A22 Amendment 2_QandA.pdf

PIASA/EAGLE’S NEST – CONTRACTOR QUESTIONS

1. Island 2 and Island 3 have areas that need to be excavated to 3’ below design grade, the design calls for A Stone which top size is around 3.2’ this means you will only have a one rock high stone in this areas. Is this what you intended?

Response: The team understands there could be less rock in the locations where excavation could be required, but hopefully some of the smaller rock from the gradation could be used in these locations.

However, these areas are not critical locations such as at the head of the island where higher velocities would be observed. Additionally, the team expects the further down that excavation is required, the more likely the contractor would encounter clay material, which could significantly increase construction efforts and costs.

2. Are we allowed to excavate floatation to access the shallow areas? The river elevation on 8/6/20 was at 14.9 ft (Grafton), with this stage we wouldn’t be able to access half of Island 2, almost all of Island 3 and Island 4. Our vessels that we would use for this work draft between 5’ and 6.5’, we wouldn’t be able to float in.

Response: There are permit issues with this, so if the specified river stages require work in less than 5 feet of draft at the time of construction, coordination will need to take place between the KTR and COR to communicate where the KTR would need to mechanically dredge for access. This communication with the COR would need to identify the proposed access location, maximum length, width and depth, and the amount of cubic yards to be dredged.

3. Was a topographic survey done on Island 3? The existing ground appears to be higher than 420.

Please verify. The plans says the survey was done on 10/15/2018 by single beam survey but was the land surveyed also?

Response: The land portion was surveyed. March 2018 LiDAR topographic data was supplemented where there were gaps in the October 2018 hydrographic survey information. Plans adjusted to include LiDAR information.

4. The specifications says no work will be permitted within MRM 212-207 when pool 26- Grafton, IL gage is at stage 18 or greater. This limitation needs to be increased to allow for the floating equipment and material barges to have access to the site. Also the specifications says the river stages should be 2’ or greater below the finished grade of the structure being worked on at the time of completion. This makes the structures even less accessible by water.

Response: A stage of +18 is the beginning of flood stage, so this becomes a safety concern and is the reason for the requirement. It is possible to work outside of the stated requirements, but in order to do so, the KTR will need to coordinate with the COR to proceed, as stated in the specifications. The construction tolerances of the specs document will satisfy constructability concerns, so the limitation for river stages being 2 feet or greater below the finished grade of the structure being worked on has been removed.

5. The specifications says the as-builts depth measurements has to be done by a multibeam echo sounder. The river would need to be at Grafton +28 to allow the head of the Multibeam boat to safely cross over the islands? If this is required would the corps require the contractor to remobilize to the site and add more rock if an area is found to need more stone? Also most of the areas wont be able to be mutlibeamed even at normal levels because the head hangs down 3-4’ below the boat, there isn’t enough water. We suggest a single beam survey with a topo survey matched up to it.

Response: Specifications have been updated for as-builts to require a single beam hydrographic survey with a topographic survey to cover areas above the water surface.

6. How should bids be submitted if they are not physically being received at the RAY Building?

As this is an Invitation for Bid, normally a public bid opening would be held. In this instance, bids may be submitted electronically to the following email address: lisa.white@usace.army.mil, or via the DoD Safe Site: https://safe.apps.mil, POC Lisa White, please use the previously mentioned e-mail address.

7. Will the Bid Due date be extended?

The bid due date is extended to August 27, 2020 at 10:00 a.m.