NGWA Jetting and Driving Wells
Certification Exam (Exam H) Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
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1. The primary purpose of jetting a well is to:
A. Fracture bedrock
B. Install casing in unconsolidated formations
C. Increase pump horsepower
D. Seal abandoned wells
Answer: B
Jetting is mainly used to install well casing into loose or unconsolidated
materials such as sand and gravel.
2. Driving a well point is most appropriate in formations composed
mainly of:
A. Solid granite
B. Claystone
C. Unconsolidated sand and gravel
D. Shale bedrock
,Answer: C
Driven wells are suitable only in unconsolidated materials that allow
penetration.
3. A driven well typically uses what diameter casing?
A. 10–12 inches
B. 6–8 inches
C. 2–3 inches
D. Over 16 inches
Answer: C
Driven wells are generally small-diameter wells, commonly 2 to 3
inches.
4. The screened portion at the bottom of a driven well is called the:
A. Casing shoe
B. Well collar
C. Well point
D. Drive cap
Answer: C
The well point contains the screen and allows water to enter the well.
5. Before jetting a well, the contractor should first:
A. Start pumping immediately
B. Determine soil and groundwater conditions
, C. Install the pump
D. Grout the casing
Answer: B
Understanding subsurface conditions is critical to determine feasibility
and safety.
6. Jetting water is usually supplied by:
A. Hand pump
B. Gravity tank only
C. High-pressure pump
D. Air compressor
Answer: C
Jetting requires sufficient pressure and volume to loosen and remove
soil.
7. Excessive jetting pressure can result in:
A. Better well efficiency
B. Improved screen life
C. Formation collapse
D. Higher yield
Answer: C
Too much pressure can destabilize the formation and cause collapse.
8. The primary hazard during driving operations is:
A. Electrical shock
, B. Flying metal or equipment failure
C. Chemical exposure
D. Pump cavitation
Answer: B
Driving tools and impact forces can cause serious injury if equipment
fails.
9. A drive cap is used to:
A. Seal the well permanently
B. Prevent casing damage during driving
C. Increase water flow
D. Attach the pump
Answer: B
The drive cap protects the threaded casing during impact.
10. Jetting is least effective in:
A. Fine sand
B. Coarse sand
C. Gravel
D. Clay
Answer: D
Clay resists erosion by water jetting.
11. The recommended practice after reaching target depth is to:
A. Leave the well idle
Certification Exam (Exam H) Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
1. The primary purpose of jetting a well is to:
A. Fracture bedrock
B. Install casing in unconsolidated formations
C. Increase pump horsepower
D. Seal abandoned wells
Answer: B
Jetting is mainly used to install well casing into loose or unconsolidated
materials such as sand and gravel.
2. Driving a well point is most appropriate in formations composed
mainly of:
A. Solid granite
B. Claystone
C. Unconsolidated sand and gravel
D. Shale bedrock
,Answer: C
Driven wells are suitable only in unconsolidated materials that allow
penetration.
3. A driven well typically uses what diameter casing?
A. 10–12 inches
B. 6–8 inches
C. 2–3 inches
D. Over 16 inches
Answer: C
Driven wells are generally small-diameter wells, commonly 2 to 3
inches.
4. The screened portion at the bottom of a driven well is called the:
A. Casing shoe
B. Well collar
C. Well point
D. Drive cap
Answer: C
The well point contains the screen and allows water to enter the well.
5. Before jetting a well, the contractor should first:
A. Start pumping immediately
B. Determine soil and groundwater conditions
, C. Install the pump
D. Grout the casing
Answer: B
Understanding subsurface conditions is critical to determine feasibility
and safety.
6. Jetting water is usually supplied by:
A. Hand pump
B. Gravity tank only
C. High-pressure pump
D. Air compressor
Answer: C
Jetting requires sufficient pressure and volume to loosen and remove
soil.
7. Excessive jetting pressure can result in:
A. Better well efficiency
B. Improved screen life
C. Formation collapse
D. Higher yield
Answer: C
Too much pressure can destabilize the formation and cause collapse.
8. The primary hazard during driving operations is:
A. Electrical shock
, B. Flying metal or equipment failure
C. Chemical exposure
D. Pump cavitation
Answer: B
Driving tools and impact forces can cause serious injury if equipment
fails.
9. A drive cap is used to:
A. Seal the well permanently
B. Prevent casing damage during driving
C. Increase water flow
D. Attach the pump
Answer: B
The drive cap protects the threaded casing during impact.
10. Jetting is least effective in:
A. Fine sand
B. Coarse sand
C. Gravel
D. Clay
Answer: D
Clay resists erosion by water jetting.
11. The recommended practice after reaching target depth is to:
A. Leave the well idle
