excavated with no fill or silt that may have been washed in. The contractor is responsible for monitoring the weather carefully when bedding materials and riprap are started, as to not allow the toe keyway to get contaminated with debris and silt due to a highwater event. The contractor may need to schedule to place portions of filter materials, riprap and then install grout to protect those lower elevation sensitive areas.

6. Q: Who will be testing the grout for compliance with the contract specifications?

A: It is the responsibility of the contractor to perform or have a qualified individual to perform all concrete tests as stated in the contract. The contractor shall submit to the COR the qualifications of the individual or entity performing the test (typical certifications include ACI and state DOH/DOT). NRCS may also perform periodic tests for compliance.

Grout requirements which shall be verified via testing are listed under Construction Specification 62 – Grouted Rock Riprap.

8 .Q: How much time is allowed to empty a concrete truck of grout?

A: The contract states the grout mix shall be delivered to the site and placed within 1.5 hours after the introduction of the cement to the aggregate. In hot weather or under conditions contributing to accelerated stiffening of the concrete. The time between the introduction of the cement to the aggregate and complete discharge of the grout batch shall be a maximum of 45 minutes. All grout batches delivered to the site shall have a batch ticket to be considered for placement. Grout must be vibrated in as well. Refer to the construction specifications for all concrete placement requirements.

9. Q: Where do we store the excavation until needed for backfill?

A: That is up to the successful bidder as long as it’s not obstructing the stream. If a storage location is selected outside of the construction limits, written permission must be obtained from the landowner of the storage location prior to using for storage. Storage locations outside of the construction limits must be restored to existing conditions or better after they are finished being used. Areas to be reseeded must be seeded and mulched in accordance with Construction Specification 6 – Seeding, Sprigging, and Mulching.

10. Q: Can equipment be operated in the stream?

A: In-stream equipment operating time shall be kept to a minimum. Continuous traversing in the stream will not be permitted. Small berms or other means need to be constructed to traverse the equipment above flow to allow the stream to pass under or around the tracks of the equipment.

11. Q: Are existing pipes supposed to be replaced?

A: All existing and in service pipes are to be replaced with a material that is equal to or of greater quality and shall be extended out 6” from riprap/gabion baskets.

12. Q: Is dewatering required? Can gabion stone be placed in the baskets in standing water?

A: Dewatering the foundation is required, but blocking the entire stream is not allowed. The excavated foundation needs to remain dewatered until grade can be established, gabion basket set, and the bottom two feet of stone installed, in accordance with the drawings and specifications, prior to allowing water to enter the work area. Notice, at the gabion site specifically, the depth of the water needing to be dewatered in the scoured hole is roughly

2.5 feet in the scoured hole at the beginning of the gabion wall, which varies from the rest of the site as well as at the site with grouted riprap. The contract requires that after the foundation has been excavated, there is a 24-hour timeframe to have the base basket completely installed, filled with stone and backfill in accordance with the drawings and specifications. A dewatering plan is not required to be shown, but bids should reflect the cost to dewater. If contaminates or debris are allowed to get into the gabions due to water entering the work area, the contractor is responsible for removing the contaminates and debris prior to continuing the filling process.

13. Q: Can we pump water from the stream to perform the flushing of riprap prior to placing grout as required by the contract?

A: Yes, as long as the water is clean and free of any oils. Flushing shall require a pump using a minimum diameter of 1-1/2” intake and discharge. The flushing process is expected to remove silt, fines, debris, and open voids to allow free grout placement without disturbing the riprap placement. Flushing will need to be repeated if contamination of the riprap occurs before grout can be placed.

14. Q: Can lacing be done on site and is there any room on site to lace gabion baskets?

A: Lacing can be done on site and there should be sufficient room to do the lacing on site within the construction limits. Anything done outside of the construction limits requires permission to be granted by the landowner in handwritten form prior to using areas outside of the construction limits. Gabions may also be laced together off site to the extent possible prior to placing, if that is desirable.

15. Q: Does the gabion stone need to be hand placed in the gabions?

A: All exposed faces (including top of steps) plus 1 foot beyond, of the gabion baskets need to have the gabion stone placed in a fashion to give a void free face as much as possible (called facing). The laborers need to use larger, flat rocks in this process to perform the facing. All layers throughout the gabion stone placement matrix will need some hand work to level out 1’ lifts of gabion stone, filling in all voids and to facilitate the required cross tying as shown in the drawings.

16. Q: What are the hours of operation, will we be able to work over the designated hours in the contract?

A: Your work schedule needs to be approved by the CO prior to work commencement, and work and non-work holidays are spelled out in the solicitation. The Contracting Officer needs to approve any work schedule changes and non-work holidays. The contractor needs to request these changes within 5 days prior to a work schedule change. The entire work needs to be completed no later than 50 calendar days after receiving the Notice to Proceed. The maximum workweek allowed is 10 hours per day, 6 days a week (Monday through Saturday).

17. Q: Will we need to pay prevailing wage?

A: The awarded contractor will need to pay Davis Bacon wages as shown in the solicitation.

A minimum of group 2 power equipment operator will need to be paid for equipment operators, and a minimum of group 2 will be paid for laborers.

18. Q: If we hit a footer during excavation, what do we do?

A: The contractor shall plan to saw-cut the footer at the limits of the work area, remove and dispose of the footer as per contract requirements.

19. Q: Do we need to haul dirt in?

A: It’s not anticipated that materials need to be hauled in. Extra materials from one site can be used on the other site provided the materials are as per contract requirements. If additional material is needed to backfill any areas of the site, it is the contractor’s responsibility to obtain needed material. Care needs to be used during the excavation process to try and save any topsoil, if possible, to be used in the final grading. If materials are hauled from site to site, Davis Bacon wages will apply to the truck driver hauling those materials.

20. Q: Can rock riprap or gabion stone be dumped directly into the stream when placing those materials?

A: Yes, but care needs to be taken to not disturb areas of the opposite bank, and restricting the stream’s flow will not be permitted. The contractor must take care to not create a flooding situation for the work area if this is practiced.

21. Q: Can curing compound be used on the grouted riprap?

A: Yes, follow Construction Specification 62 – Grouted Rock Riprap and Material Specification 534 – Concrete Curing Compound. For bonding purposes, care needs to be practiced if grouting is performed in sections as to not get curing compound on surfaces that need to have additional grout placed in the future. Other methods of curing will need to be performed on surfaces that will have additional grout applied at a later date or time.

22. Q: Does Miss Utility need to be contacted?

A: Yes, it’s the responsibility of the contractor to provide a confirmation number to the COR or inspector prior to any excavation being performed.

23. Q: Can work be performed on both sites at the same time?

A: Possibly, as long as government inspection requirements can be met by the available inspection staff. Working at multiple sites simultaneously shall be coordinated with the CO, COR, and Inspector. In any case, a CPR/first aid card holder must always be present at any site where work is being carried out.

24. Q: Can we use the church parking lot to unload materials or to unload grout from the concrete truck?

A: The contractor shall work within the construction limits shown in the drawings. Any areas that the contractor desires to use outside of the construction limits shall require written permission from the landowner. Grout placement may be required via hauling in an excavator bucket, pumping, or other means. Method of placement should be considered in the contractors’ bid.

25. Q: What is the weight limit of the bridge at the gabion site?

A: It’s the responsibility of the contractor to obtain the weight limits of that bridge to be sure loaded trucks can cross the bridge safely.

26. Q: Do we have to provide a portable restroom facility for both sites?

A: A portable restroom facility is required to be provided. If the contractor chooses to only supply a restroom to one of the sites, the contractor must allow employees from either site location to travel to the portable restroom location.

27. Q: Does the contractor need to obtain permits to work in the stream?

A: Only if the contractor elects to work outside of the planned construction limits. All applicable permits have been obtained for planned works of this contract. It’s the contractor’s responsibility to always keep the stream access permits on site along with all other documents required by the solicitation.

28 Q: Will the gravel in the gravel drain stand on a 1.5:1 slope?

A: The contractor may have to install the geotextile, gravel drain and riprap in portions as it progresses up the slope to obtain the required thickness.

29 Q: Does the grout have gravel in it?

A: The grout specification is essentially a 4000-psi conventional concrete with a coarse aggregate. It is not like a slurry grout. It is the contractor’s responsibility to obtain a grout mix design from their chosen supplier and submit to the COR for approval prior to grout delivery to the site.

30 Q: Can the COR and inspector visually inspect the rock riprap prior to delivery to help assist on the correct rock riprap sizing?

A: It’s the contractor’s responsibility to find a quarry/supplier and provide a scheduled appointment for the rock riprap inspection. Then a representative from NRCS would be willing to inspect the rock riprap prior to hauling it on site. Note that all rock must pass the DOH certifications as stated in Construction Specification 61 – Rock Riprap. NRCS will not be held responsible for any delays in construction for this action.

31 Q: Can the riprap be end-dump placed?

A: No. The riprap needs to be equipment placed and care needs to be practiced as to not to damage the geotextile or change the template of the gravel drain or the drainpipes during the riprap placement?

32 Q: Can gabion baskets be laced off site to avoid prevailing wages?

A: Only at the contractor’s official business or shop location. The contractor cannot construct gabions just outside the construction limits to avoid prevailing wages. Also note that if the gabions are constructed off site, and they were laced incorrectly, the contractor will need to re-lace the gabions in accordance with the contract requirements at no additional cost to the government.

33 Q: Can the grout be placed right out of the concrete truck chute?

A: Thoroughly read the grouted riprap specifications for placing the grout. There’s a specific placement detail. The entire grouted riprap specification needs to be read thoroughly.

34 Q: Does the bid price need to match the solicitation estimated project cost?

A: No. That is just an estimate. Care needs to be taken when bidding so as to consider all subsidiary items, bid items that may or may not get used, or items that are not used in their entirety as shown on the drawings estimates on page 2.

35. Q: Is there any incumbent/recompete or this is a brand-new project? If yes, could you please provide us with their award number or even if the customer bought similar services in the past

A: No incumbent, new project