Questions_and_Answers_-_Stanford_Road_NPS_Responses_0001.pdf

Solicitation #: P6424B0006

Amendment #: 001

Stanford Road Parking Lot Project – CUVA

Questions and Answers listed below:

QUESTIONS:

Question # Question Answer/Response

1. Section 3.4.A.1 of the specifications state "If excavated materials intended for fill and backfill include unsatisfactory soil materials and rock, replace with satisfactory soil materials."

As the project is a balanced project for excavation and embankment, as per 2.1.A.3 and in an area bordering a wetlands, there is a high probability that existing soils will need to be removed and replaced with satisfactory material.

Can the NPS provide an estimated quantity for bidding purposes and a specification for the replacement material?

As potential for borrow soils due to wetland proximities is an unknown condition, there is no estimated quantity of borrow soil material to be provided as response to the question. For replacement soil material, reference Earth Moving Specification Section 312000, part

1.4 A. for the two ASTM testing and

Clean Fill Protocol for what constitutes acceptable soil material.

2. Will additive items be awarded in order or will no 3, for example, be awarded alone or ahead of other items?

Additives will be awarded sequentially in the order listed until funding has been exhausted.

3. Sheets C10 and C11 show a 2’ shoulder typical along asphalt surface with chip seal trail. Asphalt surface with chip seal detail shown on sheet C15 appears to show a 6” shoulder with an assumed topsoil depth of 1.5”. Please advise as to the should requirements along the asphalt trail.

Detail on C15 indicating 6” is the dimension the asphalt base course is to extend beyond the asphalt surface course in constructing the pavement profile. The 2’ shoulder typical noted on plan drawings C10 and C11 is the finish grading of earthwork in providing a ‘flat’ area immediately adjacent to trail’s finish surface. Both typical dimensions apply in their 2 respective references.

4. The submittal list provided with the solicitation, nor the specifications call out any close‐out type documents such as As‐Builts. Are as‐builts or other close‐out documents required?

Per this Addendum, add to Specifications 01 10 00, add Part 12.6, Project Record Drawings to read as follows:

1.Maintain one complete full-size set of contract drawings and one full-size set of vendor-supplied drawings.

Clearly mark changes, deletions, and additions using National Park Service drafting standards to show actual construction conditions.

Show additions in red, deletions in green and special instructions in blue.

2. Keep record drawings current.

Make record drawings available to the Contracting Officer for inspection at the time of monthly progress payment requests. If project record drawings are not current, the Contracting Officer may retain an appropriate amount of the progress payment.

3. On completion of the total project, submit complete record drawings. Include shop drawings, sketches, and additional drawings that are to be included in the final set, with clear instructions showing the location of these drawings.

5. Sheet C9 shows three culverts that require cleaning of sediment. The northern culvert is shown with wingwalls and the other two appear as underground storm drains. Please provide the dimensions of the three culverts and their lengths.

Culverts were captured by topographic survey. Lengths to be estimated from bar scale on sheet.

Size of structures not known from survey and can infer culvert by bar scale and make assumption for two smaller storm pipes.

6. The drawings call for f’c 3,500 psi concrete.

However, there is no specification section indicating any other mix or testing requirements.

Please provide a specification for concrete or its features of the mix design and it’s testing requirements.

The concrete called out is reference to sign post footings (3500psi), bid additive 7, equestrian hitching rail footings (2500 psi), and bid additive 8, kiosk footing (3000 psi). Strength requirement shall serve as prevailing minimum characteristic to comply with and no testing requirements are required. Concrete for bid additive 5, vault toilet building, shall be as included in the specifications for the vault toilet on sheet L2 of the Visitor Amenities supplemental drawings.

7. A hydrologic study was found in the specifications.

Is a geotechnical report available? Is the depth to groundwater and the soils hydraulic conductivity known?

Geotechnical investigations were not performed and no geotechnical report is available. Depth to groundwater and soils hydraulic conductivity not known.

8. Please confirm the survey datum used. It is currently assumed to be NAD 83, 2011 State Plane Ohio North.

Sheets C6 and C6 for Control Point (C.P.) 1 and 2 are stated in NAD 83 with NAVD 88 for horizontal and vertical control. Please verify from those control points confirmation of the State Plane used.

9. Sheet C8 shows Water Quality Riser Pipe #1 with a rim elevation of 663.25 and an invert elevation of

661.58. The bottom of the detention pond appears

to be 662’. Water Quality Riser Pipe #2 with a rim elevation of 661.50 and an invert elevation of

659.58. The bottom of the detention pond appears

to be 660’. However, profiles for the storm drain show subgrade below the invert elevation. Water Quality Riser Pipe Detail on sheet C16 depicts the invert elevation to coincide with the invert of the Water Quality Orifice at 661.24’ for the #1 riser (East) and 659.06’ for the #2 riser (West). Both conditions will result in a lower invert elevation by roughly 6 to 9” and will result in the Water Quality Orifice being below grade. Please confirm the invert elevation for each of the risers, the bottom elevation (subgrade, below rip rap cover) along with any slope required (depicted in profiles) and the placement elevation of the Water Quality Orifice.

Elevations as shown are correct in their relationship to each other. The bottom of basin elevations by contours shown are 662 (#1) and 660 (#2), however in the profile, finish grade extends lower in order to meet invert (flow) elevation of the 1.5” and 2” Water Quality Orifice within the basins. Intent is to provide positive drainage across bottom of basin to allow the water quality orifice to drain the basin post-storm event.

10. Sheet C11 shows additive item #3 for a portion of the road at and just north of the gravel drive to the Stanford House to receive milling and overlay.

However, Site Key Note D indicates mill and overlay of existing asphalt along the road on sheets C10 and C11. Is the portion of the road that is outside of the enclosed additive item no. 3 area apart of the base bid or is all milling and overlay apart of additive item #3.

The portion of the existing Stanford Road north of the enclosed bid additive 3 limits shall receive the mill and overlay as a base bid item.

11. If additive item no. 3 is not accepted, will the grading need to be changed?

If bid additive 3 is not accepted, grading within the enclosed bid additive 3 limits will not be required. The grading from base bid mill and overlay shall be conducted as shown and match existing elevation of the transition to existing pavement.

12. Do the Superintendent, SSHO and QC Manager need to be 3 separate individuals?

No, they do not have to be 3 individuals.

13. Are soil boring reports available? If not, it will be assumed that excavation will be clear of rocks and obstructions.

No soil boring reports were produced during design nor readily available by the park. Any assumption of subsurface conditions during excavation within these valley lowlands cannot be affirmed by NPS.

14. Please provide bidding quantities for the base course (paving).

All quantities are to be determined by the Contractor in the formulation of their bid based on the drawings and profiles provided in the Construction Drawings. Bidding quantities will not be provided by

NPS.