S01 Amendment 01 Site Showing QA.pdf

ARS Field Station Lake Rehabilitation Project Site Showing Questions and Answers

April 13, 2022

Questions/Answers:

• Q1: How will the earthfill for the voids under the existing auxiliary spillway be paid?

A1: Construction Spec 23, page 10 states ‘Earthfill, Concrete Voids’ is subsidiary to Bid Item 9, Earthfill Embankment. So, the voids space will not be measured or paid separately.

• Q2: Does the new RCC spillway need to be fully functionable before work can begin on the auxiliary spillway?

A2: Auxiliary spillway clearing and backfill can begin prior to the completion of the RCC spillway. HOWEVER, the backfill cannot extend higher in elevation than the crest of the existing AS, and the existing AS width must be maintained. Any damage to earthfill placed is, of course, the responsibility of the contractor. Also, performance time has been updated.

• Q3: Will the remaining portion of the dam need to be shaped?

A3: Sheet 5 of the drawings shows that the top of dam will be widened to 14’ and the back slope will be flattened to a 2.5:1 slope. Reshaping of the dam may be necessary to complete this task.

• Q4: Pages 9 and 10 of the drawings show an impermeable membrane, but it is not mentioned in the specifications?

A4: The notes on pages 9 and 10 of the drawings state that the impermeable membrane is used to “separate the concrete bedding from the drain filter”. That is just for a short section where the pipe bedding crosses the drain. A material such as heavy plastic has been acceptable in the past.

• Q5: Can ‘slab 3’ be built with conventional concrete?

A5: Slab 3 should be built as designed.

• Q6: Does the foundation drain have to be built vertically with no slope the entire length of the dam?

A6: The foundation drain must be built as shown in the drawings.

• Q7: Can the compaction of the foundation drain be completed with saturation, or will a density test be needed?

A7: Construction specification 24 doesn’t specify the method of compaction, just that it must meet the specified density.

ARS Field Station Lake Rehabilitation Project Site Showing Questions and Answers

April 13, 2022

• Q8: Can the outer edge of the RCC remain unformed and back filled with soil?

A8: No. Bid as designed.

• Q9: Can the step lengths be altered for ease of construction?

A9: No, step lengths will not be altered. RCC steps shall be vertical and formed as it says in Construction Specification 36.

• Q10: The foundation drain is shown on page 9 of the drawings. Which of the three drains on page 10 of the drawings corresponds to the foundation drain?

A10: The foundation drain is the center drain as pointed out of sheet 23 of the drawings.

• Q11: Are there 3 or 4 foundation drains?

A11: The foundation drain design has been updated. See Addendum 1.

• Q12: Is there geotextile under the RCC, foundation drains, and rip rap? The quantities don’t seem to match up.

A12: Geotextile quantities have been updated. See updated bid schedule in Addendum 1.

• Q13: Can the performance time be extended?

A13: Performance time has been updated.

• Q14: Can the boring logs be provided? The information provided in the plan sheets is nearly impossible to decipher and interpret. Specifically, I am trying to interpolate the anticipated ground conditions at the location of the proposed new Principal Spillway pipe that is bored and jacked with a 48" diameter steel casing pipe through the embankment.

A14:GI report has been included.

• Q15: How will the lake be drained prior to construction? How will the lake levels be maintained throughout construction?

A15: The ARS staff is responsible for the initial draining of the lake prior to construction.

After construction begins, the level of the water will be the responsibility of the contractor. See Construction Specification 8, Mobilization and Demobilization, for added verbiage regarding unplugging of the principal spillway pipe.

• Q16: Can the Powerline ROW be used as an access road to the bottom of the AS?

A16: No other ingress/egress routes have been agreed upon as of now.

• The contractor will need to unplug principle spillway conduit before construction and maintain it during construction

A: Specification 8, Mobilization was adjusted to include this item.