NGWA WELL SERVICING AND
MAINTENANCE CERTIFICATION EXAM
(EXAM N) – QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. The primary purpose of well servicing activities is to
A. Increase aquifer recharge
B. Maintain well efficiency and water quality
C. Change groundwater flow direction
D. Eliminate the need for water treatment
Answer: B
Rationale: Well servicing focuses on restoring or maintaining
proper well performance and protecting water quality.
2. Which condition most commonly indicates the need for well
rehabilitation?
A. Stable static water level
B. Increased pumping efficiency
C. Reduced specific capacity
D. New pump installation
Answer: C
, Rationale: A drop in specific capacity is a key sign of clogging or
fouling in a well.
3. Biofouling in wells is primarily caused by
A. Excessive drawdown
B. Microbial growth and byproducts
C. Pump misalignment
D. Improper well depth
Answer: B
Rationale: Biofouling results from bacteria producing slimes and
deposits that restrict flow.
4. Which well component prevents surface contaminants from
entering the borehole?
A. Screen
B. Gravel pack
C. Sanitary seal
D. Pump column
Answer: C
Rationale: The sanitary seal protects the well from surface-borne
contamination.
5. Air surging is best described as
A. Continuous low-pressure pumping
B. Introduction of compressed air to agitate well water
C. Chemical dissolution of mineral scale
D. Mechanical brushing of casing walls
Answer: B
Rationale: Air surging uses compressed air to loosen deposits
and improve flow.
, 6. Which mineral commonly contributes to encrustation in
groundwater wells?
A. Sodium chloride
B. Calcium carbonate
C. Potassium nitrate
D. Silica gel
Answer: B
Rationale: Calcium carbonate precipitates frequently cause scale
formation in wells.
7. The primary purpose of a gravel pack is to
A. Seal the annulus
B. Support the pump
C. Filter formation material
D. Increase casing strength
Answer: C
Rationale: Gravel packs prevent fine formation materials from
entering the well.
8. What is the safest first step before beginning any well servicing
operation?
A. Increase pumping rate
B. Review site history and well records
C. Add disinfectant
D. Remove the pump
Answer: B
Rationale: Reviewing records ensures proper planning and
hazard awareness.
MAINTENANCE CERTIFICATION EXAM
(EXAM N) – QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. The primary purpose of well servicing activities is to
A. Increase aquifer recharge
B. Maintain well efficiency and water quality
C. Change groundwater flow direction
D. Eliminate the need for water treatment
Answer: B
Rationale: Well servicing focuses on restoring or maintaining
proper well performance and protecting water quality.
2. Which condition most commonly indicates the need for well
rehabilitation?
A. Stable static water level
B. Increased pumping efficiency
C. Reduced specific capacity
D. New pump installation
Answer: C
, Rationale: A drop in specific capacity is a key sign of clogging or
fouling in a well.
3. Biofouling in wells is primarily caused by
A. Excessive drawdown
B. Microbial growth and byproducts
C. Pump misalignment
D. Improper well depth
Answer: B
Rationale: Biofouling results from bacteria producing slimes and
deposits that restrict flow.
4. Which well component prevents surface contaminants from
entering the borehole?
A. Screen
B. Gravel pack
C. Sanitary seal
D. Pump column
Answer: C
Rationale: The sanitary seal protects the well from surface-borne
contamination.
5. Air surging is best described as
A. Continuous low-pressure pumping
B. Introduction of compressed air to agitate well water
C. Chemical dissolution of mineral scale
D. Mechanical brushing of casing walls
Answer: B
Rationale: Air surging uses compressed air to loosen deposits
and improve flow.
, 6. Which mineral commonly contributes to encrustation in
groundwater wells?
A. Sodium chloride
B. Calcium carbonate
C. Potassium nitrate
D. Silica gel
Answer: B
Rationale: Calcium carbonate precipitates frequently cause scale
formation in wells.
7. The primary purpose of a gravel pack is to
A. Seal the annulus
B. Support the pump
C. Filter formation material
D. Increase casing strength
Answer: C
Rationale: Gravel packs prevent fine formation materials from
entering the well.
8. What is the safest first step before beginning any well servicing
operation?
A. Increase pumping rate
B. Review site history and well records
C. Add disinfectant
D. Remove the pump
Answer: B
Rationale: Reviewing records ensures proper planning and
hazard awareness.
