1305M324B0001 Additional Q and A - Final 5-13-2024.pdf

CONSTRUCTION SERVICES: FISH RIVER & WEEKS BAY MARSH RESTORATION

SOLICITATION NUMBER 1305M324B0001

QUESTIONS AND ANSWERS #2

a. Question: After further review and analysis of the site conditions, the provided design documentation and the RFI responses, we wanted to provide an opportunity for clarification that could greatly affect the proposals. In general, the design directs the contractor to take soil from the borrow areas and use to fill the fill areas. The borrow areas are generally taken down to an elevation of 1’ while the fill areas are raised to an elevation of 1.5’. However, during multiple site visits we have experienced water levels ranging from 1’ to closer to 3’ and have documented that the mean water level in this area is closer to 2.5’. Coupling this with the RFI response that the Gov would not allow the use of “temporary levees, dikes, coffer dams, sheet piles” or pumps and it is basically going to limit the ability to work in these areas based on tidal activity and drive many other environment and construction concerns that would have to be compensated for in the proposal approach. One method that would be less invasive would be to utilize the borrow soil and fill the fill areas and adjacent borrow areas to a higher elevation than the planned finish elevations to allow the contractor to work on more consistent drier ground above the water level. After utilizing what soil is available, the contractor would then work back from their starting point, pushing the soil forward as additional fill as the areas are graded to the appropriate elevations.

However, there is concern that this approach would not be allowed due to the RFI response that said somewhat similar methods would not be approved. The alternative methods would be much more costly and more invasive to the environment but is possible if required. Could the Gov clarify whether this approach would be acceptable?

Answer: Water Levels: All elevations in the contract documents are referenced to the vertical datum North American Vertical Datum of 1988 (NAVD88). The water level datums listed on sheet G-002 of the Drawings are all referenced to NAVD88 and are based on data from the NOAA-COOPS station Weeks Bay, Mobile Bay, AL (Station ID:

8732828) from August 2007 through April 2018. This station is near the project construction site however is no longer operational (no water level data exists at this station past April 2018). Mean High Water is listed as +1.04’ (NAVD88). The nearest operating water level station that is accurately referenced via survey to NAVD88 is the NOAA-COOPS station Dauphin Island (Station ID: 8735180) and can be used to determine present-time water levels referenced to NAVD88. The nearby USGS gauge in Fish River is not accurately referenced by survey to NAVD88 and is provided by USGS as station datum.

In order to compare water level observations from site visits, it would be required to know the vertical datum of the water level observations, and the water level observations should be referenced to the project vertical datum NAVD88.

Historical water levels and tidal datums are for reference/information and should not be completely relied upon by the contractor to determine what the future water levels will be during construction. Water levels within the Mobile Bay system are widely varying based on tides, winds, atmospheric pressure, and seasonal variability, as water levels trend higher during the summer months.

Based on the fact that the historical MHW is referenced as +1.04’ NAVD88, and the borrow areas are to be degraded to +1.0’ NAVD88, and the fill area elevations are a maximum of +1.5’, it should be understood by the contractor that at times during construction the borrow areas and/or fill areas will be underwater and this occurrence shall not result in added Days to the contract time and shall not result in the contractor being compensated for down time due to the high water. Contractor shall plan accordingly for periods of high water.

Means and methods: Contractor may construct the project using their own determined means and methods if these means and methods do not violate the permit and can achieve the stated project objectives. The use of sheet piles to build coffer dams, etc.

would be a violation of the project permit. Temporary earthen structures would be allowable provided they are degraded to pre-construction conditions or are incorporated into the design lines, grades and elevations of project fill features. The use of trucked in fill to create a temporary land bridge or other temporary construction features (clean fill, free of contaminants, etc.) would also be allowable per the project permit, but these costs would need to be included in the Contractor’s price under an appropriate Bid Item, and no additional payment would be made to the Contractor.

The stated approach involving the temporary overfilling of fill areas or temporary construction of dikes using the material excavated from the borrow areas would be considered means and methods that are within the scope of the permitted project activities. However, the project fill areas have been designed to maximize the amount of available material in the borrow area. Using borrow material to build temporary dikes, etc. provides a risk to the project in that any material loss may affect the ability to complete the fill areas and meet project objectives. The Contractor alone will be responsible if there is insufficient material available to construct the project features due to losses of material from their means and methods.

b. Question: The response to question “e” states that “All borrow areas are connected by land”.

However, based on reviews of the drawings and site visits, it is the contractor’s belief that one of the largest (by sqft) borrow areas (Borrow Area 2C) has no land bridge connecting it to the mainland that would allow for land access. This would also be the same situation for borrow area 3D since it is situation on the same “island” mass.

This was one of the main reasons for requesting the ability to construct a land bridge to allow full access to that area. Once the proposed fill area 2 is complete, there would be more of a land connection. However, given the elevations, this would still be below water level.

Answer: After further review it has been determined that the previous response to bidders incorrectly stated that there was a land bridge to Borrow Area 2C. It was thought that the location indicated by the white line in the image below was a land bridge, however it has been determined that it is not connected and is just a narrow area of the canal.

The Government re-states that Bidders shall make their own determination of borrow area accessibility. Paragraph 5.2 of the Technical Provisions of the Specifications states that “Areas that may not be accessed by land may be accessed through the canals on the Project Construction Site.”

The construction of a land bridge would be considered Contractor means and methods by the Government provided the methodology does not violate the project permit.

c. Question: The ADEM permit shows an expiration date of March 31, 2021. However, the solicitation documents state that the Government has received the appropriate approvals from ADEM. Can the government elaborate on whether an extension has been approved and, if so, what the new expiration date is?

Answer: The Contractor is responsible for obtaining and maintaining compliance with a construction stormwater National Pollutant Discharge Elimination System (NPDES) Permit from the Alabama Department of Environmental Management (ADEM). The updated ADEM NPDES System General Permit with an effective date of April 1, 2021 is provided for reference in Appendix I of the Environmental Protection Provisions of the Specifications via this amendment. Please see bid amendment number 3 for more information.

d. Question: The ADEM permit Part III.B states that a 25’ undisturbed natural riparian buffer must be maintained. However, this area is what is classified as “borrow area” by the design documentation.

Answer: The Permit allows for the excavation of the borrow areas as shown in the Drawings.

e. Question: Will a Standard Form 30 be provided/used for acknowledgement of Amendments? If not, how would you prefer that we acknowledge Amendments?

Answer: No, an updated SF1447 is included with this amendment. Section III – Instructions to

Bidders has been updated to require Submission of Section I of the SF1447 with blocks 13 and 27 completed. Submission of Section I of the SF1447 will be regarded as acknowledgement of this amendment. Note that pricing information need not be completed on the SF1447, as Attachment A – Bid Schedule will be used to evaluate pricing.

f. Question: Does the information provided in "Section II - Supplies or Services and Price/Costs"

(p.4 of solicitation) need to be added to SF1447 (#s 17-20 typically reserved for CO to add information) with bidder completing #s 21 & 22 per usual/form instructions? Or would you like for us to reference p. 4 "Section II..." in the space for 21 & 22 and complete p. 4 and include in response?

Answer: No, bidders are not required to submit pricing information in Section I or Section II.

Attachment A – Bid Schedule is the submission the Government will use to evaluate pricing.