B09_Amendment_1_-_Attachment_12_-_Questions_and_Answers_0001.docx

Questions and Answers for Solicitation 140P3022R0017 – CHOH 4 Locks Boat Ramp

1. Are Government or Contractor Field Offices required for this project?

0. Government or contractor field offices are not required for this project.

1. Can horizontal construction joints be incorporated into the strong-arm foundations? The access into the work area will prohibit using standard ready-mix trucks and given such, we will need the ability make multiple pours on the large foundation.

1. Confirmed – See Section 033000 Paragraph 3.7 of the Specifications.

1. Will the Government allow cast in place concrete as an alternate for the asphalt milling and resurfacing on the boat ramp? If so, please provide an allowable concrete pavement section and details. Concrete maybe more cost effective than mobilizing in a mill and paver for such limited quantities.

2. No, contractor is to submit bids based on the requirements listed in the drawings and specifications.

1. Will the Government allow a CAT 315 size excavator to traverse on the tow path from the alternate access point to the work zone?

3. See section 01 50 00—3.5.E.2. This paragraph is revised via this response as shown below.

3. “The worksite and the access to the worksite is the Historic Towpath. The contractor shall insure that all employees are aware of and fully comply with the rules for operating equipment and vehicles on the towpath. There is a maximum 15mph speed limit and 15 ton (GVW) single axle vehicle weight restriction on the towpath unless authorized otherwise by the Contracting Officer. All vehicles using the towpath must comply with the most recent version of the NPS C&O Canal NHP Safety Officer Memo for towpath driving. Any equipment that exceeds the 15-ton GVW will require detailed structural calculations to be submitted by the contractor for government review and approval. The calculations must be accompanied by relevant sketches that clearly depict how you intend to accomplish the intended tasks without any adverse impact to the historic stone culverts and locks along haul route. Calculations and sketches must be signed and sealed by a professional engineer registered in the State of Maryland. Any equipment larger than a pickup truck must be accompanied by flaggers on the towpath. Contractor shall provide visual pre-construction inspection of existing features along access route and adjacent to existing work area. Upon completion of construction activities, a post- construction inspection of the existing features will be completed for comparison to the pre-construction conditions. Conditions shall be documented using photographs with horizontal and vertical scales. Repair of any damaged areas/features will be accomplished by the contractor at no additional cost to the government via approved repair plan. Where existing branches of trees extend into the construction access route or work areas, the contractor shall identify the branches of concern and submit locations and method for removal to the CO for approval. Pruning of trees is considered incidental to the project and any costs included in CLIN 001 for Mobilization/Demolition. If pruning is determined to be required, trees shall be assessed by a current ISA certified arborist or ISA board certified master arborist to determine the most prudent work prescription. Pruning for clearance objectives shall be performed to the minimal extent necessary to facilitate the work while maintain health and aesthetics. All tree work shall be performed/completed in accordance with the most current version of ANSI A300 Standards (Part 1). All prescribed tree work must be completed under the supervision of an ISA certified arborist. Hard lines are prohibited: trees shall be pruned to have soft aesthetic lines and a natural form to the extent possible. Trees should be pruned with consideration for the health and aesthetics of the entire grouping, not trees in singularity. Reasonable symmetry of form and linear progression should be maintained through the grouping. All debris and green waste shall be removed from the park boundary. The following shall be provided to the government for any pruning: SA Arborist Certification ID Number for Assessing Arborist, SA Arborist Certification ID Number for Arborist Supervising Work (prior to work execution), work plan describing work to be executed in accordance with standardized trade verbiage (ANSI A300 and best management practices), and certification of schedule, completion and completion photos. NPS will approve any reasonable arborist work plan.”

1. Will the Government allow a small crane such as a 22-ton picker to traverse the tow path from the alternate access point to the work zone? (spec sheet is attached)

4. See section 01 50 00—3.5.E.2. This paragraph is revised via this response as shown below.

4. “The worksite and the access to the worksite is the Historic Towpath. The contractor shall insure that all employees are aware of and fully comply with the rules for operating equipment and vehicles on the towpath. There is a maximum 15mph speed limit and 15 ton (GVW) single axle vehicle weight restriction on the towpath unless authorized otherwise by the Contracting Officer. All vehicles using the towpath must comply with the most recent version of the NPS C&O Canal NHP Safety Officer Memo for towpath driving. Any equipment that exceeds the 15-ton GVW will require detailed structural calculations to be submitted by the contractor for government review and approval. The calculations must be accompanied by relevant sketches that clearly depict how you intend to accomplish the intended tasks without any adverse impact to the historic stone culverts and locks along haul route. Calculations and sketches must be signed and sealed by a professional engineer registered in the State of Maryland. Any equipment larger than a pickup truck must be accompanied by flaggers on the towpath. Contractor shall provide visual pre-construction inspection of existing features along access route and adjacent to existing work area. Upon completion of construction activities, a post- construction inspection of the existing features will be completed for comparison to the pre-construction conditions. Conditions shall be documented using photographs with horizontal and vertical scales. Repair of any damaged areas/features will be accomplished by the contractor at no additional cost to the government via approved repair plan. Where existing branches of trees extend into the construction access route or work areas, the contractor shall identify the branches of concern and submit locations and method for removal to the CO for approval. Pruning of trees is considered incidental to the project and any costs included in CLIN 001 for Mobilization/Demolition. If pruning is determined to be required, trees shall be assessed by a current ISA certified arborist or ISA board certified master arborist to determine the most prudent work prescription. Pruning for clearance objectives shall be performed to the minimal extent necessary to facilitate the work while maintain health and aesthetics. All tree work shall be performed/completed in accordance with the most current version of ANSI A300 Standards (Part 1). All prescribed tree work must be completed under the supervision of an ISA certified arborist. Hard lines are prohibited: trees shall be pruned to have soft aesthetic lines and a natural form to the extent possible. Trees should be pruned with consideration for the health and aesthetics of the entire grouping, not trees in singularity. Reasonable symmetry of form and linear progression should be maintained through the grouping. All debris and green waste shall be removed from the park boundary. The following shall be provided to the government for any pruning: SA Arborist Certification ID Number for Assessing Arborist, SA Arborist Certification ID Number for Arborist Supervising Work (prior to work execution), work plan describing work to be executed in accordance with standardized trade verbiage (ANSI A300 and best management practices), and certification of schedule, completion and completion photos. NPS will approve any reasonable arborist work plan.”

1. Please specify the size of trailer that is to be purchased for the floating dock removal and storage.

5. The requirement to provide a trailer for floating dock removal and storage has been removed from this project in the initial solicitation. See the strikethrough Section 01 11 00 Paragraph 1.3.B.10 of the specifications.

1. Can the Government provide the contact information for any approved certified arborists that work in this area?

6. Please reference Section 015639 – Paragraph 1.6 of the specifications for required arborist qualifications. NPS does not have any contacts to provide at this time.

1. The location of this project presents unique challenges for installing a cofferdam. The contract specifications make reference to a sheet pile cofferdam. Based on the borings, rock elevation is 340.5 +/-. The elevation of the streambed at the limit of excavation is 347.5 +/-. The low pool water elevation is 356.7. This only allows for 7 ft of embedment with 9 ft of freeboard which is not workable. I have investigated other cofferdam options such as water barriers and port a dams. The project water depth exceeds the allowable limits of the water barriers and is at best, questionable for the port a dam. Additionally, the water barrier and port a dam system will extend past the LOD. This situation could be improved by shortening the ramp and allowing in the wet construction by causeway.

7. As noted in Section 31 23 19—1.8.C. “The contractor shall be responsible for the design of the dewatering system including, but not necessarily limited to, the temporary cofferdam, required pump equipment, temporary shoring, as well as any miscellaneous temporary structures and dewatering equipment required such as wells, well points, or similar methods.” As shown on Sheet C-24 of the plans, cofferdam is not required around the boat ramp footprint and can be constructed in the wet using turbidity curtains. Sheets C-23 and C-24 of the plans show the extent of the required cofferdams.

1. Please confirm that cofferdam experience is required for past performance.

8. This has been revised to as follows. “The offeror may coordinate completion of the form entitled “Past Performance Questionnaire” in the Attachment 9 – Proposal Submission Package for construction projects of the same scope and complexity as the contemplated contract which required work with heavy civil features, dewatering, and marine construction.”

1. If cofferdam experience is required for this bid, does that has to be GC’s experience? Or is a subcontractor’s experience acceptable?

9. Subcontractor’s experience may be taken into account during proposal evaluation in lieu of prime contractor’s.

1. Due to the winter weather conditions at the park, will NPS consider push the job starting date to next year and/ or extend the period of performance?

10. NPS’s perspective is that the Period of Performance already includes reasonable allowances for winter weather conditions and therefore will not be extended as part of the solicitation.