CS-49_Amend_4_QAs_revised.pdf

CS-49 Cameron-Creole Freshwater Introduction

Amendment #4 – July 2019

NRCS Responses to Requests for Information

Q1: I have a question regarding treatment of piling. On the spec pages titled, 14. Items of work and construction details. There is timber piling wood preservative spec labeled. “b.

Bid Item 9, Round Timber Piling, Batter Piles”. Item 3 is worded as follows; (3) All timber piles shall be treated in accordance with Material Specification 585 and the AWPA Standard U1, Commodity Specification G, to the requirements of Dual Treatment (Marine Piles) for Maximum Protection in Use Classification UC5C, Southern waters. If I read the treatment specification for U1, which states that timber piles in fresh water require only .80 CCA treatment. I believe “Dual Treatment” to mean both CCA and creosote treatment for each pile. Does the government want "Dual Treatment" for the timber batter piles and navigational aid piles?

A1: Yes. NRCS requires Dual Treatment of all timber piles (Batter Piles, Permanent Warning Sign Piles and 4-pile dolphins). All piles should be treated as stated in the specifications - Dual Treatment (Marine Piles) for Maximum Protection in Use Classification UC5C, Southern waters. Treatment using only 0.80 CCA does not comply with APWA Standard U1, Commodity Specification G.

Q2: Will vibratory hammers be allowed to drive timber piles?

A2: NRCS will allow the use of vibratory hammers to install timber piles provided their use will not negatively impact surrounding project features as determined by the COR. If project features are negatively impacted, the contractor will be required to develop an alternate method of pile installation, approved by NRCS. The contractor will also be required to remedy the negative effects resulting from the use of vibratory hammers without additional compensation or an increase of performance time.

Q3: Will de-watering be required for the borrow areas that will be created to allow the access for the rock dike placement?

A3: No de-watering is required here. Excavation is required only to the extent needed for flotation and that which is necessary to install the required project features according to the contractor’s means and methods.

Q4: Will the contractor be allowed to de-water the freshwater introduction canal structure area by creating barriers using earthen plugs at the ends of the canal that would be pre-existing or built using the excavation from the structure area?

A4: Construction Specification 21, Excavation, 10a(7) states "If the contractor choses to use earthen material from the site as the dewatering structure the contractor’s licensed engineer for dewatering shall determine suitability."

Q5: Drawing page 41 of 64 Note 5 states that pile cap shall be galvanized. Spec. Section 81 Metal Fabrication page 81-4 Item 7.C.4 states that the cap shall be shop painted with 2 coats of CTE. Which is correct?

A5: The pile cap will be shop painted as per construction specification 82, Painting Metalwork. Note 5 on sheet 41 of 64 has been amended.

Q6: Can holes be neatly torch cut for bolts in the steel sheet pile wall system (i.e. waler to sheet pile to waler, bolt holes at clips to fasten cap to sheet pile)?

A6: The contractor will be allowed to NEATLY torch cut bolt holes within the steel sheet pile structure for the following assemblages… Attaching the whaler beams (MC 8X22) to the sheet pile structure. Bolt holes for the whaler beam itself, however, must be drilled.

Attaching the gate frame to the sheet pile structure at all L6” x 4” x 3/8” clip locations.

Attaching the flap gates and slide gates to the gate frame at all gate bolt hole locations. Under no circumstances shall any parts of the flap or slide gates be torch cut.

The diameter of the bolt holes created by torch cutting shall be of sufficient size to accommodate the required bolt, but no larger than 125% of the bolt’s nominal diameter.

Q7: The bid schedule shows there are a total of eight 4-pile dolphins, but the note states that bid item 10 will have 12 total pilings. How many 4-pile dolphins is the contractor installing?

A7: The contractor is required to install two (2) 4-pile dolphins. The contractor will also be required to install four (4) single piles for the permanent warning sign supports. The four single piles are subsidiary to the two 4-pile dolphins.

Q8: From 61-1 Rock Rip Rap Subgrade Preparation - The subgrade surface on which the rock riprap, filter, bedding, or geotextile is to be placed must be cut or filled and graded to the lines and grades shown on the drawings. When fill to subgrade lines is required, it must consist of approved material and must conform to the requirements of the specified class of earth fill.

Rock riprap, filter, bedding, or geotextile must not be placed until the foundation preparation is completed and the subgrade surface has been inspected and approved.

For Rock Dike is it the intention to place stone on existing ground surface covered by geotextile. We expect no excavation or grading in these areas. We expect no foundation preparation except for placing woven geotextile.

A8: Yes, rock is to be placed on existing ground surface once the geotextile is placed. It is not anticipated that any excavation or foundation preparation will be required. However, the contractor is expected to clear the rock tie-in areas as specified in Construction Specification 1, Clearing, prior to geotextile and rock placement.

Q9: For Drawing 21 of 64 Earthen Terrace- Typical layout and Section we have the following questions. The note states “Toe to toe 10’ terrace” while drawing shows 40 feet approximately toe to toe of terrace.

A9: NRCS was not able to locate the note you are referencing on sheet 21 of 64. However, while typical cross sections are not intended to show actual field conditions, the approximate toe-to-toe distance for any given earthen terrace will 35 to 40 feet. The distance between the end of an earthen terrace and the beginning of the next adjacent terrace is 50 feet.

Q10: For Drawing 21 of 64 Earthen Terrace- Typical layout and Section we have the following questions. With a top elevation of + 2.5 NAVD 88 terrace will only be + 1.5 feet above MHW. This will make it difficult to make material stand up and shape the section. We recommend minimum of 3.5 top elevation for this location.

A10: Mean High Water elevation, shown on sheet 21 of 64, is +0.47 NAVD88. Therefore, the earthen terraces will normally be approximately 2 feet above water level. The top elevation of the terraces will remain +2.5 NAVD88.

Q11: For Drawing 21 of 64 Earthen Terrace- Typical layout and Section we have the following questions. Note for excavation shows “Excavation = 25 bottom with 3:1 slope” while drawing shows 2:1 slope with 25’ bottom. Which slope is correct?

A11: NRCS was not able to locate the note you are referencing on sheet 21 of 64. However, the side slopes for the excavation for borrow area adjacent to terraces are 2H:1V.

Q12: For Drawing 21 of 64 Earthen Terrace- Typical layout and Section we have the following questions. Is construction equipment allowed within earthen terrace footprint between the toes? We believe equipment is allowed in this area to shape and grade earth fill for earthen terrace.

A12: No construction equipment will be allowed within 15 feet of the proposed earthen terrace toe or within the footprint of the terraces. Construction specification 23 has been amended to clarify this.

Q13: For Drawing 21 of 64 Earthen Terrace- Typical layout and Section we have the following questions. We assume excavation for borrow shown in typical is mostly suitable for use in earthen terrace and sufficient quantity is available within the borrow limits.

A13: NRCS concurs with your assumption, however, the contractor is encouraged to perform his or her own investigation into the extent and suitability of the borrow material. The geotechnical report is available upon request.

Q14: For Drawing 21 of 64 Earthen Terrace- Typical layout and Section we have the following questions. The 38’ w top to top appears to not match drawing we believe top to top of excavation will be at least 55 feet if existing ground line is at minus 2.5 elevation.

A14: You are correct that, given a maximum cut depth to elevation -10, the maximum top to top distance for the borrow area would be 55 feet for an existing ground elevation of -2.5.

However, NRCS finds no reference to the “38’ w” you are referring to in your question.

Q15: On page 23- 6 the contract states ‘(3) The earthen plug shall be constructed to an elevation of +1.5 feet as shown in the drawings and contractor shall have the final elevation maintained until approval of the foreshore rock dike on the west side to the intake complex. “and the drawings on sheet 54 of 64 also shows top elevation of earthen plug to be +1.5’ NAVD88.

This elevation will be under water at high tide and water will flow over plug. We believe to construct plug top elevation will need to be higher. We recommend match adjoining high ground.

A15: The Mean High Water (MHW) elevations at the project site are +0.73 NAVD88 feet in the GIWW and +0.47 NADV88 feet in the marsh. The top elevation of the earthen plug is +1.5 NAVD88 and will therefore usually be higher than the top of water elevation. The water elevation on the day of the site showing (6/18/2019) were higher than normal due to area flooding.

Q16: Page 11-1 States “4. Dewatering borrow areas The contractor shall maintain all borrow areas free of surface water or otherwise provide for timely and effective removal of surface and subsurface water that accumulates within the borrow area, unless waived in section 8 of this specification. Borrow material shall be processed as necessary to achieve proper and uniform moisture content at the time of placement.”

If pumping to dewater borrow areas is included as a bid item of work in the bid schedule, each pump discharge pipe shall be equipped with a water meter. The meter shall be such that the measured quantity of water is accurate within 3 percent of the true quantity. The contractor shall provide necessary support to perform accuracy tests of the water meter when requested by the contracting officer.

We do not expect to dewater borrow/access excavation for Rock Dikes, channel plug, earthen terrace. Additionally, most intake channel excavation will not be dewatered.

Water will be removed to the extent necessary to place the flap and slide gates in the intake structure sheet pile.

A16: Please refer to the Items of Work and Construction Details section of construction specification 11, Removal of Water. It is under this section where site specific requirements are specified. The section referenced in your question, “4. Dewatering borrow areas” is a general clause which does not apply for this project. No other de-watering except as described in section 8a(1) of construction specification 11, Removal of Water, is required.

Q17: Please confirm the location of any additional borrow sites not identified on a drawing.

There was a comment on the site visit that implied borrow sites in addition to the demarcation points on the drawings

A17: There are no other borrow areas other than those shown on the drawings and referenced in the construction specifications.

Q18: Please Confirm the construction limit footprint is covered under a wetland permit and any additional restoration responsibilities the user has that are not currently identified in the specifications and general SWPPP.

A18: Construction activities for this project are covered under Corp of Engineers 404 permit # MVN-2009-03158-WPP as stated in the Special Provisions. No other restoration responsibilities are required of the contractor other than shown on the drawings and described in the construction specifications.

Q19: The Terrace Centerline profiles shown on drawings sheets 6 through 20 show the existing ground elevations vary from about El - 2 to almost El 0. This represents nearly 5 ft of fill from existing ground. While at site visit the water depth appeared to be 4 to 6 feet deep in many areas we traveled. We are relying on the profiles provided for our bid. The unit price for terrace construction is linear feet. If the existing ground is significantly deeper we expect an equitable adjustment would be required due to an increase in the quantity of fill required.

A19: The contractor is referred to the following: IAW the solicitation, 52.236-3 -- Site Investigation and Conditions Affecting the Work, the contractor is responsible for taking steps reasonably necessary to investigate the site and satisfied itself as to the general and local conditions which can affect the work or its cost. Additionally, 52.236-2, Differing Site Conditions will be used in the event subsurface or latent physical conditions at the site which differ materially from those indicated in this contract; or unknown physical conditions at the site, of an unusual nature, which differ materially from those ordinarily encountered and generally recognized as inhering in work of the character provided for in the contract.

Q20: On the walkway as per the spec it call for aluminum grating to be installed .What is the proposed method to securing the grating to the steel walkway? Please advise

A20: As stated in note #2 on sheet 40A4 of 64 of the drawings, “Grating connects to walkway as per manufacturer’s specifications”

Q21: In the geotextile specification item 95-3 a 7. States that the berm is not to be disturbed and that is understood, but it also says that we cannot float over the berm. We have to be able to float over it to place the geotextile for the dikes. We understand that we cannot work on the berm but floating over it will not disturb it. Please consider removing the word “Floated” from that spec.

A21: The word “floated” will be removed from Construction Cpecification 95, Geotextile, section 7.a.(7). The words “or floated” will be removed from Construction Specification 21, Excavation, section 10.c.(4). The words “or float” will be removed from Construction Specification 23 Item 10.a.(7).

Q22: In regard to the spoils created from access excavation and dike spoils, I did not see a requirement for clearing and grubbing the existing bank line and by extension earthfill stabilization for the aforementioned spoils. Can your team confirm the expectation as TCL believes some measure of seeding will assist the sustainability of the application.

A22: There is no requirement to clear and grub the existing bank line for spoil placement other than the foreshore rock dike tie-in areas. For other areas requiring clearing, refer to construction specification 1, Clearing, section No seeding is required.

Q23: Can powerline over Conveyance Canal be temporally lowered to get dredge equipment in and out?

A23: The contractor is encouraged to contact the powerline company directly. See section 8(l) of the Special Provisions for contact information.

Q24: Can bid date be extended due to the July 4th Holiday?

A24: See latest amendment posted on FedBizzOpps for current bid due date, time and location of bid opening.

Q24: In what direction does the Aluminum grating run is it the length of the walkway or the width of the walkway And does the open ends have to be banded?

A24: The bearing bars that are spaced at 1 3/16” shall run perpendicular to centerline of the sheet pile structure. The cross rods that are spaced on 4-inch center to center shall run parallel to the centerline of the sheet pile structure. Banding is not required. Construction Specification 81 has been amended to clarify this.

Q25: I have not been able to find a domestically milled sheet pile that meets the specifications required for the instake structure. Will the contractor be allowed to use imported steel sheet piles using the COTS clause in the Buy American (b) (3) (iii)?

A25: See the amended 52.225-9 Buy American - Construction Materials. (MAY 2014) section (b)(2) in the Amendment_0004_Addendum

Q26: The sheet pile that fit the required size and section modulus are an AZ 46 hot rolled sheet pile. We have contacted all of the major suppliers of this sheet and the steel is foreign not domestic. We are aware of clause 52.225-9 Buy American and want to ensure we are meeting the specifications. Our supplier has asked the below question:

From Meever USA:

“We are not aware of a domestic steel sheet pile section that meets the minimum specifications of section modulus at 85.5 in3/ft and minimum flange thickness of .709 inches. Could the minimum requirements be clarified or adjusted to meet what is currently available in the market?”

A26: The minimum requirements will not be adjusted. See the amended 52.225-9 Buy American - Construction Materials. (MAY 2014) section (b)(2) in the Amendment_0004_Addendum