Q&A Letter.pdf

DEPARTMENT OF THE AIR FORCE

319TH CONTRACTING SQUADRON (AMC)

GRAND FORKS AIR FORCE BASE, NORTH DAKOTA

3 April 2009

MEMORANDUM FOR PROSPECTIVE OFFERORS

FROM: 319 CONTRACTING SQUADRON

575 TUSKEGEE AIRMEN BLVD, BLDG 418

GRAND FORKS AFB, ND 58205

SUBJECT: FA4659-09-R-0005 – Locate Natural Gas Distribution: Questions and Answers

1. Due to the size of the anticipated bid award, will progress invoicing be allowed for this project?

Yes, progress invoicing will be allowed.

2. Does the Land Surveyor/Engineering Firm /Project Engineer need to have a North Dakota

License to practice on base?

Yes, they will need to be licensed in North Dakota.

3. Can the spoil materials from the subsurface locate be dumped/spread on site or does it have to be hauled offsite at the Contractor's expense?

Spoils shall be disposed of location on base. Location will be designated at a later time.

4. Please confirm that water will be available for Contractor's use.

Water will be made available for the contractor at a designated location on base. Location will be provided at a later date.

5. What format(s) will the deliverables be required in paper, CAD and/or ESRI GIS?

The updated gas line map shall be provided in ESRI GIS or compatible equal as provided for in the specifications. In addition, the contractor shall provide the government 3 hard copies and one electronic copy of their final report as outlined in section 2.1 of the specifications.

6. Page 2 of the second amendment states:

For areas directly around buildings, if there is adequate signal from the tracer wire, the contractor will not be required to expose the pipe within 20 feet of the building as the service line will have an XYZ from exposure and there will also be an XY from where the gas piping emerges to enter the outside of the building. Using the tracer signal, XYZ, and XY, this should be sufficient information to map the line.”

Define “adequate.” Why will the line have XYZ exposure? Are holes supposed to be dug at all “tees” in the line?

I will try to explain in more detail what we expect for locate around buildings in more detail. We expect the contractor to locate all tees (this would give us a XYZ point). By locating the tees, this would give us our first XYZ location for the service line. We also have a XY location from where the pipe emerges from the ground. Given the information from the two locates, we now have two exact locations for the service line. We feel that with the two locates and the tracer signal, one could now accurately survey the natural gas line around a building.

7. Where should we expect to find trace wires?

Tracer wire was installed on top of natural gas piping.

8. Can you clarify the requirements under Options 1, 2 & 3? The first sentence in each option begins “Gas lines shall be exposed by means of non-destructive vacuum exposure (hydro or air) every X feet at minimum unless there is a change of direction or intersection of a line.” Does this mean for lines with tracer wire, that we can trace with electromagnetic locators or by other means on the surface and place markings. I ask this question because at the end of the paragraph is the statement: “For all other areas, if a tracer wire is not available, the line shall be exposed every X feet.”

For areas with tracer wire we expect natural gas piping to be exposed as designated in the bid option (xx feet) and areas without tracer wire to be exposed as designated in the bid option (xx feet). Areas between each excavation shall be surveyed by means of electromagnetic locators or ground penetrating radar.

9. For building 314, off of Steen Boulevard - Beginning at the building you have in order:

A. 90 degree elbow;

B. 45 degree bend;

C. Another 45 degree bend;

D. 90 degree elbow connecting to the pipeline main.

We would need four test holes – is this a correct interpretation?

For building 314, I see three test hole: (A.), (B.), and (C.). For the second 90 degree elbow referenced in (D.), XY can be determine at building entrance where pipe emerges from the ground. And the four point referenced below can be determined by the intersection of (C.) and building entrance. This can be verified with the electromagnetic locator or GPR.

10. Are there areas of the base where the gas lines will be in a secured area, where there may be environmental hazards or other issues that we need to be aware of such as:

A. Flight or ready line access;

B. Hazardous waste areas;

C. Other restricted access areas?

There are areas within the flight line that are part of the survey. For these areas the contractor will need to coordinate with the construction inspector for escorts. The escorts are required 100% of the time within this area.

11. What tolerance shall the vertical GPS points be held to? Horizontal GPS tolerance for our unit shall comply too the +/- 2cm requirement (stated 8.5.4.4 page 01000-10of 28), however our unit shall only comply to +/- 2.5cm vertically. Will this be acceptable? (Industry Standard also states this as vertical tolerance) +-2.5 cm vertically is acceptable.

12. According to the CFR191/192 the Gas Leak Detection Survey shall be conducted after the Natural Gas Distribution System has been properly located (aboveground and belowground). As stated in the technical provisions (01000-1 of 28) the Natural Gas Line Survey (2.1) the performance threshold is 6 weeks post award. Would it be acceptable to contracting that the Gas Leak Detection Survey segment of the contract be the final field activity conducted for this project, once all required GPS points have been completed in the field?

Method provided is acceptable.

13. How many aboveground Natural Gas risers are located on Main Base?

There is only one natural gas riser on base other than at the connections at each facility. The riser is located near the main entrance on the east side of the base.

14. What is the tallest building that we will encounter during our GPS survey?

The tallest building that you may encounter is the control tower, but the this building is quite narrow so it may not affect your signal. The hangars are next tallest buildings and are approximately 70 - 75 feet tall.

15. Are there any gas lines that have been predetermined by the engineer that required excavation that are located under concrete or asphalt?

No, the gas line can be marked outside of pavement sections if necessary.

16. What is the condition of the natural gas systems underground tracer wire with in the Main

Base area? Valcon Tech installed the Natural Gas services and some of the Natural Gas mains in the new housing area’s during Sundt’s contract. And during our installation phase’s we encountered difficulties locating the existing Natural Gas mains due to the tracer wire and its connection points not being installed properly. We ask this in order to gauge time for locating efforts, in conjunction with ND 1 Call for excavation areas.

The integrity of the tracer wire is in better outside of housing. Tracer wire will be available in most areas.

17. Will we have access to the contractors as-builts with measurements for the Natural Gas mains/services that do not have tracer wire?

As-builts will be made available upon request.

18. When was the last time the Underground Natural Gas Main Control Valves were exercised?

All gas valves were exercised Summer '08.

19. For the areas of excavation is there a compaction test requirement?

Excavation shall be compacted to 90% Std. proctor.

20. For the Gas Leak Detection Survey we classify the leaks detected according the CFR 192 requirements (aboveground and belowground). This method of classification is; Class 1 – urgent requires immediate action, Class 2 – action is required with in an acceptable period of time (30 days), & Class 3 – minor action is required with in 90 days. Will this method of reporting be acceptable?

Method provided is acceptable.

21. We have a question regarding the reasoning with three different Clin’s. Why the variance between footage (1,250’LF – 1,000’LF – 750’LF)? Just by observing the gas map on Fedbizops most identifiable system attributes are with a 750’LF distance. (Does not identify the UG gas main control valve locations.)

We feel that there are multiple areas that could fall within the 1250 ft and 1000 ft range. Map posted on Fedbizops does contain the gas valves, but they are hard to see. The original posted map was more clear.

22. How many underground natural gas main control valves are located with in the Main Base area?

63 gas valves

23. Will we be given the existing natural gas system data for our attribute information as required with in the technical specifications? Is that data in hard copy or digital format?

Yes, GIS file will be posted on FedBizOpps on Monday, 6 April 2009.

24. Does the vertical GPS requirement include the elevations of the aboveground natural gas risers (typically on top of the gas regulator or gas meter) ?

If you are asking if we want the vertical elevator of the gas riser (above ground portion) at the building, the answer is yes.

25. On page 1, under PROJECT DESCRIPTION, paragraph 2.1.1, "quality D for the survey" should read "quality A for the survey."

Quality Level A involves the use of nondestructive digging equipment at critical points to determine the precise horizontal and vertical position of underground utilities, as well as the type, size, condition, material, and other characteristics. This activity is called "locating." It is the highest level presently available. When surveyed and mapped, precise plan and profile information are available for use in making final design decisions. By knowing exactly where a utility is positioned in three dimensions, the designer can often make small adjustments in