NGWA - GENERAL 2025
DRILLING EXAM
ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
The diameter of a screen is not a critical factor in the specific capacity. Double the
diameter of a screen generally increases the specific capacity by what percent? -
ANSWERS-7% to 10%.
QUESTION 2
When drilling in an unfamiliar area, the collection of samples... - ANSWERS-...
can enable the ground water professional to correlate formations from one area to
another.
QUESTION 3
A well screen... - ANSWERS-1. Is a filtering device.
2. Permits water to enter the well from the saturated aquifer.
3. Precent sediment from entering the well.
QUESTION 4
END OF
PAGE 1
, NGWA - GENERAL 2025
DRILLING EXAM
(T/F) Gravel-packed wells should be sealed at the top of the gravel pack as well as
in the annulus. - ANSWERS-True.
QUESTION 5
(T/F) Dry cement may be mixed with water in the annulus to form an acceptable
surface seal. - ANSWERS-False.
QUESTION 6
Pressure grouting requires that the grout must be... - ANSWERS-... under
sufficient pressure to drive it into the zone to be grouted.
QUESTION 7
When only 40' of cement is required to grout the surface casing, one can achieve a
good seal by... - ANSWERS-... placing from the bottom up using a tremie grout
pipe.
QUESTION 8
END OF
PAGE 2
DRILLING EXAM
ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
The diameter of a screen is not a critical factor in the specific capacity. Double the
diameter of a screen generally increases the specific capacity by what percent? -
ANSWERS-7% to 10%.
QUESTION 2
When drilling in an unfamiliar area, the collection of samples... - ANSWERS-...
can enable the ground water professional to correlate formations from one area to
another.
QUESTION 3
A well screen... - ANSWERS-1. Is a filtering device.
2. Permits water to enter the well from the saturated aquifer.
3. Precent sediment from entering the well.
QUESTION 4
END OF
PAGE 1
, NGWA - GENERAL 2025
DRILLING EXAM
(T/F) Gravel-packed wells should be sealed at the top of the gravel pack as well as
in the annulus. - ANSWERS-True.
QUESTION 5
(T/F) Dry cement may be mixed with water in the annulus to form an acceptable
surface seal. - ANSWERS-False.
QUESTION 6
Pressure grouting requires that the grout must be... - ANSWERS-... under
sufficient pressure to drive it into the zone to be grouted.
QUESTION 7
When only 40' of cement is required to grout the surface casing, one can achieve a
good seal by... - ANSWERS-... placing from the bottom up using a tremie grout
pipe.
QUESTION 8
END OF
PAGE 2
