Attchmt 10 Q and A_001.pdf

Solicitation no. 140P8320R0005, Amendment 001, Attachment no. 10 (8/31/20)

Rehabilitation Wastewater System, LEWI

1. Specification section 01 50 00 1.1 A.1(b) states that potable water is not available for contractor’s use.

QUESTION: Is non-potable water for construction purposes available on site?

ANSWER: While NPS can provide the contractor use of water on-site during construction, there is definitely not enough quantity available to allow filling the 15,000 tank. Therefore, Offeror shall plan to include cost in proposal for filling the 15,000 tank.

2. Specification section 01 50 00 1.1 A.1(c) indicates that the contractor is required to provide 6 temporary toilets for the use of Park Staff and Visitors during any system disruptions.

QUESTION: Does this requirement also apply to the Administrative Building, where the leach field will need to be taken out of service? How many temporary toilets would be required for the Admin building?

ANSWER: Contractor shall provide one temporary toilet for the Administration

Building.

3. Specification section 31 10 00 3.1.D(2) requires all clearing waste (except salvaged logs) to be removed from the site.

QUESTION: During the site visit there was some discussion that all biomass including slash and brush would be disposed of near the staging area along the old highway. Please clarify.

ANSWER: Contractor can haul and pile all vegetation and plant materials (including woody debris, soft plants, top soils, slash, and trees) within LEWI at the designated area pointed out during the site visit.

4. Specification section 33 31 13 2.1.A calls for PVC pipe rated at 160 psi for the 2” forcemain.

QUESTION: Specification section 33 31 13 3.1.H requires pressure testing pressure pipe to 200 psi, is this correct? Typical hydrostatic test pressures (per AWWA C605) are set at

150% of the maximum expected working pressure.

ANSWER: Adhere to the AWWA at 150% max expected working pressure.

5. Specification section 46 07 53 2.5.D.1(j) indicates that the filtration package includes a remote telemetry unit.

QUESTION: Are any external communication connections required?

ANSWER: None. It is a remote read. Will require power to that package plant.

6. Specification section 46 07 53 2.5.D.2 lists a number of “Optional” components for the filter assembly.

QUESTION: Are any (or all) of these optional items required?

ANSWER. This question relates to Price Schedule Line Item no. 7, Wastewater

Treatment System. The term used in the specifications as “Optional” refers to the

Advantex AX-MAX which can come with any, all, or none of these features:

To clarify, NPS expects contractor to include the above items as mandatory, not as optional. The price proposal shall include these items as part of the overall price for Price

Schedule Line Item no. 7.

7. Plan sheet C02, (note next to the existing drainfield) requires removal of “all surface appurtenances.”

QUESTION: Does this include the old tower foundation?

ANSWER: No. Remove only the culvert risers and accessible valves. The tower foundation stays.

8. Plan sheet C03 shows the new 6” gravity sewer main west of the Visitor Center (call out #17) passing under an existing concrete walkway.

QUESTION: If the concrete walkway is cut and removed for this installation what is desired regarding “matching” restoration of the existing exposed aggregate surface.

ANSWER. Match the existing exposed aggregate surface.

9. Plan sheet C03 shows the location of the new 15,000 gallon septic tank and plan sheets C05-C07 show details for this tank. The excavation to the bottom of the tank bedding will be 15’ below the surface at the down slope end and about 19’ deep at the up slope end.

a) QUESTION: We expect significant dewatering for this excavation. Is there a desired discharge point available for the dewatering discharge?

ANSWER: Yes, into the forest 50 feet from stream in a swaddle contained area identified by resources just north 20 feet of excavation.

b) The tank manufacturer recommends a minimum ½ tank diameter flat pad on each side of the tank at the bottom of the excavation (in unstable clay excavations). With this bottom width and 1.5:1 excavation slopes the footprint of the excavated area will be about 90’ x 80’ (plus access requirements and any spoils area).

i. QUESTION: Will this large of an area create any clearing concerns? Shoring can reduce the size of this footprint, but it is a more expensive option.

ANSWER: Some shoring may be required. NPS archaeologist recommends that the contractor stay within the 41' x 40' for excavation, maintaining the 50' set back-back from the stream. Staying within the footprint of the existing trees is preferred and a minimalist approach, for minimal disturbance of the historical site. Offerors shall prepare proposal to include any shoring as part of Price Schedule Line Item no. 5.

Area Map of Potential Effects/Impacts

c) QUESTION: It is likely the sloped excavation walls will expose basement walls and possibly basement footings, are there any specific structural concerns in this area?

ANSWER: None other than the preservation of the footing drainage, and backfill with like material removed-sand.

QUESTION: Is there a foundation drain running between the building basement wall and the planned septic tank location?

ANSWER: Yes.

QUESTION: Is there any as-built information available on the basement walls/footings and any information on foundation drains?

ANSWER: Yes, footing drain along that wall zip tied to footing.

d) This deep excavation will generate significant amounts of wet clay spoils.

QUESTION: Can this material be stored near the excavation to allow it to drain before hauling it off site?

ANSWER. Yes, by the powder shed is a staging area to handle excavated clay, allowing for drainage. It is 50 feet from the excavation site, to the west of tank location.

Photo of elevator shaft sump pump: