Q A _W9128F-16-R-0020 _GA _West_Terrace_21Mar16.docx

Powerhouse West Terrace Drain Rehab, Phase II Garrison Dam, ND

Questions and Answers 21 March 2016

1) Section 00 22 00, Pg. 19 states the requirement for submission of completed CLIN Pricing Schedule as well as a completed CSI Masterformat Cost Schedule. The CSI Masterformat Cost Schedule included in Attachment 2 does not appear to correlate to the CLIN Pricing Schedule, as there are multiple divisions of work that do not pertain to the CLIN Pricing Schedule. Please provide further explanation for the completion of the CSI Masterformat Cost Schedule included in Attachment 2.

A- Per instructions contained in Paragraph (3), contractor shall breakdown cost for each CLIN using the Construction Specifications Institute (CSI) Master Format®. The costs should be broken down by CLIN to correlate to the appropriate CSI sections in the project specifications.

2) Sheet B1.01 states that contractor is to re-establish design slope of excavation previously performed by others (from approximately 170’ east of MH 154.9/3 to MH B. Is contractor to assume that section shown in Detail B on Sheet B5.02 has been completed previously, and that re-establishment of design slope consists solely of placing common borrow fill and topsoil, or; is contractor to assume that additional pervious filter material B will have to be placed as a part of the re-establishment of the design slope of excavation previously performed by others. If contractor is to place additional pervious filter material B, please provide further clarification of Detail B on Sheet B5.02 denoting where work performed under previous contract was completed to.

A- Re-establishment of the design slope from MH “B” to approximately 170 feet east of MH 154.9/3 will require placement and compaction of random fill material and topsoil; no additional filter material B is required in this stretch other than to repair any disturbances to previously placed filter materials that may be disturbed while tying into the previously replaced pipe. Refer to CLIN Item No. 8 for measurement and payment of slope re-establishment (MH “B” to 170’ east of MH 154.9/3).

3) Sheet B5.02 Detail B shows “vertical trench wall” 3’ wide centered over pipe, and “excavation outside of trench” with uphill side of excavation being cut to angle of repose. Is conformance with this detail required for excavation, or are alternative excavation methods allowed (assuming that a minimum 2’ width of pervious filter material B can be placed for the full height of the excavation).

A- The excavation method is not specified. The proposed excavation method shall be detailed in the shoring and/or work plans for review and approval. Note that any additional material, equipment, and/or labor costs associated with the proposed excavation method that are in excess of those necessary to construct the design trench details on Sheet B5.02 will be provided by the contractor at no additional cost to the government.

4) Section 33 46 16 Pg. 3 Table 1 contains a list of Government furnished materials. Riser Cover and 12” Diameter CMP do not appear on the inventory. Please clarify if contractor is to provide these materials.

A- The riser covers and 12-inch diameter CMP are to be provided by the contractor.

5) Sheet B1.03, Erosion Control Plan, shows erosion control blanket on slopes and mulch on benches. Please clarify if CLIN 0009 is for erosion control blanket and mulch, or just erosion control blanket. If CLIN 0009 is for erosion control blanket, is mulch included under CLIN 0007?

A- CLIN 0009 includes both erosion control blanket and mulch. Paragraph 9.1 states “This work shall include but not limited to all materials, equipment, labor, erosion control blanket, straw waddles, mulching, and all other incidental work needed for installing erosion control materials…”

6) Sheet B1.03, Erosion Control Plan Note 2 states that all topsoil, seeding and erosion control in areas disturbed by dewatering installation shall be included in CLIN 0002, Dewatering. Will topsoil, seeding and erosion control be required on the haul road to stockpile site and stockpile site? If so, how will this be measured and paid?

A- Areas disturbed by dewatering system installation and/or operation shall be topsoiled, seeded, and erosion controlled under CLIN 0002. All other disturbed areas including vegetated haul roads and stockpile areas (depending on the location) shall be topsoiled, seeded, and erosion controlled under CLIN’s 0006, 0007, and 0009, respectively.

7) Sheet B3.04 Section 8 shows the new 18” solid PVC drain to be installed perpendicular to the slope from MH 154.9/3 to MH 155.7/3. There is a callout pointing to a fill material layer. Callout says “Existing adjacent filter blanket to be protected”. Please provide more clarification of the location and extents of the filter blanket.

A- The adjacent filter blanket note is referencing the pervious backfill/filter for the existing 12” subdrain running parallel to the slope on the lower bench (shown in plan on sheet B1.01). The lower bench subdrain was replaced under a previous contract and was constructed similar to Detail B on sheet B5.02.

8) Please provide clarification of backfill requirements at new manholes.

A- It is assumed that the request for clarification is in relation to how the trenching and bedding detail transitions into the manhole backfill? Excavation methods are not identified for installation of the manholes and backfilling will therefore be partially dependent on the approved method. It can be assumed that pervious filter material B will be placed/continued upstream/upslope of each manhole to ensure interconnectivity of the inclined filter; the remainder of the backfill will be random fill.