21R1339 Note 6.pdf

Notice No. 6

1 September 2021

PRE-PROPOSAL QUESTIONS & ANSWERS

RFP N62742-21-R-1339

FY18 MCON P-103 WATER WELL FIELD US NAVSUPACT ANDERSEN, GUAM

NOTE: The following questions and answers are provided for INFORMATION ONLY. The RFP remains unchanged unless it is amended in writing on a Standard Form 30.

47. Ref. Specification Section 33 11 13. Pages 2 (item 1.2.4.1) and 4 (item 1.2.4.3).

The Specification states that: “The design of the well is to be based on various aspects including sieve analysis.”

Sieve analysis not possible as there is no on-island drill rig capable of collecting undisturbed “insitu” samples from the water-bearing zone depths (~500’) for these wells. Please waive the requirements of section 1.2.4.3.

ANSWER: See response to Question 17.

48. Ref. Specification Section 33 11 13. Page 3 (item 1.2.4.1, l.).

The Specification states that: “Description and discussion of geophysical techniques to be employed at the site.”

Please advise on what geophysical techniques are being referred to.

ANSWER: See response to Question 18.

49. Ref. Specification Section 33 11 13. Page 3 (item 1.2.4.1, o.).

The Specification states that: “Description of plumbness and alignment testing.”

No on-island equipment capable of meeting the plumbness and alignment specs mentioned in section 3.3.2, a. (150mm/5.9” deviation per 30m/98.43’lf) in Guam’s karst lithology. Please waive the plumbness and alignment requirement as it appears to pertain to line shaft turbine pumps rather than submersible type. The contractor will guarantee the successful installation/removal of the pump column.

ANSWER: See response to Question 19.

DEPARTMENT OF THE NAVY

NAVAL FACILITIES ENGINEERING SYSTEMS COMMAND, PACIFIC

258 MAKALAPA DRIVE, SUITE 100

JOINT BASE PEARL HARBOR HICKAM, HAWAII 96860-3134

50. Ref. Specification Section 33 11 13. Page 3 (item 1.2.4.1, p.).

The Specification states that: “Description of specific methods employed to test for sand.”

a. Is sand content percentage testing during constant rate/final pump test being asked for?

ANSWER: See response to Question 20.

b. Will parameter measurements such as turbidity suffice?

ANSWER: See response to Question 20.

51. Ref. Specification Section 33 11 13. Page 3 (item 1.2.4.2).

The Specification states that: “100mm test well, upper aquiclude, case, grout, and seal the boring, use test well to determine flow & water quality, etc. The test well may be converted to the permanent well.”

There is no upper aquiclude at this site. Cannot case, grout and seal a test well that may be converted to a larger diameter permanent well. Drilling a 12” open (pilot) test hole for capacity testing has previously been done successfully.

ANSWER: See response to Question 21.

52. Ref. Specification Section 33 11 13. Page 6 (item 2.1.5).

The Specification states that: “Casing guides below the double cement baskets and midway between the cement baskets and the ground surface.”

Installing casing guides above the screened water bearing zone is unnecessary and will prohibit the measurement of the filter pack and the well plug. Please refer to the filter pack & bentonite comment directly below.

ANSWER: See response to Question 22.

53. Ref. Specification Section 33 11 13. Page 6 (item 2.1.7).

The Specification states that: “Commercially made cement baskets, with all steel parts made of type 304 stainless steel.”

The use of cement baskets rather than filter pack and a bentonite plug poses the risk that the cement basket/s won’t provide a sufficient seal due to the high probability of borehole irregularities in the karst formation. Well construction utilizing a closed bottom shoe, a coarse filter pack, followed by a 2-foot layer of fine sand and a 5-foot hydrated bentonite plug then grouting to ground surface is standard local industry practice and has resulted in many successful supply well installations.

ANSWER: See response to Question 23.

54. Ref. Specification Section 33 11 13. Page 7 (item 2.4.3). Cored Rock Samples Is the intention to do rock coring on this project? And if so what quantity and for what purpose?

ANSWER: See response to Question 24.

55. Ref. Specification Section 33 11 13. Page 8 (item 3.2.1).

The Specification states that: “The diameter of borehole for the well shall provide a minimum of 75mm all around the outside diameter of the casing.”

A 12-inch casing plus welding collar has an outer diameter of 13.25-inches and shoe outer diameter of 14.121-inches. This necessitates a borehole diameter greater than 19 inches to over 500’ bgs. An 18-inch diameter hole will still exceed the GEPA requirement for sealing the annular space, however an 18-inch hole is extremely risky in this karst lithology and the risk increases substantially with a larger diameter borehole. Please advise.

ANSWER: See response to Question 25.

56. Ref. Specification Section 33 11 13. Page 9 (item 3.2.2, d.).

The Specification states that: “DTW measurements shall be taken immediately after water is encountered and thereafter at the beginning of each work shift.”

Not feasible to collect DTW measurements immediately after encountering water due to the presence of the drilling foam. Drilling foam normally takes approximately 48 hours to settle.

Please advise.

ANSWER: See response to Question 26.

57. Ref. Specification Section 33 11 13. Page 9 (item 3.2.5, c.).

The Specification states that: “The casing shall be temporarily secured and the well initially developed and cleaned by bailing. When the well has been cleaned of drilling muds, drill cuttings, cave-in materials, etc., the casing shall then be lowered to its final position.”

Developing, bailing and cleaning the well while the casing is temporarily suspended above its final position runs the risk of sloughing materials from the sidewalls and not being able to set the casing/screen at the proper elevation. Additionally, if these wells were completed with filter pack and a bentonite plug (filter pack well) this process would not be needed. Please advise.

ANSWER: See response to Question 27.

58. Ref. Specification Section 33 11 13. Page 10 (item 3.2.7.2, b.).

The Specification states that: “Grout placed in the annuls shall be installed by tremie pipe.”

Use of a 2” OR 3” tremie would require an ~ 22" to 24" dia borehole that is perfectly straight.

Tremie has always been waived by GEPA and calculations of the annular materials to show there was no bridging is local standard industry practice. Could this item be waived as it will be hard to find a drilling contractor willing to drill a 24" diameter hole to over 500' bgs. In Guam’s karst lithology?

ANSWER: See response to Question 28.

59. Ref. Specification Section 33 11 13. Page 10 (item 3.3.1.1).

The Specification states that: “Pump test shall be conducted in the open borehole…”

This statement contradicts section 1.2.4.2 that asks to case, grout and seal the test well. Please advise.

ANSWER: See response to Question 29.

60. Ref. Specification Section 33 11 13. Page 14 (item 3.3.2, a.).

The Specification states that: “The maximum deviation from the vertical shall not be more than 150mm/5.9” deviation per any 30m/98.43LF of depth for the plumbness test.”

There is no on-island equipment capable of meeting these specs in Guam’s karst lithology.

Please waive the plumbness and alignment requirement as it appears to pertain to line shaft turbine pumps rather than submersible type. In lieu of the plumbness and alignment testing the contractor could guarantee the successful installation/removal of the pump column.

ANSWER: See response to Question 30.

61. Ref. Specification Section 33 11 13. Page 14 (item 3.3.2, a.).

The Specification states that: “the alignment shall be tested by lowering a section of pipe or dummy 12.2m/40’ long to the bottom of the well. The OD of the plumb shall be equivalent to the ID of the well casing.”

This appears to be a typo as it is impossible to accomplish. Please advise.

ANSWER: See response to Question 31.

62. Ref. Specification Section 33 11 13. Page 15 (item 3.5.1, a. & b.).

The Specification states that: “A well shall be considered abandoned if the contractor does not complete the well to depth ordered by the Contracting Officer, if the contractor should abandon the well due to loss of tools or other cause. No payment shall be made for any work performed on an abandoned well.”

The statement “other cause” is very vague, open to interpretation and seems to put all the liability on the drilling subcontractor. What happens if a well cannot be completed to the depth ordered by the Contracting Officer due to the presence of large voids that cause a loss of circulation or borehole collapse through no fault of the driller? Please advise.

ANSWER: See response to Question 32.

63. Ref. Specification Section 33 11 13. Page 16 (item 3.5.1, f.).

The Specification states that: “Well decommissioning or abandonment include the removal of all materials left in the borehole or well, including backfill materials. Casing, screen and any other material placed into the hole before the decision was made to abandon the borehole orwell.”

It is impossible to remove steel casing and screen in a 500’ well that has been backfilled. Please advise.

ANSWER: See response to Question 33.

64. Ref. Specification Section 33 11 13. Page 17 (item 3.5.2.1, j. & l.).

The Specification states that: “Indication of penetration resistance such as drive hammer blows given in blows per 150mm of driven sample tubes. Description of material in accordance with ASTM D2488 or standard rock nomenclature in accordance with CED TR GL-85-3…USCS etc.”

Is geotechnical drilling using a hollow stem auger rig required and if so, what are the sample intervals and to what depth? If hollow stem auger drilling is waived will all the requirements of section 3.5.2.1, l. still be applicable? The subsurface will be predominantly paleokarstic coralliferous limestone of a similar nature with heterogeneously occurring voids. All of the disturbed cuttings from Air-Rotary drilling will be mostly the same size and material type? And what type of "chemical field screening" is being referred to? Please advise.

ANSWER: See response to Question 34.

65. Ref. Specification Section 33 11 13. Page 19 (item 3.5.2.3, c.).

The Specification states that: “Type and make of equipment, bailer and pump used during development.”

Is a submersible pump being required as part of well development?

ANSWER: See response to Question 35.

66. Ref. Specification Section 33 11 13. Page 19 (item 3.5.2.3, m.).

The Specification states that: “Name and description of the disposal facility or area, for the waters removed during development/”

Could the development water be allowed to percolate into the nearby ground the same as the >1 million gallons of water from the 72 hr. pump test? The development water could be run through filter material to remove the fines if necessary.

ANSWER: See response to Question 36.

67. Ref. Specification Section 33 11 13. Page 21 (item 3.6).

The Specification states that: “Submit well operating permit for each well to the Contracting Officer.”

Will the owner cover the GEPA well operating permit fees and provide all the necessary plans and documentation for submittal?

ANSWER: Specification Section 01 57 19 Paragraph 1.8 states “obtain licenses and permits required for the construction of the project.” The Contractor is responsible for preparing the necessary plans and documentation for the GEPA Well Operating Permit submittal as stated in Specification Section 33 11 13 paragraph 3.6.

Paragraph 3.6 will be revised to require Contractor to submit to GEPA directly after Government review. See forthcoming amendment.

68. Ref. Specification Section 33 11 13. Pages 22 & 23. Water Quality Analysis Table.

Analytes listed in this table don’t appear to coincide with US EPA and Guam EPA drinking water standards. Please advise.

ANSWER: See response to Question 38.

69. How you will be judging a firm’s SPRS number? How will the number affect our proposal rating? Is there a range of grades (ie.,100-110 = A; 50-100 = B; 1-50 = C……). What would be a “good”/acceptable range?

ANSWER: Only the Basic NIST SP 800-171 DoD Assessment is required prior to award. This is a self-assessment and there is no judgement on this score. Refer to DFARS 252.204-7020 NIST SP 800-171 DOD ASSESSMENT REQUIREMENTS for more information.

End of Notice