Answer: C
Aquifers contain permeable materials that allow groundwater to
NGWA Water Systems General move and be extracted.
Certification Practice Exam Questions
3. Which material is most permeable for groundwater movement?
And Correct Answers (Verified Answers) A. Clay
B. Silt
Plus Rationales 2026 Q&A | Instant C. Sand and gravel
Download Pdf D. Bedrock
Answer: C
Sand and gravel have large pore spaces that allow water to flow
1. The primary purpose of a water well is to: easily.
A. Store surface water
B. Collect stormwater runoff
C. Access groundwater from an aquifer 4. The water table refers to:
D. Treat wastewater A. The deepest part of an aquifer
B. The top of the saturated zone
Answer: C
C. The bottom of a well
Wells are designed to reach underground aquifers and bring
D. A surface reservoir level
groundwater to the surface.
Answer: B
The water table marks where soil and rock pores become fully
2. An aquifer is best defined as: saturated.
A. A layer of clay that blocks water flow
B. A body of surface water
C. A geologic formation that stores and transmits groundwater 5. A confined aquifer is characterized by:
D. A man-made underground tank A. Direct exposure to the atmosphere
B. Being under pressure between impermeable layers
, C. Shallow depth only 8. Common well casing materials include:
D. Poor water quality A. Copper and aluminum
B. PVC and steel
Answer: B
Confined aquifers are trapped between low-permeability layers and C. Wood and concrete
D. Rubber and plastic tubing
often produce artesian pressure.
Answer: B
PVC and steel are durable and widely approved for well construction.
6. Artesian conditions occur when:
A. Water must be pumped mechanically
B. Water flows naturally due to pressure 9. A well screen is used to:
C. The well is dry A. Seal the top of the well
D. The aquifer is unconfined B. Filter water at the pump
C. Allow water entry while keeping sediment out
Answer: B
D. Measure water depth
Pressure in confined aquifers can force water upward without
pumping. Answer: C
Screens admit groundwater while blocking sand and gravel.
7. The purpose of well casing is to:
A. Increase water pressure 10. The annular space is the area:
B. Store water A. Inside the pump
C. Prevent borehole collapse and contamination B. Between casing and borehole wall
D. Improve taste C. At the well cap
Answer: C D. Below the screen
Casing stabilizes the well and protects groundwater from surface Answer: B
pollutants. This space must be properly sealed to prevent contamination.
, 11. Grouting a well primarily helps to: 14. A pitless adapter allows:
A. Improve water taste A. Above-ground piping only
B. Increase yield B. Horizontal discharge below frost line
C. Seal off surface contaminants C. Temporary pump installation
D. Reduce pumping cost D. Manual water lifting
Answer: C Answer: B
Grout prevents polluted surface water from traveling down the casing. Pitless adapters protect water lines from freezing.
12. Which grout material is commonly used? 15. Which factor most affects well yield?
A. Sand only A. Casing color
B. Bentonite or cement B. Aquifer permeability
C. Gravel C. Pump voltage
D. Clay soil D. Well cap type
Answer: B Answer: B
Bentonite and cement expand or harden to create effective seals. The ability of water to move through the aquifer determines yield.
13. The sanitary well seal is installed to: 16. Static water level is measured:
A. Improve pump efficiency A. While pumping
B. Keep insects and debris out B. After pump shutdown recovery
C. Increase water storage C. During peak demand
D. Reduce pipe friction D. At installation only
Answer: B Answer: B
Sanitary seals protect the well opening from contamination. Static level is taken when the well is not being pumped.
Aquifers contain permeable materials that allow groundwater to
NGWA Water Systems General move and be extracted.
Certification Practice Exam Questions
3. Which material is most permeable for groundwater movement?
And Correct Answers (Verified Answers) A. Clay
B. Silt
Plus Rationales 2026 Q&A | Instant C. Sand and gravel
Download Pdf D. Bedrock
Answer: C
Sand and gravel have large pore spaces that allow water to flow
1. The primary purpose of a water well is to: easily.
A. Store surface water
B. Collect stormwater runoff
C. Access groundwater from an aquifer 4. The water table refers to:
D. Treat wastewater A. The deepest part of an aquifer
B. The top of the saturated zone
Answer: C
C. The bottom of a well
Wells are designed to reach underground aquifers and bring
D. A surface reservoir level
groundwater to the surface.
Answer: B
The water table marks where soil and rock pores become fully
2. An aquifer is best defined as: saturated.
A. A layer of clay that blocks water flow
B. A body of surface water
C. A geologic formation that stores and transmits groundwater 5. A confined aquifer is characterized by:
D. A man-made underground tank A. Direct exposure to the atmosphere
B. Being under pressure between impermeable layers
, C. Shallow depth only 8. Common well casing materials include:
D. Poor water quality A. Copper and aluminum
B. PVC and steel
Answer: B
Confined aquifers are trapped between low-permeability layers and C. Wood and concrete
D. Rubber and plastic tubing
often produce artesian pressure.
Answer: B
PVC and steel are durable and widely approved for well construction.
6. Artesian conditions occur when:
A. Water must be pumped mechanically
B. Water flows naturally due to pressure 9. A well screen is used to:
C. The well is dry A. Seal the top of the well
D. The aquifer is unconfined B. Filter water at the pump
C. Allow water entry while keeping sediment out
Answer: B
D. Measure water depth
Pressure in confined aquifers can force water upward without
pumping. Answer: C
Screens admit groundwater while blocking sand and gravel.
7. The purpose of well casing is to:
A. Increase water pressure 10. The annular space is the area:
B. Store water A. Inside the pump
C. Prevent borehole collapse and contamination B. Between casing and borehole wall
D. Improve taste C. At the well cap
Answer: C D. Below the screen
Casing stabilizes the well and protects groundwater from surface Answer: B
pollutants. This space must be properly sealed to prevent contamination.
, 11. Grouting a well primarily helps to: 14. A pitless adapter allows:
A. Improve water taste A. Above-ground piping only
B. Increase yield B. Horizontal discharge below frost line
C. Seal off surface contaminants C. Temporary pump installation
D. Reduce pumping cost D. Manual water lifting
Answer: C Answer: B
Grout prevents polluted surface water from traveling down the casing. Pitless adapters protect water lines from freezing.
12. Which grout material is commonly used? 15. Which factor most affects well yield?
A. Sand only A. Casing color
B. Bentonite or cement B. Aquifer permeability
C. Gravel C. Pump voltage
D. Clay soil D. Well cap type
Answer: B Answer: B
Bentonite and cement expand or harden to create effective seals. The ability of water to move through the aquifer determines yield.
13. The sanitary well seal is installed to: 16. Static water level is measured:
A. Improve pump efficiency A. While pumping
B. Keep insects and debris out B. After pump shutdown recovery
C. Increase water storage C. During peak demand
D. Reduce pipe friction D. At installation only
Answer: B Answer: B
Sanitary seals protect the well opening from contamination. Static level is taken when the well is not being pumped.
