B09 40527268 AM01 RFP Att10 RFP QA_0001.docx

140P1321R0008 AMIS, PMIS 269091 – Replace Deteriorated Water System at Diablo East Attachment 10: Solicitation Questions and Answers

1. What are the latest drawings?

Amendment 0001 incorporates drawings dated January 2021.

2. Is a temporary water line needed? Can the existing line be left in use until the switch over?

The drawings show the removal of the existing waterline in a number of locations to allow installation of the new waterline; therefore, the existing waterline can’t be left in service to meet this requirement. Water service to all existing facilities shall be maintained at all times for the duration of the project, except when tying-in or disconnecting lines. Outages associated with tying-in or disconnecting lines should be kept as short as possible. Contractors shall provide temporary lines and connections as needed to accomplish this, unless an alternative method is approved by the CO. Amendment 0001 incorporates the revised Specifications; please reference the section under “Summary of Work”.

3. Are there any restrictions on how to cross the road with temporary water lines or will this be left up to the contractor?

There are no restrictions except that pipe needs to be protected with appropriate load limit for large vehicles. The contractor’s work plan should address this.

4. Please clarify Contract Line Item #1 which calls for the removal and disposal of the existing piping vice abandon in-place as we’ve called for.

The line item is intended to cover removal of any pipe that they come across, not necessarily removing and disposing of the entire waterline. Per the drawings and specifications, the contractor shall cap and abandon pipe in-place unless installation of the new piping requires the old pipings to be removed. Amendment 0001 incorporates the revised Specifications; please reference the section under “Definition of Contract Line Items”.

5. Thrust Block Details: Is any material required between the HDPE piping and the concrete? Do we want to leave as shown on the drawings, and put material between the concrete and HDPE, or cover the entire pipe and associated joints with concrete to form the thrust block?

The park does not believe encasing the joints and valves in concrete is a good idea for long term maintenance. Pouring the concrete around the pipe/elbow/fitting to form and encase the thrust block could work but by itself, does not provide a barrier between the fitting/valve and concrete. However, each fitting must have an HDPE wrap, as per the plans and specifications, which will provide some abrasion protection (even though the primary purpose is for corrosion protection). If the entire gate valve or fitting would ever need to be replaced, it will be very difficult if concrete is poured so that the entire fitting is covered. The current thrust block detail does not show the fitting being completely encased. This photo shows a good thrust block installation; the wooden forms were removed after the concrete cured.

6. How far does the additional 4” of top cover need to extend out from the trench, i.e., were we looking at extending 4 or 5 feet on each side of the trench?

The 4” of cover shall cover the entirety of the cut trench and slope out on ~1 ft on each side. In other words, the contractor shall cover the trench itself with an additional 4" of fill and taper it back to the original grade approximately a foot or so away from the trench.

7. Can the depth of the existing pipes be more defined?

It is anticipated that most pipe will be in the 2’ to 3’ range, but there could be some locations deeper, maybe up to 10’. Contractors shall propose based on the drawings. Any major differences in what was expected would follow the differing site conditions clause.

8. In drawing C5 there is a graph plotting distance and elevation of the water after the wye on the 8" main. However after the site visit we noticed that this graph does not follow the actual elevation of the terrain, and there is a steep change in elevation. Can we clarify if we are to follow the terrain elevation or if the government is implying that we must backfill the area so that the new main follows the elevation shown in the drawings?

The drop/dip is shown where the wye starts regarding the slope. The alignment for sheet C5 starts at 30+00, shown in bottom left hand corner of the plan view.

9. Can the lower parking lot be shutdown to do all trenching at one time?

Yes, so long as the contractor provides access to the fuel tanks at the bottom of the parking lot if needed. Final approval and coordination will be handled with the awardee at the pre-construction conference.

10. Where do the new waterlines tie into the existing system?

Please reference the drawings; the system will be tied into the booster pump house outlet.

11. Across the street from the pump house, along where the new line is supposed to run, there is a large concrete slab with a curb. It’s about 4 or 5 feet wide and maybe 10 to 12 feet long. Can this be removed?

Yes, though contractors shall base their decision on the most expeditious way to accomplish the work, i.e., if removing that slab was far more expensive and time consuming than running the line 18” further over to avoid it, then they probably shouldn’t remove the slab. Pictures are provided for reference:

12. Drawing C1 shows the existing pipes and new pipe on the South side of the road (left side of the road driving away from pump house and storage tank); however, when walking the site the Park told the contractors they were on the North side of the road (right side).

Offerors shall plan to accomplish the work as shown in the drawings. If the existing pipeline is on the other side of the road, it should be abandoned in place similar to other locations for this work.

13. Is the depth of the electrical at the intersection down from the pump house and storage tank known?

The NPS does not have this information.

14. What should be done with the removed brush? Can it be abandoned on-site, i.e., pushed to the side and left, or broken up/crushed by the equipment running over it and leaving it where it falls? Or does it need to be hauled off site?

Brush can be abandoned on-site. It can be thrown back into the landscape behind where the work is being done and the trees or brush, whichever the contractor prefers.

15. Same as question number 12, but for small trees down by the LE Facility.

These small trees can also be abandoned on-site with the brush as well. There is no need to replant them.

16. Regarding the trench and the brush, how much should/could be cleared?

The contractor shall clear the minimal amount needed to get their equipment through, i.e., if they needed 10’, that’s all they could clear, no clear cutting a 20’ wide stretch just to make it easier or more convenient. The contractor shall minimize disturbance and damage as a priority

17. Where is the IT conduit to be installed?

While the drawings don’t show it, the IT conduit is to be installed in the trench from the access box near the pump house/storage tank area down to the main road as well as the other trenches.

18. Can contractors “burst” the existing pipe?

The NPS will not consider or accept this approach for multiple reasons: 1) the approach wouldn’t completely eliminate trenching and therefore, might be of dubious cost savings; 2) TCEQ may not agree with this approach due to issues with the broken up cast iron pipe being left in the ground and it may be viewed as backtracking on the original agreement to abandon in-place and require total removal of the old pipe.

19. After the site visit it was evident that the vast majority of the excavation to be performed is to be done in a narrow area next to the road where utility power is buried immediately adjacent to the old water mains to be removed. It was unclear if we would be allowed to turn off utility power to allow for safe work. This raises several concerns.

a. Will the contractor be allowed to disconnect utility power for the duration of any excavation on the related areas with buried power lines?

Contractor must ensure safety of employees, and if it’s required to disconnect utility power, coordination must be handled for minimal downtime.

b. If so, will the contractor be responsible for providing temporary power to facilities?

Contractor must lease and connect utilities to ensure power keeps water and lift stations running. Awardee shall submit a plan via submittal after award for review/approval by the NPS. Amendment 0001 incorporates revised Specifications with details. Please reference Section 01 50 00, Temporary Facilities and Controls.

c. If so, is the noise impact of the temporary power supply subject to the restriction on noise levels currently included in the specs? (This is important because it determines the type of power generation unit that must be used)

Yes, specifications regarding noise impacts/restrictions must be followed.

d. Since there is an evident electrical hazard and chance of damaging conductors, will an electrical contractor or at least a competent supervisor (with electrical contracting experience) be required on the jobsite during excavation operations?

This is up to the contractor for safety/supervision on site. The NPS assumes all contractors will have competent employees and supervisors on site as needed to successfully perform the work.

20. The contract specifies that this contract will require a bond or guarantee. Sections 52.228-1 described this Bid bond to be 20% of the total proposal price.

a. Does this conclude the bonding requirements, or will the government require a performance bond as well?

Payment and Performance bonds will be required. Bonding requirements are covered under 12a of the SF1442 and clause 52.228-15.

b. Will the government reserve the right to implement FAR 28.102-1 (a) (quoted on clause 52.228-15), on this contract?

Please reference the contract clauses, as the government requires payment bonds on anything over $35,000 and performance bonds on anything over $150,000.

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