RFI Official Responses - 2.pdf

FOR OFFICIAL USE ONLY

REQUEST FOR INFORMATION (RFI) OFFICIAL RESPONSES - 2

129JGP20R0008 - Incline Lake Dam Demolition

RFI #1 – It appears that there may be far more trees that are >6” DBH than listed in the Schedule of items. Is the USFS considering removal of additional trees and how would this be paid, or are there only 75 in Item 20102 and all others (even with >6” DBH) are to be removed and paid under Item

20101 regardless of size?

USFS Response - The quantity is only an estimate and not an actual inventory. The payment will be based on the actual quantity identified during construction, but only for trees 6” dbh and greater, all smaller trees are included lump sum as grubbing.

RFI #2 – Is individual tree protection required along the access road?

USFS Response - No

RFI #3 – Is any pruning or removal of trees permitted along the access road?

USFS Response – If needed pruning and removal of trees can be allowed.

RFI #4 – Some tree removal on the auxiliary dam and area between dams may be required

(regardless of whether the optional items are selected or not) to allow access from main dam to disposal site. If a marked tree must be removed for access, does the USFS want it decked and paid as an extra if the optional items AREN’T selected?

USFS Response – If optional items aren’t selected trees on the auxiliary dam can be treated the same as trees removed along the access road.

RFI #5 – Temporary BMPs are clearly included for the Main Dam, Auxiliary Dam, and Disposal

Site, specifically, however, ground disturbance will occur between these sites. Are temporary BMPs required for the areas between the sites?

USFS Response – No additional BMPs are anticipated

RFI #6 – In the revised drawings the construction of a coffer dam with 10 mil HDPE liner and

36” N12 outlet pipe is now included. To that end:

• RFI 6A - Is there a specific method required for joining the pipe and the liner at the pipe protrusion through the liner?

USFS Response-the method to secure liner to the pipe can be proposed by the contractor and will be approved by the COR provided that the liner is secured to the pipe in a secure water proof manner.

• RFI 6B – Is there adequate acceptable borrow material onsite with which to construct the coffer dam and, if so, where is the borrow area?

USFS Response – the borrow material for the coffer dam is available within the footprint of the material disposal site.

• RFI 6C – Similar to a question earlier in this RFI, are BMPs required between the coffer dam and borrow area during construction and then between coffer dam and disposal area during removal?

USFS Response –bmps will not be required during construction. After construction, all disturbed surfaces including the coffer dam footprint shall be stabilized with mulch/wood chips.

• RFI 6D – Is a liner specification available?

USFS Response –geomembrane liner specifications are in Section 714 of FP14 STANDARD

SPECIFICATIONS FOR CONSTRUCTION OF ROADS AND BRIDGES ON FEDERAL

HIGHWAY PROJECTS. Liner thickness shall be 10 mil and may be either HDPE, PVC, or

LLDPE material. https://flh.fhwa.dot.gov/resources/specs/fp-14/fp14.pdf

• RFI 6E – I’m assuming the cofferdam will be removed. Will permanent erosion control be required after removal of the cofferdam?

USFS Response –Yes coffer dam will be removed, permanent bmps will include mulch/wood chip and will be installed by the contractor.

• RFI 6F – The earthwork quantities should be revised to include removal of cofferdam and disposal of the liner if the cofferdam is removed.

USFS Response –The approximate volume of the cofferdam is 200 cubic yard.

RFI #7 – In the revised drawings there is a reference to minimum compaction standards for the placement of fill in the disposal area and the construction of the coffer dam. To that end:

• RFI 7A – What is the minimum frequency of verification of compaction?

USFS Response – excavation and embankment specifications are in Section 204 of FP14

STANDARD SPECIFICATIONS FOR CONSTRUCTION OF ROADS AND BRIDGES ON

FEDERAL HIGHWAY PROJECTS. Frequency and method of testing is outlined in Table

204-1. https://flh.fhwa.dot.gov/resources/specs/fp-14/fp14.pdf

• RFI 7B – Is it permissible to use a Nuclear Density Gauge to verify compaction?

https://flh.fhwa.dot.gov/resources/specs/fp-14/fp14.pdf https://flh.fhwa.dot.gov/resources/specs/fp-14/fp14.pdf

USFS Response –see response to RFI 7A